Work machine and diagnostic method

Abstract

This work machine comprises an obstacle sensor, a position sensor that detects the self-position, and a processor. The processor acquires an other-vehicle position indicating the position of another vehicle traveling in a work site, and diagnoses the obstacle sensor on the basis of detection data of the obstacle sensor, the self-position, and the other-vehicle position.

Description

Work machine and diagnostic method

[0001] The present disclosure relates to a work machine and a diagnostic method.

[0002] In the technical field related to work machines, a work vehicle as disclosed in Patent Document 1 is known. In Patent Document 1, the work vehicle includes a detection device (obstacle sensor) that non-contact detects an object around the work vehicle. In the inspection work of the detection device, a reflection member called a target is used. In the inspection work of the detection device using the target, the target is installed at a determined position with respect to the detection device. The inspection work is often carried out only once a day, for example.

[0003] International Publication No. 2015 / 162800

[0004] If an abnormality occurs in the obstacle sensor, it may interfere with the work of the work machine. Therefore, a technology that can detect an abnormality or a sign of an abnormality in the obstacle sensor is desired.

[0005] An object of the present disclosure is to diagnose an obstacle sensor.

[0006] According to the present disclosure, a work machine is provided that includes an obstacle sensor, a self-position sensor that detects its own position, and a processor. The processor acquires the position of another vehicle indicating the position of another vehicle traveling at the work site, and diagnoses the obstacle sensor based on the detection data of the obstacle sensor, the self-position, and the position of the other vehicle.

[0007] According to the present disclosure, the obstacle sensor can be diagnosed.

[0008] Figure 1 is a schematic diagram showing a work site according to the embodiment. Figure 2 is a schematic diagram showing a work site management system according to the embodiment. Figure 3 is a perspective view showing a dump truck according to the embodiment. Figure 4 is a diagram showing an obstacle sensor positioned at the front of the vehicle body according to the embodiment. Figure 5 is a diagram for explaining the actual detection area of ​​a radar sensor according to the embodiment. Figure 6 is a diagram for explaining the actual detection area of ​​one radar sensor according to the embodiment. Figure 7 is a diagram for explaining the actual detection area of ​​a laser sensor according to the embodiment. Figure 8 is a hardware configuration diagram showing the controller of the dump truck according to the embodiment. Figure 9 is a functional block diagram showing the management system according to the embodiment. Figure 10 is a diagram for explaining the driving data of a dump truck according to the embodiment. Figure 11 is a diagram for explaining the detection area set in the actual detection area of ​​a radar sensor according to the embodiment. Figure 12 is a diagram for explaining the detection area set in the actual detection area of ​​a laser sensor according to the embodiment. Figure 13 is a diagram for explaining the success or failure of light vehicle detection according to the embodiment. Figure 14 is a diagram for explaining the success or failure of light vehicle detection according to the embodiment. Figure 15 is a diagram for explaining the relationship between the detection area and a light vehicle according to the embodiment. Figure 16 is a diagram illustrating the relationship between a dump truck and a light vehicle according to the embodiment. Figure 17 is a diagram illustrating the relationship between a dump truck and a light vehicle according to the embodiment. Figure 18 is a flowchart illustrating the diagnostic method of the obstacle sensor according to the embodiment. Figure 19 is a diagram illustrating the aggregated results of the success or failure of light vehicle detection according to the embodiment.

[0009] The embodiments of this disclosure will be described below with reference to the drawings, but this disclosure is not limited to these embodiments. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0010] [Work Site] Figure 1 is a schematic diagram showing a work site 1 according to an embodiment. A mine or quarry is an example of a work site 1. A mine is a place or business establishment where minerals are extracted. A quarry is a place or business establishment where stone materials are extracted. Examples of mines include metal mines where metals are extracted, non-metallic mines where limestone is extracted, and coal mines where coal is extracted.

[0011] Multiple machines operate at work site 1. Examples of machines include a transport machine that carries cargo, a loading machine that loads cargo onto the transport machine, and an excavator that excavates at least a portion of work site 1. The excavator can perform leveling work to flatten the ground at work site 1.

[0012] In this embodiment, a dump truck 2, an example of a transport machine, a shovel 3, an example of a loading machine, and a bulldozer 4 and a motor grader 5, examples of excavating machines, operate at the work site 1. The dump truck 2 has a dump body. The dump truck 2 can load cargo onto its dump body and perform transport operations. The shovel 3 has an implement. The shovel 3 can perform loading and excavation operations using its implement. The bulldozer 4 and the motor grader 5 each have an implement. The bulldozer 4 and the motor grader 5 each can perform leveling operations using their implements.

[0013] A loading area 6, a soil removal area 7, and a transport route 8 are provided at the work site 1. Each of the loading area 6, soil removal area 7, and transport route 8 is a work area where the work machinery operates.

[0014] Loading area 6 refers to the work area where loading operations are carried out to load cargo onto dump truck 2. An example of cargo is excavated material excavated in loading area 6. Excavator 3 performs excavation and loading operations in loading area 6.

[0015] The soil removal area 7 is the work area where the soil removal operation is carried out, in which the dump truck 2 unloads its cargo. A crusher 9 may be installed in the soil removal area 7. The bulldozer 4 performs leveling work in the soil removal area 7. The bulldozer 4 may also perform leveling work in the loading area 6.

[0016] The transport path 8 refers to the road on which the dump truck 2 travels. The transport path 8 leads to the loading area 6 and the soil removal area 7, respectively. The transport path 8 is provided to connect at least the loading area 6 and the soil removal area 7. The dump truck 2 traveling towards at least one of the loading area 6 and the soil removal area 7 travels along the transport path 8. The dump truck 2 travels along the transport path 8, for example, by going back and forth between the loading area 6 and the soil removal area 7. The motor grader 5 performs leveling work on the transport path 8.

[0017] Each of the dump truck 2, shovel 3, bulldozer 4, and motor grader 5 may be either an unmanned or manned work machine. An unmanned work machine is a work machine that performs work without operator operation. A manned work machine is a work machine that performs work based on operator operation. In this embodiment, the dump truck 2 is an unmanned work machine. Each of the shovel 3, bulldozer 4, and motor grader 5 is a manned work machine.

[0018] Furthermore, a light vehicle 10 travels within the work site 1. A light vehicle 10 is a lightweight vehicle that travels within the work site 1. The external dimensions of the light vehicle 10 are smaller than those of the dump truck 2. The weight of the light vehicle 10 is lighter than that of the dump truck 2. The light vehicle 10 can travel within the loading area 6, the soil removal area 7, and the transport route 8. The light vehicle 10 travels to inspect the work site 1 and to transport workers. The light vehicle 10 may be an unmanned vehicle or a manned vehicle. A manned vehicle is a vehicle that travels based on driving operations by a driver. An unmanned vehicle is a vehicle that travels without a driver. In this embodiment, the light vehicle 10 is a manned vehicle.

[0019] [Management System] Figure 2 is a schematic diagram showing the management system 11 of a work site 1 according to an embodiment. The management system 11 manages the work site 1. The management system 11 manages the work machinery. The management system 11 manages the light vehicles 10. In Figure 2, a dump truck 2 is shown as work machinery. The management system 11 manages not only the dump truck 2, but also the shovel 3, bulldozer 4, and motor grader 5. In the following description, for the sake of simplicity, an example in which the management system 11 manages the dump truck 2 and the light vehicles 10 will be described.

[0020] The management system 11 comprises a management device 12 and a communication system 13. The management device 12 includes a computer. The management device 12 is located outside the dump truck 2 and the light vehicle 10. The management device 12 is installed in the control facility 14 at the work site 1. The communication system 13 includes at least one of the following: the internet, a mobile phone network, a satellite network, and a local area network (LAN).

[0021] The light vehicle 10 includes a controller 15 and a wireless communication device 13A. The controller 15 includes a computer. The wireless communication device 13A is connected to the controller 15.

[0022] The dump truck 2 has a controller 16 and a wireless communication device 13B. The controller 16 includes a computer. The wireless communication device 13A is connected to the controller 16.

[0023] The communication system 13 includes a wireless communication device 13A for the light vehicle 10, a wireless communication device 13B for the dump truck 2, and a wireless communication device 13C connected to the management device 12. The management device 12 and the controller 15 of the light vehicle 10 communicate wirelessly via the communication system 13. The management device 12 and the controller 16 of the dump truck 2 communicate wirelessly via the communication system 13.

[0024] [Dump Truck] Figure 3 is a perspective view showing a dump truck 2 according to an embodiment. As shown in Figures 2 and 3, the dump truck 2 comprises a vehicle body 17, a running gear 18, a dump body 19, and an obstacle sensor 20. The vehicle body 17 includes a vehicle frame. The vehicle body 17 is supported by the running gear 18. The running gear 18 supports the vehicle body 17 and travels around the work site 1. The dump body 19 is the component into which the cargo is loaded. The dump body 19 is supported by the vehicle body 17.

[0025] The running gear 18 includes wheels 18A and tires 18B mounted on the wheels 18A. There are four wheels 18A. Two of the wheels 18A are front wheels mounted on the front of the vehicle body 17. Two of the wheels 18A are rear wheels mounted on the rear of the vehicle body 17. The tires 18B are in contact with the ground at the work site 1. The running gear 18 is driven by power generated by an engine (not shown). The running gear 18 is braked by the operation of a brake device (not shown). The running gear 18 turns by a steering device (not shown).

[0026] The dump body 19 performs dumping and lowering operations. Dumping refers to the operation of tilting the dump body 19 in the dumping direction, separating it from the vehicle body 17. Lowering refers to the operation of bringing the dump body 19 closer to the vehicle body 17. When performing soil removal work, the dump body 19 performs a dumping operation to remove the load, and then lowers to return to its original position.

[0027] When the dump truck 2 is moving straight, the direction parallel to the axis of rotation of the wheel 18A is the left-right direction of the dump truck 2. The left-right direction is the width direction of the dump truck 2. The direction perpendicular to the contact surface of the tire 18B that contacts the ground is the up-down direction of the dump truck 2. The directions perpendicular to both the left-right direction and the up-down direction are the front-rear direction of the dump truck 2. In this embodiment, the direction parallel to a predetermined plane that includes a left-right axis parallel to the left-right direction and a front-rear axis parallel to the front-rear direction is appropriately referred to as the planar direction. The predetermined plane is substantially parallel to the contact surface of the tire 18B.

[0028] [Obstacle Sensor] The obstacle sensor 20 detects objects in its vicinity without contact. The obstacle sensor 20 detects objects in its vicinity without contact. The obstacle sensor 20 detects objects by emitting energy waves. Examples of obstacle sensors 20 include a laser sensor (LiDAR: Light Detection and Ranging) that detects objects by emitting laser light, a radar sensor (RADAR: Radio Detection and Ranging) that detects objects by emitting radio waves, and an ultrasonic sensor (Ultrasonic Sensor) that detects objects by emitting ultrasonic waves. The obstacle sensor 20 can detect the presence or absence of an object, its relative position to the object (relative distance and direction), and its relative velocity to the object.

[0029] The obstacle sensor 20 is fixed to the vehicle body 17. Multiple obstacle sensors 20 are provided. Multiple obstacle sensors 20 are positioned at the front of the vehicle body 17. At least one obstacle sensor 20 is positioned at the rear of the vehicle body 17. The obstacle sensor 20 positioned at the front of the vehicle body 17 detects at least objects in front of the dump truck 2. The obstacle sensor 20 positioned at the rear of the vehicle body 17 detects at least objects behind the dump truck 2.

[0030] Figure 4 shows an obstacle sensor 20 arranged at the front of the vehicle body 17 according to the embodiment. As shown in Figures 3 and 4, a plurality of obstacle sensors 20 are arranged at the lower part of the front of the vehicle body 17. The plurality of obstacle sensors 20 are arranged in the left-right direction. In the embodiment, the obstacle sensor 20 includes a plurality of radar sensors 21 (RADAR) and a plurality of laser sensors 22 (LiDAR). Note that the obstacle sensor 20 may include either a plurality of radar sensors 21 (RADAR) or a plurality of laser sensors 22 (LiDAR). The obstacle sensor 20 may include one radar sensor 21 (RADAR) and one laser sensor 22 (LiDAR). The obstacle sensor 20 may include either one radar sensor 21 (RADAR) or one laser sensor 22 (LiDAR).

[0031] In this embodiment, five radar sensors 21 are provided at the front of the vehicle body 17. The five radar sensors 21 are arranged with spacing between them in the left-right direction. The radar sensors 21 include a central radar sensor 21C located in the center of the vehicle body 17 in the left-right direction, a first left radar sensor 21L1 located to the left of the central radar sensor 21C, a second left radar sensor 21L2 located to the left of the first left radar sensor 21L1, a first right radar sensor 21R1 located to the right of the central radar sensor 21C, and a second right radar sensor 21R2 located to the right of the first right radar sensor 21R1.

[0032] The laser sensor 22 is positioned outside the radar sensor 21 in the left-right direction. In this embodiment, two laser sensors 22 are provided at the front of the vehicle body 17. The laser sensor 22 includes a left laser sensor 22L positioned to the left of the second left radar sensor 21L2 and a right laser sensor 22R positioned to the right of the second right radar sensor 21R2.

[0033] Figure 5 is a diagram illustrating the actual detection area 23 of the radar sensor 21 according to this embodiment. As described with reference to Figure 4, five radar sensors 21 (21C, 21L1, 21L2, 21R1, 21R2) are arranged at the front of the vehicle body 17. A rear radar sensor 21B is arranged at the rear of the vehicle body 17 as a radar sensor 21.

[0034] The actual detection area 23 refers to the actual detection area of ​​the radar sensor 21. The actual detection area 23 is the area to which the radar sensor 21 can emit radio waves. Radio waves emitted from the radar sensor 21 spread in both the planar and vertical directions. The actual detection area 23 spreads in both the planar and vertical directions as it moves away from the radar sensor 21. The actual detection area 23 of the radar sensors 21 (21C, 21L1, 21L2, 21R1, 21R2) located at the front of the vehicle body 17 is formed to extend at least in front of the dump truck 2. The actual detection area 23 of the radar sensor 21 (21B) located at the rear of the vehicle body 17 is formed to extend at least in rearward of the dump truck 2.

[0035] The size and shape of the actual detection area 23 are known data that can be derived, for example, from the specifications data of the radar sensor 21. Alternatively, the size and shape of the actual detection area 23 may be derived, for example, by a measurement process that measures the size and shape of the actual detection area 23.

[0036] Each of the multiple radar sensors 21 has a detection area 23. The detection area 23 includes the detection area 23C of the central radar sensor 21C, the detection area 23L1 of the first left radar sensor 21L1, the detection area 23L2 of the second left radar sensor 21L2, the detection area 23R1 of the first right radar sensor 21R1, the detection area 23R2 of the second right radar sensor 21R2, and the detection area 23B of the rear radar sensor 21B. The detection area 23C is formed to extend forward from the center of the front of the vehicle body 17. At least a portion of the detection area 23L1 is formed to the left of the detection area 23C. The detection area 23L1 is formed to extend forward and to the left from the front of the vehicle body 17. At least a portion of the detection area 23L2 is formed to the left of the detection area 23L1. Actual detection area 23L2 is formed to extend forward and to the left from the front of the vehicle body 17. At least a portion of actual detection area 23R1 is formed to the right of actual detection area 23C. Actual detection area 23R1 is formed to extend forward and to the right from the front of the vehicle body 17. At least a portion of actual detection area 23R2 is formed to the right of actual detection area 23R1. Actual detection area 23R2 is formed to extend forward and to the right from the front of the vehicle body 17. Actual detection area 23B is formed to extend rearward from the center of the rear of the vehicle body 17.

[0037] Figure 6 is a diagram illustrating the actual detection area 23 of a radar sensor 21 according to an embodiment. The radar sensor 21 can be set to a first range mode for detecting objects located close to the radar sensor 21 and a second range mode for detecting objects located far from the radar sensor 21. When the radar sensor 21 is set to the first range mode, radio waves are emitted from the radar sensor 21 so that the actual detection area 23 becomes the first actual detection area 23N. When the radar sensor 21 is set to the second range mode, radio waves are emitted from the radar sensor 21 so that the actual detection area 23 becomes the second actual detection area 23F. The distance from the radar sensor 21 to the tip of the second actual detection area 23F is longer than the distance from the radar sensor 21 to the tip of the first actual detection area 23N. The spread angle of the first actual detection area 23N in the planar direction is greater than the spread angle of the second actual detection area 23F.

[0038] Figure 7 is a diagram illustrating the actual detection area 24 of the laser sensor 22 according to this embodiment. As described with reference to Figure 4, two laser sensors 22 (22L, 22R) are arranged at the front of the vehicle body 17.

[0039] The actual detection area 24 refers to the actual detection area of ​​the laser sensor 22. The actual detection area 24 is the area to which the laser sensor 22 can emit laser light. The laser light emitted from the laser sensor 22 spreads in both the planar and vertical directions. The actual detection area 24 spreads in both the planar and vertical directions as it moves away from the laser sensor 22. The actual detection area 24 of the laser sensor 22 positioned at the front of the vehicle body 17 is formed to extend at least in front of the dump truck 2.

[0040] The size and shape of the actual detection area 24 are known data that can be derived, for example, from the specifications data of the laser sensor 22. Alternatively, the size and shape of the actual detection area 24 may be derived, for example, by a measurement process that measures the size and shape of the actual detection area 24.

[0041] Each of the multiple laser sensors 22 has a detection area 24. The detection area 24 includes the detection area 24L of the left laser sensor 22L and the detection area 24R of the right laser sensor 22R. The detection area 24L is formed to extend forward and to the left from the left side of the front of the vehicle body 17. The detection area 24R is formed to extend forward and to the right from the right side of the front of the vehicle body 17. Parts of the detection areas 24L and 24R overlap in front of the vehicle body 17.

[0042] [Controller] Figure 8 is a hardware configuration diagram showing the controller 16 of the dump truck 2 according to the embodiment. The controller 16 includes a computer. The controller 16 has a processor 31 such as a CPU (Central Processing Unit), a main memory 32 including non-volatile memory such as ROM (Read Only Memory) and volatile memory such as RAM (Random Access Memory), a storage 33, an input / output interface 34 including input / output circuits, and a communication interface 35 including communication circuits. The functions of the controller 16 are stored in the storage 33 as a computer program 36. The processor 31 reads the computer program 36 from the storage 33, loads it into the main memory 32, and executes processing according to the computer program 36. The computer program 36 may be distributed to the controller 16 via a network.

[0043] Similar to the controller 16, the management device 12 and the controller 15 of the light vehicle 10 each include a computer. The management device 12 and the controller 15 of the light vehicle 10 each also have a processor, main memory, storage for storing computer programs, an input / output interface, and a communication interface.

[0044] FIG. 9 is a functional block diagram showing the management system 11 according to the embodiment. The dump truck 2 includes a controller 16, an obstacle sensor 20, a position sensor 25, an azimuth sensor 26, a speed sensor 27, and a traveling device 18. Each of the obstacle sensor 20, the position sensor 25, the azimuth sensor 26, and the traveling device 18 is connected to the controller 16. The light vehicle 10 includes a controller 15 and a position sensor 28. The position sensor 28 is connected to the controller 15.

[0045] The position sensor 25 detects its own position. The position sensor 25 is disposed on the vehicle body 17 of the dump truck 2. The position sensor 25 detects the position of the dump truck 2. The position sensor 25 detects the position of the dump truck 2 using a global navigation satellite system (GNSS: Global Navigation Satellite System). The global navigation satellite system includes a global positioning system (GPS: Global Positioning System). The global navigation satellite system detects a position in a global coordinate system defined by coordinate data of latitude, longitude, and altitude. The global coordinate system refers to a coordinate system fixed to the earth. The position sensor 25 includes a GNSS receiver disposed on the vehicle body 17. The position sensor 25 detects the position of the dump truck 2 in the global coordinate system. In the following description, the position of the dump truck 2 detected by the position sensor 25 is appropriately referred to as its own position.

[0046] The orientation sensor 26 detects the orientation of the dump truck 2. The orientation sensor 26 is arranged on the vehicle body 17 of the dump truck 2. The orientation of the dump truck 2 includes an orientation angle with respect to a reference orientation. The reference orientation is, for example, north. As the orientation sensor 26, an inertial sensor (IMU: Inertial Measurement Unit) is exemplified. Note that the orientation sensor 26 may include an arithmetic unit that calculates the orientation from position data detected by two GNSS antennas provided on the dump truck 2. The arithmetic unit can calculate the orientation from the vector connecting the two GNSS antennas. The orientation sensor 26 may detect the inclination angle of the dump truck 2 with respect to the horizontal plane. When the orientation sensor 26 is an inertial sensor (IMU), the inclination angle of the dump truck 2 with respect to the horizontal plane can be detected.

[0047] The speed sensor 27 detects the traveling speed of the dump truck 2. The speed sensor 27 detects the traveling speed of the dump truck 2 by detecting, for example, the rotational speed of a drive shaft connected to the wheel 18A.

[0048] The position sensor 28 detects the position of the light vehicle 10. The position sensor 28 is arranged on the light vehicle 10. The position sensor 25 includes a GNSS receiver arranged on the light vehicle 10. The position sensor 28 detects the position of the light vehicle 10 in the global coordinate system. In the following description, the position of the light vehicle 10 detected by the position sensor 28 is appropriately referred to as the position of the other vehicle.

[0049] Each of the controller 16 and the management device 12 has a plurality of functional units. The functions of the functional units of the controller 16 are exerted by the processor 31 of the controller 16. The functions of the functional units of the management device 12 are exerted by the processor of the management device 12.

[0050] The functional unit of the management device 12 includes a driving data generation unit 38 and an other vehicle position communication unit 39. The functional unit of the controller 16 includes a driving data acquisition unit 41, a control unit 42, a detection area setting unit 43, an other vehicle position acquisition unit 44, an object position calculation unit 45, a diagnostic unit 46, and a storage unit 47. The function of the storage unit 47 is performed by the storage unit 33 of the controller 16.

[0051] The driving data generation unit 38 generates driving data indicating the driving conditions of the dump truck 2. The driving conditions of the dump truck 2 include the target position of the dump truck 2, the target direction of the dump truck 2, and the target driving speed of the dump truck 2. The driving data generation unit 38 transmits the generated driving data to the controller 16 of the dump truck 2.

[0052] The other vehicle position communication unit 39 acquires the position of the light vehicle 10 that is traveling through the work site 1. The controller 15 of the light vehicle 10 transmits the detection data from the position sensor 28 to the management device 12. The detection data from the position sensor 28 indicates the position of the other vehicle. The other vehicle position communication unit 39 acquires the other vehicle position from the controller 15 of the light vehicle 10. The other vehicle position communication unit 39 transmits the other vehicle position transmitted from the controller 15 to the controller 16 of the dump truck 2.

[0053] The driving data acquisition unit 41 acquires driving data transmitted from the driving data generation unit 38. The control unit 42 outputs control commands to control the driving device 18 of the dump truck 2 based on the driving data.

[0054] Figure 10 is a diagram illustrating the driving data of a dump truck 2 according to an embodiment. In this embodiment, the dump truck 2 is an unmanned work machine (unmanned vehicle). The driving data of the dump truck 2 defines the driving conditions of the dump truck 2. The driving data of the dump truck 2 includes the driving point 50, the driving path 51, the target position of the dump truck 2, the target direction of the dump truck 2, and the target driving speed of the dump truck 2.

[0055] Multiple travel points 50 are set at the work site 1. Each travel point 50 defines the target position of the dump truck 2. For each of the multiple travel points 50, the target direction and target travel speed of the dump truck 2 are set. The multiple travel points 50 are set at intervals. The intervals between the travel points 50 may be uniform or uneven.

[0056] The target position of dump truck 2 refers to the target position of dump truck 2 when it passes through point 50. The target position of dump truck 2 may be defined in the dump truck 2's local coordinate system or in the global coordinate system. The target bearing of dump truck 2 refers to the target bearing of dump truck 2 when it passes through point 50. The target driving speed of dump truck 2 refers to the target driving speed of dump truck 2 when it passes through point 50.

[0057] The driving path 51 refers to a virtual line indicating the target driving route of the dump truck 2. The driving path 51 is defined by a trajectory that passes through multiple driving points 50. The dump truck 2 travels around the work site 1 according to the driving path 51. The dump truck 2 travels such that the center of the dump truck 2 and the driving path 51 coincide in the width direction of the dump truck 2.

[0058] The control unit 42 controls the running gear 18 so that the dump truck 2 travels according to the travel path 51, based on the detection data from the position sensor 25 and the orientation sensor 26. Specifically, the control unit 42 controls the running gear 18 so that the deviation between the detected position of the dump truck 2 detected by the position sensor 25 and the target position of the dump truck 2 set at the travel point 50 is reduced when passing through the travel point 50. The control unit 42 controls the running gear 18 so that the deviation between the detected orientation of the dump truck 2 detected by the orientation sensor 26 and the target orientation of the dump truck 2 set at the travel point 50 is reduced when passing through the travel point 50. The control unit 42 controls the running gear 18 so that the dump truck 2 travels at the target travel speed, based on the detection data from the speed sensor 27. Specifically, the control unit 42 controls the running gear 18 so that the deviation between the detected travel speed of the dump truck 2 detected by the speed sensor 27 and the target travel speed of the dump truck 2 set at the travel point 50 is reduced when passing through the travel point 50.

[0059] The detection area setting unit 43 sets the detection area 61 to the actual detection area 23 of the radar sensor 21. The detection area setting unit 43 sets the detection area 62 to the actual detection area 24 of the laser sensor 22.

[0060] Figure 11 is a diagram illustrating a detection area 61 set in the actual detection area 23 of the radar sensor 21 according to an embodiment. The detection area setting unit 43 sets the detection area 61 in the actual detection area 23. The detection area setting unit 43 sets the detection area 61 so that it does not extend beyond the actual detection area 23. At least a part of the outline of the detection area 61 may coincide with the outline of the actual detection area 23. The outline of the detection area 61 may be located inside the actual detection area 23. The shape of the detection area 61 and the shape of the actual detection area 23 may coincide or be similar. The size (area) of the detection area 61 and the size (area) of the actual detection area 23 may coincide or be approximate. The size and shape of the detection area 61 can be arbitrarily determined. The size and shape of the detection area 61 are predetermined and stored in the storage unit 47.

[0061] As shown in Figure 11, the detection area 61 includes detection area 61C set in actual detection area 23C, detection area 61L1 set in actual detection area 23L1, detection area 61L2 set in actual detection area 23L2, detection area 61R1 set in actual detection area 23R1, detection area 61R2 set in actual detection area 23R2, and detection area 61B set in actual detection area 23B.

[0062] The detection area 61C is set so as not to extend beyond the actual detection area 23C. At least a portion of the outline of the detection area 61C may coincide with the outline of the actual detection area 23C. The outline of the detection area 61C may be located inside the actual detection area 23C. The shape of the detection area 61C and the shape of the actual detection area 23C may coincide or be similar. The size (area) of the detection area 61C and the size (area) of the actual detection area 23C may coincide or be approximate. The same applies to detection areas 61L1, 61L2, 61R1, 61R2, and 61B.

[0063] The detection area setting unit 43 divides the detection area 61 (61C, 61L1, 61L2, 61R1, 61R2) into a plurality of divided areas. The detection area setting unit 43 divides the detection area 61 into a plurality of divided areas in the planar direction. The detection area setting unit 43 divides the detection area 61 into a plurality of divided areas at least in the direction of propagation of radio waves emitted from the radar sensor 21. The direction of propagation of radio waves is substantially the front-to-back direction. The divided area includes a first divided area and a second divided area set at a position further from the radar sensor 21 than the first divided area. The detection area setting unit 43 divides the detection area 61 into a first divided area and a second divided area further from the radar sensor 21 than the first divided area.

[0064] In the example shown in Figure 11, detection area 61C is divided into division area 61CN and division area 61CF, which is further from the central radar sensor 21C than division area 61CN. Detection area 61L1 is divided into division area 61L1N and division area 61L1F, which is further from the first left radar sensor 21L1 than division area 61L1N. Detection area 61L2 is divided into division area 61L2N and division area 61L2F, which is further from the second left radar sensor 21L2 than division area 61L2N. Detection area 61R1 is divided into division area 61R1N and division area 61R1F, which is further from the first right radar sensor 21R1 than division area 61R1N. The detection area 61R2 is divided into division area 61R2N and division area 61R2F, which is further from the second right radar sensor 21R2 than division area 61R2N. The detection area 61B is divided into division area 61BN and division area 61BF, which is further from the rear radar sensor 21B than division area 61BN.

[0065] Figure 12 is a diagram illustrating a detection area 62 set in the actual detection area 24 of the laser sensor 22 according to the embodiment. The detection area setting unit 43 sets the detection area 62 in the actual detection area 24. The detection area setting unit 43 sets the detection area 62 so that it does not extend beyond the actual detection area 24. At least a part of the outline of the detection area 62 may coincide with the outline of the actual detection area 24. The outline of the detection area 62 may be located inside the actual detection area 24. The shape of the detection area 62 and the shape of the actual detection area 24 may coincide or be similar. The size (area) of the detection area 62 and the size (area) of the actual detection area 24 may coincide or be approximate. The size and shape of the detection area 62 can be arbitrarily determined. The size and shape of the detection area 62 are predetermined and stored in the storage unit 47.

[0066] As shown in Figure 12, the detection area 62 includes a detection area 62L set in the actual detection area 24L and a detection area 62R set in the actual detection area 24R.

[0067] The detection area 62L is set so as not to extend beyond the actual detection area 24L. At least a portion of the outline of the detection area 62L may coincide with the outline of the actual detection area 24L. The outline of the detection area 62L may be located inside the actual detection area 24L. The shape of the detection area 62L and the shape of the actual detection area 24L may coincide or be similar. The size (area) of the detection area 62L and the size (area) of the actual detection area 24L may coincide or be approximate. The same applies to the detection area 62R.

[0068] The detection area setting unit 43 divides the detection area 62 (62L, 62R) into multiple sub-areas. The detection area setting unit 43 divides the detection area 62 into multiple sub-areas in the planar direction. The detection area setting unit 43 divides the detection area 62 into multiple sub-areas at least in the direction of propagation of the laser light emitted from the laser sensor 22. The detection area setting unit 43 divides the detection area 62 into multiple sub-areas in a direction perpendicular to the direction of propagation of the laser light. The direction of propagation of the laser light is substantially the front-to-back direction. The direction perpendicular to the direction of propagation of the laser light is substantially the left-to-right direction.

[0069] In the example shown in Figure 12, the detection area 62L is divided into a divided area 62LCN, a divided area 62LCF that is further from the left laser sensor 22L than divided area 62LCN, a divided area 62LLN to the left rear of divided area 62LCN, a divided area 62LLF that is further from the left laser sensor 22L than divided area 62LLN, a divided area 62LRN to the right of divided area 62LCN, and a divided area 62LRF that is further from the left laser sensor 22L than divided area 62LRN.

[0070] The detection area 62R is divided into division area 62RCN, division area 62RCF which is further from the right laser sensor 22R than division area 62RCN, division area 62RRN which is to the right rear of division area 62RCN, division area 62RRF which is further from the right laser sensor 22R than division area 62RRN, division area 62RLN which is to the left of division area 62RCN, and division area 62RLF which is further from the right laser sensor 22R than division area 62RLN.

[0071] The other vehicle position acquisition unit 44 acquires the position of the light vehicle 10 that is traveling through the work site 1. The other vehicle position acquisition unit 44 acquires the other vehicle position transmitted from the other vehicle position communication unit 39.

[0072] The object position calculation unit 45 calculates the object position, which indicates the location of the object detected by the obstacle sensor 20, based on the detection data from the obstacle sensor 20 and the self-position of the dump truck 2 detected by the position sensor 25. In this embodiment, the object position calculation unit 45 calculates the object position in the global coordinate system based on the detection data from the obstacle sensor 20, the detection data from the position sensor 25, and the detection data from the orientation sensor 26.

[0073] The diagnostic unit 46 diagnoses the obstacle sensor 20 based on the detection data from the obstacle sensor 20, its own position detected by the position sensor 25, and the position of other vehicles detected by the position sensor 28. The diagnostic unit 46 determines whether the light vehicle 10 is located in at least one of the detection area 61 and detection area 62 of the obstacle sensor 20, based on the self-position detected by the position sensor 25 and the position of other vehicles detected by the position sensor 28. The diagnostic unit 46 diagnoses the obstacle sensor 20 based on the detection data from the obstacle sensor 20 when it determines that the light vehicle 10 is located in at least one of the detection area 61 and detection area 62 of the obstacle sensor 20.

[0074] In this embodiment, the diagnostic unit 46 diagnoses the obstacle sensor 20 based on the detection data from the obstacle sensor 20, the detection data from the position sensor 25, the detection data from the position sensor 28, and the detection data from the compass sensor 26. The diagnostic unit 46 determines whether the light vehicle 10 is present in at least one of the detection area 61 and detection area 62 of the obstacle sensor 20 based on its own position detected by the position sensor 25, the position of other vehicles detected by the position sensor 28, and the direction of the dump truck 2 detected by the compass sensor 26. The diagnostic unit 46 diagnoses the obstacle sensor 20 based on the detection data from the obstacle sensor 20 when it has determined that the light vehicle 10 is present in at least one of the detection area 61 and detection area 62 of the obstacle sensor 20. In this embodiment, diagnosing the obstacle sensor 20 includes determining whether the obstacle sensor 20 successfully detected the light vehicle 10.

[0075] [Success or Failure of Light Vehicle Detection] Figures 13 and 14 are diagrams illustrating the process for determining the success or failure of light vehicle detection according to the embodiment. In the following description, for the sake of simplicity, the process for determining the success or failure of light vehicle detection by the right laser sensor 22R will be described.

[0076] At work site 1, at least one of the dump truck 2 and the light vehicle 10 is in motion. As shown in Figure 13, when at least one of the dump truck 2 and the light vehicle 10 is in motion, the light vehicle 10 may enter the detection area 62R of the right laser sensor 22R. Figure 13 shows an example in which the light vehicle 10 enters the divided area 62RCF of the detection area 62R.

[0077] The right laser sensor 22R detects objects present around the dump truck 2. The right laser sensor 22R detects objects present in the detection area 62R. The right laser sensor 22R can detect the relative position (relative distance and orientation) of objects present in the detection area 62R. When the right laser sensor 22R detects an object, the object position calculation unit 45 can calculate the object position 72, which indicates the position of the object detected by the right laser sensor 22R, based on the detection data from the right laser sensor 22R and the self-position of the dump truck 2 detected by the position sensor 25. The object position calculation unit 45 can calculate the object position 72 in the global coordinate system based on the detection data from the right laser sensor 22R, the self-position of the dump truck 2 detected by the position sensor 25, and the orientation of the dump truck 2 detected by the orientation sensor 26.

[0078] The other vehicle position acquisition unit 44 receives the other vehicle position 71, which indicates the position of the light vehicle 10 detected by the position sensor 28, from the management device 12. The other vehicle position acquisition unit 44 acquires the other vehicle position 71 in the global coordinate system. The diagnostic unit 46 can determine whether the light vehicle 10 is located in the detection area 62R of the right laser sensor 22R based on the dump truck 2's own position detected by the position sensor 25, the orientation of the dump truck 2 detected by the orientation sensor 26, and the other vehicle position 71 of the light vehicle 10 acquired by the other vehicle position acquisition unit 44.

[0079] When the diagnostic unit 46 determines that the light vehicle 10 is present in the detection area 62R, and determines that the distance between the object position 72 and the other vehicle position 71 is less than or equal to a predetermined distance threshold, the right laser sensor 22R determines that it has successfully detected the light vehicle 10. In this embodiment, the other vehicle position acquisition unit 44 sets a determination circle 70 centered on the other vehicle position 71 in the planar direction. The radius 70R of the determination circle 70 corresponds to the distance threshold. When the diagnostic unit 46 determines that the object position 72 is inside the determination circle 70, the right laser sensor 22R determines that it has successfully detected the light vehicle 10.

[0080] The size of the determination circle 70 is larger than the outer shape of the light vehicle 10. The light vehicle 10 is positioned inside the determination circle 70. The range inside the determination circle 70 is the range in which the light vehicle 10 can be considered to exist. When the position of the other vehicle 71 moves, the determination circle 70 also moves. The radius 70R of the determination circle 70 corresponds to a distance threshold and is predetermined. The size of the radius 70R may be changed based on the relative speed between the dump truck 2 and the light vehicle 10. The higher the relative speed between the dump truck 2 and the light vehicle 10, the larger the radius 70R may be.

[0081] When it is determined that the light vehicle 10 is present in the detection area 62R based on the position of the other vehicle 71, if the right laser sensor 22R detects the other vehicle position 71 or an object near the other vehicle position 71, that is, if the object position 72 is inside the determination circle 70, the object detected by the right laser sensor 22R can be considered to be the light vehicle 10. The other vehicle position 71 is known data detected by the position sensor 28. When it is determined that the light vehicle 10 is present in the detection area 62R based on the position of the other vehicle 71, and the right laser sensor 22R detects the other vehicle position 71 or an object near the other vehicle position 71, the diagnostic unit 46 determines that the right laser sensor 22R has successfully detected the light vehicle 10.

[0082] When it is determined that the light vehicle 10 is present in the detection area 62R based on the position of the other vehicle 71, if the right laser sensor 22R detects an object that is far from the position of the other vehicle 71, that is, if the object's position 72 is outside the determination circle 70, the object detected by the right laser sensor 22R cannot be considered the light vehicle 10. When it is determined that the light vehicle 10 is present in the detection area 62R based on the position of the other vehicle 71, if the right laser sensor 22R detects an object that is far from the position of the other vehicle 71, the diagnostic unit 46 determines that the right laser sensor 22R has failed to detect the light vehicle 10.

[0083] As shown in Figure 14, even though the light vehicle 10 is in the detection area 62R, the right laser sensor 22R may not be able to detect the object. The inability of the right laser sensor 22R to detect an object includes the inability of the object position calculation unit 45 to calculate the object position 72. When the right laser sensor 22R does not detect an object after determining that the light vehicle 10 is in the detection area 62R based on the position of other vehicles 71, the diagnostic unit 46 determines that the right laser sensor 22R has failed to detect the light vehicle 10.

[0084] The diagnostic unit 46 determines whether the right laser sensor 22R has successfully detected the light vehicle 10 for each of the multiple divided areas. In the example shown in Figures 13 and 14, when the diagnostic unit 46 determines that the light vehicle 10 is present in the divided area 62RCF based on the position of the other vehicle 71, and determines that the distance between the object position 72 and the position of the other vehicle 71 is less than or equal to the distance threshold, the diagnostic unit 46 determines that the right laser sensor 22R has successfully detected the light vehicle 10 in the divided area 62RCF. When the diagnostic unit 46 determines that the light vehicle 10 is present in the divided area 62RCF based on the position of the other vehicle 71, and determines that the distance between the object position 72 and the position of the other vehicle 71 exceeds the distance threshold, the diagnostic unit 46 determines that the right laser sensor 22R has failed to detect the light vehicle 10 in the divided area 62RCF. When the diagnostic unit 46 determines that the light vehicle 10 is present in the divided area 62RCF based on the position of other vehicles 71, and the right laser sensor 22R does not detect an object, the diagnostic unit 46 determines that the right laser sensor 22R has failed to detect the light vehicle 10 in the divided area 62RCF.

[0085] Similarly, when the diagnostic unit 46 determines, based on the position of other vehicles 71, that the light vehicle 10 is located in one of the divided areas (62RCN, 62RRN, 62RRF, 62RLN, 62RLF) of the detection area 62R of the right laser sensor 22R, it determines whether the right laser sensor 22R successfully detected the light vehicle 10 in the divided area (62RCN, 62RRN, 62RRF, 62RLN, 62RLF).

[0086] The above describes an example of diagnosing the right laser sensor 22R. As mentioned above, multiple obstacle sensors 20 are provided. The diagnostic unit 46 diagnoses each of the multiple obstacle sensors 20. That is, when the diagnostic unit 46 determines, based on the position of other vehicles 71, that the light vehicle 10 is located in the divided areas (62LCN, 62LCF, 62LLN, 62LLF, 62LRN, 62LRF) of the detection area 62L of the left laser sensor 22L, it determines whether the left laser sensor 22L successfully detected the light vehicle 10 in the divided areas (62LCN, 62LCF, 62LLN, 62LLF, 62LRN, 62LRF) of the detection area 62L. Based on the position of other vehicles 71, the diagnostic unit 46 determines that the light vehicle 10 is located in a divided area (61CN, 61CF, 61L1N, 61L1F, 61L2N, 61L2F, 61R1N, 61R1F, 61R2N, 61R2F, 61BN, 61BF) of the detection area (61C, 61L1, 61L2, 61R2F, 61R1N, 61R1F, 61R2N, 61R2F, 61BN, 61BF) of the radar sensor 21. At that time, the radar sensor 21 determines whether or not it has successfully detected the light vehicle 10 in the divided areas (61CN, 61CF, 61L1N, 61L1F, 61L2N, 61L2F, 61R1N, 61R1F, 61R2N, 61R2F, 61BN, 61BF) of the detection area (61C, 61L1, 61L2, 61R2, 61R2F, 61BN, 61BF).

[0087] [Cases where the success or failure of light vehicle detection is not determined] Next, we will explain cases where the success or failure of light vehicle detection by the obstacle sensor 20 is not determined.

[0088] Figure 15 is a diagram illustrating the relationship between the detection area 62R and the light vehicle 10 according to the embodiment. As shown in Figure 15, if the diagnostic unit 46 determines that the light vehicle 10 is not present in the detection area 62R based on the position of other vehicles 71, it does not perform a determination of whether the right laser sensor 22R successfully detected the light vehicle 10.

[0089] Figure 16 is a diagram illustrating the relationship between the dump truck 2 and the light vehicle 10 according to the embodiment. As shown in Figure 16, there may be a difference in elevation between the ground on which the dump truck 2 is traveling and the ground on which the light vehicle 10 is traveling. As described above, the position sensor 25 can detect the altitude of the dump truck 2. The position sensor 28 can detect the altitude of the light vehicle 10. If the elevation difference ΔH between the dump truck 2's own position and the other vehicle's position 71 of the light vehicle 10 is greater than or equal to a predetermined height threshold, the diagnostic unit 46 does not perform a determination of whether the obstacle sensor 20 has successfully detected the light vehicle 10. Even if the obstacle sensor 20 is functioning normally and the other vehicle's position 71 is inside the detection area 61 and detection area 62 of the obstacle sensor 20 in the planar direction, if the elevation difference ΔH is large, there is a high possibility that the obstacle sensor 20 will fail to detect the light vehicle 10. Therefore, if the height difference ΔH is greater than or equal to the height threshold, the diagnostic unit 46 does not determine whether the obstacle sensor 20 has successfully detected the light vehicle 10.

[0090] Figure 17 is a diagram illustrating the relationship between a dump truck 2 and a light vehicle 10 according to an embodiment. As shown in Figure 17, there is a possibility that an object 80 exists between the dump truck 2 and the light vehicle 10. The object 80 may be a structure, an obstacle, or a vehicle without a position sensor. The other vehicle position acquisition unit 44 can acquire the other vehicle position 71 of the light vehicle 10, but cannot acquire the position of the object 80. The diagnostic unit 46 can acquire the dump truck 2's own position. The object position calculation unit 45 calculates the object position 72 indicating the position of the object 80 based on the detection data of the obstacle sensor 20. If an object 80 exists between the dump truck 2 and the light vehicle 10, the obstacle sensor 20 cannot detect the light vehicle 10. If the obstacle sensor 20 detects an object 80 that exists between the dump truck 2's own position and the other vehicle position 71 of the light vehicle 10, the diagnostic unit 46 does not perform a determination of whether the obstacle sensor 20 succeeded in detecting the light vehicle 10.

[0091] More specifically, the diagnostic unit 46 determines that the obstacle sensor 20 has failed to detect the light vehicle 10 if the light vehicle 10 is located in at least one of the detection areas 61 and 62 of the obstacle sensor 20, and the distance between the object 80 and the position of the other vehicle 71 is greater than the first distance threshold and less than the second distance threshold. The diagnostic unit 46 does not determine whether the obstacle sensor 20 successfully detected the light vehicle 10 if the light vehicle 10 is located in at least one of the detection areas 61 and 62 of the obstacle sensor 20, and the distance between the object 80 and the position of the other vehicle 71 is greater than or equal to the second distance threshold. The first distance threshold corresponds to the radius 70R (distance threshold) of the determination circle 70 described above. The second distance threshold is a value greater than the first distance threshold.

[0092] [Diagnostic Method] Figure 18 is a flowchart showing a diagnostic method for the obstacle sensor 20 according to this embodiment. The detection area setting unit 43 sets a detection area 61 in the actual detection area 23 of the radar sensor 21 and sets a detection area 62 in the actual detection area 24 of the laser sensor 22. Each of the detection area 61 and detection area 62 includes a plurality of divided areas (step S1).

[0093] The other vehicle position acquisition unit 44 acquires the other vehicle position 71, which indicates the position of the light vehicle 10, from the management device 12 (step S2).

[0094] The diagnostic unit 46 determines whether the light vehicle 10 is located in at least one of the detection area 61 and detection area 62 of the obstacle sensor 20, based on the dump truck 2's own position and the position 71 of the light vehicle 10. In this embodiment, the diagnostic unit 46 determines whether the light vehicle 10 is located in at least one of the detection area 61 and detection area 62 of the obstacle sensor 20, based on the detection data from the position sensor 25, the detection data from the orientation sensor 26, and the detection data from the position sensor 28 (step S3).

[0095] In step S3, if it is determined that the light vehicle 10 is not present in the detection area 61 and detection area 62 of the obstacle sensor 20 (step S3: No), the diagnostic unit 46 does not perform a determination of whether or not the obstacle sensor 20 successfully detected the light vehicle 10, as explained with reference to Figure 15.

[0096] In step S3, if it is determined that the light vehicle 10 is located in at least one of the detection areas 61 and 62 of the obstacle sensor 20 (step S3: Yes), the diagnostic unit 46 determines whether or not the obstacle sensor 20 has detected an object (step S4).

[0097] In step S4, if it is determined that the obstacle sensor 20 has detected an object (step S4: Yes), the object position calculation unit 45 calculates the object position 72, which indicates the position of the object detected by the obstacle sensor 20, based on the detection data from the obstacle sensor 20 and the self-position of the dump truck 2. In this embodiment, the object position calculation unit 45 calculates the object position 72 in the global coordinate system based on the detection data from the obstacle sensor 20, the detection data from the position sensor 25, and the detection data from the orientation sensor 26 (step S5).

[0098] The diagnostic unit 46 determines whether the distance between the object position 72 and the other vehicle position 71 is less than or equal to a predetermined distance threshold. That is, the diagnostic unit 46 determines whether the object position 72 is inside the determination circle 70 (step S6).

[0099] In step S6, if it is determined that the distance between the object position 72 and the position of the other vehicle 71 is less than or equal to a predetermined distance threshold (step S6: Yes), the diagnostic unit 46 determines that the obstacle sensor 20 has successfully detected the light vehicle 10, as explained with reference to Figure 13 (step S7).

[0100] In step S4, if it is determined that the obstacle sensor 20 has not detected an object (step S4: No), the diagnostic unit 46 determines that the obstacle sensor 20 has failed to detect the light vehicle 10, as explained with reference to Figure 14 (step S8).

[0101] Furthermore, in step S6, if it is determined that the distance between the object position 72 and the position of the other vehicle 71 exceeds the distance threshold (step S6: No), the diagnostic unit 46 determines that the obstacle sensor 20 has failed to detect the light vehicle 10 (step S8).

[0102] [Summary of Success / Failure of Light Vehicle Detection] Figure 19 is a diagram illustrating the summary results of the success / failure of light vehicle detection according to the embodiment. The diagnostic unit 46 determines whether the obstacle sensor 20 has successfully detected the light vehicle 10 for each of the multiple divided areas of the detection area 61 and detection area 62 of the obstacle sensor 20. Figure 19 is a diagram showing the summary results for each of the multiple divided areas (62LLN, 62LLF, 62LCN, 62LCF, 62LRN, 62LRRF, 62RLN, 62RLF, 62RCN, 62RCF, 62RRN, 62RRF) of the detection area 62, for a predetermined period, showing the number of successes, the number of times the light vehicle 10 was present in the detection area 62, and the success rate, which shows the ratio of successes to the number of times the light vehicle was present. The predetermined period is, for example, 24 hours.

[0103] The diagnostic unit 46 determines whether the laser sensor 22 is functioning normally based on the number of times the laser sensor 22 has successfully detected the light vehicle 10 during a predetermined period. In this embodiment, a success rate threshold is predetermined and stored in the storage unit 47. Different success rate thresholds may be predetermined for each detection area 61 and detection area 62 of the obstacle sensor 20. Also, different success rate thresholds may be predetermined for each of the multiple divisions of the detection area 61 and each of the multiple divisions of the detection area 62 of the obstacle sensor 20. The diagnostic unit 46 may determine that the laser sensor 22 is abnormal if the success rate is below the success rate threshold.

[0104] As described above, the detection area 62 is divided into a first division area and a second division area set to be further from the laser sensor 22 than the first division area. The control unit 42 causes the running device 18 to run at the target running speed specified in the running data if the success rate of detecting the light vehicle 10 in the first division area is equal to or greater than the success rate threshold, and the success rate of detecting the light vehicle 10 in the second division area is also equal to or greater than the success rate threshold. In other words, if the laser sensor 22 is functioning normally, the control unit 42 controls the running device 18 to run at the target running speed.

[0105] The control unit 42 may reduce the travel speed of the travel device 18 if the success rate of detecting the light vehicle 10 in the first divided area is equal to or greater than the success rate threshold, and the success rate of detecting the light vehicle 10 in the second divided area is less than the success rate threshold. In other words, if the laser sensor 22 can detect an object in the first divided area but has difficulty detecting an object in the second divided area, the control unit 42 may control the travel device 18 to travel at a travel speed lower than the target travel speed defined in the travel data.

[0106] The control unit 42 may stop the operation of the running gear 18 if the success rate of detecting the light vehicle 10 in the first divided area is below the success rate threshold, and the success rate of detecting the light vehicle 10 in the second divided area is also below the success rate threshold.

[0107] [Effects] As described above, in this embodiment, the dump truck 2, which is an example of a work machine, includes an obstacle sensor 20, a position sensor 25 that detects the dump truck 2's own position, and a controller 16 including a processor 31. The processor 31 of the controller 16 includes an other vehicle position acquisition unit 44 that acquires the position of another vehicle 71 indicating the position of a light vehicle 10, which is an example of another vehicle traveling on the work site 1, and a diagnostic unit 46 that diagnoses the obstacle sensor 20 based on the detection data of the obstacle sensor 20, the dump truck 2's own position, and the other vehicle position 71 of the light vehicle 10.

[0108] According to the embodiment, the processor 31 can use a light vehicle 10 traveling around the work site 1 to frequently diagnose the obstacle sensor 20 while the dump truck 2 is operating. Furthermore, the processor 31 can use the light vehicle 10 traveling around the work site 1 to diagnose whether or not the obstacle sensor 20 can detect objects in the entire actual detection area 23 and actual detection area 24 of the obstacle sensor 20. As a result, the processor 31 can detect abnormalities or signs of abnormalities in the obstacle sensor 20 at an early stage.

[0109] When diagnosing the obstacle sensor 20 using a target, it is necessary to place the target at a predetermined position relative to the obstacle sensor 20, which may make it difficult to adequately diagnose whether the obstacle sensor 20 can detect objects in the entire actual detection area 23 and actual detection area 24 of the obstacle sensor 20. Furthermore, when diagnosing the obstacle sensor 20 using a target, it is difficult to perform the diagnosis of the obstacle sensor 20 at a high frequency. According to this embodiment, the processor 31 can perform a high-frequency diagnosis of whether the obstacle sensor 20 can detect objects in the entire actual detection area 23 and actual detection area 24 of the obstacle sensor 20.

[0110] The diagnostic unit 46 determines whether the light vehicle 10 is present in the detection area 61 and detection area 62 of the obstacle sensor 20 based on its own position detected by the position sensor 25 and the position of other vehicles 71 detected by the position sensor 28. The diagnostic unit 46 diagnoses the obstacle sensor 20 based on the detection data of the obstacle sensor 20 when it determines that the light vehicle 10 is present in the detection area 61 and detection area 62 of the obstacle sensor 20. When the obstacle sensor 20 detects an object at or near the position of other vehicles 71 when it is determined that the light vehicle 10 is present in the detection area 61 and detection area 62 of the obstacle sensor 20 based on its own position and the position of other vehicles 71, the object detected by the obstacle sensor 20 can be considered to be the light vehicle 10. Therefore, the diagnostic unit 46 can diagnose the obstacle sensor 20 based on the detection data of the obstacle sensor 20 when it determines that the light vehicle 10 is present in the detection area 61 and detection area 62 of the obstacle sensor 20.

[0111] In this embodiment, diagnosing the obstacle sensor 20 includes determining whether the obstacle sensor 20 has successfully detected the light vehicle 10. The processor 31 of the controller 16 has an object position calculation unit 45 that calculates an object position 72 indicating the position of an object detected by the obstacle sensor 20, based on the detection data of the obstacle sensor 20 and its own position detected by the position sensor 25. The diagnostic unit 46 can determine that the obstacle sensor 20 has successfully detected the light vehicle 10 if it determines that the object position 72 is less than or equal to a predetermined distance threshold when it determines that the light vehicle 10 is present in the detection area 61 and detection area 62 of the obstacle sensor 20. The diagnostic unit 46 can determine that the obstacle sensor 20 has failed to detect the light vehicle 10 if it determines that the obstacle sensor 20 does not detect an object when it determines that the light vehicle 10 is present in the detection area 61 and detection area 62 of the obstacle sensor 20.

[0112] As explained with reference to Figure 19, in this embodiment, the diagnostic unit 46 can determine whether the obstacle sensor 20 is functioning correctly based on the number of times the obstacle sensor 20 has successfully detected the light vehicle 10 during a predetermined period. This allows the diagnostic unit 46 to statistically determine whether the obstacle sensor 20 is functioning correctly.

[0113] As explained with reference to Figure 16, in this embodiment, the diagnostic unit 46 does not determine whether the obstacle sensor 20 has successfully detected the light vehicle 10 if the height difference ΔH between its own position and the position of the other vehicle 71 is greater than or equal to a predetermined height threshold. This allows the diagnostic unit 46 to properly determine whether the obstacle sensor 20 is functioning correctly.

[0114] As explained with reference to Figure 17, in this embodiment, when the obstacle sensor 20 detects an object 80 located between its own position and the position of another vehicle 71, the diagnostic unit 46 does not determine whether the obstacle sensor 20 has successfully detected the light vehicle 10. This allows the diagnostic unit 46 to properly determine whether the obstacle sensor 20 is functioning correctly.

[0115] In this embodiment, the processor 31 of the controller 16 includes a detection area setting unit 43 that sets detection areas 61 and 62 in the actual detection areas 23 and 24 of the obstacle sensor 20. The detection area setting unit 43 divides detection areas 61 and 62 into a plurality of sub-areas. The diagnostic unit 46 determines for each of the plurality of sub-areas whether the obstacle sensor 20 has successfully detected the light vehicle 10. When the light vehicle 10 passes through the detection areas 61 and 62 of the obstacle sensor 20 while at least one of the dump truck 2 and the light vehicle 10 is in motion, the detection accuracy of the light vehicle 10 by the obstacle sensor 20 may decrease. By dividing detection areas 61 and 62 into a plurality of sub-areas, and determining for each of the plurality of sub-areas whether the obstacle sensor 20 has successfully detected the light vehicle 10, the decrease in the accuracy of the determination of success or failure of detection of the light vehicle 10 by the obstacle sensor 20 is suppressed.

[0116] Each of the detection areas 61 and 62 is divided into at least a first divided area and a second divided area set to be further from the obstacle sensor 20 than the first divided area. The diagnostic unit 46 can determine that the obstacle sensor 20 is normal if the success rate of detecting the light vehicle 10 in the first divided area is equal to or greater than a predetermined success rate threshold, and the success rate of detecting the light vehicle 10 in the second divided area is also equal to or greater than the success rate threshold. The diagnostic unit 46 can determine that the obstacle sensor 20 has a minor malfunction if the success rate of detecting the light vehicle 10 in the first divided area is equal to or greater than the success rate threshold, but the success rate of detecting the light vehicle 10 in the second divided area is less than the success rate threshold. The diagnostic unit 46 can determine that the obstacle sensor 20 has a minor malfunction if the success rate of detecting the light vehicle 10 in the first divided area is less than the success rate threshold, but the success rate of detecting the light vehicle 10 in the second divided area is equal to or greater than the success rate threshold. The diagnostic unit 46 can determine that the obstacle sensor 20 is severely malfunctioning if the success rate of detecting the light vehicle 10 in the first divided area is below the success rate threshold, and the success rate of detecting the light vehicle 10 in the second divided area is also below the success rate threshold.

[0117] The processor 31 of the controller 16 has a control unit 42 that reduces the travel speed of the travel device 18 when the success rate of detecting light vehicles 10 in the first divided area is above the success rate threshold and the success rate of detecting light vehicles 10 in the second divided area is below the success rate threshold, that is, when the obstacle sensor 20 is experiencing a minor malfunction. When the obstacle sensor 20 is experiencing a minor malfunction, reducing the travel speed of the travel device 18 suppresses the occurrence of unforeseen events while suppressing a decrease in productivity at the work site 1. When the success rate of detecting light vehicles 10 in the first divided area is below the success rate threshold and the success rate of detecting light vehicles 10 in the second divided area is also below the success rate threshold, that is, when the obstacle sensor 20 is experiencing a severe malfunction, the control unit 42 stops the travel device 18. When the obstacle sensor 20 is experiencing a severe malfunction, stopping the travel device 18 prevents unforeseen events from occurring.

[0118] [Other Embodiments] In the above embodiment, the other vehicle detected by the obstacle sensor 20 of the dump truck 2 is assumed to be a light vehicle 10. The other vehicle detected by the obstacle sensor 20 of the dump truck 2 may be an excavator 3, a bulldozer 4, or a motor grader 5. For example, if a position sensor is provided to detect the position of the excavator 3, the other vehicle position acquisition unit 44 can acquire the position of the excavator 3 as the other vehicle position 71. The same applies to the bulldozer 4 and the motor grader 5. In addition, the other vehicle detected by the obstacle sensor 20 of the dump truck 2 may be another dump truck.

[0119] In the above-described embodiment, the obstacle sensor 20 is provided on the dump truck 2. Its own position is set to the position of the dump truck 2. The obstacle sensor 20 may also be provided on the shovel 3, the bulldozer 4, or the motor grader 5. Its own position may be the position of the shovel 3, the bulldozer 4, or the motor grader 5.

[0120] In the above-described embodiment, the detection data from the position sensor 28 of the light vehicle 10 is transmitted to the controller 16 of the dump truck 2 via the management device 12. The detection data from the position sensor 28 of the light vehicle 10 may be transmitted to the controller 16 of the dump truck 2 without going through the management device 12.

[0121] In the above-described embodiment, at least a portion of the functional parts of the controller 16 may be provided in the management device 12. At least a portion of the functional parts of the management device 12 may be provided in the controller 16. For example, the detection area setting unit 43, the object position calculation unit 45, and the diagnostic unit 46 may each be provided in the management device 12. In that case, the detection data from the obstacle sensor 20, the detection data from the position sensor 25, and the detection data from the orientation sensor 26 may each be transmitted to the management device 12 via the communication system 13.

[0122] In the above-described embodiment, each of the multiple functional units of the controller 16 may be configured by a separate computer (hardware). Each of the functional units of the management device 12 may be configured by a separate computer (hardware).

[0123] 1...Work site, 2...Dump truck (working machine), 3...Excavator (working machine), 4...Bulldozer (working machine), 5...Motor grader (working machine), 6...Loading area, 7...Soil removal area, 8...Transportation route, 9...Crusher, 10...Light vehicle (other vehicle), 11...Management system, 12...Management device, 13...Communication system, 13A...Wireless communication device, 13B...Wireless communication device, 13C...Wireless communication device, 14...Control facility, 15...Controller, 16...Controller, 17...Vehicle body, 18...Running gear, 18A...Wheels, 18B...Tires, 19...Dump body, 20...Obstacle sensor, 21 ...Radar sensor, 21B...Rear radar sensor, 21C...Center radar sensor, 21L1...First left radar sensor, 21L2...Second left radar sensor, 21R1...First right radar sensor, 21R2...Second right radar sensor, 22...Laser sensor, 22L...Left laser sensor, 22R...Right laser sensor, 23...Actual detection area, 23B...Actual detection area, 23C...Actual detection area, 23L1...Actual detection area, 23L2...Actual detection area, 23R1...Actual detection area, 23R2...Actual detection area, 23N...First actual detection area, 23F...Second actual detection area, 24...Actual detection area, 24L...Actual 24R...Actual detection area, 25...Position sensor (self-position sensor), 26...Direction sensor, 27...Speed ​​sensor, 28...Position sensor, 31...Processor, 32...Main memory, 33...Storage, 34...Input / output interface, 35...Communication interface, 36...Computer program, 38...Driving data generation unit, 39...Other vehicle position communication unit, 41...Driving data acquisition unit, 42...Control unit, 43...Detection area setting unit, 44...Other vehicle position acquisition unit, 45...Object position calculation unit, 46...Diagnostic unit, 47...Storage unit, 50...Driving point, 51...Driving path, 61...Detection area , 61B...Detection area, 61BN...Divided area, 61BF...Divided area, 61C...Detection area, 61CN...Divided area, 61CF...Divided area, 61L1...Detection area, 61L1N...Divided area, 61L1F...Divided area, 61L2...Detection area, 61L2N...Divided area, 61L2F...Divided area, 61R1...Detection area, 61R1N...Divided area, 61R1F...Divided area, 61R2...Detection area, 61R2N...Divided area, 61R2F...Divided area, 62...Detection area, 62L...Detection area, 62LCN...Divided area, 62LCF...Divided area,62LLN...Divided area, 62LLF...Divided area, 62LRN...Divided area, 62LRF...Divided area, 62R...Detection area, 62RCN...Divided area, 62RCF...Divided area, 62RRN...Divided area, 62RRF...Divided area, 62RLN...Divided area, 62RLF...Divided area, 70...Judgment circle, 70R...Radius, 71...Other vehicle position, 72...Object position, 80...Object.

Claims

1. A work machine comprising an obstacle sensor, a position sensor for detecting its own position, and a processor, wherein the processor acquires the position of other vehicles indicating the position of other vehicles traveling on the work site, and diagnoses the obstacle sensor based on the detection data of the obstacle sensor, its own position, and the position of other vehicles.

2. The work machine according to claim 1, wherein the processor determines whether the other vehicle is present in the detection area of ​​the obstacle sensor based on its own position and the position of the other vehicle, and diagnoses the obstacle sensor based on the detection data of the obstacle sensor when it is determined that the other vehicle is present in the detection area.

3. The work machine according to claim 2, wherein diagnosing the obstacle sensor includes determining whether the obstacle sensor has successfully detected the other vehicle, the processor calculates an object position indicating the location of an object detected by the obstacle sensor based on the detection data of the obstacle sensor and its own position, and determines that the obstacle sensor has successfully detected the other vehicle if it determines that the distance between the object position and the other vehicle position is less than or equal to a predetermined distance threshold when it determines that the other vehicle is in the detection area.

4. The work machine according to claim 2, wherein the processor determines that the other vehicle is present in the detection area and the obstacle sensor does not detect an object, and the obstacle sensor determines that the obstacle sensor has failed to detect the other vehicle.

5. The work machine according to claim 3, wherein the processor determines whether the obstacle sensor is functioning correctly based on the number of times the obstacle sensor has successfully detected the other vehicle during a predetermined period.

6. The work machine according to claim 5, wherein the processor does not determine whether the obstacle sensor has successfully detected the other vehicle if the height difference between its own position and the position of the other vehicle is greater than or equal to a predetermined height threshold.

7. The work machine according to claim 5, wherein the processor does not perform a determination of whether or not the obstacle sensor has successfully detected the other vehicle when the obstacle sensor detects an object existing between its own position and the position of the other vehicle.

8. The work machine according to claim 3, wherein the processor sets the detection area in the actual detection area of ​​the obstacle sensor, divides the detection area into a plurality of subdivided areas, and determines for each of the plurality of subdivided areas whether the obstacle sensor has successfully detected the other vehicle.

9. The work machine according to claim 8, wherein the divided area includes a first divided area and a second divided area set to be further from the obstacle sensor than the first divided area.

10. The work machine according to claim 9, comprising a traveling device, wherein the processor reduces the traveling speed of the traveling device when the success rate of detecting the other vehicle in the first divided area is equal to or greater than a predetermined success rate threshold, and the success rate of detecting the other vehicle in the second divided area is less than the success rate threshold.

11. A diagnostic method comprising: acquiring the self-position indicating the position of a work machine traveling on a work site; acquiring the position of other vehicles indicating the position of other vehicles traveling on the work site; and diagnosing the obstacle sensor based on detection data from an obstacle sensor provided on the work machine, the self-position, and the other vehicle position.

12. The diagnostic method according to claim 11, comprising determining whether the other vehicle is present in the detection area of ​​the obstacle sensor based on the position of the self and the position of the other vehicle, and diagnosing the obstacle sensor based on the detection data of the obstacle sensor when it is determined that the other vehicle is present in the detection area.

13. The diagnostic method according to claim 12, wherein diagnosing the obstacle sensor includes determining whether the obstacle sensor has successfully detected the other vehicle, calculating an object position indicating the location of an object detected by the obstacle sensor based on the detection data of the obstacle sensor and its own position, and determining that the obstacle sensor has successfully detected the other vehicle when it is determined that the other vehicle is present in the detection area and the distance between the object position and the other vehicle position is less than or equal to a predetermined distance threshold.

14. The diagnostic method according to claim 12, wherein if the obstacle sensor does not detect an object when it is determined that the other vehicle is present in the detection area, the obstacle sensor determines that it has failed to detect the other vehicle.

15. The diagnostic method according to claim 13, wherein the obstacle sensor is determined to be functioning normally based on the number of times the obstacle sensor has successfully detected the other vehicle during a predetermined period.

16. The diagnostic method according to claim 15, wherein if the height difference between the self-position and the position of the other vehicle is greater than or equal to a predetermined height threshold, the obstacle sensor does not perform a determination of whether or not it has successfully detected the other vehicle.

17. The diagnostic method according to claim 15, wherein when the obstacle sensor detects an object located between its own position and the position of the other vehicle, the obstacle sensor does not perform a determination as to whether or not it has successfully detected the other vehicle.

18. The diagnostic method according to claim 13, comprising setting the detection area in the actual detection area of ​​the obstacle sensor, and dividing the detection area into a plurality of divided areas, wherein for each of the plurality of divided areas, it is determined whether the obstacle sensor has successfully detected the other vehicle.

19. The diagnostic method according to claim 18, wherein the divided area includes a first divided area and a second divided area set at a position further from the obstacle sensor than the first divided area.

20. The diagnostic method according to claim 19, wherein if the success rate of detecting other vehicles in the first divided area is equal to or greater than a predetermined success rate threshold, and the success rate of detecting other vehicles in the second divided area is less than the success rate threshold, the travel speed of the work machine is reduced.

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