An excavator includes a lower traveling body; an upper turning body turnably mounted to the lower traveling body; an acquisition device mounted to the upper turning body and configured to acquire information including a status around the excavator; and a control device configured to recognize a reference object that is in a stopped state or at a fixed position around the excavator based on the information acquired by the acquisition device, and to estimate a turning angle of the upper turning body based on a change in a position of the reference object as viewed from the upper turning body.

BACKGROUND

1. Technical Field

The present invention relates to an excavator.

2. Description of the Related Art

For example, a technique is known in which a relative angle of an upper turning body relative to a lower traveling body is obtained by providing an imaging device for capturing an image of the lower traveling body and detecting a predetermined portion of the lower traveling body from the captured image captured by the imaging device.

SUMMARY

According to an embodiment of the present invention, there is provided an excavator including a lower traveling body; an upper turning body turnably mounted to the lower traveling body; an acquisition device mounted to the upper turning body and configured to acquire information including a status around the excavator; and a control device configured to recognize a reference object that is in a stopped state or at a fixed position around the excavator based on the information acquired by the acquisition device, and to estimate a turning angle of the upper turning body based on a change in a position of the reference object as viewed from the upper turning body.

Further, in another embodiment of the present disclosure, there is provided an excavator including a lower traveling body; an upper turning body turnably mounted to the lower traveling body; an acquisition device mounted to the upper turning body and configured to acquire information including a status around the excavator; and a control device configured to recognize an object around the excavator and to identify a position of the own machine with respect to the object, based on the information acquired by the acquisition device.

DETAILED DESCRIPTION

In the conventional technology, for example, when an excavator performs work, the positional relationship between an attachment that is a working device and an object including a work target (e.g., a dump truck in which earth and sand is loaded) around the excavator, is important. Therefore, even if the excavator determines the relative angle of the upper turning body with respect to the lower traveling body, there is a possibility that the excavator cannot recognize the positional relationship between the attachment and the object around the excavator, more specifically, the orientation of the upper turning body based on the object around the excavator (i.e., the angle in a top view).

Therefore, it is desirable to provide a technique in an excavator, by which the positional relationship between the own machine (i.e., the excavator in question) and an object around the own machine can be reliably identified.

First, an outline of an excavator100according to the present embodiment will be described with reference toFIG. 1.

FIG. 1is a side view of the excavator100that is a drilling machine according to the present embodiment.

FIG. 1illustrates the excavator100located on a horizontal plane facing an upward tilt surface ES to be worked on, and an upward slope surface BS (that is, the slope shape of the upward tilt surface ES after being worked on) that is an example of an aim work surface to be described later (seeFIGS. 8A and 8B).

The excavator100according to the present embodiment includes a lower traveling body1; an upper turning body3that is mounted to the lower traveling body1in a turnable manner via a turning mechanism2; a boom4, an arm5, and a bucket6configuring attachments (work machines), and a cabin10.

In the lower traveling body1, a crawler on the left and a crawler on the right, forming a pair, are hydraulically driven by traveling hydraulic motors1L and1R, respectively, to cause the excavator100to travel. That is, a pair of the traveling hydraulic motors1L and1R that is a driving unit drives the lower traveling body1(crawlers) as a driven unit.

The upper turning body3is driven by a turning hydraulic motor2A to turn relative to the lower traveling body1. That is, the turning hydraulic motor2A that is a driving unit, is a turning driving unit that drives the upper turning body3that is the driven unit, and can change the orientation of the upper turning body3(that is, the orientation of the attachment).

The upper turning body3may be electrically driven by an electric motor (hereinafter, referred to as a “turning electric motor”) instead of the turning hydraulic motor2A. That is, similar to the turning hydraulic motor2A, the turning electric motor is a turning driving unit that drives the upper turning body3that is a driven unit, and can change the orientation of the upper turning body3.

The boom4is pivotally mounted to the front center of the upper turning body3so as to be elevated, the arm5is pivotally mounted to the leading end of the boom4so as to turn upward and downward, and the bucket6that is the end attachment is pivotally mounted to the leading end of the arm5so as to turn upward and downward. The boom4, the arm5, and the bucket6are hydraulically driven by a boom cylinder7, an arm cylinder8, and a bucket cylinder9, respectively, as hydraulic actuators.

The bucket6is an example of an end attachment, and another end attachment, such as a slope bucket, a dredging bucket, a breaker, or the like, may be attached to the leading end of the arm5instead of the bucket6, depending on the work contents or the like.

The cabin10is an operator's cabin where an operator is seated, and is mounted on the front left side of the upper turning body3.

[Example of Configuration of Excavator]

Next, one example of a specific configuration of the excavator100according to the present embodiment will be described with reference toFIG. 2in addition toFIG. 1, and more specifically, an example of the configuration concerning the method of estimating the turning angle of the excavator100(own machine, i.e., the excavator in question) described below, will be described.

FIG. 2is a diagram schematically illustrating an example of the configuration of the excavator100according to the present embodiment.

Note that inFIG. 2, the mechanical power system, the hydraulic oil line, the pilot line, and the electrical control line are indicated as double, solid, dashed, and dotted lines, respectively. Hereinafter, the same applies toFIGS. 3, 4(FIGS. 4A to 4C) and12, which will be described later.

As described above, the hydraulic drive system of the excavator100according to the present embodiment includes a hydraulic actuator that is a driving unit including the traveling hydraulic motors1L and1R, the turning hydraulic motor2A, the boom cylinder7, the arm cylinder8, and the bucket cylinder9that are for hydraulically driving the lower traveling body1, the upper turning body3, the boom4, the arm5, and the bucket6, respectively. Further, the hydraulic driving system of the excavator100according to the present embodiment includes an engine11, a regulator13, a main pump14, and a control valve17.

The engine11is the main power source in the hydraulic driving system, and is a diesel engine fueled with diesel oil, for example. For example, the engine11is mounted at the back of the upper turning body3. The engine11constantly rotates at a predetermined target revolution speed under direct or indirect control by a controller30described below, to drive the main pump14and the pilot pump15.

The regulator13controls the discharge amount of the main pump14. For example, the regulator13adjusts the angle (hereinafter, a “tilt angle”) of the swash plate of the main pump14in response to control commands from the controller30. The regulator13includes regulators13L,13R, for example, as described below.

The main pump14, for example, is mounted at the back of the upper turning body3, similar to the engine11, to supply hydraulic oil to the control valve17through a high pressure hydraulic line. The main pump14is driven by the engine11as described above. The main pump14is, for example, a variable capacity hydraulic pump, and as described above, under the control of the controller30, the tilt angle of the swash plate is adjusted by the regulator13, thereby adjusting the stroke length of the piston and controlling the discharge flow rate (discharge pressure). The main pump14includes main pumps14L,14R, for example, as described below.

The control valve17, for example, is mounted in a central portion of the upper turning body3and is a hydraulic control device that controls the hydraulic driving system in response to an operation performed by an operator with respect to an operation apparatus26. As described above, the control valve17is connected to the main pump14via a high pressure hydraulic line, and selectively supplies hydraulic oil supplied from the main pump14to a hydraulic actuator (the traveling hydraulic motors1L,1R, the turning hydraulic motor2A, the boom cylinder7, the arm cylinder8, and the bucket cylinder9) depending on the state of the operation of the operation apparatus26. Specifically, the control valve17includes control valves171to176for controlling the flow rate and flow direction of hydraulic oil supplied from the main pump14to each of the hydraulic actuators. More specifically, the control valve171corresponds to the traveling hydraulic motor1L, the control valve172corresponds to the traveling hydraulic motor1R, and the control valve173corresponds to the turning hydraulic motor2A. The control valve174corresponds to the bucket cylinder9, the control valve175corresponds to the boom cylinder7, and the control valve176corresponds to the arm cylinder8. The control valve175also includes control valves175L and175R, for example, as described below, and the control valve176includes control valves176L and176R, for example, as described below. The control valves171to176are described in detail below (seeFIG. 3).

The operation system of the excavator100according to the present embodiment includes a pilot pump15and the operation apparatus26.

The pilot pump15, for example, is mounted at the back of the upper turning body3and supplies pilot pressure to various hydraulic devices such as a proportional valve31via a pilot line. The pilot pump15is, for example, a fixed capacitive hydraulic pump driven by the engine11as described above.

The operation apparatus26is provided near the operator's seat of the cabin10and is operation input means for the operator to perform the operations on driven units of the excavator100(the lower traveling body1, the upper turning body3, the boom4, the arm5, the bucket6, and the like). That is, the operation apparatus26is operation input means for the operator to operate the hydraulic actuators (that is, the traveling hydraulic motors1L and1R, the turning hydraulic motors2A, the boom cylinder7, the arm cylinder8, the bucket cylinder9, and the like) driving the respective driven units. For example, the operation apparatus26is an electric type and outputs an electrical signal (hereinafter, “operation signal”) corresponding to the operation content thereof, which operation signal is input to the controller30. The controller30outputs a control command corresponding to the operation signal to the proportional valve31, and accordingly, pilot pressure corresponding to the operation content of the operation apparatus26is supplied from the proportional valve31to the control valve17. Thus, the control valve17can implement the motion of the excavator100according to the operation content of the operator with respect to the operation apparatus26. The operation apparatus26includes, for example, a lever device for operating the arm5(the arm cylinder8). The operation apparatus26also includes lever devices26A to26C (seeFIGS. 4A to 4C) which operate, for example, the boom4(the boom cylinder7), the bucket6(the bucket cylinder9), and the upper turning body3(the turning hydraulic motor2A). The operation apparatus26includes, for example, a lever device or a pedal device for operating the pair of left and right crawlers (the traveling hydraulic motors1L and1R) of the lower traveling body1.

The operation apparatus26may be a hydraulic pilot type. In this case, to the operation apparatus26, the pilot pressure as the source pressure is supplied from the pilot pump15through the pilot line, and pilot pressure according to the operation content with respect to the operation apparatus26is output to the pilot line on the secondary side and supplied to the control valve17via the shuttle valve. The control valves171to176in the control valve17may be electromagnetic solenoid spool valves driven by commands from the controller30, or solenoid valves that operate in response to electrical signals from the controller30may be positioned between the pilot pump15and the pilot port of each of the control valves171to176. In these cases, the controller30controls the solenoid valves and increases or decreases the pilot pressure in response to an operation signal corresponding to an operation amount (e.g., a lever operation amount) of the electrically operated operation apparatus26to operate the control valves171to176according to the operating content with respect to the operation apparatus26.

The control system of the excavator100according to the present embodiment includes the controller30, a discharge pressure sensor28, the proportional valve31, a decompression proportional valve33, a display device40, an input device42, a sound output device43, and a storage device47. Further, the control system of the excavator100according to the present embodiment includes a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a machine tilt sensor S4, an imaging device S6, a positioning device PP1, and a communication device T1.

The controller30(an example of a control device) is provided, for example, in the cabin10, to perform various kinds of control for the excavator100. The controller30may implement functions thereof by any hardware, or combinations of hardware and software or the like. For example, the controller30is configured mainly as a microcomputer including a CPU (Central Processing Unit), a memory device such as a RAM (Random Access Memory), a non-volatile auxiliary storage device such as a ROM (Read Only Memory), and an interface device relating to various inputs and outputs. Further, for example, the controller30may include computing circuitry, such as a Graphics Processing Unit (GPU), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or the like, operating in conjunction with the CPU. The controller30implements various functions by executing, for example, various programs installed in the auxiliary storage device on the CPU.

For example, the controller30sets a target revolution speed and performs drive control for constant rotation of the engine11based on a work mode and the like preset by a predetermined operation by an operator and the like.

For example, the controller30outputs a control command to the regulator13as needed to change the discharge amount of the main pump14.

For example, the controller30controls the machine guidance function that guides the manual operation to the excavator100through the operation apparatus26by, for example, an operator. Further, the controller30controls the machine control function that automatically assists the operator in manually operating the excavator100through the operation apparatus26, for example. That is, the controller30includes the machine guidance unit50as a function unit of the machine guidance function and the machine control function.

Some of the functions of the controller30may be implemented by other controllers (control devices). That is, the functions of the controller30may be implemented in a manner that is distributed over a plurality of controllers. For example, the machine guidance function and the machine control function (the functions of the machine guidance unit50) may be implemented by an exclusive-use controller (control device).

The discharge pressure sensor28detects the discharge pressure of the main pump14. A detection signal corresponding to the discharge pressure detected by the discharge pressure sensor28is loaded into the controller30. The discharge pressure sensor28includes discharge pressure sensors28L and28R, for example, as described below.

The proportional valve31is provided on the pilot line connecting the pilot pump15to the control valve17. The proportional valve31is configured, for example, to change the flow area thereof (the cross-sectional area in which hydraulic oil is allowed to flow). The proportional valve31operates in response to a control command input from the controller30. Thus, the controller30can apply a pilot pressure according to the operation content of the operation apparatus26, to the pilot port of the corresponding control valve in the control valve17via the proportional valve31in response to an operation content signal input from the operation apparatus26. Further, the controller30may supply hydraulic oil discharged from the pilot pump15to the pilot port of the corresponding control valve in the control valve17via the proportional valve31, even if the operation apparatus26(specifically, the lever devices26A to26C) is not operated by an operator. The proportional valve31includes proportional valves31AL,31AR,31BL,31BR,31CL,31CR, as described below, for example.

Further, the proportional valve31can switch the operation with respect to the operation apparatus26, that is, the operation with respect to various driven elements of the excavator100, between an enabled state and a disabled state, by reducing the cross-sectional area through which the hydraulic oil can flow to zero regardless of the operation state with respect to the operation apparatus26or by changing the cross-sectional area to a flow path area corresponding to the operation state. Thus, the controller30can limit (stop) the motion of the excavator100by outputting a control command to the proportional valve31.

Further, when the operation apparatus26is a hydraulic pilot type, a pilot line between the pilot pump15and the operation apparatus26may be provided with a hydraulic control valve that switches the state of the pilot line between a communication state and a blocked state (non-communication state), in response to a control command from the controller30. The hydraulic control valve may be, for example, a gate lock valve configured to operate in response to control commands from controller30. For example, when a gate lock lever provided near the entrance of the cabin10where an operator is seated is pulled up, the gate lock valve switches to the communication state, and the state of an operation to the operation apparatus26becomes the enabled state (operable state). When the gate lock lever is pushed down, the gate lock valve switches to the blocked state, and the state of an operation to the operation apparatus26becomes the disabled state (inoperable state). Thus, the controller30can limit (stop) the motion of the excavator100by outputting a control command to the corresponding hydraulic control valve.

Note that, as the operation apparatus26, if a hydraulic pilot type is employed instead of an electric type, the pilot line on the secondary side of the proportional valve31is connected to the control valve17via the shuttle valve described above. In this case, the pilot pressure supplied from the shuttle valve to the control valve17is the higher pilot pressure between the pilot pressure, which is in accordance with the operation content, output from the operation apparatus26, and a predetermined pilot pressure, which is unrelated to the operation content of the operation apparatus26, output from the proportional valve31.

The decompression proportional valve33is disposed in the pilot line between the proportional valve31and the control valve17. The controller30reduces the pilot pressure by discharging the hydraulic oil on the pilot line into the tank, when the controller30determines that a braking operation to decelerate or stop the hydraulic actuator is necessary, based on a signal from an object detection device (e.g., the imaging device S6). This allows the control valve spool in the control valve17to move in the neutral direction, regardless of the state of the proportional valve31. Accordingly, the decompression proportional valve33is effective when the braking characteristic is desired to be improved. The decompression proportional valve33includes, for example, decompression proportional valves33AL,33AR,33BL,33BR,33CL, and33CR as described below.

As the operation apparatus26, when the hydraulic pilot type is adopted instead of the electric type, the decompression proportional valve33is omitted.

The display device40is provided at a location within the cabin10where the display device40is readily visible from a seated operator and displays various information images under the control of the controller30. The display device40may be, for example, a liquid crystal display or an organic electroluminescent (EL) display. The display device40may be connected to the controller30via in-vehicle communication networks such as CAN (Controller Area Network) or may be connected to the controller30via a one-to-one exclusive-use line.

The input device42accepts various inputs from an operator in the cabin10, and outputs a signal according to the accepted input, to the controller30. For example, the input device42is positioned within reach of a seated operator in the cabin10and includes an operation input device for accepting operation inputs from the operator. The operation input device includes a touch panel mounted on a display of the display device40for displaying various information images, a knob switch mounted on the leading end of a lever portion of the lever devices26A to26C, a button switch, a lever, a toggle, a rotating dial, and the like mounted around the display device40. Further, the input device42may include, for example, a sound input device or a gesture input device for accepting the sound input or gesture input from an operator in the cabin10. The sound input device includes, for example, a microphone provided in the cabin10. The sound input device includes, for example, an imaging device disposed within the cabin10, that is capable of capturing an image of the operator's appearance. A signal corresponding to the input content to the input device42is loaded into the controller30.

The sound output device43is provided, for example, in the cabin10, and outputs predetermined sounds under the control of the controller30. The sound output device43may be, for example, a speaker, a buzzer, or the like. The sound output device43outputs various types of information by sound, i.e., outputs auditory information, in accordance with a control command from the controller30.

The storage device47is provided in the cabin10, for example, for storing various kinds of information under the control of the controller30. The storage device47is a non-volatile storage medium such as, for example, a semiconductor memory. The storage device47may store information output by the various devices during operation of the excavator100and may store information acquired through the various devices before operation of the excavator100is started. The storage device47may store, for example, data relating to an aim work surface acquired through the communication device T1or the like or set through the input device42or the like. The aim work surface may be set (stored) by an operator of the excavator100or may be set by a construction manager or the like.

The boom angle sensor S1is mounted to the boom4and detects the depression/elevation angle of the boom4relative to the upper turning body3(hereinafter, the “boom angle”), for example, the angle of a straight line connecting the fulcrums points at both ends of the boom4relative to the turning plane of the upper turning body3in a side view. The boom angle sensor S1may include, for example, a rotary encoder, an acceleration sensor, a 6-axis sensor, an IMU (Inertial Measurement Unit), or the like. Further, the boom angle sensor S1may include a potentiometer using a variable resistor and a cylinder sensor for detecting the stroke amount of a hydraulic cylinder (the boom cylinder7) corresponding to the boom angle. The same applies to the arm angle sensor S2and the bucket angle sensor S3. A detection signal corresponding to the boom angle output by the boom angle sensor S1is loaded into the controller30.

The arm angle sensor S2is mounted to the arm5and detects the rotation angle of the arm5with respect to the boom4(hereinafter, an “arm angle”), for example, the angle formed between a straight line connecting the fulcrum points at both ends of the boom4and a straight line connecting the fulcrum points at both ends of the arm5in a side view. A detection signal corresponding to the arm angle output by the arm angle sensor S2is loaded into the controller30.

The bucket angle sensor S3is mounted to the bucket6and detects the rotation angle (hereinafter, a “bucket angle”) of the bucket6with respect to the arm5, for example, the angle formed between a straight line connecting the fulcrum points at both ends of the arm5and a straight line connecting the fulcrum point and the leading end (claw tip) of the bucket6in a side view. A detection signal corresponding to the bucket angle output by the bucket angle sensor S3is loaded into the controller30.

The machine tilt sensor S4detects the tilt state of the machine (the upper turning body3or the lower traveling body1) relative to a predetermined plane (for example, a horizontal plane). For example, the machine tilt sensor S4is mounted on the upper turning body3and detects the tilt angle of the excavator100(i.e., the upper turning body3) about the two axes in the frontward-backward direction and the left-right direction (hereinafter, a “front-back tilt angle” and a “left-right tilt angle”). The machine tilt sensor S4may include, for example, a rotary encoder, an acceleration sensor, a 6-axis sensor, an IMU, or the like. A detection signal corresponding to the tilt angle (front-back tilt angle and left-right tilt angle) output by the machine tilt sensor S4is loaded into the controller30.

The imaging device S6captures the surroundings of the excavator100, and acquires image information representing the appearance of the area around the excavator100. The imaging device S6includes a camera S6F for capturing images in front of the excavator100, a camera S6L for capturing images on the left of the excavator100, a camera S6R for capturing images on the right of the excavator100, and a camera S6B for capturing images behind the excavator100.

The camera S6F (an example of an acquisition device) is mounted, for example, on the ceiling of the cabin10, i.e., inside the cabin10. The camera S6F (an example of an acquisition device) may be mounted on the outside of the cabin10, such as the roof of the cabin10, the side surface of the boom4, or the like. The camera S6L (an example of an acquisition device) is mounted on the left end of the upper surface of the upper turning body3, the camera S6R (an example of an acquisition device) is mounted on the right end of the upper surface of the upper turning body3, and the camera S6B (an example of an acquisition device) is mounted on the back end of the upper surface of the upper turning body3.

The imaging device S6(the cameras S6F, S6B, S6L, and S6R) is, for example, a monocular wide angle camera having a very wide angle of view. The imaging device S6may be a stereo camera, a distance image camera, or a depth camera. An image captured by the imaging device S6is loaded into the controller30via the display device40.

Further, the imaging device S6(the cameras S6F, S6B, S6L, and S6R) may be replaced by or additionally provided with other sensors capable of acquiring information representing the appearance of the surroundings of the excavator100. The other sensors may be, for example, ultrasonic sensors, millimeter wave radars, LIDAR (Light Detection and Ranging), infrared sensors, and the like. Specifically, the other sensors may receive a reflected signal of the output signal output to the surroundings of the excavator100, to calculate the distance to the object around the excavator100using point group data or the like. The imaging device S6and/or other sensors may function as an object detection device. In this case, the imaging device S6and/or other sensors may detect an object that is a predetermined detection target that is present around the excavator100. The object that is a detection target may include, for example, humans, animals, vehicles, construction machinery, buildings, holes, and the like. The imaging device S6and/or other sensors may acquire (calculate) the distance from the sensor itself or from the excavator100to the recognized object.

For example, based on the output of the imaging device S6and/or other sensors, the controller30performs control (hereinafter, referred to as “contact avoidance control”) to avoid contact or the like between the excavator100and an object that is the monitor target when the object (e.g., a person, a truck, another construction machine, or the like) that is the monitor target is detected in a predetermined monitor region (e.g., a work region within a distance of 5 meters from the excavator100) around the excavator100. Specifically, the controller30may output a control command to the display device40or the sound output device43and output an alarm as an example of contact avoidance control. The controller30may output a control command to the proportional valve31, the decompression proportional valve33, or the control valve to limit the motion of the excavator100as an example of contact avoidance control. In this case, the target of the motion limitation may be all of the driven elements, or only some of the driven elements that need to be limited for avoiding contact between the object that is the monitor target with the excavator100.

Determination by the controller30of the presence of a monitor target in the monitor region is performed even in the inoperable state. The excavator100may determine whether a monitor target is present in the monitor region of the excavator100, and also determine whether a monitor target is present outside the monitor region of the excavator100. The determination of whether a monitor target is present outside the monitor region of the excavator100may also be performed even when the excavator100is inoperable.

The imaging device S6may be directly communicably connected to the controller30.

The positioning device PP1measures the position of the excavator100(the upper turning body3). The positioning device PP1is, for example, a GNSS (Global Navigation Satellite System) module which detects the position of the upper turning body3, and the detection signal corresponding to the position of the upper turning body3is loaded into the controller30.

The position of the excavator100may be acquired by using an estimation method described below. In this case, the positioning device PP1may be omitted.

The communication device T1is connected to a predetermined network that may include a mobile communication network having a base station as the terminal, a satellite communication network using a communication satellite, the Internet network, or the like, and communicates with an external device (for example, a management apparatus200to be described later). The communication device T1is, for example, a mobile communication module compatible with a mobile communication standard such as LTE (Long Term Evolution), 4G (4th Generation), and 5G (5th Generation), or a satellite communication module for connecting to a satellite communication network.

The machine guidance unit50performs control of the excavator100with respect to, for example, the machine guidance function. The machine guidance unit50communicates to an operator, for example, through the display device40or the sound output device43, work information such as a distance between an aim work surface and a leading end of an attachment, specifically, the working portion of an end attachment. The data relating to the aim work surface is pre-stored in the storage device47as described above, for example. The data relating to the aim work surface is represented, for example, by a reference coordinate system. The reference coordinate system is, for example, a local coordinate system unique to the construction site. The operator may define any point of the construction site as a reference point and set the aim work surface by the relative positional relationship with the reference point through the input device42. The working portion of the bucket6is, for example, the claw tip of the bucket6, the back surface of the bucket6, and the like. If, for example, a breaker is employed instead of the bucket6as an end attachment, the leading end of the breaker corresponds to the working portion. The machine guidance unit50notifies an operator of work information through the display device40, the sound output device43, or the like, and guides the operator to operate the excavator100through the operation apparatus26.

Further, the machine guidance unit50controls the excavator100with respect to, for example, the machine control function. For example, the machine guidance unit50causes the automatic motion of at least one of the lower traveling body1, the upper turning body3, the boom4, the arm5, and the bucket6, so that the working portion of the bucket6moves along a predetermined target trajectory, in response to an operation by the operator with respect to the operation apparatus26. Specifically, when the operator is performing a manual drilling operation, the machine guidance unit50may cause at least one of the boom4, the arm5, and the bucket6to be automatically operated so that the aim work surface and the leading end position of the bucket6(that is, the position that is the control reference in the working portion) coincide with each other. Further, the machine guidance unit50may cause the upper turning body3to be automatically operated so that the upper turning body3front-faces, for example, a predetermined work target (for example, a dump truck to be loaded with earth and sand, a slope to be worked on by cutting soil or rolling, etc.). Further, the machine guidance unit50may, for example, cause the automatic motion of the lower traveling body1so that the excavator100moves along a predetermined path.

The machine guidance unit50acquires information from the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the machine tilt sensor S4, the imaging device S6, the positioning device PP1, the communication device T1, and the input device42. The machine guidance unit50, for example, calculates the distance between the bucket6and the aim work surface based on the acquired information, notifies the operator of the extent of the distance between the bucket6and the work target (for example, the aim work surface) based on the sound from the sound output device43and the image displayed on the display device40, and automatically controls the operation of the attachment so that the leading end of the attachment (specifically, the working portion such as the claw tip or the back surface of the bucket6) coincides with the aim work surface. The machine guidance unit50includes a position calculating unit51, a distance calculating unit52, an information transmitting unit53, an automatic control unit54, a turning angle calculating unit55, and a relative angle calculating unit56, as detailed functional configurations relating to the machine guidance function and the machine control function.

The position calculating unit51calculates a position of a predetermined positioning target. For example, the position calculating unit51calculates a coordinate point in the reference coordinate system of the leading end of the attachment, specifically, the working portion such as the claw tip or the back surface of the bucket6. Specifically, the position calculating unit51calculates the coordinate point of the working portion of the bucket6from the respective elevation angles (the boom angle, the arm angle, and the bucket angle) of the boom4, the arm5, and the bucket6.

The distance calculating unit52calculates the distance between the two positioning targets. For example, the distance calculating unit52calculates the distance between the leading end of the attachment, specifically, the working portion such as the claw tip or the back surface of the bucket6, and the aim work surface. The distance calculating unit52may calculate an angle (relative angle) between the back surface as a working portion of the bucket6and the aim work surface.

The information transmitting unit53transmits (notifies) various kinds of information to an operator of the excavator100through predetermined notification means such as the display device40or the sound output device43. The information transmitting unit53notifies the operator of the excavator100of the magnitude (extent) of various distances calculated by the distance calculating unit52. For example, the distance (magnitude) between the leading end of the bucket6and the aim work surface is communicated to the operator by using at least one of the visual information displayed by the display device40and the auditory information output by the sound output device43. The information transmitting unit53may communicate to an operator the relative angle (magnitude) between the back surface of the bucket6as the work portion and the aim work surface using at least one of the visual information provided by the display device40and the auditory information provided by the sound output device43.

Specifically, the information transmitting unit53transmits the magnitude of the distance (for example, the vertical distance) between the working portion of the bucket6and the aim work surface to the operator using an intermittent sound generated by the sound output device43. In this case, the information transmitting unit53may shorten the intervals between the intermittent sounds as the vertical distance decreases and may increase the intervals between the intermittent sounds as the vertical distance increases. Further, the information transmitting unit53may use continuous sounds and may represent the difference in the magnitude of the vertical distance by changing the pitch, intensity, or the like of the sound. The information transmitting unit53may issue an alarm through the sound output device43when the leading end of the bucket6is at a position lower than the aim work surface, that is, exceeds the aim work surface. The alarm is, for example, a continuous sound that is significantly louder than an intermittent sound.

The information transmitting unit53may display, on the display device40as work information, the magnitude of the distance between the leading end of the attachment, specifically, the working portion of the bucket6, and the aim work surface, the magnitude of the relative angle between the back surface of the bucket6and the aim work surface, or the like. The display device40displays the work information received from the information transmitting unit53together with image data received from the imaging device S6, for example, under the control of the controller30. The information transmitting unit53may communicate the magnitude of the vertical distance to the operator using, for example, an image of an analog meter or an image of a bar graph indicator.

The automatic control unit54automatically assists the operator in manually operating the excavator100through the operation apparatus26, by automatically moving the actuator driving the driven units of the excavator100. Specifically, the automatic control unit54can control the proportional valve31, and individually and automatically adjust the pilot pressure acting on the control valves in the control valve17corresponding to a plurality of hydraulic actuators. Thus, the automatic control unit54can automatically move the respective hydraulic actuators. The control relating to the machine control function by the automatic control unit54may be performed, for example, when a predetermined switch included in the input device42is pressed down. The predetermined switch may be, for example, a machine control switch (“MC (Machine Control) switch”) and may be positioned as a knob switch at the tip of the operator's grip portion of the operation apparatus26(e.g., a lever device corresponding to the operation of the arm5). Hereinafter, the explanation is based on the assumption that when the MC switch is pressed down, the machine control function is enabled.

For example, when the MC switch, or the like, is pressed down, the automatic control unit54automatically expands and contracts at least one of the boom cylinder7and the bucket cylinder9, in accordance with the motion of the arm cylinder8, to assist in the drilling work or the shaping work. Specifically, the automatic control unit54automatically expands or contracts at least one of the boom cylinder7and the bucket cylinder9so that the aim work surface coincides with a position that is the control reference of a working portion, such as the claw tip or the back surface of the bucket6, when the operator performs a manual operation to close the arm5(hereinafter, an “arm closing operation”). In this case, the operator can close the arm5while matching the claw tip of the bucket6or the like to the aim work surface, for example, by simply performing an arm closing operation with respect to the lever device corresponding to the operation of the arm5.

When the MC switch is pressed down, the automatic control unit54may automatically rotate the turning hydraulic motor2A in order to cause the upper turning body3to front-face a predetermined work target (for example, a dump truck to be loaded with earth and sand, the aim work surface to be worked on, etc.). Hereinafter, the control in which the upper turning body3is caused to front-face the aim work surface by the controller30(the automatic control unit54) is referred to as “front-face control” in some cases. Accordingly, the operator, or the like, can simply press a predetermined switch or operate the lever device26C described below which corresponds to the turning operation while the switch is pressed down, so that the upper turning body3is caused to front-face the work target. Further, the operator may simply press the MC switch to cause the upper turning body3to front-face the work target and start a machine control function relating to the work of discharging soil to a dump truck or the drilling work on the aim work surface or the like.

For example, the state in which the upper turning body3of the excavator100is front-facing the dump truck that is the work target, is such that the bucket6at the leading end of the attachment can be moved along the longitudinal direction of the dump truck's loading platform, i.e., the front-back axis of the dump truck's loading platform.

For example, the state in which the upper turning body3of the excavator100front-faces the aim work surface that is the work target, is such that the leading end of the attachment (e.g., the claw tip or the back surface as the working portion of the bucket6) can be moved along the inclined direction of the aim work surface (for example, the upward slope surface BS inFIG. 1) in accordance with the motion of the attachment. Specifically, the state in which the upper turning body3of the excavator100front-faces the aim work surface is a state in which the operation plane (the operation plane of the attachment) AF of the attachment vertical to a turning plane SF of the excavator100includes a normal line of the aim work surface corresponding to the cylindrical body CB (that is, a state in accordance with the normal line) (seeFIG. 8Bdescribed below).

If the attachment operation plane AF of the excavator100is not in a state that includes the normal line of the aim work surface corresponding to the cylindrical body CB, the leading end of the attachment cannot move in the tilt direction of the aim work surface. As a result, the excavator100cannot properly perform construction work on the aim work surface (seeFIG. 8Adescribed below). On the other hand, the automatic control unit54automatically rotates the turning hydraulic motor2A, so that the upper turning body3front-faces the aim work surface. This allows the excavator100to properly perform construction work on the aim work surface (see FIG.8B described below).

In the front-face control with respect to the aim work surface (the upward slope surface), for example, when the left end vertical distance between the coordinate point at the left end of the claw tip of the bucket6and the aim work surface (hereinafter, simply referred to as “the left end vertical distance”) is equal to the right end vertical distance between the coordinate point at the right end of the claw tip of the bucket6and the aim work surface (hereinafter, simply referred to as “the right end vertical distance”), the automatic control unit54determines that the excavator front-faces the aim work surface. Further, the automatic control unit54may determine that the excavator100front-faces the aim work surface, not when the left end vertical distance is equal to the right end vertical distance (that is, when the difference between the left end vertical distance and the right end vertical distance is zero), but when this difference is less than or equal to a predetermined value.

Further, in the front-face control with respect to the aim work surface (the upward slope surface), the automatic control unit54may operate the turning hydraulic motor2A based on, for example, the difference between the left end vertical distance and the right end vertical distance. Specifically, if the lever device26C corresponding to the turning operation is operated while the predetermined switch such as the MC switch or the like is pressed down, it is determined whether the lever device26C is operated in a direction in which the upper turning body3is caused to front-face the aim work surface. For example, when the lever device26C is operated in a direction in which the vertical distance between the claw tip of the bucket6and the aim work surface (the upward slope surface) is increased, the automatic control unit54does not perform the front-face control. On the other hand, when the turning operation lever is operated in a direction in which the vertical distance between the claw tip of the bucket6and the aim work surface (the upward slope surface) is reduced, the automatic control unit54performs front-face control. As a result, the automatic control unit54can operate the turning hydraulic motor2A so that the difference between the left end vertical distance and the right end vertical distance is reduced. Thereafter, the automatic control unit54stops the turning hydraulic motor2A when the difference becomes less than or equal to a predetermined value or zero. The automatic control unit54may set the turning angle, at which the difference is less than or equal to a predetermined value or equal to zero, as a target angle, and perform operation control of the turning hydraulic motor2A so that the angle difference between the target angle and the present turning angle (specifically, a detected value based on a detection signal of the turning state sensor S5) becomes zero. In this case, the turning angle is, for example, the angle of the front-back axis of the upper turning body3relative to the reference direction.

As described above, when a turning electric motor is mounted to the excavator100instead of the turning hydraulic motor2A, the automatic control unit54performs front-face control of the turning electric motor as a control target.

The turning angle calculating unit55calculates the turning angle of the upper turning body3. This allows the controller30to identify the current orientation of the upper turning body3. For example, the turning angle calculating unit55calculates (estimates) the turning angle of the upper turning body3, based on the change in the position of the object that is stopped or fixed, included (appearing) in the captured image captured by the imaging device S6(that is, the change in in the direction in which the object can be viewed), as described below. Details will be described later (with reference toFIGS. 5 to 8B).

The turning angle expresses the direction in which the attachment operation plane extends relative to the reference direction as viewed from the upper turning body3(that is, the direction in which the attachment extends in a top view of the upper turning body3). The attachment operation plane is, for example, a virtual plane that traverses the attachment and is positioned perpendicular to the turning plane. A turning plane is, for example, a virtual plane including the bottom of a turning frame perpendicular to the turning axis. For example, the controller30(the machine guidance unit50) may determine that the upper turning body3front-faces the aim work surface when it is determined that the attachment operation plane includes the normal line of the aim work surface.

The relative angle calculating unit56calculates the turning angle (hereinafter, “relative angle”) necessary for causing the upper turning body3front-face the work target. The relative angle is a relative angle formed between the direction of the front-back axis of the upper turning body3when the upper turning body3front-faces the work target and the current direction of the front-back axis of the upper turning body3, for example. For example, when causing the upper turning body3to front-face the dump truck to be loaded with earth and sand and the like, the relative angle calculating unit56calculates the relative angle based on the captured image captured by the imaging device S6in which the loading platform of the dump truck is appearing, and the turning angle calculated by the turning angle calculating unit55. For example, when causing the upper turning body3to front-face the aim work surface, the relative angle calculating unit56calculates the relative angle based on the data relating to the aim work surface stored in the storage device47and the turning angle calculated by the turning angle calculating unit55.

When the lever device26C corresponding to the turning operation is operated while the predetermined switch such as the MC switch or the like is pressed down, the automatic control unit54determines whether the turning operation is performed in a direction in which the upper turning body3is caused to front-face the work target. When the automatic control unit54determines that the turning operation has been performed in the direction in which the upper turning body3is caused to front-face the work target, the automatic control unit54sets the relative angle calculated by the relative angle calculating unit56as the target angle. When the turning angle changes after the lever device26C is operated to reach the target angle, the automatic control unit54determines that the upper turning body3front-faces the work target and may stop the movement of the turning hydraulic motor2A. Accordingly, the automatic control unit54can assist the operation by the operator with respect to the lever device26C and allow the upper turning body3to front-face the work target on the basis of the configuration illustrated inFIG. 2. When a predetermined switch such as the MC switch or the like is pressed down, the automatic control unit54may cause the upper turning body3to automatically front-face the work target, regardless of the operation with respect to the lever device26C.

[Hydraulic System of the Excavator]

Next, a hydraulic system of the excavator100according to the present embodiment will be described with reference toFIG. 3.

FIG. 3is a diagram schematically illustrating an example of the configuration of the hydraulic system of the excavator100according to the present embodiment.

InFIG. 3, the mechanical power system, the hydraulic oil line, the pilot line, and the electrical control system are illustrated as double, solid, dashed, and dotted lines, respectively, as inFIG. 2.

The hydraulic system realized by the hydraulic circuit circulates the hydraulic oil from each of the main pumps14L and14R driven by the engine11to the hydraulic oil tank through center bypass oil lines C1L and C1R, and parallel oil lines C2L and C2R.

The center bypass oil line C1L starts at the main pump14L and passes through the control valves171,173,175L, and176L disposed in the control valve17in this order, to reach the hydraulic oil tank.

The center bypass oil line C1R starts at the main pump14R and passes through control valves172,174,175R, and176R, which are disposed in the control valve17in this order, to reach the hydraulic oil tank.

The control valve171is a spool valve which supplies hydraulic oil discharged from the main pump14L to the traveling hydraulic motor1L and discharges the hydraulic oil discharged from the traveling hydraulic motor1L to the hydraulic oil tank.

The control valve172is a spool valve which supplies hydraulic oil discharged from the main pump14R to the traveling hydraulic motor1R and discharges the hydraulic oil discharged from the traveling hydraulic motor1R to the hydraulic oil tank.

The control valve173is a spool valve which supplies hydraulic oil discharged from the main pump14L to the turning hydraulic motor2A and discharges the hydraulic oil discharged from the turning hydraulic motor2A to the hydraulic oil tank.

The control valve174is a spool valve which supplies hydraulic oil discharged from the main pump14R to the bucket cylinder9and discharges the hydraulic oil in the bucket cylinder9to the hydraulic oil tank.

The control valves175L and175R are spool valves that supply the hydraulic oil discharged by the main pumps14L and14R to the boom cylinder7, respectively, and discharge the hydraulic oil in the boom cylinder7to the hydraulic oil tank.

The control valves176L and176R supply the hydraulic oil discharged by the main pumps14L and14R to the arm cylinder8, and discharge the hydraulic oil in the arm cylinder8to the hydraulic oil tank.

The control valves171,172,173,174,175L,175R,176L, and176R each adjust the flow rate of hydraulic oil supplied to and discharged from the hydraulic actuator and switch the direction of flow, depending on the pilot pressure acting on the pilot port.

The parallel oil line C2L supplies the hydraulic oil of the main pump14L to the control valves171,173,175L, and176L in parallel with the center bypass oil line C1L. Specifically, the parallel oil line C2L branches from the center bypass oil line C1L at the upstream side of the control valve171and is configured to supply the hydraulic oil of the main pump14L in parallel with each of the control valves171,173,175L, and176R. This allows the parallel oil line C2L to supply hydraulic oil to the control valve that is further downstream, when the flow of hydraulic oil passing through the center bypass oil line C1L is limited or blocked by one of the control valves171,173, and175L.

The parallel oil line C2R supplies the hydraulic oil of the main pump14R to the control valves172,174,175R, and176R in parallel with the center bypass oil line C1R. Specifically, the parallel oil line C2R branches from the center bypass oil line C1R at the upstream side of the control valve172and is configured to supply the hydraulic oil of the main pump14R in parallel with each of the control valves172,174,175R, and176R. The parallel oil line C2R can supply hydraulic oil to a control valve further downstream when the flow of hydraulic oil passing through the center bypass oil line C1R is limited or blocked by one of the control valves172,174, and175R.

The regulators13L and13R adjust the discharge amounts of the main pumps14L and14R by adjusting the tilt angles of the swash plates of the main pumps14L and14R, respectively, under the control of the controller30.

The discharge pressure sensor28L detects the discharge pressure of the main pump14L, and a detection signal corresponding to the detected discharge pressure is loaded into the controller30. The same applies to the discharge pressure sensor28R. Thus, the controller30can control the regulators13L and13R according to the discharge pressures of the main pumps14L and14R.

In the center bypass oil lines C1L and C1R, negative control diaphragms (hereinafter, “negative control diaphragms”)18L and18R are provided between the control valves176L and176R, which are most downstream, and the hydraulic oil tank, respectively. Accordingly, the flow of hydraulic oil discharged by the main pumps14L and14R is limited by the negative control diaphragms18L and18R. The negative control diaphragms18L and18R generate a control pressure (hereinafter, “negative control pressure”) for controlling the regulators13L and13R.

Negative control pressure sensors19L and19R detect the negative control pressure, and the detection signal corresponding to the detected negative control pressure is loaded into the controller30.

The controller30may control the regulators13L and13R according to the discharge pressures of the main pumps14L and14R detected by the discharge pressure sensors28L and28R to adjust the discharge amounts of the main pumps14L and14R. For example, the controller30may control the regulator13L according to an increase in the discharge pressure of the main pump14L to adjust the tilt angle of the swash plate of the main pump14L to reduce the discharge amount. The same applies to the regulator13R. Accordingly, the controller30can control the total horsepower of the main pumps14L and14R so that the suction horsepower of the main pumps14L and14R, which is expressed as the product of the discharge pressure and the discharge amount, does not exceed the output horsepower of the engine11.

The controller30may adjust the discharge amount of the main pumps14L and14R by controlling the regulators13L and13R according to the negative control pressure detected by the negative control pressure sensors19L and19R. For example, the controller30decreases the discharge amount of the main pumps14L and14R as the negative control pressure increases, and increases the discharge amount of the main pumps14L and14R as the negative control pressure decreases.

Specifically, in the standby state in which none of the hydraulic actuators in the excavator100are operated (the state illustrated inFIG. 3), the hydraulic oil discharged from the main pumps14L and14R reaches the negative control diaphragms18L and18R through the center bypass oil lines C1L and C1R. The flow of hydraulic oil discharged from the main pumps14L and14R increases the negative control pressure generated upstream of the negative control diaphragms18L and18R. As a result, the controller30reduces the discharge amount of the main pumps14L and14R to the allowable minimum discharge amount and suppresses the pressure loss (pumping loss) when the discharged hydraulic oil passes through the center bypass oil lines C1L and C1R.

On the other hand, when any of the hydraulic actuators are operated through the operation apparatus26, the hydraulic oil discharged from the main pumps14L and14R flows into the hydraulic actuator to be operated through a control valve corresponding to the hydraulic actuator to be operated. The flow of the hydraulic oil discharged from the main pumps14L and14R decreases or eliminates the amount reaching the negative control diaphragms18L and18R, thereby lowering the negative control pressure generated upstream of the negative control diaphragms18L and18R. As a result, the controller30can increase the discharge amount of the main pumps14L and14R, circulate sufficient hydraulic oil in the hydraulic actuator to be operated, and reliably drive the hydraulic actuator to be operated.

[Details of Configuration Relating to Machine Control Function of Excavator]

Referring now toFIG. 4(FIGS. 4A-4C), details of the configuration relating to the machine control function of the excavator100will be described.

FIGS. 4A to 4Cschematically illustrate an example of a configuration relating to the operation system of the hydraulic system of the excavator100according to the present embodiment. Specifically,FIG. 4Ais a diagram illustrating an example of a pilot circuit for applying pilot pressure to the control valves175L and175R for hydraulic control of the boom cylinder7.FIG. 4Bis a diagram illustrating an example of a pilot circuit for applying pilot pressure to the control valve174for hydraulic control of the bucket cylinder9.FIG. 4Cis a diagram illustrating an example of a pilot circuit for applying pilot pressure to the control valve173for hydraulic control of the turning hydraulic motor2A.

For example, as illustrated inFIG. 4A, the lever device26A is used by an operator or the like to operate the boom cylinder7corresponding to the boom4. The lever device26A outputs an electrical signal (hereinafter, an “operation content signal”) according to the operation content (for example, the operation direction and the operation amount) to the controller30.

In the controller30, an association relationship is set in advance, with respect to the control current to the proportional valve31according to the operation amount of the operation apparatus26(e.g., the tilting angle of the lever devices26A-26C). The proportional valve31corresponding to each of the individual lever devices (such as the lever devices26A-26C) included in the operation apparatus26, is controlled based on the association relationship that is set.

The proportional valve31AL operates in response to a control current input from the controller30. Specifically, the proportional valve31AL uses the hydraulic oil discharged from the pilot pump15to output a pilot pressure corresponding to the control current input from the controller30, to the pilot port on the right side of the control valve175L and to the pilot port on the left side of the control valve175R. This allows the proportional valve31AL to adjust the pilot pressure acting on the pilot port on the right side of the control valve175L and the pilot port on the left side of the control valve175R. For example, by receiving input of a control current from the controller30corresponding to an operation for raising the boom4(hereinafter referred to as “the boom raising operation”) performed on the lever device26A, the proportional valve31AL can apply a pilot pressure according to the operation content (the amount of operation) with respect to the lever device26A, on the pilot port on the right side of the control valve175L and the pilot port on the left side of the control valve175R. Further, by inputting a predetermined control current from the controller30without depending on the operation content of the lever device26A, the proportional valve31AL can apply a pilot pressure to the pilot port on the right side of the control valve175L and the pilot port on the left side of the control valve175R, regardless of the operation content of the lever device26A.

The proportional valve31AR operates in response to a control current input from the controller30. Specifically, the proportional valve31AR uses the hydraulic oil discharged from the pilot pump15to output a pilot pressure corresponding to the control current input from the controller30to the pilot port on the right side of the control valve175R. This allows the proportional valve31AR to adjust the pilot pressure acting on the pilot port on the right side of the control valve175R. For example, by receiving input of a control current from the controller30corresponding to an operation for lowering the boom4(hereinafter referred to as “the boom lowering operation”) performed on the lever device26A, the proportional valve31AR can apply a pilot pressure according to the operation content (the amount of operation) with respect to the lever device26A, on the pilot port on the right side of the control valve175R. Further, by inputting a predetermined control current from the controller30without depending on the operation content of the lever device26A, the proportional valve31AR can apply a pilot pressure on the pilot port on the right side of the control valve175R regardless of the operation content of the lever device26A.

That is, when a boom raising operation is performed, the lever device26A outputs an operation content signal according to the operation direction and the operation amount to the controller30to apply a pilot pressure according to the operation content on the pilot port on the right side of the control valve175L and the pilot port on the left side of the control valve175R via the controller30and the proportional valve31AL. When a boom lowering operation is performed, the lever device26A outputs an operation content signal according to the operation direction and the operation amount to the controller30to apply a pilot pressure according to the operation content on the pilot port on the right side of the control valve175R via the controller30and the proportional valve31AR.

Thus, the proportional valves31AL and31AR can adjust the pilot pressure output to the secondary side so that the control valves175L and175R can be stopped at any valve position, according to the operation state of the lever device26A, under the control of the controller30. The proportional valves31AL and31AR can also adjust the pilot pressure output to the secondary side so that the control valves175L and175R can be stopped at any valve position under the control of the controller30, regardless of the operation state of the lever device26A.

The decompression proportional valve33AL is disposed on a pilot line between the proportional valve31AL, and the pilot port on the right side of the control valve175L and the pilot port on the left side of the control valve175R. The controller30reduces the pilot pressure by discharging the hydraulic oil on the pilot line into the tank when the controller30determines that a braking operation to decelerate or stop the hydraulic actuator (the boom cylinder7) is necessary based on a signal from the object detection device (e.g., the imaging device S6). This allows the spools of the control valves175L and175R to move in the neutral direction regardless of the state of the proportional valve31AL. Therefore, the decompression proportional valve33AL is effective where it is desired to improve the braking characteristics.

In the present embodiment, it is not necessarily needed to include the decompression proportional valve33AL, and the decompression proportional valve33AL may be omitted. Hereinafter, the same applies to the other decompression proportional valves33(the decompression proportional valves33AR,33BL,33BR,33CL,33CR, etc.).

The decompression proportional valve33AR is disposed on a pilot line between the proportional valve31AR and the pilot port on the right side of the control valve175R. The controller30reduces the pilot pressure by discharging the hydraulic oil on the pilot line to the tank when the controller30determines that a braking operation to decelerate or stop the hydraulic actuator (the boom cylinder7) is necessary based on a signal from an object detection device (e.g., the imaging device S6). This allows the spools of the control valves175L and175R to move in the neutral direction regardless of the state of the proportional valve31AR. Therefore, the decompression proportional valve33AR is effective where it is desired to improve the braking characteristics.

The controller30may control the proportional valve31AL in response to an operation content signal corresponding to a boom raising operation by the operator with respect to the lever device26A, to supply pilot pressure according to the operation content (the operation amount) of the lever device26A, to the pilot port on the right side of the control valve175L and the pilot port on the left side of the control valve175R. The controller30may control the proportional valve31AR in response to an operation content signal corresponding to a boom lowering operation by the operator with respect to the lever device26A, to supply pilot pressure according to the operation content (the operation amount) of the lever device26A, to the pilot port on the right side of the control valve175R. That is, the controller30may control the proportional valves31AL and31AR according to the operation content signal input from the lever device26A to implement the operation of raising or lowering of the boom4according to the operation content of the lever device26A.

The controller30may control the proportional valve31AL, regardless of the boom raising operation by the operator with respect to the lever device26A, to supply hydraulic oil discharged from the pilot pump15to the pilot port on the right side of the control valve175L and the pilot port on the left side of the control valve175R. The controller30may control the proportional valve31AR regardless of the boom lowering operation by the operator with respect to the lever device26A, to supply hydraulic oil discharged from the pilot pump15to the pilot port on the right side of the control valve175R. That is, the controller30can automatically control the raising and lowering movement of the boom4.

As illustrated inFIG. 4B, the lever device26B is used by an operator or the like to operate the bucket cylinder9corresponding to the bucket6. The lever device26B outputs an operation content signal according to the operation content of the lever device26B (e.g., the operation direction and the operation amount), to the controller30.

The proportional valve31BL operates in response to a control current input from the controller30. Specifically, the proportional valve31BL uses hydraulic oil discharged from the pilot pump15to output pilot pressure corresponding to the control current input from the controller30to the pilot port on the left side of the control valve174. This allows the proportional valve31BL to adjust the pilot pressure acting on the pilot port on the left side of the control valve174. For example, by inputting a control current corresponding to the operation of the bucket6in the closing direction (hereinafter, “bucket closing operation”) from the controller30to the lever device26B, the proportional valve31BL can apply, to the pilot port on the left side of the control valve174, a pilot pressure according to the operation content (the operation amount) of the lever device26B. Further, by inputting a predetermined control current from the controller30without depending on the operation content of the lever device26B, the proportional valve31BL can apply a pilot pressure to the pilot port on the left side of the control valve174regardless of the operation content of the lever device26B.

The proportional valve31BR operates in response to the control current output by the controller30. Specifically, the proportional valve31BR uses hydraulic oil discharged from the pilot pump15to output a pilot pressure corresponding to the control current input from the controller30, to the pilot port on the right side of the control valve174. This allows the proportional valve31BR to adjust the pilot pressure acting on the pilot port on the right of the control valve174via the shuttle valve32BR. For example, by inputting a control current corresponding to an operation in the direction of the opening the bucket6(hereinafter referred to as “the bucket opening operation”), from the controller30to the lever device26B, the proportional valve31BR can apply a pilot pressure corresponding to the operation content (the operation amount) of the lever device26B, to the pilot port on the right side of the control valve174. Further, by inputting a predetermined control current from the controller30without depending on the operation content of the lever device26B, the proportional valve31BR can apply a pilot pressure on the pilot port on the right side of the control valve174regardless of the operation content of the lever device26B.

That is, when a bucket closing operation is performed, the lever device26B outputs an operation content signal according to the operation direction and the operation amount to the controller30and causes the pilot port on the left side of the control valve174to apply a pilot pressure according to the operation content via the controller30and the proportional valve31BL. When a bucket opening operation is performed, the lever device26B outputs an operation content signal according to the operation direction and the operation amount to the controller30, and applies a pilot pressure according to the operation content on the pilot port on the right side of the control valve174via the controller30and the proportional valve31BR.

Thus, the proportional valves31BL,31BR can adjust the pilot pressure output to the secondary side so that the control valve174can be stopped at any valve position, according to the operation state of the lever device26B, under the control of the controller30. Further, the proportional valves31BL,31BR can adjust the pilot pressure output to the secondary side so that the control valve174can be stopped in any valve position, regardless of the operation state of the lever device265.

The decompression proportional valve33BL is disposed on a pilot line between the proportional valve31BL and the pilot port on the left side of the control valve174. The controller30reduces the pilot pressure by discharging the hydraulic oil on the pilot line into the tank, when the controller30determines that a braking operation to decelerate or stop the hydraulic actuator (the bucket cylinder9) is necessary, based on a signal from an object detection device (e.g., the imaging device S6). This allows the spool of the control valve174to move in the neutral direction regardless of the state of the proportional valve31BL. Therefore, the decompression proportional valve33BL is effective where it is desired to improve the braking characteristics.

The decompression proportional valve33BR is disposed on a pilot line between the proportional valve31BR and the pilot port on the right side of the control valve174. The controller30reduces the pilot pressure by discharging the hydraulic oil on the pilot line to the tank, when the controller30determines that a braking operation to decelerate or stop the hydraulic actuator (the bucket cylinder9) is necessary based on a signal from an object detection device (e.g., the imaging device S6). This allows the spool of the control valve174to move in the neutral direction regardless of the state of the proportional valve31BR. Therefore, the decompression proportional valve33BR is effective where it is desired to improve the braking characteristics.

The controller30can control the proportional valve31BL in response to an operation content signal corresponding to a bucket closing operation by the operator with respect to the lever device26B to supply pilot pressure according to the operation content (the operation amount) of the lever device26B, to the pilot port on the left side of the control valve174. Further, the controller30can control the proportional valve31BR in response to an operation content signal corresponding to an operation of opening the bucket by the operator with respect to the lever device26B to supply pilot pressure according to the operation content (the operation amount) of the lever device26B, to the pilot port on the right side of the control valve174. That is, the controller30can control the proportional valves31BL and31BR according to an operation content signal input from the lever device26B to implement the opening/closing operation of the bucket6according to the operation content of the lever device26B.

Further, the controller30can control the proportional valve31BL, regardless of the bucket closing operation by the operator with respect to on the operator lever device26B, to supply hydraulic oil discharged from the pilot pump15to the pilot port on the left side of the control valve174. Further, the controller30can control the proportional valve31BR, regardless of the bucket opening operation by the operator with respect to the operator lever device26B, to supply hydraulic oil discharged from the pilot pump15to the pilot port on the right side of the control valve174. That is, the controller30can automatically control the opening/closing operation of the bucket6.

For example, as illustrated inFIG. 4C, the lever device26C is used to operate the turning hydraulic motor2A corresponding to the upper turning body3(the turning mechanism2) by an operator or the like. The lever device26C outputs an operation content signal according to the operation content thereof (e.g., the operation direction and the operation amount) to the controller30.

The proportional valve31CL operates in response to a control current input from the controller30. Specifically, the proportional valve31CL uses hydraulic oil discharged from the pilot pump15to output pilot pressure corresponding to the control current input from the controller30to the pilot port on the left side of the control valve173. This allows the proportional valve31CL to adjust the pilot pressure acting on the pilot port on the left side of the control valve173. For example, by inputting a control current corresponding to the turning operation in the left direction of the upper turning body3(hereinafter referred to as “left turning operation”), from the controller30to the lever device26C, the proportional valve31CL can apply a pilot pressure according to the operation content (the operation amount) of the lever device26C to the pilot port on the left side of the control valve173. Further by inputting a predetermined control current from the controller30without depending on the operation content of the lever device26C, the proportional valve31CL can apply a pilot pressure on the pilot port on the left side of the control valve173regardless of the operation content of the lever device26C.

The proportional valve31CR operates in response to the control current output by the controller30. Specifically, the proportional valve31CR uses hydraulic oil discharged from the pilot pump15to output pilot pressure corresponding to the control current input from the controller30to the pilot port on the right side of the control valve173. This allows the proportional valve31CR to adjust the pilot pressure acting on the pilot port on the right side of the control valve173. For example, by inputting a control current corresponding to a turning operation in the right direction of the upper turning body3(hereinafter referred to as “right turning operation”), from the controller30to the lever device26C, the proportional valve31CR can apply a pilot pressure to the pilot port on the right side of the control valve173according to the operation content (the operation amount) of the lever device26C. Further, by inputting a predetermined control current from the controller30without depending on the operation content of the lever device26C, the proportional valve31CR can apply a pilot pressure on the pilot port on the right side of the control valve173regardless of the operation content of the lever device26C.

That is, when a left turning operation is performed, the lever device26C outputs an operation content signal according to the operation direction and the operation amount to the controller30and applies a pilot pressure according to the operation content on the pilot port on the left side of the control valve173via the controller30and the proportional valve31CL. When a right turning operation is performed, the lever device26C outputs an operation content signal according to the operation direction and the operation amount to the controller30and applies a pilot pressure according to the operation content on the pilot port on the right side of the control valve173via the controller30and the proportional valve31CR.

Thus, the proportional valves31CL and31CR can adjust the pilot pressure output to the secondary side so that the control valve173can be stopped at any valve position according to the operation state of the lever device26C, under the control of the controller30. Further, the proportional valves31CL and31CR can adjust the pilot pressure output to the secondary side so that the control valve173can be stopped at any valve position, regardless of the operation state of the lever device26C.

The decompression proportional valve33CL is positioned on a pilot line between the proportional valve31CL and the pilot port on the left side of the control valve173. The controller30reduces the pilot pressure by discharging the hydraulic oil on the pilot line into the tank when the controller30determines that a braking operation to decelerate or stop the hydraulic actuator (the turning hydraulic motor2A) is necessary based on a signal from an object detection device (e.g., the imaging device S6, etc.). This allows the spool of the control valve173to move in the neutral direction regardless of the state of the proportional valve31CL. Therefore, the decompression proportional valve33CL is effective where it is desired to improve the braking characteristics.

The decompression proportional valve33CR is disposed on a pilot line between the proportional valve31CR and the pilot port on the right side of the control valve173. The controller30reduces the pilot pressure by discharging the hydraulic oil on the pilot line to the tank when the controller30determines that a braking operation to decelerate or stop the hydraulic actuator (the turning hydraulic motor2A) is necessary based on a signal from an object detection device (e.g., the imaging device S6, etc.). This allows the spool of the control valve173to move in the neutral direction regardless of the state of the proportional valve31CR. Therefore, the decompression proportional valve33CR is effective where it is desired to improve the braking characteristics.

The controller30can control the proportional valve31CL in response to an operation content signal corresponding to a left turning operation by the operator with respect to the lever device26C to supply pilot pressure according to the operation content (the operation amount) of the lever device26C, to the pilot port on the left side of the control valve173. Further, the controller30can control the proportional valve31CR in response to an operation content signal corresponding to a right turning operation by the operator with respect to the lever device26C to supply a pilot pressure corresponding to an operation content (the operation amount) of the lever device26C to the pilot port on the right side of the control valve173. That is, the controller30can control the proportional valves31CL and31CR according to an operation content signal input from the lever device26C to implement the opening/closing operation of the bucket6according to the operation content of the lever device26C.

The controller30controls the proportional valve31CL regardless of the left turning operation by the operator with respect to the lever device26C to supply hydraulic oil discharged from the pilot pump15to the pilot port on the left side of the control valve173. Further, the controller30can control the proportional valve31CR regardless of a right turning operation by the operator with respect to the lever device26C, to supply hydraulic oil discharged from the pilot pump15to the pilot port on the right side of the control valve173. That is, the controller30can automatically control the turning motion of the upper turning body3in the right and left directions.

The excavator100may further include a configuration for automatically opening and closing the arm5and a configuration for automatically moving forward and backward the lower traveling body1(specifically, the right and left crawlers). In this case, in the hydraulic system, the configuration portions relating to an operation system of the arm cylinder8, the configuration portions relating to an operation system of the traveling hydraulic motor1L, and the configuration portions relating to an operation of the traveling hydraulic motor1R may be configured in the same manner as the configuration portions relating to the operation system, of the boom cylinder7(FIGS. 4A to 4C).

[Estimation Method of Turning Angle (First Example)]

Next, a first example of a method for estimating a turning angle by the controller30(the turning angle calculating unit55) will be described with reference toFIGS. 5 and 6(FIGS. 6A and 6B).

<Functional Configuration Relating to Estimation of Turning Angle>

FIG. 5is a functional block diagram illustrating the first example of functional configurations relating to the estimation of a turning angle of the excavator100according to the present embodiment.

As illustrated inFIG. 5, in the present example, the excavator100is communicatively connected to the management apparatus200using the communication device T1.

The functions of the management apparatus200may be implemented by any hardware or a combination of hardware and software. For example, the management apparatus200is configured mainly as a server computer including a processor such as a CPU, a memory device such as a RAM, an auxiliary storage device such as a ROM, and an interface device for communication with external devices. The management apparatus200includes a model learning unit201and a distributing unit203as functional units that are implemented by executing, for example, a program installed in the auxiliary storage device on the CPU. The management apparatus200uses a learning result storage unit202or the like. The learning result storage unit202or the like can be implemented by, for example, an auxiliary storage device of the management apparatus200or an external storage device capable of communication.

The model learning unit201performs machine learning with respect to a learning model by using a predetermined teaching dataset and outputs a learned model (an object detection model LM) as a result of what is known as supervised learning. The generated object detection model LM is stored in the learning result storage unit202upon being subjected to accuracy verification by using a verification dataset prepared in advance. Further, the model learning unit201may generate an additional learned model by performing additional learning with respect to the object detection model LM by using a teaching dataset for additional learning. The additional learned model may be subjected to the accuracy verification using the pre-prepared verification dataset, and the object detection model LM in the learning result storage unit202may be updated with the additional learned model that has undergone the accuracy verification.

The object detection model LM determines the presence or absence of a predetermined object (e.g., a person, a vehicle, another work machine, a building, a pylon, a utility pole, a tree, etc.) (hereinafter referred to as a “target object”) in a captured image of the worksite, by using a captured image of the worksite captured by the object detection device, point group data, etc., as input information, and determines the type of the target object, the position of the target object, and the size of the target object, or the like. The object detection model LM outputs information on the determination result (for example, label information representing the type of the target object or position information representing the position of the target object). That is, when the object detection model LM is applied to the excavator100, the object detection model LM can determine the presence or absence of a target object around the excavator100, the type of the target object, and the position of the target object, based on the captured image captured by the imaging device S6. The base learning model and the object detection model LM generated as a result of learning the base learning model may be configured, for example, mainly as a known deep neural network (DNN).

Note that the teaching dataset and the accuracy verification dataset may be generated, for example, based on captured images of various worksites captured by the imaging device S6, uploaded from the excavator100from time to time. Further, the teaching dataset and the accuracy verification dataset may be generated based on an image of a worksite that is artificially generated using, for example, techniques associated with computer graphics.

The learning result storage unit202stores the object detection model LM generated by the model learning unit201. The object detection model LM in the learning result storage unit202may be updated by an additional learned model generated by the model learning unit201.

The distributing unit203distributes the latest object detection model LM stored in the learning result storage unit202to the excavator100.

In the present example, the excavator100includes the imaging device S6(the cameras S6F, S6B, S6L, and S6R), the controller30, the proportional valves31CL and31CR, and the input device42as configurations relating to the estimation of the turning angle.

The controller30includes a surrounding status recognizing unit60and the machine guidance unit50as described above as configurations relating to the estimation of the turning angle.

The surrounding status recognizing unit60includes, for example, a model storage unit61, a detecting unit62, an object position map generating unit63, and a map storage unit64.

The model storage unit61stores the latest object detection model LM received from the management apparatus200through the communication device T1.

The detecting unit62detects a target object around the upper turning body3based on a captured image input from the imaging device S6(the cameras S6F, S6B, S6L, and S6R). Specifically, the detecting unit62reads the object detection model LM from the model storage unit61and makes determinations relating to the target object around the upper turning body3using the object detection model LM (for example, determines the presence or absence of a target object, the type of the target object, the position of the target object, the size of the target object, or the like). The detecting unit62outputs, for example, label information indicating the type of the detected target object, position information of the target object, information relating to the size of the target object, and the like. When no target object is detected, the detecting unit62may output label information indicating that a target object is not detected. In the present example, captured images captured by a plurality of cameras (the cameras S6F, S6B, S6L, and S6R) can be used, so that the detecting unit62can detect a target object across the entire surrounding area of the upper turning body3, that is, a target object within a wider target range. Although an example in which the imaging device S6is used is described, the detecting unit62may receive a reflected signal of an output signal (e.g., laser, infrared ray, electromagnetic wave, ultrasonic wave, or the like) output to the surroundings of the excavator100and calculate the distance to the object around the excavator100by using point group data or the like. Further, the detecting unit62can obtain label information representing the type of the target object and position information representing the position of the target object according to the shape of the point group and the distance to the point group or the like based on the received reflected signal.

The object position map generating unit63generates map information (an object position map MP) representing the position of the target object detected by the detecting unit62, and the generated object position map MP is stored in the map storage unit64. The object position map MP includes the position information of the excavator100, the position information of each detected target object, and information on the type of the target object and the size of the target object associated with the position information of each object. For example, the object position map generating unit63may create an object position map MP according to the detection cycle of the detecting unit62from the activation to the stop of the excavator100and sequentially update the object position map MP in the map storage unit64with the latest object position map MP.

The distance range in which the target object can be detected by the detecting unit62with reference to the excavator100(the upper turning body3) is limited, and, therefore, for example, if the excavator100travels by the lower traveling body1, the position of the target object included in the object position map MP may become a position outside the detection range. That is, if the excavator100moves by the lower traveling body1, the controller30may not be able to identify whether an object at a position relatively distant from the excavator100is remaining at that position or whether this object has moved from that position. Accordingly, at the time of the updating, the object position map generating unit63may delete information on the target object located a certain distance from the excavator100(own machine) included in the object position map MP, or may leave the information to remain in the map information upon appending a flag or the like indicating that this information is of low accuracy, for example.

The map storage unit64stores the latest object position map MP generated by the object position map generation unit63.

The machine guidance unit50includes the automatic control unit54, the turning angle calculating unit55, the relative angle calculating unit56, a storage unit57, and an aim position information generating unit58as functional configurations relating to the estimation of the turning angle.

As described above, the automatic control unit54controls the proportional valves31CL and31CR based on the relative angle calculated (estimated) by the relative angle calculating unit56to cause the upper turning body3to front-face a work target around the excavator100(own machine). That is, the automatic control unit54controls the turning motion of the upper turning body3so that the upper turning body3front-faces the work target based on the relative angle calculated by the relative angle calculating unit56. In the present example, as will be described later, the automatic control unit54causes the upper turning body3to front-face the target object corresponding to the work target selected by the operator among the one or more target objects recognized in the object position map MP.

The turning angle calculating unit55recognizes a target object that is in a stopped state (hereinafter, a “stopped target object”) or a target object that is fixed (hereinafter, a “fixed target object”) around the excavator100based on a captured image captured by the imaging device S6. A stopped target object means a target object that is in a stopped state without moving (e.g., a dump truck that is in a stopped state and waiting for earth and sand to be loaded) among movable target objects. A fixed target object means a target object (e.g., a tree, a utility pole, etc.) that is fixed at a certain position without moving. Specifically, the turning angle calculating unit55recognizes (extracts) a stopped target object or a fixed target object around the excavator100based on the object position map MP stored in the map storage unit64and determines a target object to be a reference object (hereinafter, a “reference target object”) among the recognized target objects. For example, as described below, the turning angle calculating unit55may determine, as the reference target object, a stopped target object or a fixed target object corresponding to a selected work target, among a plurality of target objects included in the object position map MP, based on an operation input through the input device42. The turning angle calculating unit55estimates (calculates) the turning angle based on a change in the position of the reference target object viewed from the upper turning body3as a result of the updating of the object position map MP (that is, a change in the position of the reference target object in the captured image captured by the imaging device S6). This is because when the upper turning body3turns, the direction in which the reference target object can be viewed from the upper turning body3changes.

As described above, the relative angle calculating unit56calculates the relative angle as the turning angle, that is required for front-facing the work target. Specifically, the relative angle calculating unit56calculates (estimates) the relative angle based on the turning angle of the upper turning body3calculated by the turning angle calculating unit55and information on the position of the work target as the aim of the work (hereinafter, referred to as “aim position information”) generated by the aim position information generating unit58. When the work target is set as the reference target object, the relative angle calculating unit56may use the turning angle calculated by the turning angle calculating unit55as the relative angle. This is because, as described above, the turning angle calculating unit55calculates the turning angle (orientation of the upper turning body3) based on the work target.

In the storage unit57, aim setting information57A is stored.

The aim setting information57A is setting information concerning a work target that is the aim of the work (for example, a dump truck for loading earth and sand at the time of work) set by an operation input from a user such as an operator through the input device42.

For example, by operating a predetermined operation screen (hereinafter, “aim selection screen”) displayed on the display device40using the input device42, an operator or the like can select a target object corresponding to the work target from among one or more target objects identified from the object position map MP, and set the selected target object as the aim of the work. Specifically, an image representing the appearance of the surroundings of the excavator100(hereinafter, “surrounding image”) is displayed on the aim selection screen of the display device40based on the captured image captured by the imaging device S6. Then, on the aim selection screen of the display device40, a marker or information representing the type of the target object is displayed in a superimposed manner at a position corresponding to the target object in the surroundings of the excavator100identified from the object position map MP in the surrounding image. An operator or the like can identify and select (set) a work target by confirming the position and type of the target object on the aim selection screen.

The aim position information generating unit58generates aim position information based on the object position map MP and the aim setting information57A.

<Specific Example of Method for Estimating Turning Angle>

FIGS. 6A and 6Bare diagrams illustrating a first example of an operation relating to estimation of a turning angle of the excavator100according to the present embodiment. Specifically,FIGS. 6A and 6Billustrate a situation in which the excavator100turns so as to front-face a dump truck DT that is the work target, while estimating the turning angle under the control of the controller30, when performing the work of loading earth and sand or the like into the dump truck DT that is the work target. More specifically,FIG. 6Ais a top view of the excavator100during work, andFIG. 6Bis a view of the excavator100(specifically, the bucket6) during work viewed in the direction of an arrow AR1ofFIG. 6A.

InFIGS. 6A and 6B, the excavator100(the bucket6) illustrated with solid lines indicates the state when the bucket6has finished scooping earth and sand, and a bucket6A indicates the bucket6in this state (position P1). InFIGS. 6A and 6B, the excavator100(the bucket6) illustrated with dashed lines indicates a state during a combined operation in which the upper turning body3is turning in a direction toward the position front-facing the dump truck DT while the boom4is being raised with the earth and sand held in the bucket6, and a bucket6B indicates the bucket6in this state (position P2). Further, inFIGS. 6A and 6B, the excavator100(the bucket6) illustrated with dash-dot-dash lines indicates a state where the upper turning body3is front-facing the dump truck DT that is the work target, before starting the operation of discharging the earth and sand held in the bucket6, and a bucket6C indicates the bucket6in this state (position P3).

In the present example, the controller (the turning angle calculating unit55) estimates (calculates) the turning angle θa using the dump truck DT that is the work target as the reference target object. That is, as illustrated inFIG. 6A, the controller30estimates (calculates) the turning angle θa of the upper turning body3by using, as the reference, the axis in the longitudinal direction of the loading platform of the dump truck DT, that is, the front-back axis of the dump truck DT.

For example, the controller30(the turning angle calculating unit55) estimates (calculates) that the turning angle θa is an angle value θa0, using the dump truck DT as a reference target object, in a state where the bucket6is at the position P1. Further, the controller30(the relative angle calculating unit56) can use the turning angle θa (the angle value θa0) as the relative angle, because the dump truck DT that is the work target is the reference target object. When the operator performs a right turning operation with respect to the lever device26C while pressing down a predetermined switch such as the MC switch, that is, when the operator performs a turning operation in a direction toward the position front-facing the dump truck DT, the controller30(the automatic control unit54) controls the proportional valve31CR so that the upper turning body3front-faces the dump truck DT, that is, so that the turning angle θa corresponding to the relative angle changes from the angle value θa0to zero.

While the bucket6moves from the position P1, passes through the position P2, toward the position P3corresponding to a state in which the upper turning body3front-faces the dump truck DT, the controller30(the turning angle calculating unit55) controls the turning operation of the upper turning body3through the proportional valve31CR while estimating the turning angle θa. For example, when the bucket6is at the position P2, the controller30(the turning angle calculating unit55) estimates (calculates) that the turning angle θa is the angle value θa1using the dump truck DT as the reference target object. The controller30(the automatic control unit54) stops the operation of the turning hydraulic motor2A when the relative angle based on the estimated turning angle θa, that is, the turning angle θa, becomes zero. Thus, the controller30assists the operator in operating the lever device26C and allows the upper turning body3to front-face the dump truck DT. When the operator presses down the predetermined switch such as the MC switch, the controller30can automatically cause the upper turning body3to front-face the dump truck DT while estimating the turning angle θa using the dump truck DT that is the work target as a reference target object. In this case, the controller30may perform automatic control of the raising of the boom4in conjunction with automatic control of the upper turning body3and perform the entire combined operation of the excavator100automatically.

Further, the controller30(the turning angle calculating unit55) may calculate the turning angle θb by using, as a reference target object, a tree TR1that is a fixed target object around the excavator100, in addition to the turning angle θa that uses the dump truck DT as the reference target object. For example, the controller30(the turning angle calculating unit55) estimates that the turning angle θb that uses the tree TR1as the reference target object is the angle value θb0, in a state where the bucket6is at the position P1. The controller30(the turning angle calculating unit55) estimates that the turning angle θb that uses the tree TR1as the reference target object is the angle value θb1, in a state where the bucket6is at the position P3. Thus, the controller30(the relative angle calculating unit56) can estimate (calculate) the relative angle using both the turning angle θa that uses the dump truck DT as the reference target object and the turning angle θb that uses the tree TR1as the reference target object. Accordingly, the controller30can improve the accuracy of the estimation of the relative angle and consequently improve the accuracy of the control for causing the upper turning body3to front-face the dump truck DT.

[Estimation Method of Turning Angle (Second Example)]

Next, a second example of a method for estimating a turning angle by the controller30(the turning angle calculating unit55) will be described with reference toFIGS. 7 and 8(FIGS. 8A and 8B).

<Functional Configuration Relating to Estimation of Turning Angle>

FIG. 7is a functional block diagram illustrating the second example of functional configurations relating to the estimation of a turning angle of the excavator100according to the present embodiment. Hereinafter, in the present example, the portions that are different from those of the above-describedFIG. 5will be mainly described.

As illustrated inFIG. 7, in the present example, similar to the first example ofFIG. 5, the excavator100is communicatively connected to the management apparatus200using the communication device T1.

The management apparatus200includes the model learning unit201and the distributing unit203as functional units that are implemented by executing, for example, a program installed in an auxiliary storage device on a CPU. The management apparatus200uses the learning result storage unit202and a work information storage unit204. The learning result storage unit202, the work information storage unit204, or the like, can be implemented by, for example, an auxiliary storage device of the management apparatus200, an external storage device capable of communication, or the like.

In the work information storage unit204, a work information database including work information of a plurality of worksites including the worksite of the excavator100is constructed. The work information includes information on the aim of work (e.g., aim work surface data, etc.). The distributing unit203extracts the work information of the worksite of the excavator100from the work information database and distributes the information to the excavator100.

In the present example, the excavator100includes the imaging device S6(the camera S6F, S6B, S6L, and S6R), the controller30, and the proportional valves31CL and31CR as the configuration relating to the estimation of the turning angle, similar to the first example ofFIG. 5.

Similar to the first example ofFIG. 5, the controller30includes the machine guidance unit50and the surrounding status recognizing unit60as configurations relating to the estimation of the turning angle.

Similar to the first example inFIG. 5, the machine guidance unit50includes the automatic control unit54, the turning angle calculating unit55, the relative angle calculating unit56, the storage unit57, and the aim position information generating unit58as functional configurations relating to the estimation of the turning angle.

The storage unit57stores work information57B distributed from the management apparatus200.

The aim position information generating unit58generates aim position information relating to the aim work surface that is a work target based on the aim work surface data included in the work information.

The relative angle calculating unit56calculates (estimates) the relative angle based on the turning angle of the upper turning body3calculated by the turning angle calculating unit55and the aim position information corresponding to the aim work surface of the work target. The automatic control unit54controls the proportional valves31CL and31CR based on the relative angle calculated (estimated) by the relative angle calculating unit56and causes the upper turning body3to front-face the aim work surface corresponding to the work information57B. When an object is detected within a predetermined range, the automatic control unit54controls the decompression proportional valve33based on the positional relationship with the detected object to perform a braking operation (deceleration or stopping).

<Specific Example of Method for Estimating Turning Angle>

FIGS. 8A and 8Bare diagrams illustrating a second example of an operation relating to the estimation of a turning angle of the excavator100according to the present embodiment. Specifically,FIGS. 8A and 8Billustrate the state where the excavator100performs work on the slope surface NS that has not yet been worked on, starting from a portion near the boundary between a slope surface CS on which work has been completed and the slope surface NS that is an example of the aim work surface corresponding to a tilt surface that has not yet been worked on.FIG. 8Aillustrates a state in which the upper turning body3is not front-facing the slope surface NS that is the work target, andFIG. 8Billustrates a state in which the excavator100has turned the upper turning body3from the state ofFIG. 8Aand the upper turning body3is front-facing the slope surface NS that is the work target.

As illustrated inFIGS. 8A and 8B, in the present example, the controller30(the turning angle calculating unit55) calculates the turning angle by using, as a reference target object, the tree TR2that is a fixed target object around the excavator100(own machine).

For example, in the state ofFIG. 8A, the controller30(the turning angle calculating unit55) estimates (calculates) the turning angle using the tree TR2as the reference target object. The controller30(the relative angle calculating unit56) estimates (calculates) the relative angle based on the estimated turning angle and aim position information corresponding to the slope surface NS that is the aim work surface. The controller30(the automatic control unit54) controls the proportional valve31CL so that the upper turning body3front-faces the slope surface NS while estimating the turning angle by using the tree TR2as a reference target object when the operator performs a left turning operation with respect to the lever device26C while pressing down a predetermined switch such as the MC switch. Thus, as illustrated inFIG. 8B, the controller30can assist the operator's operation of the lever device260to front-face the slope surface NS that is the work target. When the operator presses down a predetermined switch such as the MC switch, the controller30may automatically cause the upper turning body3to front-face the slope surface NS while estimating the turning angle by using the tree TR2as the reference target object.

[Estimation Method of Turning Angle (Third Example)]

Next, a third example of a method for estimating a turning angle by the controller30(the turning angle calculating unit55) will be described with reference toFIGS. 9 to 11.

Note that, as the functional block diagram representing the functional configuration relating to the estimation of the turning angle of the excavator100according to the present example, the functional block diagram (FIG. 5orFIG. 7) of the first example or the second example can be used, and thus, the drawing is omitted.

<Detection Method of Fixed Target Object>

FIG. 9is a diagram illustrating the third example of an estimation method of a turning angle of the excavator100. Specifically,FIG. 9is a diagram illustrating an example of a method of detecting an object (for example, a fixed target object) around the excavator100according to the present example, and a series of processes relating to detection of an object around the excavator100by the detecting unit62is illustrated.

The detecting unit62performs a process (an object detection process901) of detecting a target object around the excavator100(the upper turning body3) using the learned object detection model LM based on the output (captured image) of the imaging device S6.

In the present example, the object detection model LM is configured mainly as a neural network DNN.

In the present example, the neural network DNN is what is known as a deep neural network with more than one intermediate layer (hidden layer) between the input layer and the output layer. In the neural network DNN, a weighting parameter representing the strength of the connection with the lower layer, is defined for each of the plurality of neurons configuring each of the intermediate layers. The neurons of each layer outputs, to the neurons of a lower layer through a threshold function, a sum of values obtained by multiplying each of the input values from the plurality of neurons from an upper layer by the weighting parameter defined for each of the neurons of the upper layer, thereby configuring the neural network DNN.

With respect to the neural network DNN, machine learning, specifically, deep learning, is performed by the management apparatus200(the model learning unit201) as described below, to optimize the weighting parameters described above. Accordingly, to the neural network DNN, a captured image captured by the imaging device S6is input as input signals x (x1to xm), and the neural network DNN can output, as output signals y (y1to yn), a probability (predictive probability) that an object of each object type corresponding to a predetermined target object list (in the present example, “tree”, “dump”, . . . ), is present. Here, m represents an integer of two or more, and corresponds to, for example, the number of sections of the captured image divided into two or more image regions. Further, n is an integer of two more, and corresponds to the number of types of target objects included in the target object list.

The neural network DNN is, for example, a convolutional neural network (CNN). CNN is a neural network using existing image processing technologies (convolution process and pooling process). Specifically, the CNN repeats the combination of the convolution process and the pooling process for the captured image captured by the imaging device S6to extract feature amount data (feature map) having a smaller size than the captured image. Then, the pixel value of each pixel of the extracted feature map is input to a neural network configured by a plurality of fully connected layers, and the output layer of the neural network can output, for example, a predictive probability that an object exists for each object type.

The neural network DNN may be configured such that a captured image captured by the imaging device S6is input as an input signal x, and the position and size of the object in the captured image (that is, the region occupied by the object in the captured image) and the type of the object can be output as an output signal y. That is, the neural network DNN may be configured to detect an object in the captured image (determine the portion of the region occupied by the object in the captured image) and to determine the classification of the object. In this case, the output signal y may be configured by an image data format in which information on the region occupied by the object and the classification of the object is added, in a superimposed manner, to the captured image that is the input signal x. Accordingly, the detecting unit62can identify a relative position (distance or direction) of the object from the excavator100based on the position and size of the region occupied by the object in the captured image captured by the imaging device S6output from the object detection model LM (neural network DNN). This is because the imaging device S6(the camera S6F, the camera S6B, the camera S6L, and the camera S6R) is fixed to the upper turning body3and the imaging range (image angle) is predefined (fixed). When the position of the object detected by the object detection model LM is in the monitor region and is classified into an object in a monitor target list, the detecting unit62can determine that the object that is the monitor target is detected in the monitor region.

For example, the neural network DNN may be configured to include a neural network corresponding to each of a process of extracting an occupied region (window) in which an object is present in the captured image, and a process of identifying the type of object in the extracted region. That is, the neural network DNN may be configured to perform detection of an object and classification of the object in a stepwise manner. For example, the neural network DNN may be configured to include a neural network corresponding to each of a process of defining the classification of an object and the region occupied by the object (bounding box) for each grid cell obtained by dividing the entire region of the captured image into a predetermined number of sub-regions, and a process of combining the regions occupied by objects for each type based on the classification of the object for each grid cell and validating the final region occupied by objects. That is, the neural network DNN may be configured to perform detection of an object and classification of an object in parallel.

The detecting unit62, for example, calculates the predictive probability for each type of object in the captured image, by using the neural network DNN, in each predetermined control cycle. When calculating the predictive probability, the detecting unit62may further increase the predictive probability of the current time when the current determination result matches the previous determination result. For example, when an object appearing in a predetermined region in the captured image is determined to be “dump” (y2) by a predictive probability in the previous determination, and it is continuously determined that the object is “dump” (y2) in the current determination, the predictive probability that the object is determined to be “dump” (y2) in the current determination may be further increased with respect to the predictive probability of the previous determination. Thus, for example, when the determination result relating to the classification of an object with respect to the same image region is continuously matched, the predictive probability is calculated to be relatively high. Therefore, the detecting unit62can reduce erroneous determinations.

Further, the detecting unit62may make a determination with respect to an object in the captured image by taking into consideration the motions of the excavator100such as travelling and turning. Even when the object around the excavator100is stationary, the position of the object in the captured image may move as the excavator100travels or turns, and the object may not be recognized as the same object any longer. For example, there may be cases where an image region determined to be “tree” (y1) in the current process and an image region determined to be “tree” (y1) in the previous process are different, due to the travelling or turning of the excavator100. In this case, if the image region determined to be “tree” (y1) in the current process is within a predetermined range from the image region determined to be “tree” (y1) in the previous process, the detecting unit62may regard these objects to be the same object, and make a determination that the object is continuously matching (i.e., determination that the same object is continuously being detected) (continuously matching determination). When making the continuously matching determination, the detecting unit62may add the image region used in the current determination to the image region used in the previous determination, and include the image region within a predetermined range from this image region. This allows the detecting unit62to make the continuously matching determination with respect to the same object around the excavator100, even if the excavator100travels or turns.

Also in the cases of the above-described first and second examples, the object detection model LM may be configured mainly as the neural network DNN, similar to the present example.

The detecting unit62may also detect objects around the excavator100using an object detection method based on any kind of machine learning other than the method using the neural network DNN.

For example, it is possible to generate, by supervised learning, the object detection model LM that represents the boundary between a range of objects of a certain type and a range of objects of types other than the certain type, for each of the object types in a multivariable space, with respect to multivariable local feature quantities acquired from a captured image captured by the imaging device S6. The techniques of machine learning (supervised learning) applied to the generation of information relating to boundary may be, for example, support vector machine (SVM), a k-Neighborhood technique, a mixed Gaussian distribution model, and the like. Accordingly, the detecting unit62can detect an object on the basis of whether the local feature quantity acquired from the captured image captured by the imaging device S6is in the range of a predetermined type of object or in the range of an object that is not the predetermined type, based on the object detection model LM.

In addition to the object detection process901, the detecting unit62performs a process of calculating the distance from the excavator100to a surrounding object based on the output of the distance measuring device S7mounted on the excavator100(a distance calculation process902). In the present example, the detecting unit62calculates distances L1to Lm to an object for each direction viewed from the excavator100(the imaging device S6) corresponding to image regions x1to xm obtained by dividing a captured image captured by the imaging device S6into a plurality of image regions.

The distance measuring device S7is mounted to the upper turning body3and acquires information concerning the distance to an object around the excavator100. The distance measuring device S7may include, for example, an ultrasonic sensor, a millimeter wave radar, a LIDAR, an infrared sensor, or the like. The distance measuring device S7may be, for example, an imaging device such as a monocular camera, a stereo camera, a distance image camera, a depth camera, or the like. In the case of a monocular camera, the detecting unit62can calculate the distance based on an image captured when the excavator100is travelling or turning.

<<Target Object Information Generation Process>>

The detecting unit62combines the output of the object detection process901with the output of the distance calculation process902to perform a process of generating target object information including the predictive probability and the position for each of a plurality of target objects (a target object information generation process903). Specifically, the detecting unit62may generate the target object information including the predictive probability and the position of each target object, based on the predictive probability and the occupied region in the captured image with respect to each of a plurality of types of target objects included in the target object list, and the distance information (distances L1to Lm) for each of the image regions x1to xm in the captured image. In the present example, the target object information indicates that the “tree” corresponding to the output signal y1is positioned at the “coordinates” (e1, n1, h1) by a predictive probability of “xx %.”. In the present example, the target object information indicates that the “dump (truck)” corresponding to the output signal y2is positioned at the “coordinates” (e2, n2, h2) by the predictive probability of “xx %”. In the present example, the target object information indicates that the “xxxxxx” corresponding to the output signal yn is positioned at the “coordinates” (en, nn, hn) by the predictive probability of “xx %”. Accordingly, the detecting unit62can detect a target object within the imaging range of the imaging device S6or identify the position of the detected target object, based on the target object information and the predictive probability for each of a plurality of types of target objects in the target object list.

Note that, as described above, the detecting unit62may identify the position of each target object by using only the position and size of the occupied region of each target object. In this case, the distance calculation process902may be omitted, and the distance measuring device S7may be omitted.

<Specific Example of Method for Estimating Turning Angle>

FIGS. 10 and 11are diagrams illustrating the third example of an estimation method of a turning angle of the excavator100.

In the present example, the controller30determines a reference target object around the excavator100based on the target object information generated by the above-described target object information generation process903and calculates the orientation of the reference target object viewed from the excavator100. Then, the controller30estimates the turning angle of the excavator100based on a change in time series of the orientation of the target object viewed from the excavator100.

For example, as illustrated inFIG. 12, at time t1, the target object information indicates that the predictive probability of “tree” and “dump” is 90%. Accordingly, the controller30determines a plurality of reference target objects, including at least the tree and the dump truck, and calculates the orientation (angular direction) θk(t1) (k being an integer of 1 to n) of the reference target object viewed from the excavator100, for each of the reference target objects.

Further, at time t2, the target object information continues to indicate that the predictive probability of “tree” and “dump” is very high at 90%. Accordingly, the controller30determines a plurality of reference target objects including at least the tree and the dump truck and calculates the orientation θk(t2) of the reference target object viewed from the excavator100, for each of the reference target objects.

With respect to each reference target object, the controller30can calculate the turning angle Δθ between time t1and time t2according to the following formula (1), based on the orientation θk(t1) and θk(t2) of the reference target object viewed from the excavator100at time t1and time t2, respectively.

The controller30determines the turning angle of the excavator100between time t1and time t2based on the turning angle Δθ calculated with respect to each of a plurality of reference target objects. The controller30may determine the turning angle of the excavator100between time t1and time t2, for example, by performing statistical processing such as obtaining the average turning angle of the turning angles Le with respect to the plurality of reference target objects.

Note that, when only one target object (reference target object) is present around the excavator100based on the target object information, the controller30may determine the turning angle Le corresponding to the one reference target object, as the turning angle of the excavator100.

Thus, in the present example, the controller30can determine a reference target object around the excavator100based on the target object information and estimate the turning angle of the excavator100based on the change in time series in the orientation of the reference target object viewed from the excavator100. In the present example, with respect to each of a plurality of reference target objects, the controller30estimates the turning angle of the excavator100based on the change in time series of the orientation of the reference target object viewed from the excavator100, and determines the turning angle of the excavator100based on a plurality of estimation values of the turning angle. Therefore, it is possible to improve the estimation accuracy of the turning angle.

For example, as illustrated inFIG. 12, at time t3, the dump truck, which has been the reference target object up to time t2, moves, and in the target object information, the predictive probability of “dump” is changed to 0%. Therefore, at time t3, the controller30cannot use the dump truck as a reference target object.

On the other hand, at time t3, the target object information continues to indicate that the predictive probability of “tree” is very high at 90%. Accordingly, the controller30determines one or more reference target objects including at least the tree, and calculates the orientation θk(t3) of the reference target object viewed from the excavator100for each reference target object.

With respect to each reference target object, the controller30can calculate the turning angle Δθ between time t2and time t3according to the following formula (2), based on the orientation θk(t2) and θk(t3) of the reference target object viewed from the excavator100at time t2and time t3, respectively.

Thus, in the present example, even when some of the reference target objects cannot be detected, the controller30can estimate the turning angle of the excavator100based on the change in the orientation of the other reference target objects viewed from the excavator100, if other reference target objects that can be detected are present. That is, by using a plurality of reference target objects, the controller30can stably continue the estimation process of the turning angle of the excavator100even in a situation in which some reference target objects cannot be detected.

[Another Example of Configuration of Excavator]

Next, another example of a specific configuration of the excavator100according to the present embodiment will be described with reference toFIG. 12in addition toFIG. 1. Specifically, a description is given of a specific example of the configuration concerning an estimation method of the position of the excavator100(own machine) described below. Hereinafter, the portions that are different from the above-described example (FIG. 2) will be mainly described, and the same or corresponding contents may be omitted from the description.

FIG. 12is a schematic diagram illustrating another example of the configuration of the excavator100according to the present embodiment.

The control system of the excavator100according to the present embodiment includes the controller30, the discharge pressure sensor28, an operation pressure sensor29, the proportional valve31, the display device40, the input device42, the sound output device43, the storage device47, the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the machine tilt sensor S4, a turning state sensor S5, the imaging device S6, and the communication device T1.

The turning state sensor S5outputs detection information concerning the turning state of the upper turning body3. The turning state sensor S5detects, for example, the turning angle speed and the turning angle of the upper turning body3. The turning state sensor S5may include, for example, a gyro sensor, a resolver, a rotary encoder, or the like. The detection signal corresponding to the turning angle and the turning angle speed of the upper turning body3output by the turning state sensor S5is loaded into the controller30.

The controller30includes the machine guidance unit50.

The machine guidance unit50acquires information from the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the machine tilt sensor S4, the turning state sensor S5, the imaging device S6, the communication device T1, and the input device42. The machine guidance unit50, for example, calculates the distance between the bucket6and the aim work surface based on the acquired information, notifies the operator of the extent of the distance between the bucket6and the work target (for example, the aim work surface) based on the sound from the sound output device43and the image displayed on the display device40, and automatically controls the operation of the attachment so that the leading end of the attachment (specifically, the working portion such as the claw tip or the back surface of the bucket6) coincides with the aim work surface. The machine guidance unit50includes the position calculating unit51, the distance calculating unit52, the information transmitting unit53, the automatic control unit54, the turning angle calculating unit55, the relative angle calculating unit56, and a position estimating unit59, as detailed functional configurations relating to the machine guidance function and the machine control function.

The turning angle calculating unit55calculates the turning angle of the upper turning body3. This allows controller30to identify the current orientation of upper turning body3. The turning angle calculating unit55calculates the turning angle based on the detection signal of the turning state sensor S5. When a reference point is set at the worksite, the turning angle calculating unit55may set the direction in which the reference point is viewed from the turning axis, as the reference direction. For example, the turning angle calculating unit55may calculate (estimate) the turning angle of the upper turning body3based on a change in the position of an object (orientation in which the object can be seen) that is stopping or fixed, included in (appearing in) the captured image captured by the imaging device S6, by using the above-described estimation method (seeFIGS. 5 to 11). In this case, the turning state sensor S5may be omitted.

The position estimating unit59estimates the position of the excavator100. The position estimating unit59, for example, recognizes an object around the excavator100(own machine) based on a captured image captured by the imaging device S6, and calculates (estimates) the relative position of the excavator100with respect to the recognized object. Details are given below (seeFIGS. 13-18).

[Estimation Method of Position of Excavator (First Example)]

Next, a first example of the method of estimating the position of the excavator100(own machine) by the controller30will be described with reference toFIGS. 13 and 14.

<Functional Configuration Relating to Estimation of Excavator Position>

FIG. 13is a functional block diagram illustrating the first example of functional configurations relating to the estimation of a position of the excavator100according to the present embodiment.

As illustrated inFIG. 13, in the present example, the excavator100is communicatively connected to the management apparatus200using the communication device T1.

The functions of the management apparatus200may be implemented by any hardware or a combination of hardware and software. For example, the management apparatus200is configured mainly as a server computer including a processor such as a CPU, a memory device such as a RAM, an auxiliary storage device such as a ROM, and an interface device for communication with external devices. The management apparatus200includes a model learning unit201and a distributing unit203as functional units that are implemented by executing, for example, a program installed in the auxiliary storage device on the CPU. The management apparatus200uses a learning result storage unit202or the like. The learning result storage unit202or the like can be implemented by, for example, an auxiliary storage device of the management apparatus200or an external storage device capable of communication.

The model learning unit201performs machine learning with respect to a learning model by using a predetermined teaching dataset and outputs a learned model (an object detection model LM) as a result of what is known as supervised learning. The generated object detection model LM is stored in the learning result storage unit202upon being subjected to accuracy verification by using a verification dataset prepared in advance. Further, the model learning unit201may generate an additional learned model by performing additional learning with respect to the object detection model LM by using a teaching dataset for additional learning. The additional learned model may be subjected to the accuracy verification using the pre-prepared verification dataset, and the object detection model LM in the learning result storage unit202may be updated with the additional learned model that has undergone the accuracy verification.

The object detection model LM determines the presence or absence of a predetermined object (e.g., a person, a vehicle, another work machine, a building, a pylon, a utility pole, a tree, etc.) (hereinafter referred to as a “target object”) in a captured image of the worksite, by using a captured image of the worksite captured by the object detection device, point group data, etc., as input information, and determines the type of the target object, the position of the target object, and the size of the target object, or the like. The object detection model LM outputs information on the determination result (for example, label information representing the type of the target object or position information representing the position of the target object). That is, when the object detection model LM is applied to the excavator100, the object detection model LM can determine the presence or absence of a target object around the excavator100, the type of the target object, and the position of the target object, based on the captured image captured by the imaging device S6. The base learning model and the object detection model LM generated as a result of learning the base learning model may be configured, for example, mainly as a known deep neural network (DNN).

Note that the teaching dataset and the accuracy verification dataset may be generated, for example, based on captured images of various worksites captured by the imaging device S6, uploaded from the excavator100from time to time. Further, the teaching dataset and the accuracy verification dataset may be generated based on an image of a worksite that is artificially generated using, for example, techniques associated with computer graphics.

The learning result storage unit202stores the object detection model LM generated by the model learning unit201. The object detection model LM in the learning result storage unit202may be updated by an additional learned model generated by the model learning unit201.

The distributing unit203distributes the latest object detection model LM stored in the learning result storage unit202to the excavator100.

In the present example, the excavator100includes the imaging device S6(the cameras S6F, S6B, S6L, and S6R), and the controller30as configurations relating to the estimation of the position of the own machine.

The controller30includes a surrounding status recognizing unit60and the machine guidance unit50as described above as configurations relating to the estimation of the position of the excavator100(own machine).

The surrounding status recognizing unit60includes, for example, a model storage unit61, a detecting unit62, an object position map generating unit63, and a map storage unit64.

The model storage unit61stores the latest object detection model LM received from the management apparatus200through the communication device T1.

The detecting unit62detects a target object around the upper turning body3based on a captured image input from the imaging device S6(the cameras S6F, S6B, S6L, and S6R). Specifically, the detecting unit62reads the object detection model LM from the model storage unit61and makes determinations relating to the target object around the upper turning body3using the object detection model LM (for example, determines the presence or absence of a target object, the type of the target object, the position of the target object, the size of the target object, or the like). The detecting unit62outputs, for example, label information indicating the type of the detected target object, position information of the target object, information relating to the size of the target object, and the like. When no target object is detected, the detecting unit62may output label information indicating that a target object is not detected. In the present example, captured images captured by a plurality of cameras (the cameras S6F, S6B, S6L, and S6R) can be used, so that the detecting unit62can detect a target object across the entire surrounding area of the upper turning body3, that is, a target object within a wider target range. Although an example in which the imaging device S6is used is described, the detecting unit62may receive a reflected signal of an output signal (e.g., laser, infrared ray, electromagnetic wave, ultrasonic wave, or the like) output to the surroundings of the excavator100and calculate the distance to the object around the excavator100by using point group data or the like. Further, the detecting unit62can obtain label information representing the type of the target object and position information representing the position of the target object according to the shape of the point group and the distance to the point group or the like based on the received reflected signal.

The object position map generating unit63generates map information (hereinafter, “object position map”) representing the position of the excavator100(own machine) with respect to a surrounding object (target object). The generated object position map MP is stored in the map storage unit64. The object position map MP includes three-dimensional shape data (specifically, an assembly of three-dimensional feature points) of an object in the surroundings of the excavator100based on a captured image captured by the imaging device S6, including the target object detected by the detecting unit62, and information representing the current position of the excavator100and the current orientation of the upper turning body3relative to the three-dimensional shape data. The object position map MP includes a position for each target object detected by the detecting unit62. The object position map MP includes accompanying information such as information on the type of the target object (hereinafter referred to as “type information”) and information on the size of the target object (hereinafter referred to as “size information”) associated with the position of each target object. Specifically, the object position map generating unit63generates local map information (hereinafter, a “local map”) including the three-dimensional shape of an object (target object) around the excavator100at present time based on a captured image (detection result of the detecting unit62) captured by the imaging device S6, at every predetermined processing cycle. The local map is map information that uses, as a reference, the current position of the excavator100and the current orientation of the upper turning body3. The object position map generating unit63identifies that the three-dimensional shape of an object is the same in the generated local map and in a past object position map MP created in the preceding processing cycle, and generates the latest object position map MP. At this time, in the process of identifying that the three-dimensional shape in the local map that uses, as a reference, the current position of the excavator100and the current orientation of the upper turning body3is the same as the three-dimensional shape in the past object position map MP, the object position map generating unit63simultaneously identifies the position of the excavator100and the orientation of the upper turning body3in the object position map MP. For example, the object position map generating unit63may create an object position map MP in accordance with the detection cycle by the detecting unit62, from the activation to the stop of the excavator100, and sequentially update the object position map MP in the map storage unit64with the latest object position map MP.

Note that when a distance sensor (an example of a distance information acquisition device) capable of acquiring the distance to an object in the imaging range of the imaging device S6is mounted to the upper turning body3in addition to the imaging device S6, the object position map generating unit63may generate an object position map MP based on the captured image captured by the imaging device S6and the detection information of the distance sensor. That is, the controller30may estimate the position of the excavator100(own machine) or estimate the orientation (turning angle) of the upper turning body3based on the captured image captured by the imaging device S6and the detection information of the distance sensor (i.e., information on the distance to the object around the excavator100). Specifically, the object position map generating unit63may generate data corresponding to a three-dimensional shape around the excavator100based on the detection information of the distance sensor, and generate an object position map MP by applying, on the generated data, the information relating to the target object detected by the detecting unit62based on the captured image captured by the imaging device S6. Accordingly, the distance sensor can directly acquire the detection information relating to the distance to an object around the excavator100, and, therefore, the processing load can be reduced and the processing time can be shortened compared to when the distance is calculated from the captured image captured by the imaging device S6. Further, the accuracy of the distance corresponding to the detected information acquired by the distance sensor, is generally higher than the accuracy of the distance calculated from the captured image captured by the imaging device S6, and, therefore, the accuracy of the object position map MP can be improved. Further, the distance range within which an object can be detected by the detecting unit62is limited with reference to the excavator100(the upper turning body3), and, therefore, for example, if the excavator100travels by the lower traveling body1, the position of a certain target object included in the object position map MP may become a position outside the detection range. That is, if the excavator100moves by the lower traveling body1, the controller30may not be able to identify the movement of an object at a position relatively distant from the excavator100or changes according to work on the landform at a position relatively distant from the excavator100. Accordingly, at the time of updating the object position map MP, the object position map generating unit63may delete information on the three-dimensional shape including the target object at a position that is relatively distant from the excavator100(own machine) included in the object position map MP, or may leave this information in the map information, for example, upon linking this information with a flag indicating that this information has low accuracy.

The map storage unit64stores the latest object position map MP generated by the object position map generation unit63.

The machine guidance unit50includes the turning angle calculating unit55and the position estimating unit59as functional configurations relating to the estimation of the position of the excavator100(own machine).

The turning angle calculating unit55recognizes a target object that is stopping around the excavator100(hereinafter, “stopped target object”) or a target object that is fixed (hereinafter, “fixed target object”) based on the captured image captured by the imaging device S6and estimates (calculates) the turning angle of the upper turning body3(that is, the orientation of the upper turning body3) with respect to the stopped target object or the fixed target object. A stopped target object means a target object that is stopping without moving (e.g., a dump truck that is stopping) among movable target objects. A fixed target object means a target object that is fixed to a position and does not move (e.g., a tree, a utility pole, various devices fixedly installed in a scrap yard as described below, etc.). Specifically, the turning angle calculating unit55estimates (calculates) the orientation of the upper turning body3in the latest object position map MP stored in the map storage unit64, that is, the orientation (turning angle) of the upper turning body3viewed from the stopped target object or the fixed target object identified from the object position map MP. More specifically, the turning angle calculating unit55may estimate (calculate) the turning angle of the upper turning body3with respect to the direction in which the turning axis is viewed from the stopped target object or the fixed target object in the object position map MP.

The position estimating unit59recognizes (estimates) a target object (specifically, a stopped target object or a fixed target object) around the excavator100and identifies (estimates) the position of the excavator100(own machine) with respect to the recognized target object, based on the captured image captured by the imaging device S6. Specifically, the position estimating unit59identifies (estimates) the position of the excavator100in the object position map MP stored in the map storage unit64, that is, the position of the excavator100with respect to the stopped target object or the fixed target object identified from the object position map MP. This allows the excavator100to identify the position of the own machine without using GNSS.

<Specific Example of Estimation Method of Position of Excavator>

FIG. 14(FIGS. 14A and 14B) illustrates a first example of an operation relating to estimation of a position of the excavator100according to the present embodiment.

As illustrated inFIG. 14, the position estimating unit59estimates (calculates) the position of the excavator100in the XY coordinate system having the tree TR21that is the fixed target object around the excavator100(own machine) as the reference (the origin), identified from the object position map MP. The turning angle calculating unit55estimates (calculates) the turning angle of the upper turning body3with respect to the direction of the excavator100(turning axis) viewed from the tree TR21.

For example, in the work status ofFIG. 14A, the position estimating unit59calculates the position of the excavator100in the XY coordinate system using the tree TR21as a reference, such that the X coordinate is a predetermined value X1(>0) and the Y coordinate is a predetermined value Y1(>0). Further, the position estimating unit59calculates that the turning angle of the upper turning body3is a predetermined value θ1(>0), with respect to the direction of the excavator100(the turning axis AX) as viewed from the tree TR21.

Then, the excavator100transitions from the work status ofFIG. 14Ato the work status ofFIG. 14B, that is, the excavator100moves away from the tree TR21by the lower traveling body1and causes the upper turning body3to turn left. In this case, in the working status ofFIG. 14B, the position estimating unit59calculates the position of the excavator100in the XY coordinate system using the tree TR21as a reference, such that the X coordinate is a predetermined value X2(>X1>0) and the Y coordinate is a predetermined value Y2(>Y1>0). The turning angle calculating unit55calculates that the turning angle of the upper turning body3with respect to the direction of the excavator100(turning axis AX) as viewed from the tree TR21, is a predetermined value θ2(>θ1>0).

Thus, in the present example, the position estimating unit59estimates the position of the excavator100with respect to the tree TR21around the excavator100(own machine). Thus, the controller30can continue to identify the position of the excavator100with respect to the tree TR21in accordance with the movement of the excavator100, in a situation where the excavator100performs work while moving around the tree TR21. The turning angle calculating unit55estimates the turning angle of the upper turning body3with respect to the direction in which the excavator100(turning axis) is viewed from the tree TR21. This allows the controller30to continue to identify the orientation of the upper turning body3(i.e., the orientation of the attachment) with respect to the tree TR21in a situation where the excavator100is working while moving around the tree TR21and turning the upper turning body3.

[Estimation Method of Position of Excavator (Second Example)

Next, a second example of the method of estimating the position of the excavator100(own machine) by the controller30will be described with reference toFIG. 15. Hereinafter, the functional configuration relating to the estimation of the position of the excavator100according to the present example is illustrated inFIG. 13, and, therefore, a figure of the functional configuration will be omitted.

<Functional Configuration Relating to Estimation of Excavator Position>

In the present example, the portions that are different from the above-described first example will be mainly described.

As illustrated inFIG. 13, in the present example, the excavator100includes the imaging device S6(the camera S6F, S6B, S6L, and S6R) and the controller30as a configuration relating to the estimation of the position of the own machine.

The controller30includes the machine guidance unit50and the surrounding status recognizing unit60as configurations relating to the estimation of the position of the excavator100.

The object position map generating unit63generates an object position map MP representing the position of the excavator100(own machine) with respect to a surrounding object (target object) similar to the above-described first example. In the present example, the object position map MP includes accompanying information such as type information of the target object, size information of the target object, information indicating the accuracy of the position of the target object (hereinafter referred to as “accuracy information”) and the like associated with the position of each target object. Accordingly, the object position map generating unit63can refer to the accuracy information and identify the accuracy of the position of the target object included in the object position map MP. For this reason, the object position map generating unit63may, for example, compare the accuracy information of a certain target object in the local map corresponding to the current position of the excavator100with the accuracy information of the same target object in a past object position map MP generated in the most recent processing cycle, and generate the latest object position map MP so as to apply the position with higher accuracy. That is, the object position map generating unit63may update the object position map MP based on information relating to a relatively highly accurate object (target object) acquired by the imaging device S6. Accordingly, the object position map generating unit63can improve the accuracy of the object position map MP.

As illustrated inFIG. 15, it can be understood that the distance range in which the imaging device S6(the cameras S6F and S6B) can perform imaging at a constant angle in the vertical direction, becomes relatively short as the region is closer to the excavator100and becomes relatively long as the region is distant from the excavator100. That is, the imaging device S6can acquire relatively highly dense pixel information for a region relatively close to the excavator100, while the imaging device S6can only acquire relatively rough pixel information for a region relatively distant from the excavator100. Therefore, as the distance between the excavator100and the target object becomes the longer, the position of the target object is estimated from relatively rough pixel information, and the accuracy becomes relatively low. Accordingly, the accuracy information may be generated based on the distance from the excavator100when a target object is detected by the detecting unit62. In this case, the accuracy information is generated in such a manner that the longer the distance from the excavator100when the target object is detected by the detecting unit62, the lower the accuracy of the position of the target object.

Further, the accuracy information may be generated, for example, based on the elapsed time from the last time the target object is detected. This is because, when the distance between the excavator100and a certain target object becomes relatively long and the target object can no longer be detected by the detecting unit62, thereafter, it is not possible to determine whether the target object is present at the position in the same shape. In this case, the accuracy information may be generated in such a manner that the longer the elapsed time, the lower the accuracy of the target object.

The accuracy information may be generated based on the recognition probability of a target object by the detecting unit62(object detection model LM). In this case, the accuracy information may be generated in such a manner that as the recognition probability of the target object output by the object detection model LM relatively decreases, the accuracy of the target object becomes lower.

The machine guidance unit50includes the turning angle calculating unit55and the position estimating unit59as functional configurations relating to the estimation of the position of the excavator100.

The turning angle calculating unit55estimates (calculates) the orientation (turning angle) of the upper turning body3based on a target object whose position is relatively highly accurate, among the stopped target objects or the fixed target objects around the excavator100, identified from the object position map MP stored in the map storage unit64. For example, the turning angle calculating unit55may automatically select a target object to be used as a reference of the orientation of the upper turning body3, according to a predetermined condition (for example, “the distance from the excavator100is closest” or the like), from among the target objects whose positions are relatively highly accurate (specifically, greater than or equal to a predetermined reference), among the stopped target objects or the fixed target objects around the excavator100. Further, for example, the turning angle calculating unit55may use, as a reference of the orientation of the upper turning body3, a stopped target object or a fixed target object selected from among target objects whose positions are relatively highly accurate, among a plurality of target objects identified in an object position map MP based on an operation input through the input device42. Accordingly, the turning angle calculating unit55can estimate the turning angle of the upper turning body3on the basis of the target object whose position is relatively highly accurate. Therefore, it is possible to improve the estimation accuracy of the turning angle.

The position estimating unit59estimates (calculates) the position of the excavator100(own machine) on the basis of a target object whose position is relatively highly accurate, among target objects around the excavator100identified from the object position map MP stored in the map storage unit64. For example, the position estimating unit59may automatically select a target object that is used as a reference of the position of the excavator100according to a predetermined condition (for example, “the distance from the excavator100is the closest” or the like) from among target objects whose positions are relatively highly accurate (specifically, greater than or equal to a predetermined reference) among stopped target objects or fixed target objects around the excavator100. For example, the position estimating unit59may use, as a reference of the position of the excavator100, a stopped target object or a fixed target object selected from among target objects whose positions are relatively highly accurate among a plurality of target objects identified from the object position map MP based on an operation input through the input device42. Accordingly, the position estimating unit59can estimate the position of the excavator100(own machine) based on a target object whose position is relatively highly accurate. Therefore, the accuracy of estimating the position of the excavator100can be improved.

[Estimation Method of Position of Excavator (Third Example)]

Next, a third example of the method of estimating the position of the excavator100(own machine) by the controller30will be described with reference toFIG. 16andFIG. 8(FIGS. 8Aand8B). In the present embodiment, the excavator100is configured to automatically advance and reverse the right and left crawlers of the lower traveling body1. Specifically, a configuration portion relating to the operation system of the traveling hydraulic motor1L and a configuration portion relating to the operation system of the traveling hydraulic motor1R are configured in the same manner as the configuration portion relating to the operation system of the boom cylinder7(FIGS. 4A to 4C). Hereinafter, in the configuration portion relating to the operation system of the traveling hydraulic motor1L and the configuration portion relating to the operation system of the traveling hydraulic motor1R, the configurations corresponding to the proportional valves31AL and31AR illustrated inFIG. 4A, are referred to as proportional valves31DL and31DR and proportional valves31EL and31ER, respectively.

<Functional Configuration Relating to Estimation of Excavator Position>

FIG. 16is a functional block diagram illustrating a third example of functional configurations relating to the estimation of a position of the excavator100according to the present embodiment. Hereinafter, the portions of the present example that are different from the above-described example inFIG. 13will be mainly described. In the present example, the excavator100is configured to automatically advance and reverse the lower traveling body1(specifically, the right and left crawlers).

As illustrated inFIG. 16, in the present example, similar to the case ofFIG. 13, the excavator100is communicatively connected to the management apparatus200using the communication device T1.

The management apparatus200includes the model learning unit201and the distributing unit203as functional units that are implemented by executing, for example, a program installed in an auxiliary storage device on a CPU. The management apparatus200uses the learning result storage unit202and the work information storage unit204. The learning result storage unit202and the work information storage unit204can be implemented by, for example, an auxiliary storage device of the management apparatus200or an external storage device capable of communication.

In the work information storage unit204, a database of work information including work information of a plurality of worksites including the worksite of the excavator100is constructed. The work information includes information on the aim of work (e.g., aim work surface data, etc.).

The distributing unit203extracts the work information of the worksite of the excavator100from the work information database and distributes the information to the excavator100.

In the present example, the excavator100includes the imaging device S6(the camera S6F, S6B, S6L, and S6R), the controller30, and the proportional valves31CL,31CR,31DL,31DR,31EL, and31ER as configurations relating to the estimation of the position of the own machine.

Similar to the case ofFIG. 13, the controller30includes the machine guidance unit50and the surrounding status recognizing unit60as configurations relating to the estimation of the position of the excavator100.

The surrounding status recognizing unit60includes the model storage unit61, the detecting unit62, the object position map generating unit63, the map storage unit64, the storage unit65, and an aim position information generating unit66as functional configurations relating to the estimation of the position of the excavator100.

The storage unit65stores the work information65A distributed from the management apparatus200.

The aim position information generating unit66generates information (hereinafter, referred to as “aim position information”) relating to the position of the work target that is the aim when performing work, and registers the information onto the object position map MP. In the present example, the aim position information generating unit66generates aim position information relating to the aim work surface that is the work target based on the work information65A, specifically, aim position information defining the position of the aim work surface on the object position map MP and the three-dimensional shape of the aim work surface, and registers the aim position information on the object position map MP. That is, the aim position information generating unit66generates an object position map MP for associating the position of the aim of work (the aim work surface) corresponding to the work information65A, with the position of the excavator100(own machine) with respect to an object around the excavator100(the target object), and holds the generated object position map MP in the map storage unit64. Accordingly, the controller30(the automatic control unit54) can identify the position of the excavator100and the positional relationship between the position of the excavator100and the aim of work (the aim work surface), on the object position map MP.

The machine guidance unit50includes the automatic control unit54, the turning angle calculating unit55, the relative angle calculating unit56, and the position estimating unit59as functional configurations relating to the estimation of the position of the excavator100.

The relative angle calculating unit56calculates (estimates) the relative angle based on the orientation (turning angle) of the upper turning body3on the object position map MP calculated by the turning angle calculating unit55, and the position and three-dimensional shape of the aim work surface that is the work target identified from the object position map MP. Specifically, the relative angle calculating unit56may calculate (estimate) the relative angle based on the orientation (turning angle) of the upper turning body3viewed from a certain target object calculated by the turning angle calculating unit55, and the orientation of the aim work surface viewed from the same target object on the object position map MP.

The automatic control unit54controls the proportional valves31DL,31DR,31EL, and31ER based on the position of the excavator100with respect to a target object around the excavator100(own machine) calculated (estimated) by the position estimating unit59, and causes the lower traveling body1to travel, to move the excavator100to the front of the aim work surface corresponding to the work information65A (specifically, the non-worked portion (portion not yet subjected to work) on the aim work surface). Specifically, the automatic control unit54may control the lower traveling body1to travel, based on the position of the excavator100on the object position map MP estimated by the position estimating unit59and the position of the aim work surface on the object position map MP. The automatic control unit54controls the proportional valves31CL,31CR,31DL,31DR,31EL, and31ER based on the relative angle calculated (estimated) by the relative angle calculating unit56to cause the upper turning body3to front-face the aim work surface corresponding to the work information65A. The automatic control unit54may turn the upper turning body3so that the upper turning body3front-faces the aim work surface after the excavator100is moved to the front of the non-worked portion of the aim work surface. The automatic control unit54may control the travelling path of the lower traveling body1so that the upper turning body3front-faces the aim work surface when the excavator100approaches a certain distance to the aim work surface. When an object is detected within a predetermined range, the automatic control unit54may control the decompression proportional valve33based on the positional relationship with the detected object and perform a braking operation (deceleration or stop).

<Specific Example of Estimation Method of Position of Excavator>

As illustrated inFIG. 8A, in the present example, the controller30(the position estimating unit59) estimates the position of the excavator100with respect to the tree TR2that is a fixed target object around the excavator100(own machine), which is identified on the object position map MP.

For example, the controller30(the position estimating unit59) sequentially calculates (estimates) the position of the excavator100with respect to the tree TR2. Then, when the operator operates the lower traveling body1(specifically, the left and right crawlers) through the operation apparatus26while pressing a predetermined switch such as the MC switch or the like, the controller30(the position estimating unit59) the controls the lower traveling body1to travel, via the proportional valves31DL,31DR,31EL, and31ER based on the difference between the position of the excavator100and the position of the slope surface NS with respect to the tree TR2. Thus, as illustrated inFIG. 8A, the controller30can assist the operator in performing operations with respect to the operation apparatus26for operating the lower traveling body1, to move the excavator100to the front of the slope surface NS. When a predetermined switch, such as a MC switch, is pressed down, the controller30may automatically control the lower traveling body1through the proportional valves31DL,31DR,31EL, and31ER and automatically move the excavator100to the front of the slope surface NS, regardless of the operation to the operation apparatus26.

As illustrated inFIGS. 8A and 8B, the controller30(the turning angle calculating unit55) calculates a turning angle using the tree TR2that is a fixed target object around the excavator100(own machine) as a reference target object, which is identified on the object position map MP. Specifically, the controller30calculates a turning angle with respect to the direction in which the excavator100(turning axis) is viewed from the tree TR2.

For example, in the state ofFIG. 8A, the controller30(the turning angle calculating unit55) estimates (calculates) the turning angle using the tree TR2as the reference target object. The controller30(the relative angle calculating unit56) estimates (calculates) the relative angle based on the estimated turning angle and aim position information corresponding to the slope surface NS that is the aim work surface. When the operator performs a left turning operation with respect to the lever device26C while pressing down a predetermined switch such as the MC switch, the controller30(the automatic control unit54) controls the proportional valve31CL so that the upper turning body3front-faces the slope surface NS while estimating the turning angle using the tree TR2as the reference target object. Thus, as illustrated inFIG. 8B, the controller30can assist the operator's operation of the lever device26C to front-face the slope surface NS that is the work target. When the operator presses down a predetermined switch such as the MC switch, the controller30may automatically cause the upper turning body3to front-face the slope surface NS while estimating the turning angle using the tree TR2as the reference target object.

[Estimation Method of Position of Excavator (Fourth Example)]

Next, a fourth example of the method of estimating the position of the excavator100(own machine) by the controller30will be described with reference toFIGS. 17 and 18.

<Functional Configuration Relating to Estimation of Excavator Position>

FIG. 17is a functional block diagram illustrating a fourth example of functional configurations relating to the estimation of the position of the excavator100according to the present embodiment. Hereinafter, the portions of the present example that are different from the above-describedFIG. 13will be mainly described.

In the present example, the excavator100includes the imaging device S6(the camera S6F, S6B, S6L, and S6R), the controller30, and the proportional valves31CL,31CR,31DL,31DR,31EL, and31ER as configurations relating to the estimation of the position of the own machine.

Similar to the case ofFIG. 13, the controller30includes the machine guidance unit50and the surrounding status recognizing unit60as a configuration relating to the estimation of the position of the excavator100.

The surrounding status recognizing unit60includes the model storage unit61, the detecting unit62, the object position map generating unit63, the map storage unit64, the storage unit65, and the aim position information generating unit66as functional configurations relating to the estimation of the position of the excavator100.

Aim setting information65B is stored in the storage unit65.

The aim setting information65B is setting information relating to a work target that is the aim of the work (for example, a dump truck that has come to unload to a scrap yard STP to be described later, various devices in the scrap yard STP, the storage place of scrap, etc.) set by an operation input from a user such as an operator through the input device42.

For example, by operating a predetermined operation screen (hereinafter, “aim selection screen”) displayed on the display device40using the input device42, an operator or the like can select a target object corresponding to the work target from one or more target objects identified in the object position map MP and set the selected target object as the aim of the work. Specifically, an image representing the appearance of the surroundings of the excavator100(hereinafter, “surrounding image”) is displayed on the aim selection screen of the display device40based on the captured image captured by the imaging device S6. Then, on the aim selection screen of the display device40, information representing a marker or the type of the target object is displayed in a superimposed manner at a position corresponding to a target object around the excavator100identified by the object position map MP, on the surrounding image. An operator or the like can identify and select (set) a work target by confirming the position and type of the target object on the aim selection screen.

The aim position information generating unit66generates aim position information corresponding to a work target set (selected) by an operator or the like based on the aim setting information65B and registers the aim position information on the object position map. In the present example, the aim position information generating unit66generates, based on the aim setting information65B, aim position information identifying a target object corresponding to a work target set by an operator or the like among the target objects on the object position map MP, and registers the aim position information in the object position map MP. Specifically, the aim position information generating unit66registers the aim position information on the object position map MP, at the position of the target object that is the work target corresponding to the aim setting information65B on the object position map MP, upon linking this information with accompanying information such as flag information indicating this information is a work target, identification information for distinguishing the work target from other work targets, and the like. That is, the aim position information generating unit66generates the object position map MP that associates the position of a predetermined work target corresponding to the aim setting information65B with the position of the excavator100(own machine) with respect to a surrounding object (target object), and holds the object position map MP in the map storage unit64. Accordingly, the controller30(the automatic control unit54) can identify the positional relationship between the position of the excavator100and the position of the work target set by an operation input from an operator or the like, on the object position map MP.

The machine guidance unit50includes the automatic control unit54, the turning angle calculating unit55, the relative angle calculating unit56, and the position estimating unit59as functional configurations relating to the estimation of the position of the excavator100.

The relative angle calculating unit56calculates (estimates) the relative angle based on the orientation (turning angle) of the upper turning body3on the object position map MP calculated by the turning angle calculating unit55, and the position and three-dimensional shape of the aim work surface that is the work target identified from the object position map MP. Specifically, the relative angle calculating unit56may calculate (estimate) the relative angle based on the orientation (turning angle) of the upper turning body3viewed from a certain target object calculated by the turning angle calculating unit55, and the orientation of the aim work surface viewed from the same target object on the object position map MP.

The automatic control unit54controls the proportional valves31DL,31DR,31EL, and31ER based on the position of the excavator100with respect to the target object corresponding to a work target around the excavator100(own machine), calculated (estimated) by the position estimating unit59, and causes the lower traveling body1to travel. Specifically, the automatic control unit54may control the lower traveling body1to travel, based on the position of the excavator100on the object position map MP estimated by the position estimating unit59and the position of the target object corresponding to the work target on the object position map MP. Accordingly, the automatic control unit54can control the lower traveling body1by assisting the operator in performing operations with respect to the operation apparatus26or regardless of the operation with respect to the operation apparatus26, to move the excavator100to the front of the work target or to move between a plurality of work targets, so as not to collide with any work targets. Further, the automatic control unit54controls the proportional valves31CL and31CR based on the relative angle calculated (estimated) by the relative angle calculating unit56to cause the upper turning body3to front-face the target object corresponding to the work target.

<Specific Example of Estimation Method of Position of Excavator>

FIG. 18is a diagram illustrating a fourth example of an operation relating to the estimation of the turning angle of the excavator100according to the present embodiment. Specifically,FIG. 18is a top view illustrating a situation in which work is performed while moving between a plurality of work targets in a scrap yard STP. The work targets in the present example are the dump truck DT that has come to unload scrap, a scrap storage place specified in the scrap yard STP (a scrap carry-in place, a scrap dismantling place, accumulation places that are located before and after various devices), and various devices in the scrap yard STP (a crushing machine, a line selecting machine, and a vibration sieving machine).

The excavator100identifies various devices under the control of the controller30to determine whether there is a possibility of contact (with another object). Under the control of the controller30, the excavator100determines whether a braking operation is possible and generates an aim trajectory of an end attachment or the lower traveling body1based on the determination result of whether there is a possibility of contact.

In the present example, the excavator100performs a work ST1for extracting scrap from the loading platform of the dump truck DT that is a work target, under the control of the controller30. The work ST1may be performed in a manner that assists the operation to the operation apparatus26by an operator and the like, or may be performed automatically regardless of the operation to the operation apparatus26by an operator and the like. The same applies hereinafter to a work ST2. The controller30monitors the position of the excavator100and the orientation (turning angle) of the upper turning body3with respect to a predetermined work target (such as the dump truck DT and a pile of scrap at the scrap carry-in place) while sequentially updating the object position map MP. Accordingly, the excavator100may operate an attachment

or rotate the upper turning body3so as to move back and forth between the loading platform of the dump truck DT and the scrap carry-in place under the control of the controller30, so that the own machine does not contact the dump truck DT, the scrap at the scrap carry-in place, and the like.

Further, under the control of the controller30, the excavator100continuously performs the work ST2of loading, into the crushing machine, the scrap in the accumulation place that has undergone the dismantling work, and then moving to the line selecting machine, and loading, into the line selecting machine from the accumulation place, the scrap that has been crushed by the crushing machine. The controller30monitors the position of the excavator100and the orientation (turning angle) of the upper turning body3with respect to a predetermined work target (such as a pile of scrap at the accumulation place, the crushing machine, the line selecting machine, and the like) while sequentially updating the object position map MP. Accordingly, the excavator100may operate an attachment or may turn the upper turning body3back and forth between the accumulation place and the loading port of the crushing machine under the control of the controller30so that the own machine does not contact a pile of scrap in the accumulation place or the crushing machine. Further, the excavator100may travel by the lower traveling body1from the front of the crushing machine to the front of the line selecting machine under the control of the controller30so that the excavator100does not contact a pile of scrap in the accumulation place, the crushing machine, the line selecting machine, or the like. Further, the excavator100may operate the attachment or may turn the upper turning body3back and forth between the accumulation place and the loading port of the line selecting machine under the control of the controller30to prevent the own machine from contacting a pile of scrap at the accumulation place or the line selecting machine.

As described above, in the present example, a plurality of work targets in the scrap yard STP are set in advance (registered) in the object position map MP, and, therefore, the excavator100can safely proceed with work under the control of the controller30such that the own machine does not contact various devices in the scrap yard STP.

[Estimation Method of Position of Excavator (Fifth Example)]

Next, a fifth example of the method of estimating the position of the excavator100(own machine) by the controller30will be described.

Note that, as the functional block diagram representing the functional structure relating to the estimation of the position of the excavator100according to the present example, any of the functional block diagrams (FIG. 13orFIG. 17) of the first to fourth examples described above can be used, and thus, the drawing is omitted.

The controller30may estimate (calculate) a movement distance and a movement direction of the excavator100based on the change in time series of the position of a reference target object viewed from the excavator100, similar to case of the above-described third example of the method for estimating a turning angle (FIG. 10andFIG. 11). The controller30may estimate (calculate) the position of the excavator100by accumulating the movement distance and the movement direction in the time series with respect to a certain time, based on the change in time series of the position of the reference target object viewed from the excavator100. Accordingly, the controller30can calculate (estimate) the movement distance, the movement direction, the position and the like of the excavator100by identifying the track records of positions of the reference target object viewed from the excavator100.

The controller30may estimate (calculate) the movement distance, the movement direction, the position, or the like of the excavator100by using a plurality of reference target objects around the excavator100, similar to the case of the above-described third example of the method for estimating a turning angle (FIGS. 10 and 11). Accordingly, even when some of the reference target objects cannot be detected, as long as there is another reference target object that can be detected, the controller30may estimate the movement distance, the movement direction, the position, etc., of the excavator100based on a change in the position of the other reference target object viewed from the excavator100. That is, by using a plurality of reference target objects, the controller30can stably continue estimating the movement distance, the movement direction, the position, and the like of the excavator100even in a situation where some of the reference target objects cannot be detected.

While the embodiments have been described in detail above, the disclosure is not limited to such particular embodiments, and various modifications and variations are possible within the scope of the appended claims.

For example, in the above described embodiments, the function of estimating the turning angle and position of the excavator100may be transferred to a predetermined external device (e.g., the management apparatus200) that is communicatively connected with the excavator100. In this case, the output of the imaging device S6, the distance measuring device S7, or the like is transmitted from the excavator100to the management apparatus200. Accordingly, the management apparatus200can identify the positional relationship between the excavator100and an object around the excavator100while estimating the turning angle and the position based on the information received from the excavator100, and transmit the result to the excavator100as feedback. Therefore, the processing load on the excavator100side (the controller30) can be reduced.

In the above described embodiment, information relating to a monitor target detected inside or outside of the monitor region of the excavator100may be transmitted from the excavator100to the management apparatus200. In this case, in the management apparatus200, information relating to the type of the monitor target, the position of the monitor target, and the like, inside or outside the monitor region of the excavator100is stored in a predetermined storage unit in time series. The information relating to the monitor target stored in the storage unit of the management apparatus200may include information relating to the type of the monitor target, the position of the monitor target, etc., outside the monitor region of the target excavator100and within the monitor target of another excavator100(in the same worksite).

According to an aspect of the present invention, a technique in an excavator, by which the positional relationship between the own machine and an object around the own machine can be reliably identified, can be provided.