Patent Description:
As a related technology, a work machine control system (controller) for controlling a work machine (hydraulic excavator) is known (see, for example, Patent Document <NUM>). The work machine control system according to the related technology has a target detection function that limits a motion of the work machine based on a result of detection at an ambient monitoring device for detecting whether or not a to-be-recognized target is present within a set area set around the work machine. That is, the work machine control system limits the motion of the work machine when the target detection function detects the target present around the work machine. Then, the work machine control system according to the related technology, with a lock portion (lock lever) switched to a locked state, switches the target detection function to the non-execution setting. When the target detection function is being set to the non-execution, if the lock is switched to the unlocked state and an operation signal from an operation device (operation lever) is detected, the work machine control system switches the target detection function to the execution setting. Patent Document <NUM> discloses a surroundings monitoring system including a person detecting part configured to detect a person present around a shovel and a control part configured to control an output apparatus mounted on the shovel.

In the above related technology, when the lock portion (lock lever) is switched to the unlocked state and the operation device is further operated, a human operator must carefully operate the operation device so as to prevent the work machine from vigorously operating suddenly, for example.

An object of the present invention is to provide a work machine control system, a work machine, a method of controlling the work machine, and a work machine control program which easily decrease a burden on a human operator related to an operation.

A work machine control system according to one aspect of the present invention includes: an acquisition process unit; and a limit process unit. The acquisition process unit acquires a detection result of an object around a machine body of a work machine in a state incapable of operating the work machine. The limit process unit creates a limit state capable of limitedly operating the work machine, when the detection result meets a predetermined condition and then a gate lock lever is so operated as to create a state capable of operating the work machine.

A work machine according to the one aspect of the present invention includes: the work machine control system; and the machine body.

A method of controlling a work machine according to the one aspect of the present invention includes: acquiring a detection result of an object around a machine body of a work machine in a state incapable of operating the work machine; and creating a limit state capable of limitedly operating the work machine, when the detection result meets a predetermined condition and then a gate lock lever is so operated as to create a state capable of operating the work machine.

A work machine control program according to the one aspect of the present invention is a program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method of controlling the work machine.

According to the present invention, it is possible to provide a work machine control system, a work machine, a method of controlling the work machine, and a work machine control program that can easily decrease a burden on a human operator related to an operation.

The following embodiments are each an embodied example of the present invention and are not intended to limit the technical scope of the present invention.

As shown in <FIG>, a work machine <NUM> according to the present embodiment includes a machine body <NUM> having a travel unit <NUM>, a swivel unit <NUM>, and a work unit <NUM>. The work machine <NUM> further includes a work machine control system <NUM> (hereinafter, simply referred to as a "control system <NUM>"), as shown in <FIG>. In addition, as shown in <FIG> and <FIG>, the machine body <NUM> is further provided with a display unit <NUM>, an activating unit <NUM>, an operation unit <NUM> and a sound output unit <NUM>.

The "work machine" in the present invention refers to a machine for various types of work, examples thereof including work vehicles such as a backhoe (including a hydraulic excavator and a mini excavator), a wheel loader and a carrier. The work machine <NUM> is provided with the work unit <NUM> so configured as to be capable of performing one or more works. The work machine <NUM> is not limited to a "vehicle" but may be, for example, a work vessel or a flying work body such as a drone or a multi-copter. Further, the work machine <NUM> is not limited to a construction machine (construction instrument), but may also be an agricultural machine (farm machine) such as a rice transplanter, a tractor or a combine harvester. According to the present embodiment, unless otherwise specified, the case in which the work machine <NUM> is a riding-type backhoe and can perform digging, land preparation, trenching, or loading operations as its work will be taken as an example.

Further, according to the present embodiment, for convenience of description, a vertical direction in a state where the work machine <NUM> is usable is defined as an upper-lower direction D1. Further, a front-rear direction D2 and a right-left direction D3 are defined based on a direction viewed from a user (human operator) riding on (a drive unit <NUM> of) the work machine <NUM> in a non-swivel state of the swivel unit <NUM>. That is, each direction used in the present embodiment is a direction defined based on the machine body <NUM> of the work machine <NUM>, and a direction in which the machine body <NUM> moves when the work machine <NUM> moves forward is referred to as a "front" and a direction in which the machine body <NUM> moves when the work machine <NUM> moves rearward is referred to as a "rear". Similarly, a direction in which a front end portion of the machine body <NUM> moves when the work machine <NUM> swivels to the right is referred to as a "right," and a direction in which the front end portion of the machine body <NUM> moves when the work machine <NUM> swivels to the left is referred to as a "left". However, these directions are not intended to limit a use direction (a direction in use) of the work machine <NUM>.

The work machine <NUM> is provided with an engine <NUM> (see <FIG>) that serves as a power source. In the present embodiment, as one example, the engine <NUM> is a diesel engine. The engine <NUM> is driven by fuel (herein, light oil) supplied from a fuel tank. In the work machine <NUM>, for example, the engine <NUM> drives a hydraulic pump <NUM> (refer to <FIG>), and hydraulic oil is supplied from the hydraulic pump <NUM> to hydraulic actuators (including hydraulic motor <NUM>, hydraulic cylinder <NUM> and the like) of portions in the machine body <NUM> thereby to drive the machine body <NUM>. The above work machine <NUM> is controlled, for example, by the user (human operator), who is riding on the drive unit <NUM> of the machine body <NUM>, by operating an operation lever and the like of the operation unit <NUM>.

It is assumed according to the present embodiment that the work machine <NUM> is a passenger-use backhoe as described above; therefore, the work unit <NUM> is driven according to the operation performed by the user (human operator) riding on the drive unit <NUM> thereby to perform work such as excavation work. The drive unit <NUM>, on which the user rides, is disposed on the swivel unit <NUM>.

Here, the drive unit <NUM> of the machine body <NUM> is provided with the display unit <NUM>, the operation unit <NUM>, and the sound output unit <NUM>; the user can operate the operation unit <NUM> while viewing various types of information that is displayed on the display unit <NUM> and related to the work machine <NUM>. As an example, a display screen of the display unit <NUM> shows information on an operation status of the work machine <NUM>, such as the cooling water temperature and hydraulic oil temperature, so that the user can check, on the display unit <NUM>, the information that is necessary for operating the operation unit <NUM> and that is on the operation status of the work machine <NUM>.

The travel unit <NUM> has a traveling function, and is so configured as to be capable of traveling (including swiveling) on the ground. The travel unit <NUM> includes, for example, a pair of right and left crawlers <NUM> and a blade <NUM>. The travel unit <NUM> further includes a travel-directed hydraulic motor <NUM> (hydraulic actuator) for driving the crawlers <NUM>.

The swivel unit <NUM> is located above the travel unit <NUM> and is so configured as to swivel relative to the travel unit <NUM> around a rotation axis along the upper-lower direction D1. The swivel unit <NUM> has a swivel-directed hydraulic motor (a hydraulic actuator). The swivel unit <NUM> includes, other than the drive unit <NUM>, the engine <NUM> and the hydraulic pump <NUM>. At the front end portion of the swivel unit <NUM>, a boom bracket <NUM> on which the work unit <NUM> is mounted is disposed.

The work unit <NUM> is so configured as to perform one or more works. The work unit <NUM> is supported by a boom bracket <NUM> of the swivel unit <NUM> and performs works. The work unit <NUM> has a bucket <NUM>. The bucket <NUM> is a type of attachment (work instrument) that is mounted on the machine body <NUM> of the work machine <NUM>, and is composed of an arbitrary instrument selected from among a plurality of types of attachments according to content of the work. The bucket <NUM>, as an example, is removably mounted on the machine body <NUM>, and is replaced according to content of the work. In addition to the bucket <NUM>, the attachments for the work machine <NUM> include various instruments, such as a breaker, an auger, a crusher, a fork, a fork claw, a steel cutter, an asphalt cutter, a mower, a ripper, a mulcher, a tilt rotator, and a tamper.

The work unit <NUM> further has a boom <NUM>, an arm <NUM> and a hydraulic actuator (including hydraulic cylinder <NUM> and hydraulic motor and the like) and the like. The bucket <NUM> is mounted to a tip end of the arm <NUM>.

The boom <NUM> is rotatably supported at the boom bracket <NUM> of the swivel unit <NUM>. Specifically, the boom <NUM> is supported at the boom bracket <NUM> in a manner to rotate about a rotation axis along the horizontal direction. The boom <NUM> is so shaped as to extend upward from a base end portion supported at the boom bracket <NUM>. The arm <NUM> is coupled to a tip end of the boom <NUM>. The arm <NUM> is supported at the boom <NUM> in a manner to rotate relative to the boom <NUM> about a rotation axis along the horizontal direction.

The work unit <NUM> operates under power from the engine <NUM> as the power source. Specifically, the engine <NUM> drives the hydraulic pump <NUM> thereby to supply the hydraulic oil from the hydraulic pump <NUM> to the hydraulic actuator (hydraulic cylinder <NUM> or the like) of the work unit <NUM>, thereby to operate portions (the bucket <NUM>, the boom <NUM>, and the arm <NUM>) of the work unit <NUM>.

According to the present embodiment, in particular, the work unit <NUM> has an articulated configuration in which the boom <NUM> and the arm <NUM> are individually rotatable. That is, the boom <NUM> and the arm <NUM> each rotate about the rotation axis extending along the horizontal direction, so that the articulated work unit <NUM> including the boom <NUM> and the arm <NUM> is capable of performing motions such as extending and folding as a whole.

Each of the travel unit <NUM> and the swivel unit <NUM>, as well as the work unit <NUM>, is powered by the engine <NUM> as the power source. That is, the hydraulic oil is supplied from the hydraulic pump <NUM> to the hydraulic motor <NUM> of the travel unit <NUM>, hydraulic motors of the swivel unit <NUM>, and the like, so that the swivel unit <NUM> and the travel unit <NUM> are operated.

The machine body <NUM> is provided with various sensors (including cameras) so as to detect an object Ob1 (see <FIG>) in a monitor area A1 (see <FIG>) around the work machine <NUM>, such as a camera to capture an image around the machine body <NUM>. In the present embodiment, as one example, as shown in <FIG>, a plurality of cameras (herein, three cameras), including a left camera <NUM>, a right camera <NUM> and a rear camera <NUM>, are mounted on the swivel unit <NUM> of the machine body <NUM>. The left camera <NUM>, the right camera <NUM> and the rear camera <NUM> are connected to the control system <NUM> and output, to the control system <NUM>, images captured by each camera. <FIG> is a plan view of the work machine <NUM> viewed from above, schematically showing the monitor area A1 set up around the work machine <NUM>, the object Ob1, and the machine body <NUM> (including the left camera <NUM>, right camera <NUM> and rear camera <NUM>) of the work machine <NUM>.

The left camera <NUM>, the right camera <NUM>, and the rear camera <NUM> are installed to face left, right, and rear, respectively, based on the drive unit <NUM>, so as to capture images of the monitor area A1 on left, right, and rear viewed from the human operator riding on the drive unit <NUM> of the swivel unit <NUM>. That is, as shown in <FIG>, the monitor area A1 includes a plurality (in this case, three) of small areas A11, A12, and A13, and the left camera <NUM> captures an image of the small area A11 (left area) which is on the left as seen from the human operator riding on the drive unit <NUM>. Similarly, the right camera <NUM> captures an image of the small area A12 (right area) which is on the right as seen from the human operator riding on the drive unit <NUM>, and the rear camera <NUM> captures an image of the small area A13 (rear area) which is in the rear as seen from the human operator riding on the drive unit <NUM>. This enables the left camera <NUM>, the right camera <NUM>, and the rear camera <NUM> to cover the both sides (left and right) and the rear which are often blind spots for the human operator.

<FIG> schematically shows a hydraulic circuit and an electric circuit (electric connection) of the work machine <NUM> according to the present embodiment. In <FIG>, solid lines indicate high-pressure oil paths (for hydraulic oil), dotted lines indicate low-pressure oil paths (for pilot oil), and dashed-dotted lines indicate electric signal paths.

As shown in <FIG>, the work machine <NUM> has the hydraulic pump <NUM>, the hydraulic motor <NUM> (omitted from <FIG>) and the hydraulic cylinder <NUM>, as well as a pilot pump <NUM>, a remote control valve <NUM>, a first limit unit <NUM>, a second limit unit <NUM>, a direction switch valve (control valve) <NUM>, a flowrate limit unit <NUM> and the like.

The hydraulic oil from the hydraulic pump <NUM> driven by the engine <NUM> is supplied to the hydraulic motor <NUM> of the travel unit <NUM>, the hydraulic motor of the swivel unit <NUM>, the hydraulic cylinder <NUM> of the work unit <NUM>, and the like. This drives the hydraulic actuators such as the hydraulic motor <NUM> and the hydraulic cylinder <NUM>.

Here, the flowrate of the hydraulic oil supplied from the hydraulic pump <NUM> is not fixed, but can be changed (variable) by an appropriate measure. The work machine <NUM> according to the present embodiment is provided with the flowrate limit unit <NUM>, making it possible to adjust the flowrate of the hydraulic fluid at the flowrate limit unit <NUM>. In the present embodiment, as one example, the hydraulic pump <NUM> includes a variable displacement pump that can change the hydraulic oil volume discharged per revolution of a drive shaft.

The flowrate limit unit <NUM> has a control signal input port <NUM>, a solenoid proportional valve <NUM>, and an engine control unit <NUM>. The control signal input port <NUM> is a port where a control signal is input so as to adjust the discharge rate (flowrate) of the hydraulic oil of the hydraulic pump <NUM> composed of the variable displacement type pump. Specifically, pilot oil, which serves as the control signal, is supplied from the pilot pump <NUM> to the control signal input port <NUM>, and the discharge rate of the hydraulic oil of the hydraulic pump <NUM> changes according to the supply rate (pilot pressure) of the pilot oil. The solenoid proportional valve <NUM> is an electromagnetic proportional control valve installed on the pilot oil supply path to the control signal input port <NUM>, and adjusts the pilot pressure input to the control signal input port <NUM>. The solenoid proportional valve <NUM> is connected to the control system <NUM>, and according to the control signal (supply current) from the control system <NUM>, adjusts the pilot pressure input to the control signal input port <NUM>, thereby to change the discharge rate of the hydraulic oil of the hydraulic pump <NUM>. The engine control unit <NUM> controls the speed of the engine <NUM>. That is, the engine control unit <NUM> controls the speed of the hydraulic pump <NUM> thereby to change the discharge rate of the hydraulic oil of the hydraulic pump <NUM>.

Thus, the flowrate limit unit <NUM> controls at least one of the flowrate of the hydraulic pump <NUM> that supplies the hydraulic oil, the speed of the engine <NUM> that drives the hydraulic pump <NUM>, and the pilot pressure, thereby making it possible to adjust the flowrate of the hydraulic oil discharged from the hydraulic pump <NUM>. The flowrate limit unit <NUM> may, without steps, continuously vary the flowrate of the hydraulic fluid discharged from the hydraulic pump <NUM>, or may vary the flowrate in steps (for example, <NUM>, <NUM>, or <NUM> steps).

Each of the hydraulic actuators, such as the hydraulic motor <NUM> and the hydraulic cylinder <NUM>, includes a pilot-type direction switch valve <NUM> capable of switching a direction and flowrate of the hydraulic oil from the hydraulic pump <NUM>. The direction switch valve <NUM> is driven when the pilot oil serving as an input instruction is supplied from the pilot pump <NUM>.

Here, the remote control valve <NUM> is disposed in the pilot oil's supply path to the direction switch valve <NUM> that corresponds to the hydraulic cylinder <NUM> of the work unit <NUM>. The remote control valve <NUM> outputs a work operation instruction of the work unit <NUM> according to the operation of the operation unit <NUM> (operation lever). The work operation instruction instructs an expanding operation, a contracting operation and the like of the work unit <NUM>. The flowrate of the pilot oil supplied from the pilot pump <NUM> to the remote control valve <NUM> is adjustable at the first limit unit <NUM> and the second limit unit <NUM>. The first limit unit <NUM> has a first control valve <NUM>, a gate lock switch <NUM> and a gate lock lever <NUM>. The second limit unit <NUM> has a second control valve <NUM>.

The first control valve <NUM> and the second control valve <NUM> are each an electromagnetic control valve (solenoid valve), and are inserted in series between the remote control valve <NUM> and the pilot pump <NUM>. The first control valve <NUM> is connected via the gate lock switch <NUM> to the power supply, and operates according to the current supplied from the power source. The second control valve <NUM> is connected to the control system <NUM>, and operates according to the control signal (supply current) from the control system <NUM>. The first control valve <NUM> and the second control valve <NUM> are each a (electromagnetic) proportional control valve, however, can also be a switchable open/close valve that opens/closes the flow path, for example.

The first control valve <NUM> and the second control valve <NUM> each in an energized state, that is, when the current as the control signal is supplied, open the flow path of the pilot oil, and in a de-energized state, that is, when the current as the control signal is shut off, shut off the flow path of the pilot oil. Therefore, shutting off the supply current (control signal) to at least one of the first control valve <NUM> and the second control valve <NUM> disenabling the hydraulic actuator (hydraulic cylinder <NUM> and the like) that corresponds to the remote control valve <NUM>, thus forcibly stopping the hydraulic actuator not depending on the operation of the operation unit <NUM>.

Similarly, a remote control valve is also disposed in the pilot oil's supply path to a direction switch valve that corresponds to the hydraulic motor <NUM> of the travel unit <NUM>. This remote control valve outputs a travel operation instruction of the travel unit <NUM> according to the operation of the operation unit <NUM> (operation lever). The travel operation instruction instructs a traveling operation (for example, forward or backward) of the travel unit <NUM>. Further, a remote control valve is also disposed in the pilot oil's supply path to a direction switch valve that corresponds to the hydraulic motor of the swivel unit <NUM>. This remote control valve outputs a swivel operation instruction of the swivel unit <NUM> according to the operation of the operation unit <NUM> (operation lever). The swivel operation instruction instructs a swivel operation (for example, left swivel or right swivel) of the swivel unit <NUM>. And, to between these remote control valves and the pilot pump <NUM>, the first control valve <NUM> and the second control valve <NUM> are inserted.

The gate lock switch <NUM> is interlocked with the gate lock lever <NUM>. The gate lock lever <NUM> is located in the drive unit <NUM> of the machine body <NUM>, and receives an operation input by the user (human operator). In the present embodiment, as one example, the gate lock lever <NUM> is operable along the upper-lower direction D1. When the gate lock lever <NUM> is in "up position" which is the upper end position of the movable range, the gate lock switch <NUM> is "off"; and when the gate lock lever <NUM> is in "down position" which is the lower end position of the movable range, the gate lock switch <NUM> is "on". The gate lock switch <NUM> is connected to the control system <NUM>, and the gate lock switch <NUM> on or off is monitored by the control system <NUM>.

Therefore, when the gate lock lever <NUM> is in "down position", the first control valve <NUM> is brought in the energized state, driving the hydraulic actuator (hydraulic cylinder <NUM> and the like) by the operation of the operation unit <NUM>. In contrast, when the gate lock lever <NUM> is in the "up position", the first control valve <NUM> is brought in the de-energized state, forcibly stopping the hydraulic actuator not depending on the operation of the operation unit <NUM>. Therefore, to drive the hydraulic actuator (such as hydraulic cylinder <NUM>), the user (human operator) needs to operate the gate lock lever <NUM> to "down position".

Further, each of the swivel unit <NUM> and the travel unit <NUM> operates with the hydraulic oil supplied from the hydraulic pump <NUM> to the hydraulic actuator (hydraulic motor <NUM> and the like); therefore, when the gate lock lever <NUM> is in the "up position", the swivel unit <NUM> and travel unit <NUM> also become inoperable. That is, when the gate lock lever <NUM> is in the "up position", all of the work unit <NUM>, the swivel unit <NUM>, and the travel unit <NUM> are forcibly disenabled.

In short, the gate lock switch <NUM>, when being off, is in a "locked state" in which the motion of the work machine <NUM> is limited (including prohibited), and when being on, is in an "unlocked state" in which the motion of the work machine <NUM> is not limited. Then, when the gate lock lever <NUM> is in "up position" and the gate lock switch <NUM> is in the locked state (off), the motion of the work machine <NUM> is forcibly limited not depending on the operation of the operation unit <NUM>. The gate lock lever <NUM> is thus the lever operated so as to lock the motion of the work machine <NUM>, and is synonymous with a cutoff lever.

The operation unit <NUM> is located in the drive unit <NUM> of the machine body <NUM>, and is a user interface for receiving the operation input by the user (human operator). The operation unit <NUM> outputs an electrical signal (operation signal) that accords to the operation by the user, for example, thereby to receive various operations by the user.

The sound output unit <NUM> outputs a sound (including voice) to the user (human operator). The sound output unit <NUM> includes a buzzer or a speaker, and outputs the sound upon receiving an electric signal. The sound output unit <NUM> is connected to the control system <NUM>, and outputs sounds, such as beeps or voice, according to a sound control signal from the control system <NUM>. According to the present embodiment, the sound output unit <NUM>, as well as the display unit <NUM>, is disposed in the drive unit <NUM> of the machine body <NUM>. The sound output unit <NUM> may be disposed integrally with the display unit <NUM>.

The control system <NUM> is mainly composed of a computer system having one or more processors such as a CPU (Central Processor), and one or more memories such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and executes various processes (information process). According to the present embodiment, the control system <NUM> is an integrated control unit that controls the entire work machine <NUM>, and is configured by, for example, an electronic control unit (ECU). However, the control system <NUM> may be separate from the integrated control unit, and may primarily include one processor or a plurality of processors. The control system <NUM> will be described in detail in the column "[<NUM>] Configuration of Control System".

The display unit <NUM> is disposed in the drive unit <NUM> of the machine body <NUM>, and is a user interface for receiving the operation input by the user (the human operator) and outputting various types of information to the user. The display unit <NUM> outputs an electric signal that accords to the operation by the user, for example, thereby to receive various operations performed by the user. Accordingly, the user (the human operator) can view a display screen Dp1 (refer to <FIG>) displayed on the display unit <NUM>, and can operate the display unit <NUM> as necessary.

As shown in <FIG>, the display unit <NUM> includes a control unit <NUM>, an operation unit <NUM>, and a display unit <NUM>. The display unit <NUM> is so configured as to be communicable with the control system <NUM>, and can perform sending and receiving of data to and from the control system <NUM>. In the present embodiment, as one example, the display unit <NUM> is a dedicated device used for the work machine <NUM>.

The control unit <NUM> controls the display unit <NUM> according to data from the control system <NUM>. Specifically, the control unit <NUM> outputs an electric signal that accords to the user's operation received by the operation unit <NUM>, and displays, in the display unit <NUM>, the display screen Dp1 generated by the control system <NUM>.

The operation unit <NUM> is a user interface for receiving the user (human operator)'s operation input to the display screen Dp1 displayed in the display unit <NUM>. The operation unit <NUM> receives various operations by a user U1 (refer to <FIG>), for example, by outputting the electric signal that accords to the operation by the user U1. In the present embodiment, as one example, the operation unit <NUM> includes a plurality (herein six) of mechanical push button switches <NUM> to <NUM> as shown in <FIG>. The plurality of push button switches <NUM> to <NUM> is disposed in the vicinity of a display region of the display unit <NUM> (a lower portion in the example in <FIG>) along a periphery of the display region. The plurality of push button switches <NUM> to <NUM> each is associated with an item that is displayed on the display screen Dp1 and that is described below, and operating any of the plurality of push button switches <NUM> to <NUM> operates (selects) any of the item on the display screen Dp1.

Further, the operation unit <NUM> may include a touch screen and an operation dial. Also in this case, operating for the operation unit <NUM> operates (selects) any of the item on the display screen Dp1.

The display unit <NUM> is a user interface for displaying information to the user U1 (the human operator), such as a liquid crystal display or an organic EL display that displays various types of information. The display unit <NUM> presents various types of information to the user by means of display. In the present embodiment, as one example, the display unit <NUM> is a full-color liquid crystal display with a backlight, and has a "horizontally-long" display area that is long in a horizontal direction as shown in <FIG>.

In addition to the above configuration, the machine body <NUM> is further provided with a communication terminal, a fuel tank and a battery. Further, the machine body <NUM> is provided with various sensors (including cameras) for detecting a to-be-detected object in the monitor area around the work machine <NUM>, such as a camera for capturing an image around the machine body <NUM>.

Next, a configuration of the control system <NUM> according to the present embodiment will be described with reference to <FIG>. The control system <NUM> controls each portion of the machine body <NUM> (including the travel unit <NUM>, the swivel unit <NUM>, and the work unit <NUM> and the like). According to the present embodiment, the control system <NUM> is a component of the work machine <NUM>, constituting the work machine <NUM> together with the machine body <NUM> and others. That is, the work machine <NUM> is provided with at least the control system <NUM> and the machine body <NUM>.

As shown in <FIG>, the control system <NUM> is provided with an acquisition process unit <NUM>, a limit process unit <NUM>, a determination process unit <NUM>, a detection process unit <NUM>, a notification process unit <NUM>, and a cancelation process unit <NUM>. In the present embodiment, as one example, the control system <NUM> is mainly composed of a computer system having at least one processor; therefore at least one processor, by executing a work machine control program, realizes the plurality of functional portions (the acquisition process unit <NUM> and the like). The plurality of functional portions included in the control system <NUM> may be distributed to a plurality of cases or may be included in a single case.

The control system <NUM> is so configured as to be communicable with a device included in each portion of the machine body <NUM>. This means that, to the control system <NUM>, at least the display unit <NUM>, the left camera <NUM>, the right camera <NUM>, the rear camera <NUM>, the sound output unit <NUM>, the gate lock switch <NUM>, the second control valve <NUM>, the solenoid proportional valve <NUM>, the engine control unit <NUM> and the like are connected. This causes the control system <NUM> to control the display unit <NUM>, the sound output unit <NUM> and the like, and to acquire the image captured by the left camera <NUM>, the right camera <NUM>, the rear camera <NUM> and the like. Here, the control system <NUM> may send and receive various types of information (data) directly to and from each device, or indirectly through a relay or the like. The control system <NUM> and the device that is disposed in each portion of the machine body <NUM> can communicate with each other by a communication method such as CAN (Control unit Area Network) or the like, as one example.

The acquisition process unit <NUM>, at least in a state incapable of operating the work machine <NUM>, executes the acquisition process to acquire the detection result of the object Ob1 around the machine body <NUM> of the work machine <NUM>. Specifically, according to the present embodiment, the object Ob1 around the machine body <NUM> is detected by the detection process unit <NUM> based on output of the left camera <NUM>, right camera <NUM>, and rear camera <NUM>. Therefore, from the detection process unit <NUM>, the acquisition process unit <NUM> acquires the detection result of the object Ob1 around the machine body <NUM>. In the present embodiment, as one example, the object Ob1 is a "person". That is, when the "person" enters the monitor area A1 around the work machine <NUM> as a result of the work machine <NUM> moving or the "person" around the work machine <NUM> moving, the detection process unit <NUM> detects the "person" as the object Ob1. When a plurality of objects Ob1 is present in the monitor area A1, the detection process unit <NUM> may perform the detection including the number of objects Ob1 (number of persons). "the state incapable of operating the work machine <NUM>" here means a state where the work machine <NUM> is not driven by the operation of the operation unit <NUM>, and includes at least the state where the gate lock lever <NUM> is in "up position" and the gate lock switch <NUM> is off. Further, "the state incapable of operating the work machine <NUM>" includes, for example, a state where an ignition of the work machine <NUM> is off (that is, the engine <NUM> is stopped) and a state where the main power of the work machine <NUM> is off. Conversely, "the state capable of operating the work machine <NUM>" means a state where the work machine <NUM> is driven by the operation of the operation unit <NUM>, and includes at least a state where the gate lock lever <NUM> is in "down position" and the gate lock switch <NUM> is on. Further, "the state capable of operating the work machine <NUM>" includes, for example, a state where the ignition of the work machine <NUM> is on (that is, the engine <NUM> is driving) and the main power supply of the work machine <NUM> is on. In the present embodiment, as one example, the state where the gate lock lever <NUM> is in "up position" is the "state in capable of operating the work machine <NUM>" and the state where the gate lock lever <NUM> is in "down position" is "the state capable of operating the work machine <NUM>".

That is, the acquisition process unit <NUM> has the function of acquiring the detection result of the object Ob1 around the machine body <NUM> in the state where at least the gate lock lever <NUM> is in "up position". However, according to the present embodiment, the acquisition process unit <NUM> acquires the detection result of the object Ob1 around the machine body <NUM>, not limited to in the state incapable of operating the work machine <NUM>, but also in the state capable of operating the work machine <NUM>. That is, regardless of whether the gate lock lever <NUM> is in "up position" or "down position", the acquisition process unit <NUM>, from the detection process unit <NUM>, regularly or irregularly acquires the detection result of the object Ob1 around the machine body <NUM>. When distinguishing between the detection result acquired in "the state incapable of operating the work machine <NUM>" and the detection result acquired in "the state capable of operating the work machine <NUM>", the former is referred to as "at-stop detection result" and the latter is referred to as "at-steady-state detection result ".

The limit process unit <NUM> executes a limit process that creates a limit state capable of limitedly operating the work machine <NUM>, when the detection result (at-stop detection result) acquired in the state incapable of operating the work machine <NUM> meets a predetermined condition and then the lever <NUM> is so operated as to create the state capable of operating the work machine <NUM>. That is, in the state incapable of operating the work machine <NUM> (the gate lock lever <NUM> is in "up position")" and the detection result acquired by the acquisition process unit <NUM> meets the predetermined condition, the gate lock lever <NUM>, when operated from "up position" to "down position", causes the limit process unit <NUM> to create the limit state capable of limitedly operating the work machine <NUM>.

The "predetermined condition" here is a condition imposed on the detection result (at-stop detection result) so as to create the limit state capable of limitedly operating the work machine <NUM> (to execute the limit process), and includes, for example, the object Ob1 being present in the monitor area A1 around the machine body <NUM>. The "predetermined condition" is, for example, in addition to or instead of the object Ob1 being present in the monitor area A1, that the object Ob1 has a specific attribute, the object Ob1 is present in the monitor area A1 for more than or equal to a predetermined time period, a specific position around the machine body <NUM> (for example, a position in the operator's blind spot, or a position within a certain distance from the machine body <NUM>), or the like. The "specific attribute" here includes, as an example, that the object Ob1 is moving, that object Ob1 is other than a worker (a general person), that there are more than or equal to a predetermined number of objects Ob1, or the like. In the present embodiment, as one example, the "predetermined condition" is the object Ob1 (in this case, "person") being present in the monitor area A1.

The "limit state" here means the limit state capable of limitedly operating the work machine <NUM>, not a state incapable of operating the work machine <NUM> at all, but a state capable of operating the work machine <NUM> with some limit imposed. As an example, the "limit state" includes a state capable of operating the work machine <NUM> only within a certain time, a state capable of operating the work machine <NUM> only within a certain distance, a state limiting the motion speed of the hydraulic actuator, a state limiting the operation target (specific hydraulic actuator, etc.), a state inhibiting a specific operation such as swiveling and expanding of the work machine <NUM>, or a combination thereof.

In short, when the at-stop detection result meets the predetermined condition with the object Ob1 (in this case, the "person") being present in the monitor area A1 in the state incapable of operating the work machine <NUM>, operating the gate lock lever <NUM> from "up position" to "down position" causes the limit process unit <NUM> to put the work machine <NUM> in the limit state. With this, the state of the work machine <NUM> switches from a state incapable of operating even when the operation unit <NUM> is operated to a state capable of operating according to the operation of the operation unit <NUM> despite some limit imposed.

The determination process unit <NUM> determines whether "the state incapable of operating the work machine <NUM>" or "the state capable of operating the work machine <NUM>", and whether or not the at-stop detection result meets the predetermined condition. That is, the determination process unit <NUM> determines, based on at least the input signal from the gate lock switch <NUM>, whether the gate lock lever <NUM> is in "up position" or "down position". When the gate lock switch <NUM> is off, the determination process unit <NUM> determines that the gate lock lever <NUM> is in "up position", i.e., in "the state incapable of operating the work machine <NUM>". The determination process unit <NUM> outputs the determination result to at least the limit process unit <NUM>. With this, in the limit process unit <NUM>, operating the gate lock lever <NUM> to "down position" when the at-stop detection result meets the predetermined condition creates the limit state capable of limitedly operating the work machine <NUM>.

The detection process unit <NUM> detects the object Ob1 in the monitor area A1 around the machine body <NUM>. That is, the detection process unit <NUM> determines whether or not the object Ob1 is present in the monitor area A1, and outputs a detection result showing whether or not the object Ob1 is present in the monitor area A1. Specifically, according to the present embodiment, the detection process unit <NUM> regularly or irregularly acquires outputs of the left camera <NUM>, the right camera <NUM> and the rear camera <NUM> from the left camera <NUM>, the right camera <NUM> and the rear camera <NUM>. That is, the detection process unit <NUM> acquires the image data of the monitor area A1 (each of small areas A11, A12, A13) around the work machine <NUM>. The data acquired by the detection process unit <NUM> is stored in a memory, for example. Then, the detection process unit <NUM> detects the object Ob1 in the monitor area A1, based on the outputs (image data) of the left camera <NUM>, the right camera <NUM> and the rear camera <NUM>.

Specifically, the detection process unit <NUM> applies the image process to the acquired image data thereby to extract a feature quantity in the image, and based on the feature quantity, determines whether or not the object Ob1 ("person" according to the present embodiment) is reflected in the image. Here, when the object Ob1 is reflected in the image, the detection process unit <NUM> determines the object Ob1 is reflected in the image captured by which of the left camera <NUM>, the right camera <NUM> and the rear camera <NUM>. That is, the detection process unit <NUM> distinguishes the object Ob1 is present in which of the small area A11 imaged by the left camera <NUM>, the small area A12 imaged by the right camera <NUM>, and the small area A13 imaged by the rear camera <NUM>, thereby to detect the object Ob1.

The notification process unit <NUM> executes a notification process that provides a notification that is based on the detection result of the detection process unit <NUM>, i.e., the detection result of the object Ob1 in the monitor area A1 around the machine body <NUM>. "The notification" as used in the present disclosure means a notification to the user (human operator) by various measures, including, for example, sound (including voice), display (including lighting of display light), sending to another terminal, or writing in a non-transient recording medium. In the present embodiment, as one example, when the object Ob1 is present in the monitor area A1 around the machine body <NUM>, the notification process unit <NUM> causes the display unit <NUM> of the display unit <NUM> to show a display to that effect, and causes the sound output unit <NUM> to output a notification sound. The notification sound may be a simple beep, or a voice such as a message "Please be careful". Further, the notification content (display content and notification sound) may vary according to the detection result (position of the object Ob1, distance from the machine body <NUM> to the object Ob1, and the like) of the detection process unit <NUM>.

In the limit state, when at least one of the detection item related to the (at-stop) detection result and the operation item related to the operation state of the work machine <NUM> meets the cancelation condition, the cancelation process unit <NUM> executes the cancelation process so as to end the limit state. When the limit process is executed by the limit process unit <NUM> and the work machine <NUM> is in the limit state, at least one of the detection item and the operation item, if meeting the cancelation condition, causes the cancelation process unit <NUM> to end the limit state. When the limit state ends, the state of the work machine <NUM> (or the control system <NUM>) transitions to "the state incapable of operating the work machine <NUM>" or "the state capable of operating the work machine <NUM>". In the present embodiment, as one example, the process, after the end of the limit state, shall transition to the state incapable of operating the work machine <NUM>.

The "detection item" here includes various items related to the at-stop detection result, such as the at-stop detection result itself, such as the object Ob1 being present or not, and the left camera <NUM>, right camera <NUM>, and rear camera <NUM>'s operation statuses related to the detection of the object Ob1. The cancelation conditions for the detection item include, as an example, that the same object Ob1 is detected a plurality of times in the at-stop detection result, that the object Ob1 is moving in the direction approaching the machine body <NUM>, that the object Ob1 is present in a specific position around the machine body <NUM> (for example, a position in the operator's blind spot, or a position within a certain distance from the machine body <NUM>), or that a detection measure (camera and the like) is abnormal (broken). The abnormality in the detection measure includes an abnormality (malfunction or the like) of any of the left camera <NUM>, the right camera <NUM>, the rear camera <NUM>, or an illuminating device that illuminates the monitor area A1, which means that the object Ob1 cannot be detected normally.

The "operation item" here includes various items related to the operation state of the work machine <NUM>, for example, an operation state specific to the operation unit <NUM>. The cancelation condition for the operation item includes, as an example, an emergency stop operated in the operation unit <NUM>, an emergency operation leading to a sudden drive of the work machine <NUM> or a sudden stop of the work machine <NUM> in the operation unit <NUM>, or the human operator's hand away from the operation lever of the operation unit <NUM>.

That is, in the limit state, the cancelation process unit <NUM> is triggered with the above detection item and/or the above operation item meeting the cancelation condition thereby to end the limit state, and switches the state of the work machine <NUM> (or control system <NUM>) to the state incapable of operating the work machine <NUM>. In the present embodiment, as one example, the determination process unit <NUM> performs the determination as to whether or not the cancelation condition is met, and the cancelation process unit <NUM> receives the determination result on the cancelation condition in the determination process unit <NUM> thereby to execute the cancelation process to end the limit process. Here, the cancelation condition is only required to be determined for at least one of the detection item and the operation item; the cancelation condition may be set only for the detection item, only for the operation item, or for both the detection item and the operation item. In the case where the cancelation condition is set for both the detection item and the operation item, the cancelation process unit <NUM> may end the limit state if the cancelation condition for at least any one of the detection item and the operation item is met, or may end the limit state only when the cancelation condition for both the detection item and the operation item is met.

In addition, the cancelation process unit <NUM> forcibly ends the limit state not only when the detection item and/or the operation item meets the cancelation condition, but also when an allowable time has elapsed since the start of the limit state. That is, the limit state ends when the allowable time elapses. Then, in the present embodiment, as one example, even when the allowable time has elapsed, the process, after the end of the limit state, transitions to the state incapable of operating the work machine <NUM>. The "allowable time" here is the upper limit of time for which the limit state can be sustained, and may be a fixed time set regardless of the operation state of the work machine <NUM>, or may be a variable time length that varies depending on the operation content of the work machine <NUM> (for example, the motion speed of the hydraulic actuator). Also, the cancelation process unit <NUM> may advance the count of the allowable time only while the work machine <NUM> is actually operating, and may stop the count of the allowable time while the work machine <NUM> is stopped. In the present embodiment, as one example, the allowable time should be a fixed time (for example, <NUM>, <NUM>, <NUM> seconds or the like).

Hereinafter, an example of a method of controlling the work machine <NUM> (hereinafter, simply referred to as a "control method") mainly executed by the control system <NUM> will be described with reference to <FIG>.

The control method according to the present embodiment is executed by the control system <NUM> mainly constituted by the computer system, and in other words, the control method is embodied in a work machine control program (hereinafter, simply referred to as "control program"). That is, the control program is a computer program for causing one or more processors to execute each process associated with the control method. The above control program may be cooperatively executed by, for example, the control system <NUM> and the display unit <NUM>.

Here, when a specific start operation set in advance so as to cause the control program to be executed, the control system <NUM> executes the following various types of processes associated with the control method. The start operation is, for example, a startup operation (ignition on) of the engine <NUM> of the work machine <NUM>. Meanwhile, when a specific end operation set in advance is executed, the control system <NUM> ends the various types of processes associated with the control method. The end operation is, for example, a stop operation (ignition off) of the engine <NUM> of the work machine <NUM>.

Here, first, the control method according to the present embodiment, that is, a general motion of the control system <NUM> according to the present embodiment will be described, with reference to <FIG>. If it is so considered that there are three states (modes) of the work machine <NUM> (or control system <NUM>): "the state incapable of operating the work machine <NUM>", "the state capable of operating the work machine <NUM>", and "the limit state", these three modes transition as shown in <FIG>. Strictly speaking, the "limit state" is also a kind of "the state capable of operating the work machine <NUM>" in which the gate lock lever <NUM> is in "down position", but <FIG> distinguishes "the state capable of operating the work machine <NUM>" from "the limit state".

The control method according to the present embodiment assumes that the gate lock lever <NUM> is in "up position" and the gate lock switch <NUM> is off, and thereby the object Ob1 around the machine body <NUM> can be detected even in the state incapable of operating the work machine <NUM>. That is, the gate lock lever <NUM> in "up position"" creates the state incapable of operating the work machine <NUM>, but the detection process unit <NUM> of the control system <NUM> continues the process of detecting the object Ob1 around the machine body <NUM>.

Here, the control method according to the present embodiment has acquiring the detection result of the object Ob1 around the machine body <NUM> of the work machine <NUM> in the state incapable of operating the work machine <NUM>, and creating the limit state capable of limitedly operating the work machine <NUM>, when the detection result meets a predetermined condition and then the lever <NUM> is so operated as to create the state capable of operating the work machine <NUM>. That is, when the gate lock lever <NUM> is in "up position" and the work machine <NUM> cannot be operated, the acquisition process unit <NUM> of the control system <NUM> acquires the detection result of the object Ob1 around the machine body <NUM> (at-stop detection result). If the gate lock lever <NUM> is operated from "up position" to "down position" when this detection result meets the predetermined condition, the limit process unit <NUM> of the control system <NUM> creates the limit state capable of limitedly operating the work machine <NUM>.

The control method of the present embodiment further has the following: in the limit state, when at least one of the detection item related to the (at-stop) detection result and the operation item related to the operation state of the work machine <NUM> meets the cancelation condition, the limit state is ended. That is, the cancelation process unit <NUM> of the control system <NUM> ends the limit state when at least one of the detection item and the operation item meets the cancelation condition. Further, the limit state also ends when the allowable time has elapsed, so even if the cancelation condition is not met, the limit state ends when the allowable time elapses after the start of the limit state. After the end of the limit state, the process transitions to the state incapable of operating the work machine <NUM>.

As a result, when the gate lock lever <NUM> is operated to "up position" in "the state capable of operating the work machine <NUM>", the state (mode) of the work machine <NUM> (or the control system <NUM>) transitions to "the state incapable of operating the work machine <NUM>". Conversely, when the gate lock lever <NUM> is operated to "down position" in "the state incapable of operating the work machine <NUM>" without the detection result meeting the predetermined condition, the state (mode) of the work machine <NUM> (or the control system <NUM>) transitions to "the state capable of operating the work machine <NUM>".

When the detection result meets the predetermined condition and the gate lock lever <NUM> is operated to "down position" in "the state incapable of operating the work machine <NUM>", the state (mode) of the work machine <NUM> (or control system <NUM>) transitions to the "limit state". In the "limit state", when at least one of the detection item and the operation item meets the cancelation condition or the allowable time elapses, the "limit state" ends, and the state (mode) of the work machine <NUM> (or the control system <NUM>) transitions to "the state incapable of operating the work machine <NUM>".

Next, the configuration of the display screen Dp1 shown on the display unit <NUM> of the display unit <NUM> by the control method according to the present embodiment will be described with reference to <FIG>. In the drawings showing the display screen Dp1 displayed on the display unit <NUM> of the display unit <NUM>, such as <FIG>, dashed-dotted lines, leading lines, and reference numerals showing regions are merely for illustrative purposes and are not actually displayed on the display unit <NUM>.

As shown in <FIG>, the display screen Dp1 displays captured images Im11, Im12, Im13 of the monitor area A1, and detection result information I1 and I2 and the like showing the detection result of the detection process unit <NUM>. In <FIG>, only a region R1 where the captured images Im11, Im12, Im13 and the like, of monitor area A1, of the display screen Dp1 is shown, and any region other than the region R1 is omitted. The captured image Im11 is an image of the small area A11 that is captured by the left camera <NUM> and that is on the left of the drive unit <NUM>, and the captured image Im12 is an image of the small area A12 that is captured by the right camera <NUM> and that is on the right of the drive unit <NUM>. The captured image Im13 is an image of the small area A13 that is captured by the rear camera <NUM> and that is behind the drive unit <NUM>.

The control system <NUM> causes the captured images Im11, Im12, Im13, which are acquired by the detection process unit <NUM>, to be displayed in real time. An icon Im10, which imitates the machine body <NUM> as seen from the information, is displayed in the center portion of the region R1. The icon Im10 schematically shows the positional relation among the imaging areas (small areas A11, A12, and A13) of the left camera <NUM>, the right camera <NUM> and the rear camera <NUM> as seen from the machine body <NUM>.

The detection result information I1 is a band-shaped (frame-shaped) graphical image that highlights the captured image containing the object Ob1, of the captured images Im11, Im12, Im13. The detection result information I2 is a graphical image showing the direction in which the object Ob1 is present from the viewpoint of the drive unit <NUM>. The example in <FIG> assumes a case where the object Ob1 (in this case, "person") is present in the small area A11 that is captured by the left camera <NUM> and that is on the left of the drive unit <NUM>. Therefore, of the captured images Im11, Im12, Im13, the captured image Im11 is highlighted in the detection result information I1; and the detection result information I2 showing the object Ob1 present on the left of the drive unit <NUM> is displayed below the captured image Im11.

The display mode of the detection result information I1 and I2 is preferably changed according to the position of the object Ob1 in the monitor area A1. For example, the display mode of the detection result information I1 and I2, such as display color, size, or display pattern (including blinking pattern and the like), is changed according to the position of the object Ob1 in the monitor area A1. For example, the closer the object Ob1 is to the machine body <NUM>, the more prominent the display color of the detection result information I1 and I2; as an example, the object Ob1 approaching the machine body <NUM> changes the display color of the detection result information I1 and I2 from yellow to red.

Thus, the display screen Dp1 not only displays the captured images Im11, Im12, Im13 of the monitor area A1, but also displays the detection result of the object Ob1 in the monitor area A1 as the detection result information I1 and I2. Therefore, the human operator (user U1), by viewing the display screen Dp1, can easily check whether or not the object Ob1 is present in the monitor area A1. Therefore, on the display screen Dp1 displayed on the display unit <NUM>, the human operator (user U1) can check the situations at the work machine <NUM>'s sides and rear which are likely to be blind spots from the drive unit <NUM>. Therefore, compared to the configuration in which only the detection result information I1 and I2 are displayed; when the object Ob1 is present in the monitor area A1, it is easier to grasp in detail the situation of the object Ob1 on the display screen Dp1.

Next, details of the control method, i.e., a specific motion of the control system <NUM>, are described with reference to a flowchart in <FIG>.

When the gate lock lever <NUM> is in "down position" and in "the state capable of operating the work machine <NUM>", the control system <NUM> can operate the work machine <NUM> according to the operation of the operation unit <NUM> without any particular limit on the motion of the work machine <NUM>. Meanwhile, when the gate lock lever <NUM> is operated from "down position" to the "up position", the control system <NUM> starts the processes as shown in the flowchart in <FIG>.

That is, as shown in <FIG>, when the gate lock lever <NUM> is operated from "down position" to "up position" as a trigger (S1: Yes), the control system <NUM> starts the processes from step S2 onward. Here, the determination process unit <NUM> of the control system <NUM> determines whether the gate lock lever <NUM> is in "up position" or "down position" by the gate lock switch <NUM> on or off, and therefore determines, by the gate lock switch <NUM> switched from on to off, that the gate lock lever <NUM> is operated to "up position" (S1: Yes ). Here, when the gate lock lever <NUM> is brought to "up position", the gate lock switch <NUM> is turned off and the first control valve <NUM> of the first limit unit <NUM> on the primary pressure side of the pilot oil path is shut off, causing "the state incapable of operating the work machine <NUM>".

In step S2, from the detection process unit <NUM>, the acquisition process unit <NUM> of the control system <NUM> acquires the detection result of the object Ob1 around the machine body <NUM>. That is, based on the outputs of the left camera <NUM>, the right camera <NUM> and the rear camera <NUM>, the detection process unit <NUM> outputs a detection result showing whether or not the object Ob1 is present in the monitor area A1. The acquisition process unit <NUM> acquires the (at-stop) detection result from the detection process unit <NUM>.

In step S3, the determination process unit <NUM> of the control system <NUM> determines whether or not the at-stop detection result meets the predetermined condition. At this time, when the object Ob1 (in this case, a "person") is present in the monitor area A1, the determination process unit <NUM> determines that the at-stop detection result meets the predetermined condition (S3: Yes), and moves the process to step S4. Meanwhile, when the object Ob1 (in this case, a "person") is not present in the monitor area A1, the determination process unit <NUM> determines that the at-stop detection result does not meet the predetermined condition (S3: No), and moves the process to step S10.

In step S4, the notification process unit <NUM> of the control system <NUM> notifies the detection result of the detection process unit <NUM>, i.e., that the object Ob1 is present in the monitor area A1 around the machine body <NUM>. At this time, the notification process unit <NUM> causes the display unit <NUM> of the display unit <NUM> to display the detection result information I1 and I2 (see <FIG>), and causes the sound output unit <NUM> to output the notification sound. Thus, the human operator (user U1) can recognize the object Ob1 present around the machine body <NUM>. However, when the gate lock lever <NUM> is in "up position", i.e., "the state incapable of operating the work machine <NUM>", the notification process unit <NUM> does not have to output the notification sound by the sound output unit <NUM>, for example. This allows the human operator (user U1) to recognize the object Ob1 present around the machine body <NUM>, but is freed from the annoyance caused by the notification sound.

Step S5 determines whether or not the gate lock lever <NUM> is operated from "up position" to "down position". At this time, the determination process unit <NUM> of the control system <NUM> determines whether the gate lock lever <NUM> is in "up position" or "down position" by the gate lock switch <NUM> on or off, and therefore, determines, by the gate lock switch <NUM> switched from off to on, that the gate lock lever <NUM> is operated to "down position" (S5: Yes ), and moves the process to step S6. Meanwhile, when determining that the gate lock lever <NUM> is not operated to "down position" (S5: No), the determination process unit <NUM> moves the process to step S2.

In step S6, the limit process unit <NUM> of the control system <NUM> executes the limit process, and starts the limit state capable of limitedly operating the work machine <NUM>. That is, when the detection result (at-stop detection result) acquired in the state incapable of operating the work machine <NUM> meets the predetermined condition (S3: Yes), when the gate lock lever <NUM> is operated so that the work machine <NUM> can be operated (S5: Yes), the limit process unit <NUM> creates the limit state capable of limitedly operating the work machine <NUM>.

In this case, the limit process unit <NUM> may create the state capable of operating the work machine <NUM> only within a certain time period as the limit state; the present embodiment, however, creates the state capable of operating the work machine <NUM> after imposing a limit on the motion itself of the work machine <NUM>. That is, in the limit state, the work machine <NUM> is operated in the state where the motion mode of the work machine <NUM> is limited. This allows the work machine <NUM> to operate carefully compared to a configuration in which the work machine <NUM> operates fully only within the certain time period. Therefore, it is easier to prevent the work machine <NUM> from being closer or having contact to or with the object Ob1 present around the machine body <NUM>.

More in detail, in the limit state, at least the motion speed of the work machine <NUM> is limited. That is, according to the present embodiment, the limit process unit <NUM> realizes the limit state by slowing down at least the motion speed of the work machine <NUM> (such as the hydraulic actuator) as the motion mode of the work machine <NUM>. For example, when the motion speed of the work machine <NUM> varies according to the operation rate of the operation lever of the operation unit <NUM>; for the same operation rate, the limit process unit <NUM> as a whole limits the motion speed of the work machine <NUM> to several tens of % (as an example, <NUM>% or <NUM>%) relative to the ordinary motion speed of the work machine <NUM>. This prohibits a sudden motion of the work machine <NUM>, making it easier to prevent the work machine <NUM> from being closer or having contact to or with the object Ob1 present around the machine body <NUM>. In addition, the motion speed of the work machine <NUM> is slower than normal, which also serves to alert the human operator (user U1) to the object Ob1 being present around the machine body <NUM>.

Specifically, the motion speed is limited by controlling at least one of the flowrate of the hydraulic pump <NUM> that supplies the hydraulic oil, the speed of the engine <NUM> that drives the hydraulic pump <NUM>, and the pilot pressure. According to the present embodiment, in step S6, the limit process unit <NUM> controls at least one of the flowrate of the hydraulic pump <NUM>, the speed of the engine <NUM> that drives the hydraulic pump <NUM>, and the pilot pressure, thereby to limit the motion speed of the work machine <NUM> and creates the limit state.

That is, the limit process unit <NUM> controls the solenoid proportional valve <NUM> of the flowrate limit unit <NUM> thereby to decrease the pilot pressure input to the control signal input port <NUM> and to decrease an inclination angle of a swash plate of the hydraulic pump <NUM>. As the inclination angle of the swash plate of the hydraulic pump <NUM> decreases, the discharge rate (flowrate) of the hydraulic oil of the hydraulic pump <NUM> decreases, and the motion speed of the hydraulic actuator driven by the hydraulic oil decreases. If the hydraulic pump <NUM> is a variable displacement pump, such control allows the limit process unit <NUM> to easily decrease the motion speed of the work machine <NUM>.

Similarly, the limit process unit <NUM> controls the speed of the engine <NUM> by the engine control unit <NUM> of the flowrate limit unit <NUM>, making it possible to decrease the speed of the engine <NUM> (speed of hydraulic pump <NUM>). As a result, when the speed of the hydraulic pump <NUM> decreases, the discharge rate (flowrate) of the hydraulic oil of the hydraulic pump <NUM> decreases, and the motion speed of the hydraulic actuator driven by the hydraulic oil decreases. In short, switching the speed of the engine <NUM> from high idle speed to low idle speed allows the limit process unit <NUM> to easily decrease the motion speed of the work machine <NUM>. Further, in this case, the fluctuation of a noise of the engine <NUM> can also alert the human operator (user U1) to the object Ob1 being present around the machine body <NUM>.

Similarly, the limit process unit <NUM> controls the second control valve <NUM> of the second limit unit <NUM> thereby to decrease the flowrate of the pilot oil supplied from the pilot pump <NUM> to the remote control valve <NUM>, making it possible to decrease the pilot pressure. As the pilot pressure decreases (depressurizes), an opening amount of a spool of the direction switch valve <NUM> decreases; when the control of the hydraulic pump <NUM> is LS (Load Sensing) control, the decrease in the opening amount of the spool decreases the flowrate of the hydraulic pump <NUM> so as to maintain the LS differential pressure constant, and the motion speed of the hydraulic actuator driven by the hydraulic oil decreases. Even when the control of the hydraulic pump <NUM> is negative control; together with the decrease in the opening of the spool, an opening of a spool to an open center flow path leading to a tank increases, thus increasing a negative control pressure detected downstream. As a result, the flowrate of the hydraulic pump <NUM> decreases, and the motion speed of the hydraulic actuator driven by the hydraulic oil decreases. Further, in the case of positive control; even in the following situation: the gate lock lever <NUM> is in "up position", the operation of the operation unit <NUM> is detected, the flowrate of the hydraulic pump <NUM> is decreased, and the gate lock lever <NUM> is operated to "down position", for example, decrease in the flowrate of the hydraulic pump <NUM> is maintained. With of the above control, the limit process unit <NUM> can easily decrease the motion speed of the work machine <NUM>.

In step S7, the determination process unit <NUM> of the control system <NUM> determines whether or not at least one of the detection item and the operation item meets the cancelation condition. At this time, if there is an abnormality in the detection measure such as the left camera <NUM>, right camera <NUM> or rear camera <NUM>, for example, leading to a state where the object Ob1 cannot be ordinarily detects, the determination process unit <NUM> determines that the detection item meets the cancelation condition (S7: Yes) and moves the process to step S9. Meanwhile, when both of the detection item and the operation item fail to meet the cancelation condition (S7: No), the determination process unit <NUM> moves the process to step S8.

In step S8, the cancelation process unit <NUM> of the control system <NUM> determines whether or not the allowable time has elapsed from the start of the limit state (S6). At this time, the cancelation process unit <NUM> compares the elapsed time from the start of the limit state (S6) with the allowable time; if the elapsed time has reached the allowable time, the cancelation process unit <NUM> determines that the allowable time has elapsed (S8: Yes), and moves the process to step S9. Meanwhile, if the elapsed time has not reached the allowable time, the cancelation process unit <NUM> determines that the allowable time has not elapsed (S8: No), and moves the process to step S7.

In step S9, the cancelation process unit <NUM> of the control system <NUM> ends the limit state. That is, after the start of the limit state (S6), depending on whether the detection item and/or the operation item meets the cancelation condition (S7: Yes), or based on that the allowable time elapses (S8: Yes), the cancelation process unit <NUM> ends the limit state. At this time, the cancelation process unit <NUM> cancels the limit process unit <NUM>'s limiting on the motion mode (motion speed) of the work machine <NUM>. Specifically, when the limit process unit <NUM> is decreasing the flowrate of the hydraulic pump <NUM>, the cancelation process unit <NUM> increases the flowrate of the hydraulic pump <NUM> (for example, to the maximum value). When the limit process unit <NUM> is decreasing the speed of the engine <NUM>, the cancelation process unit <NUM> increases the speed of the engine <NUM>; when the limit process unit <NUM> is decreasing the pilot pressure, the cancelation process unit <NUM> increases the pilot pressure.

According to the present embodiment; when the limit state ends, the state (mode) of the work machine <NUM> (or control system <NUM>) transitions to "the state incapable of operating the work machine <NUM>". Therefore, in step S9, although the limit process unit <NUM>'s limiting on the motion mode (motion speed) of the work machine <NUM> is cancelled, the cancelation process unit <NUM> puts the second control valve <NUM> of the second limit unit <NUM> in a shut-off state, for example, to thereby create "the state incapable of operating the work machine <NUM>". That is, when the second control valve <NUM> is in the shut-off state, even if the gate lock lever <NUM> is in "down position", "the state incapable of operating the work machine <NUM>" is created same as the gate lock lever <NUM> being in "up position".

Step S10 determines whether or not the gate lock lever <NUM> has been operated from "up position" to "down position". At this time, the determination process unit <NUM> of the control system <NUM> determines whether the gate lock lever <NUM> is in "up position" or "down position" by the gate lock switch <NUM> on or off, and therefore determines, by the gate lock switch <NUM> switched from off to on, that the gate lock lever <NUM> is operated to "down position" (S10: Yes), and ends the series of processes by creating "the state capable of operating the work machine <NUM>". Meanwhile, when determining that the gate lock lever <NUM> is not operated to "down position" (S10: No), the determination process unit <NUM> moves the process to step S2.

However, in step S10 in the case where the predetermined condition is determined to be met (S3: Yes), the gate lock lever <NUM> is already in "down position" (S5: Yes). Therefore, in this case, when the gate lock lever <NUM> is operated once to "up position" and then to "down position", it is determined that the gate lock lever <NUM> is operated to "down position" (S10: Yes). Then, the cancelation process unit <NUM> puts the second control valve <NUM> of the second limit unit <NUM> in the open state, thereby switching from "the state incapable of operating the work machine <NUM>" to "the state capable of operating the work machine <NUM>".

The control system <NUM> repeatedly executes the processes in step S1 to step S10. However, the flowchart shown in <FIG> merely constitutes one example, and therefore, the process may appropriately be added or omitted, or the order of the processes may appropriately be changed.

As described above, the control method according to the present embodiment has acquiring the detection result of the object Ob1 around the machine body <NUM> of the work machine <NUM> in the state incapable of operating the work machine <NUM>, and creating the limit state capable of limitedly operating the work machine <NUM>, when the detection result meets the predetermined condition and then the gate lock lever <NUM> is so operated as to create the state capable of operating the work machine <NUM>. Thus, even if the gate lock lever <NUM> is switched to the unlocked state (down position), the object Ob1 being present around the machine body <NUM>, for example, creates the limit state capable of limitedly operating the work machine <NUM>. Therefore, even when the object Ob1 is present around the machine body <NUM>; with the gate lock lever <NUM> operated to the unlocked state (down position), the work machine <NUM> can be operated for the time being. Further, without the human operator (user U1) having to take special care, it is easier to avoid problems such as sudden and vigorous motion of the work machine <NUM>, for example. As a result, it is possible to provide the work machine control system <NUM>, the work machine <NUM>, the method of controlling the work machine <NUM>, and the work machine control program which easily decrease the burden on the human operator related to the operation.

According to the present embodiment, at least one of the detection item related to the detection result and the operation item related to the operation state of the work machine <NUM>, when meeting the cancelation condition in the limit state, ends the limit state. Thus, meeting the specific cancelation condition can forcibly end the limit state. In addition, according to the present embodiment, the limit state ends when the allowable time has elapsed. Thus, the limit state does not last forever, but the limit state is to be applied at least under a time limit. According to the present embodiment, after the end of the limit state, the process transitions to the state incapable of operating the work machine <NUM>. Therefore, when it is unpreferable to continue the motion of the work machine <NUM> even in the limit state, such as an abnormality in the detection measure, the work machine <NUM> can be forcibly stopped after the end of the limit state.

A description will hereinafter be made on modified examples of the first embodiment. The modified examples, which will be described below, can be applied in an appropriate combination.

The control system <NUM> according to the present disclosure includes the computer system. The computer system has, as hardware, one or more processors and one or more memories. The processor, by executing the program recorded in the memory of the computer system, realizes the function as the control system <NUM> in the present disclosure. The program may be preliminarily recorded in the memory of the computer system, may be provided through an electric communication line, or, on a non-transitory recording medium, such as a memory card, an optical disk, a hard disk drive, or the like, that is readable by the computer system, may be recorded and then provided. Further, a part of or all the functional portions included in the control system <NUM> may be composed of an electronic circuit.

A configuration in which at least a part of the functions of the control system <NUM> is integrated in one case is not essential and the components of the control system <NUM> may be provided in a plurality of cases in a distributed manner. Conversely, functions that are distributed to a plurality of devices (such as the control system <NUM> and the display unit <NUM>) in the first embodiment may be integrated in one case. Further, at least a part of the functions of the control system <NUM> may be realized by a cloud (cloud computing) or the like.

The power source of the work machine <NUM> is not limited to the diesel engine, but may be, for example, the engine <NUM> other than the diesel engine, a motor (an electric motor), or a hybrid power source that includes the engine <NUM> and the motor (electric motor).

The display unit <NUM> is not limited to a dedicated device, but may be a general-purpose terminal, such as a laptop computer, a tablet terminal, or a smartphone. Further, the display unit <NUM> is not limited to a mode in which a display screen is directly displayed, such as a liquid crystal display or an organic EL display, but may be a configuration that displays the display screen by projection, such as a projector.

Further, as a mode for inputting information on the operation unit <NUM>, a mode other than the push button switch, the touch screen, and the operation dial may also be employed. For example, the operation unit <NUM> may employ modes of input, such as a keyboard, a pointing device such mouse, a voice input, a gesture input, or an operation signal from another terminal.

The limit state can be any state as long as being capable of limitedly operating the work machine <NUM>, and is not limited to a state limiting the speed of the motion (traveling, switching and the like) of the work machine <NUM>. For example, the limit state may be a state capable of operating the work machine <NUM> only within the certain time period, a state capable of operating the work machine <NUM> only within the certain distance, a state where the moveable range of the hydraulic actuator is limited, a state where the operation target (such as a specific hydraulic actuator) is limited, and a state where the certain operation such as swiveling and expanding of the work machine <NUM> are prohibited, or a combination of these states and the like.

The sensors for detecting the object Ob1 in the monitor area A1 around the machine body <NUM> may include, without limitation, the left camera <NUM>, the right camera <NUM> and the rear camera <NUM>, and may include one, two or four or more cameras (image sensors). Further, for example, a camera that can capture images in all directions as seen from the work machine <NUM>, such as a <NUM>-degree camera, may be used to detect the object Ob1 in the monitor area A1. The sensors for detecting the object Ob1 in the monitor area A1 may include, in addition to or instead of the camera, for example, a motion sensor, a sonar sensor, a radar or LiDAR (Light Detection and Ranging) or the like. The sensor that detects the object Ob1 in the monitor area A1 may be a <NUM>-dimension sensor that measures the distance to the object Ob1 by the TOF (Time Of Flight) method that measures the distance to the distance measurement point based on the round trip time from the arrival of light or sound at the distance measurement point to its return.

The detection process unit <NUM>, which detects the object Ob1 around the machine body <NUM>, is not a component essential to the control system <NUM>. For example, the detection process unit <NUM> may be included in a detection system other than the control system <NUM>; in this case, the acquisition process unit <NUM> of the control system <NUM> acquires, from outside (detection system) of the control system <NUM>, the detection result of the object Ob1 around the machine body <NUM> of the work machine <NUM>.

The object Ob1 may include, in addition to or instead of a "person", a mobile object such as a vehicle (including other work machine), structures such as walls and pillars, plants, animals, steps, ditches, or other obstacles.

It is not essential to move the work machine <NUM> in the limited state limiting the motion mode of the work machine <NUM>. That is, in the limit state, the work machine <NUM> may perform all possible motions only within the certain time period, for example. It is not essential that at least the motion speed of the work machine <NUM> should be limited in the limit state. In addition, it is not essential to limit the motion speed by controlling at least one of the flowrate of the hydraulic pump <NUM> that supplies the hydraulic oil, the speed of the engine <NUM> that drives the hydraulic pump <NUM>, and the pilot pressure.

In the limit state, it is not essential to end the limit state when at least one of the detection item related to the detection result and the operation item related to the operation state of the work machine <NUM> meets the cancelation condition. It is also not essential that the limit state should end after the allowable time has elapsed. It is not essential to perform the transition, after the end of the limit state, to the state incapable of operating the work machine <NUM>. In addition, it is not essential that the notification process unit <NUM> should provide the notification that is based on the detection result of the detection process unit <NUM>, i.e., based on the detection result of the object Ob1 in the monitor area A1 around the machine body <NUM>.

As shown in <FIG>, the control system <NUM> according to the present embodiment differs from the control system <NUM> according to the first embodiment in that the former performs the transition, after the end of the limit state, to the state capable of operating the work machine <NUM>. Hereinafter, the same components as those in the first embodiment will be denoted by the same reference signs, and the description thereof will appropriately be omitted.

That is, in the present embodiment, when the detection item and/or the operation item meets the cancelation condition, or when the allowable time has elapsed from the start of the limit state and the limit state has ended, the process transitions to "the state capable of operating the work machine <NUM>" instead of "the state incapable of operating the work machine <NUM>". Therefore, when the detection result meets the predetermined condition in "the state incapable of operating the work machine <NUM>", the human operator merely needs to once operate the gate lock lever <NUM> from "up position" to "down position" (S5: Yes in <FIG>), then the process automatically transitions to "the state capable of operating the work machine <NUM>" through the limit state. This allows that at least the allowable time having elapsed after the start of the limit state switches the process to "the state capable of operating the work machine <NUM>" without the need of the human operator operating the gate lock lever <NUM> again.

As a modified example of the second embodiment, only when the allowable time has elapsed from the start of the limit state, the process may be transitioned to "the state capable of operating the work machine <NUM>" after the end of the limit state. That is, when the limit state is ended by the detection item and/or the operation item meeting the cancelation condition, the process transitions to "the state capable of operating the work machine <NUM>" as in the first embodiment.

Claim 1:
A work machine control system (<NUM>), comprising:
an acquisition process unit (<NUM>) that acquires a detection result of an object (Ob1) around a machine body (<NUM>) of a work machine (<NUM>) in a state incapable of operating the work machine (<NUM>); and
a limit process unit (<NUM>) characterised in that the limit process unit (<NUM>) creates a limit state capable of limitedly operating the work machine (<NUM>) when the detection result meets a predetermined condition and then a gate lock lever (<NUM>) is so operated as to create a state capable of operating the work machine (<NUM>).