Construction machine

A construction machine includes a posture sensor provided on a front member of a front work implement. An external environment recognition device detects an object around a main body, and a controller calculates a dead angle range from a recognition range of the external environment recognition device. An assumed movement range in which a moving body is assumed to exist in the dead angle range in a period of time determined in advance is calculated; and a movable range within which the front work implement is movable in a period of time determined in advance is calculated on the basis of the posture information detected by the posture sensor. Preventative control is then performed for preventing contact between the moving body and the front work implement on the basis of the assumed movement range of the moving body and the movable range of the front work implement.

TECHNICAL FIELD

The present invention relates to a construction machine.

BACKGROUND ART

In construction machines such as hydraulic excavators in the construction civil engineering industry, as measures for preventing contact of a front work implement, which performs work, with a worker, a technique is available by which the working velocity of the front work implement is controlled as disclosed in Patent Document 1.

Patent Document 1 discloses a swing work machine that includes an attachment attached for swing motion to a track structure (base), a swing mechanism that swings the attachment, a controller that controls the swing mechanism, and an intruding object detection device that detects a position of an intruding object having intruded a working area. The controller controls the swing motion of the attachment on the basis of a first physical quantity that relates at least to an angular velocity of the attachment at the current point of time and an inertial moment of the attachment at the current point of time and the position of the intruding object detected by the intruding object detection device.

PRIOR ART DOCUMENT

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

However, in the conventional technique described above, since this does not take it into consideration that a possibility that a moving body may exist in the dead angle of a detected object, when a moving body appears from the dead angle, the conventional technique cannot deal with this sufficiently.

The present invention has been made taking the foregoing into consideration, and it is an object of the present invention to provide a construction machine that can deal also with a moving body in a dead angle of an object and that can prevent contact between a front work implement and a moving body with a higher degree of certainty.

Means for Solving the Problem

Although the present application includes plural means for solving the subject described above, by way of example, there is provided a construction machine that includes: a main body including a lower track structure and an upper swing structure provided swingably with respect to the lower track structure; a front work implement of articulated type attached to the upper swing structure and including a plurality of front members pivotably connected to each other; and a plurality of actuators that individually drive the plurality of front members of the front work implement, the construction machine including: a posture sensor that is provided on each of the front members of the front work implement and detects posture information of the front member; an external environment recognition device that detects an object around the main body; and a controller configured to calculate a dead angle range that is a range that becomes a dead angle from a recognition range of the external environment recognition device, the dead angle arising from an object recognized by the external environment recognition device, to calculate an assumed movement range that is a range within which a moving body assumed to exist in the dead angle is movable in a period of time determined in advance, to calculate a movable range that is a range within which the front work implement is movable in a period of time determined in advance on a basis of the posture information detected by the posture sensor, and to perform preventive control for preventing contact between the moving body and the front work implement on a basis of the assumed movement range of the moving body and the movable range of the front work implement.

Advantages of the Invention

According to the present invention, the construction machine can deal also with a moving body in a dead angle of an object sufficiently and can prevent contact between the front work implement and a moving body with a higher degree of certainty.

MODES FOR CARRYING OUT THE INVENTION

In the following, embodiments of the present invention are described with reference to the drawings. It is to be noted that, although the embodiments of the present invention are described exemplifying a hydraulic excavator that includes a front work implement as an example of a construction machine, the present invention can be applied also to a wheel loader or other construction machines including a work implement such as a crane.

First Embodiment

A first embodiment of the present invention is described with reference toFIGS.1to13.

FIG.1is a view schematically depicting an appearance of a hydraulic excavator that is an example of a construction machine according to the present embodiment. Further,FIG.2is a side elevational view schematically depicting an appearance of the hydraulic excavator.

Referring toFIGS.1and2, the hydraulic excavator100includes a front work implement24of articulated type configured by connecting a plurality of driven members (a boom8, an arm9, and a bucket (work tool)10), which are individually pivoted in a vertical direction, and an upper swing structure22and a lower track structure20that configure an excavator main body (hereinafter referred to simply “main body”). The upper swing structure22is provided for swing motion on and relative to the lower track structure20through a swing mechanism21. The swing mechanism21includes a swing motor23and a swing angle sensor27. The upper swing structure22is driven to swing with respect to the lower track structure20by the swing motor23, and the swing angle thereof with respect to the lower track structure20is detected by the swing angle sensor27.

The boom8of the front work implement24is supported at a proximal end thereof pivotably in the vertical direction at a front portion of the upper swing structure22. The arm9is supported at one end thereof pivotably in the vertical direction at an end portion (distal end) of the boom8different from the proximal end of the boom8, and the bucket10is supported pivotably in the vertical direction at the other end of the arm9. The boom8, the arm9, the bucket10, the upper swing structure22, and the lower track structure20are driven by a boom cylinder5, an arm cylinder6and a bucket cylinder7which are hydraulic actuators, the swing motor23, and left and right track motors3(note that only one of the track motors is depicted), respectively.

Here, a main body coordinate system is set which has the origin at a point of intersection of a swing central axis25of the upper swing structure22and a lower face of the upper swing structure22and has a z-axis along the swing central axis25with the upper side from the origin as positive, an x-axis that extends in a forward and rearward direction perpendicular to the z-axis with the forward direction from the origin as positive and a y-axis that extends in a leftward and rightward direction perpendicular to the z-axis and the x-axis with the rightward direction from the origin as positive.

A cab2to be boarded by an operator is mounted on the front left side of the upper swing structure22. Further, a controller44for controlling operation of the entire hydraulic excavator100is arranged on the upper swing structure22. The cab2includes operation levers (operation devices)2aand2bfor outputting operation signals for operating the hydraulic actuators5to7and23. Though not depicted, the operation levers2aand2bare individually tiltable forwardly, rearwardly, leftwardly and rightwardly, and each includes a detection device not depicted that electrically detects a tilting amount of a lever which is an operation signal, namely, a lever operation amount. A lever operation amount detected by the detection device is outputted to the controller44(hereinafter described) through an electric line. Specifically, operations of the hydraulic actuators5to7and23are individually allocated to the forward and backward directions or the leftward and rightward directions of the operation levers2aand2b.

Motion control of the boom cylinder5, the arm cylinder6, the bucket cylinder7, the swing motor23, and the left and right track motors3is performed by controlling directions and flow rates of hydraulic operating oil supplied from a hydraulic pump apparatus which is driven by a prime mover such as an engine or an electric motor not depicted, to the hydraulic actuators3,5to7and23, using control valves or the like. The control valves are controlled in operation by the controller44on the basis of operation signals from the operation levers2aand2b, and operation of the hydraulic actuators5to7and23is controlled by the control valves.

Posture sensors34A,34B, and34C are attached to a proximal portion of the boom8, a connection portion between the boom8and the arm9, and a connection portion between the arm9and the bucket10, respectively. The posture sensors34A,34B, and34C are mechanical angle sensors, for example, like potentiometers. As depicted inFIG.3, the posture sensor34A measures an angle β1defined by the longitudinal direction of the boom8(straight line connecting the centers of pivotal motion at the opposite ends) and the x-y plane and transmits the angle β1to the controller44. Meanwhile, the posture sensor34B measures an angle β2defined by the longitudinal direction of the boom8(straight line connecting the centers of pivotal motion at the opposite ends) and the longitudinal direction of the arm9(straight line connecting the centers of pivotal motion at the opposite ends) and transmits the angle β2to the controller44. Further, the posture sensor34C measures an angle β3defined by the longitudinal direction of the arm9(straight line connecting the centers of pivotal motion at the opposite ends) and the longitudinal direction of the bucket10(straight line connecting the center of pivotal motion and a claw tip) and transmits the angle β3to the controller44. Here, the swing angle sensor27and the posture sensors34A to34C configure a posture sensor60that detects posture information of the upper swing structure22and the front work implement24.

It is to be noted that, although the present embodiment described here exemplifies a case in which the swing center38of the front work implement24(connection portion of the boom8to the upper swing structure22) is arranged at a position different from the swing central axis25, the swing central axis25and the swing center38may be arranged so as to intersect with each other.

Further, although the present embodiment described here exemplifies a case in which an angle sensor or the like is used as the posture sensor60, an inertial measurement device (IMU: Inertial Measurement Unit) may be used for the swing angle sensor27and the posture sensors34A to34C. Also such a configuration may be applied that a stroke sensor is arranged on each of the boom cylinder5, the arm cylinder6, and the bucket cylinder7such that relative orientations (posture information) at the individual connection portions of the upper swing structure22, the boom8, the arm9, and the bucket10are calculated from stroke change amounts and the individual angles are calculated from results of the calculation.

On the upper swing structure22, a plurality of (for example, four) external environment recognition devices26for detecting an object around the excavator main body (the upper swing structure22and the lower track structure20) are arranged on the upper swing structure22. The locations and the number of the external environment recognition devices26to be arranged are not specifically restricted to examples of present embodiment, and it is sufficient if the omnidirectional field of view of the main body (namely, the field of view of 360 degrees around the hydraulic excavator100) can be assured. The present embodiment described here exemplifies a case in which the four external environment recognition devices26are arranged at an upper portion of the cab2and a left side portion, a right side front portion, and a right side rear portion of the upper swing structure22such that the field of view of 360 degrees around the main body is covered. The external environment recognition devices26are sensors for which, for example, the LiDAR (Laser Imaging Detection and Ranging, laser image detection and distance measurement) technique is used, and detect an object existing around the hydraulic excavator100(for example, an obstacle14hereinafter described) and transmit coordinate data of the object to the controller44.

FIG.3is a functional block diagram schematically depicting part of processing functions of the controller incorporated in the hydraulic excavator. Meanwhile,FIG.4is a functional block diagram depicting part of the functions inFIG.3in detail.

Referring toFIGS.3and4, the controller44includes a decision section31, an operation range calculation section35, a dead angle calculation section37and a moving body course prediction section45. Meanwhile, the operation range calculation section35includes a posture calculation section43, a swing angle calculation section48, a velocity limit area calculation section50, a front work implement velocity calculation section51, and an angular velocity calculation section52. Further, the velocity limit area calculation section50includes a braking distance calculation section30and a braking time calculation section49.

Referring toFIG.3, the dead angle calculation section37calculates a dead angle from a relative positional relation to the upper swing structure22obtained from the external environment recognition devices26. The operation range calculation section35calculates a braking period of time on the basis of information obtained from the posture sensor60, transmits the braking period of time to the moving body course prediction section45, and transmits an operation range of the main body to the decision section31. The calculation performed by the operation range calculation section35is hereinafter described in detail. The moving body course prediction section45decides from the obtained position and shape of a dead angle16whether or not there is a possibility that a moving body such as a worker may be hidden in the dead angle16. Further, the moving body course prediction section45calculates an assumed movement range41from the obtained braking period of time, the assumed movement range41being a range within which the moving body may move in a period in which braking of the front work implement24is completed. Then, the moving body course prediction section45transmits the assumed movement range41to the decision section31. The decision section31limits the velocity of a work device33or decides whether or not an alarm device59is to be operated on the basis of the information obtained by the moving body course prediction section45and the operation range calculation section35. Details of the calculation of the decision section31are hereinafter described.

Referring toFIG.4, the posture calculation section43calculates the length of the front work implement24on the basis of the angle information of the boom8, the arm9, and the bucket10obtained by the posture sensors34and transmits the length of the front work implement24to the velocity limit area calculation section50. Further, the front work implement velocity calculation section51calculates the velocity at which the front work implement24is to move (front work implement velocity), on the basis of fluctuations of the angles of the boom8, the arm9, and the bucket10obtained by the posture sensors34and transmits the velocity to the velocity limit area calculation section50. Further, the swing angle calculation section48calculates a turning angle of an own vehicle13where the forward direction of the lower track structure20is determined as 0 degrees and the left turn direction of the upper swing structure22is determined as positive, and transmits the turning angle to the velocity limit area calculation section50. Further, the angular velocity calculation section52calculates the angular velocity of the front work implement24, on the basis of the changing velocity of the swing angle inputted from the swing angle sensor27and transmits the angular velocity to the velocity limit area calculation section50. The velocity limit area calculation section50is configured from the braking distance calculation section30and the braking time calculation section49. The braking distance calculation section30calculates a braking distance of the front work implement24from the front work implement length obtained by the posture calculation section43, the moving velocity of the front work implement24obtained by the front work implement velocity calculation section51, the swing angle obtained by the swing angle calculation section48, and the angular velocity obtained from the angular velocity calculation section52, and transmits the braking distance to the decision section31. Further, the braking time calculation section49calculates a braking period of time of the front work implement24from the front work implement length obtained by the posture calculation section43, the moving velocity of the front work implement24obtained by the front work implement velocity calculation section51, the swing angle obtained by the swing angle calculation section48, and the angular velocity obtained by the angular velocity calculation section52, and transmits the braking period of time to the moving body course prediction section45.

The controller44configured in such a manner as described above calculates a dead angle area (dead angle16) that is a range that becomes a dead angle by an object recognized by the external environment recognition devices26from the recognition range of the external environment recognition device and calculates an assumed movement range41that is a range in which a moving body39assumed to exist in the dead angle is movable in a period of time determined in advance. Further, the controller44calculates a movable range that is a range in which the front work implement24is movable in a period of time determined in advance, on the basis of the posture information detected by the posture sensor60and performs preventive control for preventing contact between the moving body39and the front work implement24, on the basis of the assumed movement range41of the moving body39and the movable range of the front work implement24.

FIG.13is a flow chart depicting the contents of processing for prevention control.

Referring toFIG.13, the controller44first decides whether or not there is present an obstacle (step S101). When the decision result is YES, the controller44detects the posture of the hydraulic excavator main body (step S102) and performs dead angle range calculation of calculating a dead angle caused by the obstacle (step S103).

Then, the controller44decides whether or not there is a possibility that a moving body may be hidden in the dead angle (step S104). When the decision result is YES, the controller44performs braking time calculation of calculating braking time of the front work implement24(step S105), performs a motion range calculation process of calculating a motion range of the front work implement24(step S106), and performs assumed movement range calculation of calculating a relative movement range of the moving body (step S107).

Then, the controller44decides whether or not there is a possibility that the moving body and the front work implement24may contact with each other (step S108). When the decision result is YES, the controller44determines a limit velocity relating to the driving of the front work implement24(step S109), and performs activation of the alarm device59and control operation of the working velocity (step S110).

Then, the controller44decides whether or not the main body is stopped (step S111), and when the decision result is NO, the process at step S110is repeated until the decision result becomes YES. On the other hand, when the decision result at S111is YES, the controller44ends the processing.

Further, when the decision result at any of steps S101, S104and S108is NO, the processing is ended.

Such preventive control as described above is described in more detail.

First, a calculation method of a front work implement length R and a bucket height Zb depicted inFIG.2is described. The front work implement length R is a distance R from the swing central axis25to the distal end of the front work implement24. The lengths of the boom8, the arm9, and the bucket10are represented by L1, L2, and L3, respectively. The angle β1defined by the x-y plane and the longitudinal direction of the boom8is measured by the posture sensor34A. The angle β2defined by the boom8and the arm9and the angle β3defined by the arm9and the bucket10are measured by the posture sensors34B and34C, respectively. The height Z0from the x-y plane to the swing center38is obtained in advance. Also the distance L0from the swing central axis25to the swing center38is obtained in advance.

An angle β2adefined by the xy plane and the longitudinal direction of the arm9can be calculated from the angle β1and the angle β2. An angle β3bdefined by the xy plane and the longitudinal direction of the bucket10can be calculated from the angle β1, and the angles β2and β3. The bucket height Zb and the front work implement length R can be calculated by the following (expression 1) and (expression 2), respectively.
Zb=Z0+L1 sinβ1+L2 sinβ2+L3 sinβ3:  (expression 1)
R=L0+L1 cosβ1+L2 cosβ2+L3 cosβ3:  (expression 2)

Now, a calculation method of the dead angle16performed by the controller44of the first working example according to the present invention is described with reference toFIGS.5to11. First, a dead angle calculation method on the xy plane is described with reference toFIG.5. On the basis of the coordinates of the obstacle14obtained by the external environment recognition devices26, relative angles θxya and θxyb and relative distances XA and XB between the own vehicle13on the xy plane and the opposite left and right end portions14A and14B of the obstacle14are calculated by an obstacle position calculation section36in the controller44. On the basis of these pieces of information, the dead angle calculation section37calculates whether or not a dead angle16arising from the obstacle14exists. In this case, the dead angle16points to a range indicated by slanting lines, and when the front face side of the detected obstacle14is determined as the forward direction, the dead angle calculation section37recognizes a region behind the position at which the obstacle14is detected as the dead angle16. In particular, when the distances from the external environment recognition devices26to the opposite left and right end portions14A and14B of the obstacle14are represented by XA and XB, respectively, the dead angle calculation section37recognizes the rear of a range of the angle θxy defined by the distances XA and XB from the external environment recognition devices26to the end portions of the obstacle14as the dead angle16. It is to be noted that, when the size of the dead angle16is smaller than a general moving body (worker)39, the dead angle calculation section37may determine that there is no dead angle16. This can avoid excessive intervention for control.

Now, a dead angle detection method on the xy plane is described with reference toFIGS.6to8.

When the height Z of the detected obstacle14is equal to the height Zs at which the external environment recognition device26is arranged as depicted inFIG.6, the height of the dead angle16is defined as the height Z. The rear of a range of the angle θxz defined by the distances XC and XD from the external environment recognition device26to the upper and lower end portions14C and14D of the obstacle14is recognized as the dead angle16.

On the other hand, when the height Z of the obstacle14is lower than the height Zs at which the external environment recognition device26is arranged as depicted inFIG.7, the depth of the obstacle14can be calculated on the basis of end portions14C,14D, and14E of the obstacle14. Here, since the opposite ends of the obstacle14are given by14D and14E, the dead angle16has an angle given by the distances XD and XE to the end portions14D and14E of the obstacle14. Since, by arranging the external environment recognition device26at a position higher than the obstacle14, it is possible to detect the depth of the obstacle14, it is desirable to arrange the external environment recognition devices26at a position as high as possible. In addition, also when it is difficult to arrange the external environment recognition devices26at a high position, where the height of the detected height Z is not a height at which the moving body (worker)39can be hidden, the control may not be carried out.

On the other hand, when the height Z of the detected obstacle14is higher than the height Zs at which the external environment recognition device26is arranged as depicted inFIG.8, within a range of an angle θxzs that is the sum of θxza and δxzb where θxza is an angle between the upper end portion14C of the obstacle14and the height Zs of the external environment recognition devices26and δxzb is an angle between the lower end portion14D of the obstacle14and the height Zs of the external environment recognition devices26, a region behind the obstacle14is recognized as the dead angle16.

Now, a case in which the bucket10of the own vehicle13becomes a dead angle16is described with reference toFIGS.9to11.

As depicted inFIG.9, depending upon the arrangement place of the external environment recognition device26, there may occur a case in which the bucket10of the own vehicle13becomes a dead angle16. As depicted inFIG.9, depending upon the posture of the hydraulic excavator100, the bucket10obstructs the visual field of the external environment recognition device26and forms a dead angle16. In this case, where the external environment recognition device26can partly recognize the obstacle14through the bucket10, the bucket10is not decided as a dead angle16.

Moreover, as depicted inFIG.10, when the external environment recognition device26is arranged at an upper portion of the cab2, a dead angle16is formed also on the xy plane. Therefore, for example, by arranging an external environment recognition device26on the upper swing structure22on the opposite side to the front work implement24as viewed from the cab2side, the range of the dead angle16can be narrowed as depicted inFIG.11In this case, the dead angle16is recognized as a dead angle in a range of an angle θb from a dead angle line cross over point58, which is a point at which both dead angle lines15of the external environment recognition devices26aand26bcross with each other, to the distance of the distal end portions57A and57B of the bucket. Here, the angle θb is the sum of θAb and θBb.

Now, a calculation method of a velocity limit area40, a position at which the moving body (worker)39may exist, a calculation technique of the assumed movement range41, how to cope with a dead angle by the bucket10and a control method of the work device33are described with reference toFIG.12.

It is assumed that the angular velocity of the front work implement24at the current point of time is co and the front work implement length is R as depicted inFIG.12. In this case, the angle θt (braking angle) over which the front work implement24swings after a point of time at which the brake for stopping the swing is operated until the front work implement24stops can be calculated, from tθ (swing braking time) that represents a period of time required until the front work implement24is braked where maximum braking force is applied, α that represents a swing acceleration, and θt0that represents an initial angle, according to the following (expression 3).
θt=θt0+ω×tθ+(α×tθ{circumflex over ( )}2)/2:  (expression 3)

Further, the distance xt (forward braking distance) over which the front work implement24stops after a point of time at which the brake for stopping the movement in the forward direction is rendered operative can be calculated from the forward velocity v, tx representing a period of time (forward-rearward braking time period) from a point of time at which the brake for stopping the movement in the forward or rearward direction is operated to a point of time at which the front work implement24stops and a representing a deceleration acceleration according to the following (expression 4).
xt=v×tx+(a×tx{circumflex over ( )}2)/2:  (expression 4)

Therefore, when the forward braking distance is represented by xt, the length of the front work implement is represented by R, and the value of the sum of the distance L0from the swing central axis25to the swing center38is represented by Rxt, the velocity limit area40is set to a range over which the radius of this Rxt is swung by θt. Further, the velocity limit area40when the front work implement24moves rearwardly is set to a range over which the radius given by the front work implement length R is swung by θt.

Now, a calculation method of the assumed movement range41of the moving body (worker)39is described. It is assumed that the moving body (worker)39existing in the dead angle16exists at a position at which it contacts with a surface line42interconnecting the opposite left and right end portions14A and14B of the obstacle14and both of the dead angle lines15. In this case, the assumed movement range41of the moving body (worker)39depends upon the walking time period of the moving body (worker)39and the distance r over which the moving body (worker)39may move. The walking time period of the moving body (worker)39is selectively set to a value of a longer period of time among periods of time taken until the front work implement24is braked in the forward or rearward direction and in the swinging direction. Meanwhile, the distance r over which the moving body (worker)39may move is defined as a distance over which, when the walking speed of the moving body (worker)39is an average walking speed of an adult, the moving body (worker)39walks for a period of time taken for the movement. Therefore, the assumed movement range41is a range in which the distance r over which the worker may move is rotated by 360 degrees from the surface of the moving body (worker)39.

Further, a countermeasure against a dead angle by the bucket10is described. If a dead angle16is formed by the bucket10, it is possible to complement a dead angle range using information before formation of a dead angle obtained by the external environment recognition devices26thereby to suppress application of excessive control.

The decision section31decides whether or not the assumed movement range41calculated by the moving body course prediction section45and the velocity limit area40calculated by the operation range calculation section35overlap with each other. When the assumed movement range41and the velocity limit area40calculated by the operation range calculation section35seem to overlap with each other, the decision section31transmits velocity limit to the work device33or operates the alarm device59. By providing such a decision section31as described, a contact probability with a moving body appearing from the dead angle16can be reduced. Further, it is also possible to provide a margin to the velocity limit area40such that, when the assumed movement range41overlaps with the margin, the alarm device59is operated and, when the velocity limit area40and the assumed movement range41seem to overlap with each other, velocity limit is applied to the work device33.

Advantageous effects of the present embodiment configured in such a manner as described above are described.

In construction machines such as hydraulic excavators in the construction civil engineering industry, as measures for preventing contact of a front work implement which performs work, with a worker, a technique is available by which the working velocity of the front work implement is limited. However, in the conventional technique described above, since this does not take it into consideration that a possibility that a moving body may exist in the dead angle of a detected object, when a moving body appears from the dead angle, the conventional technique cannot deal with this sufficiently.

In contrast, in the present embodiment, a construction machine that includes a main body configured from a lower track structure and an upper swing structure provided swingably with respect to the lower track structure, a front work implement of articulated type attached to the main body and configured from a plurality of front members pivotably connected to each other, and a plurality of actuators that individually drive the plurality of front members of the front work implement, includes a posture sensor that is provided on each of the front members of the front work implement and detects posture information of the front member, an external environment recognition device that detects an object around the main body, and a controller that calculates a dead angle range that is a range that becomes a dead angle from a recognition range of the external environment recognition device, the dead angle arising from an object recognized by the external environment recognition device, that calculates an assumed movement range that is a range within which a moving body assumed to exist in the dead angle is movable in a period of time determined in advance, that calculates a movable range that is a range within which the front work implement is movable in a period of time determined in advance on the basis of the posture information detected by the posture sensor, and that performs preventive control for preventing contact between the moving body and the front work implement on the basis of the assumed movement range of the moving body and the movable range of the front work implement. Therefore, the construction machine can deal also with a moving body in a dead angle of an object and can prevent contact between the front work implement and a moving body with a higher degree of certainty.

Second Embodiment

A second embodiment of the present invention is described with reference toFIGS.14and15.

In the first embodiment, the external environment recognition devices26is used to calculate a dead angle16from a relative distance to and a relative angle with respect to an obstacle14. However, in the present embodiment, the hydraulic excavator includes a position measurement device46that measures the position of an own vehicle13on the basis of, for example, GPS signals and a wireless communication device47that receives information of the position of the obstacle14detected by another vehicle18, the position of the other vehicle18and the orientation of the main body. The wireless communication device47transmits the information obtained from the other vehicle18to the dead angle calculation section37, and the dead angle calculation section37calculates, on the basis of information of the external environment recognition devices26, the position measurement device46, and the wireless communication device47, a dead angle16, a position at which a moving body may exist, and an assumed movement range41of a moving body (worker)39.

FIG.14is a functional block diagram schematically depicting part of processing functions of a controller incorporated in a hydraulic excavator according to the present embodiment. Meanwhile,FIG.15is a view illustrating calculation of a dead angle in the present embodiment. InFIG.14, like members to those in the first embodiment are denoted by like reference numerals, and description of them is omitted.

As depicted inFIG.14, the position measurement device46transmits a coordinate position of the own vehicle13to the dead angle calculation section37, for example, on the basis of GPS signals. Further, the wireless communication device47receives information of the external environment recognition devices26obtained by the other vehicle18, the coordinate position of the other vehicle18, and the orientation of the main body of the other vehicle18and transmits them to the dead angle calculation section37. The dead angle calculation section37calculates the dead angle16on the basis of the information of the position measurement device46, the wireless communication device47, and the external environment recognition devices26of the own vehicle13and transmits the dead angle16to the moving body course prediction section45.

As depicted inFIG.15, for example, when the other vehicle18exists at a position at which it can detect a side portion of the obstacle14from the inside or the outside of a working range17, the other vehicle18transmits the coordinate position of the vehicle and the orientation of the main body of the vehicle through the wireless communication device47. The own vehicle13receives the information obtained by the other vehicle18through the wireless communication device47, and the dead angle calculation section37calculates a positional relation with the own vehicle13from the coordinate positions of the own vehicle13and the other vehicle18. Further, the dead angle calculation section37calculates the position of the obstacle14detected by the other vehicle18and the dead angle16from the orientation of the main body of the other vehicle18. Here, the dead angle16of the obstacle14detected by the own vehicle13is represented by a range of dead angle lines15a, and the dead angle16of the obstacle14detected by the other vehicle18is represented by a range of dead angle lines15b.

Further, the dead angle calculation section37compares the dead angle16calculated on the basis of the information obtained by the own vehicle13with the dead angle16calculated on the basis of the information of the other vehicle18. If the range decided as the dead angle16by the own vehicle13has been able to be detected by the other vehicle18, then the dead angle calculation section37does not recognize the range as the dead angle16. As a result, for working and a swing motion to a direction detected by the other vehicle18, the necessity to carry out velocity limit is eliminated.

The configuration of the other part is similar to that in the first embodiment.

In this manner, also in the present embodiment, advantageous effects similar to those in the first embodiment can be achieved.

Third Embodiment

A third embodiment of the present invention is described with reference toFIGS.16to18.

In the second embodiment, the external environment recognition devices26uses the technique for obtaining coordinate data of the LiDAR or the like to obtain a relative distance and a relative angle with respect to the obstacle14, and further calculates the dead angle16from the position measurement device46that measures the position of the own vehicle13and the position information of the other vehicle18obtained from the wireless communication device47and the relative distance and the relative angle to the obstacle14. However, in the present embodiment, the hydraulic excavator includes a position estimation device that measures the position of the own vehicle13, an image discrimination device53that captures an image of the object14using a camera or the like, a wireless communication device47that receives information from the other vehicle18through wireless communication, an external environment recognition devices26that transmits the relative distance and the relative angle with respect to the obstacle14to the obstacle discrimination device54, and the obstacle discrimination device54that discriminates the obstacle14on the basis of these pieces of information, and the obstacle discrimination device54additionally incorporates a function for recognizing the obstacle14as the other vehicle18on the basis of these pieces of information and deciding a vehicle model.

FIG.16is a functional block diagram schematically depicting part of processing functions of a controller incorporated in a hydraulic excavator in the present embodiment. Further,FIG.17is a view illustrating calculation of a dead angle in the present embodiment, andFIG.18is a view illustrating an assumed movement range of a moving body in the present embodiment. In the figures, like members to those in the first and second embodiments are denoted by like reference characters, and description of them is omitted.

As depicted inFIG.16, the position measurement device46transmits the coordinate of the own vehicle13to the obstacle discrimination device54. Further, the image discrimination device53captures an image of the obstacle14and transmits the image to the obstacle discrimination device54. The wireless communication device47transmits position information and vehicle model information of the other vehicle18in which the position measurement device46is incorporated, to the obstacle discrimination device54. The obstacle discrimination device54compares the image acquired from the image discrimination device53with images of construction machines stored in advance therein to discriminate whether or not the obstacle14is the other vehicle18. Further, the obstacle discrimination device54calculates a positional relation between the own vehicle13and the other vehicle18from the position of the own vehicle13obtained from the position measurement device46and the position information of the other vehicle18obtained from the wireless communication device47. Then, when the position of the obstacle14obtained from the external environment recognition devices26coincides with the calculated position of the other vehicle18, the obstacle discrimination device54recognizes that the obstacle14is the other vehicle18.

As depicted inFIG.17, since the type of the obstacle14can be discriminated through use of the image discrimination device53and the obstacle discrimination device54, it is possible to deem a fixed distance in the rear as the obstacle14to narrow the dead angle16. As a result, the position at which the moving body (worker)39may possibly exist can be narrowed, and the probability that the assumed movement range41of the moving body (worker)39may overlap with the velocity limit area40can be reduced.

Here, it is assumed that the position of the moving body (worker)39existing in the dead angle16exists at a position that contacts with a side face56of the obstacle14and a dead angle line15and that approaches nearest to the own vehicle13. Further, when it is difficult to discriminate the obstacle14or when the obstacle14is not any registered one, the range of the dead angle is decided according to the dead angle detection method of the working example 1.

The configuration of the other part is similar to that of the first and second embodiments.

Also in the present embodiment configured in such a manner as described above, similar advantageous effects to those by the first and second embodiments can be achieved.

It is to be noted that the present invention is not limited to the embodiments described above and includes various modifications and combinations without departing from the gist of present invention. Further, the present invention is not limited to what includes all configurations described hereinabove in connection with the embodiments and includes what does not include part of the configurations. Further, the configurations, functions, and so forth described above may partly or entirely be implemented, for example, by designing them in an integrated circuit. Further, the configurations, functions, and so forth described above may be implemented by software such that a processor interprets and executes a program for implementing the individual functions.

DESCRIPTION OF REFERENCE CHARACTERS