Work machine

Abstract

To prevent leakage of hydrogen gas at a dangerous time.SOLUTION: A work machine includes: a vehicle body that can travel; a tank 13 mounted to the vehicle body; a fuel cell 24 mounted to the vehicle body and generating electric power by using hydrogen supplied from the tank 13; a valve 60 capable of shutting off supply of the hydrogen from the tank 13 to the fuel cell 24; and a detection device 80 provided in the vehicle body. The vehicle body travels on the basis of detection information from the detection device 80, and the valve 60 is closed when a traveling status of the vehicle body obtained through the detection information is determined to be dangerous.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a working machine.

Background Art

[0002] From the viewpoint of environmental protection, a working machine equipped with a fuel cell and driven by a motor that rotates by the electric power generated by the fuel cell has been proposed (for example, see Patent Document 1). Hydrogen is used as the fuel for the fuel cell. The working machine disclosed in Patent Document 1 is a tractor, and a tank is mounted on its vehicle body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the working machine as described above, measures for preventing leakage of hydrogen as fuel are essential not only during normal running of the working machine but also in dangerous situations such as when colliding with an obstacle or when the working machine overturns on the access road to a site such as a farm field. Therefore, the present disclosure provides a working machine capable of preventing leakage of hydrogen gas in dangerous situations.

Means for Solving the Problems

[0005] The work machine of the present disclosure includes a vehicle body capable of traveling, a tank mounted on the vehicle body, a fuel cell mounted on the vehicle body that generates electricity using hydrogen supplied from the tank, a valve capable of shutting off the supply of hydrogen from the tank to the fuel cell, and a detection device provided on the vehicle body. The vehicle body travels based on the detection information of the detection device, and the valve is closed when it is determined that the traveling situation of the vehicle body obtained from the detection information is dangerous.

Effect of the Invention

[0006] According to the work machine of the present disclosure, it is possible to prevent leakage of hydrogen gas in case of danger.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0008] <Outline of the Embodiment of the Present Disclosure> The following is a description of an outline of an embodiment of the present disclosure. (1) The work machine according to the embodiment of the present disclosure includes a vehicle body capable of traveling, a tank mounted on the vehicle body, a fuel cell, a valve capable of shutting off a supply path from the tank to the fuel cell, and a detection device provided on the vehicle body. The vehicle body travels based on detection information of the detection device, and the valve is closed when it is determined that the traveling situation of the vehicle body obtained from the detection information is dangerous.

[0009] According to the work machine, in accordance with the vehicle body traveling based on the detection information of the detection device, the detection information detected by the detection device is used to determine whether the traveling situation of the vehicle body is dangerous. If it is dangerous, the valve is closed, the supply of hydrogen gas from the tank is shut off, and leakage of hydrogen gas is prevented.

[0010] (2) In the work machine of (1) above, the detection device can detect obstacles around the vehicle body. When the position between the obstacle detected by the detection device and the vehicle body is equal to or less than a predetermined distance, the vehicle body executes an operation to avoid the obstacle or an operation to stop the traveling. The valve is closed assuming that the traveling situation is dangerous when the position between the obstacle and the vehicle body is equal to or less than a predetermined distance. With this configuration, obstacles around the work machine are detected by the detection device during traveling. If there is a possibility of collision with the obstacle, the valve is closed. It becomes possible to shut off the supply of hydrogen gas from the tank before the collision.

[0011] (3) In the work machine of (1) or (2) above, the detection device includes at least one of a LiDAR sensor, a millimeter-wave radar, and an ultrasonic sensor, and the valve is closed based on the detection information detected by at least one of the LiDAR sensor, the millimeter-wave radar, and the ultrasonic sensor.

[0012] (4) In any one of the working machines (1) to (3) above, when a signal from an operating device operated by a user is acquired, the valve switches from a closed state to an open state. According to the above configuration, when the safety of the work vehicle is confirmed, based on the operation of the user, the working machine can return to the state before it is determined to be dangerous.

[0013] (5) In the working machine of (4) above, when the valve switches from a closed state to an open state, the vehicle body stops the operation of avoiding the obstacle or the operation of stopping the travel. According to the above configuration, when the safety of the work vehicle is confirmed, based on the operation of the user, the working machine can return to the state before it is determined to be dangerous.

[0014] (6) In any one of the working machines (1) to (5) above, it has a tank unit having the tank and a support member that supports the tank, and the valve is provided in the tank unit.

[0015] <Details of Embodiments of the Present Disclosure> Hereinafter, with reference to the drawings, the details of the embodiments of the present disclosure will be described. Note that at least a part of the embodiments described below may be arbitrarily combined.

[0016] 〔Overall Structure of Working Machine〕 FIG. 1 is a perspective view showing an example of the overall structure of a working machine. FIG. 2 is a right side view of the working machine with some exterior parts (such as the bonnet 34 and the cover 111) removed. The working machine of the present embodiment is a work vehicle used for agricultural work, specifically a tractor. The working machine is not limited to a tractor, and may be a moving body such as a construction machine and a utility vehicle. Hereinafter, the case where the working machine is a work vehicle (tractor) 10 will be described.

[0017] The directions of the work vehicle 10 are defined. The work vehicle 10 has a driver's seat 15. Based on the driver sitting on the seat of the driver's seat 15, the front-back, left-right, and up-down directions of the work vehicle 10 are defined. That is, the front direction for that driver is "front", and the rear direction is "rear". The right direction for that driver is "right", and the left direction is "left". The front-back direction and the left-right direction are parallel to the ground, and the front-back direction and the left-right direction are orthogonal. The up-down direction is orthogonal to both the front-back direction and the left-right direction.

[0018] When explaining the left-right direction as the "vehicle width direction", the front direction becomes the "travel direction" of the work vehicle 10. In addition, when the work vehicle 10 does not have the driver's seat 15, the work progress direction of the work vehicle 10 is "front", and the opposite direction is "rear". Facing the work progress direction, the right direction of the work vehicle 10 is "right", and the left direction is "left".

[0019] The vehicle body 11 of the work vehicle 10 has a chassis 41, a drive device 14, a steering device 39, a driver's seat 15, and a cabin 16. Furthermore, the vehicle body 11 has a bonnet 34, a cover 111, a tank unit 21, a first radiator 48, and a second radiator 49.

[0020] The cabin 16 has a front pillar, a rear pillar, and a roof, and is a driver's cab partitioned by these. Instead of the cabin 16, the work vehicle 10 may have a canopy or a rollover protective structure (ROPS). When the work vehicle 10 does not have the cabin 16, the tank unit 21 is disposed above the driver's seat 15 by a mounting frame 17.

[0021] As shown in FIG. 2, at the front part of the chassis 41, the first radiator 48, the fuel cell 24, and the second radiator 49 are mounted in order from front to rear. The first radiator 48 and the fuel cell 24 are covered by the bonnet 34, and the second radiator 49 is covered by the cover 111.

[0022] The tank unit 21 (see Fig. 2) has a tank 13 for storing fuel inside. The fuel is either liquid or gas, such as hydrogen, methane, carbon monoxide (CO), etc. In this embodiment, the tank 13 stores hydrogen gas. The tank unit 21 of this embodiment has a plurality of tanks 13. The drive device 14 is driven by the stored fuel. The work vehicle 10 is a fuel cell vehicle (FCV: Fuel Cell Vehicle), and runs using the electric power generated by the chemical reaction of hydrogen and oxygen in the fuel cell 24 as an energy source.

[0023] The tank unit 21 has a support member 211 for supporting the tank 13. A safety valve 60, which will be described later, is provided in the tank unit 21. The safety valve 60 can cut off the supply of hydrogen from the tank 13 to the fuel cell 24.

[0024] The drive device 14 has a fuel cell 24, a battery unit 30, and a motor 31 (see Fig. 3). Fig. 3 is a perspective view showing an example of the internal structure of the work vehicle 10. The battery unit 30 has a battery pack (battery) for storing the electric power generated by the fuel cell 24. The work vehicle 10 has a hydrogen gas pipe 22. Hydrogen gas is supplied from a filling port 42 (see Fig. 4) connected to the end of the pipe 22 and filled into each tank 13. The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through the pipe 22.

[0025] The steering device 39 (see Fig. 2) has a steering shaft that rotates by a steering wheel 39A. The steering device 39 changes the rolling direction of the wheels (front wheels 12A) and changes the traveling direction of the work vehicle 10. The steering device 39 has an auxiliary mechanism (power steering device). The auxiliary mechanism assists the operating force of the steering wheel 39A by the driver hydraulically or electrically. When the work vehicle performs automatic driving, the auxiliary mechanism is used under the control of the control device 70 (see Fig. 4) to perform steering and change the traveling direction.

[0026] The traveling device 12 of the work vehicle 10 has front wheels 12A and rear wheels 12B. One or both of the front wheels 12A and the rear wheels 12B rotate by the power of the motor 31. One or both of the wheels 12A and 12B (drive wheels) that rotate by the power of the motor 31 may be crawlers (endless tracks). By the traveling device 12, the vehicle body 11 can travel.

[0027] 〔Internal Structure of Work Vehicle〕 As shown in FIG. 3, the chassis 41 is configured to have a steel frame that is long in the front-rear direction, and has a front frame 32 and a gear case 33. The gear case 33 is connected to the rear part of the front frame 32. The skeleton of the vehicle body 11 is formed by the gear case 33 and the front frame 32. The chassis 41 is a vehicle body frame that mounts a drive device 14, a driver's seat 15, a cabin 16, a tank 13, a fuel cell 24, etc.

[0028] A mounting frame 17 for the tank unit 21 is connected to the chassis 41. The mounting frame 17 supports the tank unit 21 above the cabin 16. The mounting frame 17 includes a substantially rectangular ceiling frame 17A whose front-rear direction is longer than the left-right direction, a plurality of pillars 17B that support the ceiling frame 17A from below, and a pair of left and right reinforcing frames 17C connected to the front end of the ceiling frame 17A. The tank unit 21 is connected to the ceiling frame 17A.

[0029] A support frame 37 is connected to the chassis 41, and by the support frame 37, the battery unit 30 is supported by the vehicle body 11. The gear case 33 located behind the motor 31 has a power transmission mechanism inside. The power transmission mechanism includes a transmission, a clutch, and a differential gear, and decelerates or accelerates the rotation of the output shaft of the motor 31 and transmits it to the traveling device 12. The power transmission mechanism inside the gear case 33 includes a branch mechanism that outputs a part of the power of the motor 31 to the PTO shaft 334 (see FIG. 2). The PTO shaft 334 is an output shaft that protrudes from the rear part of the gear case 33.

[0030] The work vehicle 10 has a connecting device 43 (see FIG. 2) for connecting a work device for performing a desired agricultural work behind the vehicle body 11. The work device is also called an implement. The work device is, for example, a tiller and a baler. The rotational motion of the PTO shaft 334 is transmitted to the input shaft of the work device, for example, while the work vehicle 10 is traveling. The work vehicle 10 can drive the work device by the power of the motor 31 while traveling on a farmland or the like.

[0031] 〔Regarding the detection device 80〕 FIG. 4 is a block diagram showing a part of the functional configuration of the work vehicle 10. The work vehicle 10 has a detection device 80 that detects the situation around the vehicle body 11, that is, the traveling situation. The detection device 80 is provided on the vehicle body 11. The work vehicle 10 includes at least one of a camera 81, a LiDAR (Light Detection And Ranging) sensor 82, a microphone sensor 83, a millimeter-wave radar 84, and an ultrasonic sensor 85 as the detection device 80. The signal acquired by the detection device 80 is transmitted to the control device 70.

[0032] The camera 81 is provided, for example, on the front, rear, left, and right of the work vehicle 10 and photographs the environment around the work vehicle 10. The camera 81 is, for example, a CCD camera equipped with a CCD image sensor or a CMOS camera equipped with a CMOS image sensor. The camera 81 has a processing circuit that processes the signal output from the image sensor, and the processing circuit acquires surrounding image information as detection information. The camera 81, which is the detection device 80, can detect obstacles around the vehicle body 11.

[0033] The LiDAR sensor 82 is a three-dimensional ranging sensor. The LiDAR sensor 82 is disposed, for example, at the lower front part of the vehicle body 11. The LiDAR sensor 82 acquires and outputs sensor data indicating the distance and direction of each measurement point on an object existing in the surroundings, and sensor data indicating the two-dimensional or three-dimensional coordinate values of each measurement point on an object existing in the surroundings. The detection information (sensor data) of the LiDAR sensor 82 is used for detecting surrounding obstacles. That is, the LiDAR sensor 82, which is the detection device 80, can detect obstacles around the vehicle body 11.

[0034] The microphone sensor 83, the millimeter-wave radar 84, and the ultrasonic sensor 85 are provided, for example, on the front, rear, left, and right sides of the work vehicle 10, and can detect obstacles around the vehicle body 11 by being contacted using sound waves, millimeter waves, and ultrasonic waves.

[0035] The work vehicle 10 may have an inertial measurement device 77 as the detection device 80. The inertial measurement device 77 has one or both of a three-axis gyro sensor and a three-direction acceleration sensor. At least one of the posture such as the inclination of the work vehicle 10 (vehicle body 11), vibration due to a collision or the like, and acceleration (acceleration and deceleration) can be detected by a detection signal from the inertial measurement device 77. The signal acquired by the inertial measurement device 77 is transmitted to the control device 70.

[0036] As described above, the detection device 80 including at least one of the camera 81, the LiDAR sensor 82, the microphone sensor 83, the millimeter-wave radar 84, and the ultrasonic sensor 85 can detect obstacles around the vehicle body 11 as the driving situation (surrounding situation) of the vehicle body 11. The inertial measurement device 77 can detect at least one of the posture, vibration, and acceleration of the vehicle body 11 as the driving situation of the vehicle body 11.

[0037] The control device 70 is capable of executing driving control for controlling the driving of the vehicle body 11, determination processing for estimating the danger (abnormality) of the vehicle body 11 based on the detection information of the detection device 80, and valve control processing for executing control to close a safety valve 60 described later when it is estimated to be dangerous by the determination processing. Note that the danger (abnormality) of the vehicle body 11 is, for example, when the vehicle body 11 collides with an obstacle, when the vehicle body 11 is about to collide with an obstacle, when the vehicle body 11 topples over, or when the vehicle body 11 is about to topple over.

[0038] The work vehicle 10 has a positioning device 76. The positioning device 76 receives satellite signals transmitted from a plurality of GNSS satellites and performs positioning based on the satellite signals. GNSS is a general term for satellite positioning systems such as GPS (Global Positioning System), QZSS (Quasi-Zenith Satellite System: for example, "Michibiki"), GLONASS (Russia), Galileo (Europe), and BeiDou (China).

[0039] The positioning device 76 has a receiver for receiving satellite signals and a processor (arithmetic processing unit). The receiver has an antenna for receiving signals from GNSS satellites. The processor calculates and obtains the position (coordinates) of the work vehicle 10 based on the signals received by the antenna. Information indicating the position of the work vehicle 10 is transmitted to the control device 70 and used for automatic driving and the like.

[0040] 〔Regarding the driving mode of the work vehicle 10〕 The work vehicle 10 of the present embodiment is provided with functions for executing both a manual driving mode by the operation of the driver and an automatic driving mode without the operation of the driver. The work vehicle 10 can perform automatic driving and manual driving both within a field or the like and on a road (rural road) outside the field.

[0041] Manual driving is driving in which the operation (including driving) of the work vehicle 10 is performed by the manual operation of a driver sitting in the driver's seat 15 provided in the work vehicle 10. Automated driving refers to the operation of the work vehicle 10 (including traveling) by the function of the control device 70 of the work vehicle 10 without manual operation by the driver.

[0042] Automated driving is realized by the function of the traveling control unit 701 described later that the control device 70 has. The control device 70 can control at least one of steering, adjustment of traveling speed, start and stop of movement necessary for the movement of the work vehicle 10. In the case of automated driving, in addition to the traveling control of the work vehicle 10, the operation control of the work implement is also executed without the driver's operation. That is, while the work vehicle 10 automatically travels, the work is automatically executed by the work implement.

[0043] As described above, the work vehicle 10 has the positioning device 76. The control device 70 (traveling control unit 701) automatically drives the work vehicle 10 based on the position of the work vehicle 10 specified by the positioning device 76 and the target route previously stored in the storage device of the control device 70.

[0044] Automated driving includes the case where the work vehicle 10 autonomously travels while sensing the surrounding environment by the detection device 80 without human involvement in the control of the movement of the work vehicle 10. Automated driving includes not only the movement of the work vehicle 10 along a predetermined route (the target route) toward the destination but also the movement following the following target. During such automated driving, avoidance driving is performed as the detection of obstacles and the avoidance operation of the obstacles.

[0045] The work vehicle 10 can also be driven by remote control by a person other than the driver sitting in the driver's seat 15. For this purpose, the work vehicle 10 has a communication device (not shown). Wireless communication is used between the work vehicle 10 and the management computer of the management office, so that the work vehicle 10 is remotely controlled. Also in the traveling of the work vehicle 10 by remote control, the detection information of the detection device 80 is used.

[0046] [Regarding the fuel system and control system of the work vehicle 10] As shown in FIG. 4, the work vehicle 10 has a fuel system FS and a control system SS. The components of the fuel system FS include a tank 13, a valve unit 45, and a safety valve 60. The components of the control system SS include a control device 70, a positioning device 76, a detection device 80, and an operation device 73. The operation device 73 is installed, for example, in the cab 16 and includes devices such as buttons operated by a user (the driver of the work vehicle 10, an operator, an agricultural worker, etc.).

[0047] The fuel system FS will be described. The tank 13 is connected to a first pipe 22A and a second pipe 22B via a valve unit 45. The first pipe 22A is a gas pipe connecting the filling port 42 and the valve unit 45, and guides the hydrogen gas introduced into the filling port 42 to the tank 13. The second pipe 22B is a gas pipe connecting the fuel cell 24 and the valve unit 45, and guides the hydrogen gas stored in the tank 13 to the fuel cell 24.

[0048] The valve unit 45 is an assembly of valves including on-off valves and pressure reducing valves inside. By controlling the operation of the internal valves, the valve unit 45 adjusts the flow rate of the hydrogen gas in the tank 13 and leads it to the fuel cell 24. A hydrogen pipe 22C is provided between the valve unit 45 and each tank 13.

[0049] The safety valve 60 is in an open state during normal driving. By becoming a closed state, the safety valve 60 can cut off the supply of hydrogen from the tank 13 to the fuel cell 24. The safety valve 60 is closed when it is determined that the driving situation of the vehicle body 11 is dangerous. The safety valve 60 may be provided in the valve unit 45, but in the case of this embodiment, it is provided in the base portion 131 of the tank 13. The base portion 131 is a part of the tank 13 and is the connection portion of the tank to which the hydrogen pipe 22C is connected.

[0050] One safety valve 60 is provided in one tank 13. The safety valve 60 is an electromagnetic valve that opens and closes based on a control signal from a control device 70 (valve control unit 703). The safety valve 60 is configured to close when the power supply to the safety valve 60 is cut off. When the work vehicle 10 is traveling normally, power is supplied to the safety valve 60 and it is in an open state. When the state (traveling situation) of the work vehicle 10 becomes dangerous, the control device 70 cuts off the power supply to the safety valve 60.

[0051] By providing the safety valve 60 in the base portion 131, for example, even if the work vehicle 10 collides with an obstacle or overturns, and the pipes (first pipe 22A, second pipe 22B, and hydrogen pipe 22C) connecting the tank 13 and the fuel cell 24 are damaged in the middle, it is possible to prevent hydrogen leakage from the tank 13.

[0052] As described above, the work vehicle 10 has a detection device 80 provided on the vehicle body 11. The work vehicle 10 includes at least one of a camera 81, a LiDAR sensor 82, a microphone sensor 83, a millimeter-wave radar 84, and an ultrasonic sensor 85 as the detection device 80. Each of the detection devices 80 can detect obstacles around the vehicle body 11.

[0053] The detection information (sensor data) by the detection device 80 is transmitted to the control device 70. The control device 70 detects obstacles around the work vehicle 10 by using the detection information. In conjunction with the vehicle body 11 traveling (autonomous driving) based on the detection information of the detection device 80, the control device 70 can use the detection information detected by the detection device 80 to determine whether the traveling situation of the vehicle body 11 is dangerous. If it is determined to be dangerous, the safety valve 60 is closed. Further, in this embodiment, if it is determined to be dangerous, an operation to avoid an obstacle or an operation to stop traveling is executed. When the work vehicle 10 is autonomously driving, it automatically executes a detour around the obstacle as it is, or stops traveling by stopping the autonomous driving.

[0054] Regarding the system configuration of the work vehicle 10 The control device 70 is composed of a control unit (computer) including a processor (arithmetic processing unit) and a memory such as RAM and ROM. The processor reads and executes a computer program from the memory, thereby executing each function of the control device 70. The control device 70 may be composed of one control unit (ECU: Electronic Control Unit), or may be composed of a plurality of control units. When the control device 70 is composed of a plurality of control units, information communication is possible between these control units.

[0055] The control device 70 includes a storage device composed of a non-volatile memory or the like that stores various information. Various computer programs for operating the control unit are stored in the storage device. Map information and the like that can be used for automatic driving are also stored in the storage device. In the case of this embodiment, the control device 70 has a travel control unit 701, a determination unit 702, and a valve control unit 703 as functional units obtained by the processor executing a computer program.

[0056] The travel control unit 701 executes control related to the travel of the vehicle body 11. Specifically, the travel control unit 701 performs overall control related to travel including the automatic travel of the work vehicle 10. The travel control unit 701 can perform control related to automatic driving. Specific examples of automatic driving will be described later.

[0057] The travel control unit 701 can also perform control to avoid travel by detouring the vehicle body 11 or control to stop the vehicle body 11 with respect to obstacles existing around the work vehicle 10. The travel control unit 701 intervenes in avoidance travel and travel stop during any one of automatic driving, remote driving, and manual driving.

[0058] The determination unit 702 estimates the danger (abnormality) of the vehicle body 11 based on the detection information of the detection device 80. When the detection device 80 is the camera 81 or the LiDAR sensor 82, the detection device 80 acquires the distance from the vehicle body 11 to the position of the obstacle. The determination unit 702 acquires the information on the distance (detection distance) as the detection information. When the detection distance is equal to or less than a predetermined distance, the determination unit 702 estimates that it is dangerous. When the detection distance exceeds the predetermined distance, the determination unit 702 estimates that it is not dangerous.

[0059] When the detection device 80 is the microphone sensor 83, the millimeter-wave radar 84, or the ultrasonic sensor 85, when the distance from the vehicle body 11 to the position of the obstacle becomes equal to or less than a predetermined distance by the detection device 80, information (approach information) indicating that the obstacle is in the approaching position is output as the detection information. When the determination unit 702 acquires the approach information, it estimates that it is dangerous. While the determination unit 702 does not acquire the approach information, it is not dangerous.

[0060] When it is estimated to be dangerous by the determination unit 702, the valve control unit 703 executes control to close the safety valve 60. The valve control unit 703 can execute control to close the safety valve 60 before the collision or overturning of the vehicle body 11 in addition to during the collision or overturning of the vehicle body 11.

[0061] 〔Regarding the operation of the work vehicle 10 in case of danger〕 FIG. 5 is a flowchart for explaining the operation of the work vehicle 10. The fuel cell 24 of the work vehicle 10 receives the supply of hydrogen gas from the tank 13 and generates electricity (step S10). The motor 31 is driven by the electric power generated by the fuel cell 24, and the vehicle body 11 travels (step S20). In step S20, the vehicle body 11 travels based on the detection information detected by the detection device 80. For example, the vehicle body 11 travels by automatic driving based on the detection information of the detection device 80 such as the camera 81 and the LiDAR sensor 82.

[0062] Here, a case where the self-driving vehicle body 11 approaches an obstacle such as a structure or a tree existing on, for example, a road or a farmland and enters a dangerous state will be described. The detection device 80 detects obstacles around the vehicle body 11 as the driving situation of the vehicle body 11. The detection device 80 is always in a state of detecting the surrounding situation during driving (step S30). The detection device 80 is at least one of, for example, a camera 81, a LiDAR sensor 82, a millimeter-wave radar 84, an ultrasonic sensor 85, and a microphone sensor 83.

[0063] When the control device 70 detects an obstacle by the detection device 80, it obtains the distance between the obstacle and the vehicle body 11, and compares this distance with a threshold value set in the control device 70. This comparison determines whether the driving situation of the vehicle body 11 is dangerous (collision) (step S40).

[0064] When the distance between the obstacle detected by the detection device 80 and the vehicle body 11 is equal to or less than a predetermined distance (in the case of "Yes" in step S40), the vehicle body 11 executes an operation to avoid danger (step S50). That is, the vehicle body 11 executes an operation to avoid the obstacle. Or, it executes an operation to stop its driving. Specifically, the driving control unit 701 controls the steering device 39 to cause the vehicle body 11 to drive in a detour so as to avoid contact with the obstacle. Or, it controls one or both of the motor 31 and the gear case 33 to stop the driving of the vehicle body 11.

[0065] Furthermore, when the distance between the obstacle and the vehicle body 11 is equal to or less than a predetermined distance (in the case of "Yes" in step S40), assuming that the driving situation of the vehicle body 11 is dangerous, the safety valve 60 is closed by the valve control unit 703 (step S60). That is, the power supply to the safety valve 60 is cut off. In this way, when it is determined that the driving situation of the vehicle body 11 obtained from the detection information of the detection device 80 is dangerous, the safety valve 60 is closed as a precaution.

[0066] As described above, in accordance with the vehicle body 11 traveling by automatic driving based on the detection information of the detection device 80 (steps S20 and S30), the detection information detected by the detection device 80 is used to determine whether the driving situation of the vehicle body 11 is dangerous (step S40). When the driving situation is dangerous, the safety valve 60 that is in an open state during normal driving is closed (step S60).

[0067] Here, an example is described where the vehicle body 11 that is automatically driving travels on a road with an uneven slope and the driving posture collapses and becomes dangerous, such as when there is a possibility of tipping over. The detection device 80 detects the posture of the vehicle body 11, that is, the inclination angle of the vehicle body 11. For this purpose, the detection device 80 that functions here has an inertial measurement device 77 by one or both of a gyro sensor and an acceleration sensor in addition to the camera 81 and the LiDAR sensor 82. When the vehicle body 11 is traveling on a flat surface, the inclination angle is zero. The inclination angle increases as the vehicle body 11 tilts.

[0068] The fuel cell 24 of the work vehicle 10 receives the supply of hydrogen gas from the tank 13 and generates electricity (step S10 in FIG. 5). The motor 31 is driven by the electric power generated by the fuel cell 24, and the vehicle body 11 travels (step S20). In step S20, the vehicle body 11 travels based on the detection information detected by the detection device 80. For example, the vehicle body 11 travels by automatic driving based on the detection information of the detection device 80 such as the camera 81 and the LiDAR sensor 82.

[0069] The inertial measurement device 77 (detection device 80) detects at least one of the posture, vibration, and acceleration of the vehicle body 11 as the driving situation of the vehicle body 11. The inertial measurement device 77 (detection device 80) always detects the posture etc. of the vehicle body 11 during driving (step S30).

[0070] When the tilt angle (posture) of the vehicle body 11 is detected, the control device 70 compares the tilt angle with a threshold value set in the control device 70. This comparison determines whether the driving situation of the vehicle body 11 is dangerous (risk of tipping over) (step S40).

[0071] When the vehicle body is running by automatic driving, for example, when the vehicle body 11 is largely tilted and the possibility of tipping over is estimated (in the case of "Yes" in step S40), the safety valve 60 that is open during normal driving is closed (step S60). That is, the power supply to the safety valve 60 is cut off. Furthermore, the driving control unit 701 controls one or both of the motor 31 and the gear case 33 and stops the running of the vehicle body 11 as a danger avoidance operation (step S50).

[0072] As described above, even when the work vehicle 10 may collide with an obstacle or when the work vehicle 10 is likely to tip over, in accordance with the vehicle body 11 running based on the detection information of the detection device 80 (steps S20, S30), the detection information detected by the detection device 80 is used to determine whether the driving situation of the vehicle body is dangerous (step S40). When the driving situation is dangerous, the safety valve 60 that is open during normal driving is closed (step S60). Therefore, it is possible to cut off the supply of hydrogen gas from the tank 13 in advance. Thus, leakage of hydrogen gas is prevented.

[0073] The return operation of the safety valve 60 will be described. Even if the determination unit 702 estimates the danger of the vehicle body 11 and then determines that it is not dangerous based on the detection information of the detection device 80, the valve control unit 703 opens the safety valve 60 that was once in the closed state. For example, when it is determined that there is no possibility of danger, that is, no possibility of collision, because the work vehicle 10 performs an avoidance operation, the valve control unit 703 returns the safety valve 60 to the open state. Or, when it is determined that the inclination angle then becomes small and there is no possibility of tipping over, the valve control unit 703 returns the safety valve 60 to the open state.

[0074] Another example of the return operation of the safety valve 60 will be described. As described above, the work vehicle 10 has an operating device 73 (see FIG. 4) operated by a user (the driver of the work vehicle 10) inside the cabin 16. The operating device 73 includes a return button. When it is confirmed by the user that the work vehicle 10 will not collide with an obstacle or will not tip over, the return button is operated.

[0075] When the return button is operated (in the case of "Yes" in step S100 of FIG. 5), the operating device 73 outputs a signal for return to the control device 70 (the travel control unit 701, the valve control unit 703). When the control device 70 acquires a signal for return from the operating device 73, the safety valve 60 is switched from the closed state to the open state by the valve control unit 703 (step S110). That is, by supplying power to the safety valve 60, the safety valve 60 becomes open.

[0076] If the vehicle body 11 is already performing an operation to avoid an obstacle (step S50), when the safety valve 60 is switched from the closed state to the open state (step S110), the vehicle body 11 stops the operation of avoiding the obstacle (step S120). That is, the avoidance operation is interrupted. In the case of automatic driving, an operation for starting automatic driving is performed again (step S130). Or, if the vehicle body 11 has already executed an operation to stop running in order to avoid an obstacle (step S50), when the safety valve 60 switches from the closed state to the open state (step S110), the operation to stop the running is stopped (step S120). That is, it enters a standby state where restarting of running becomes possible. In the case of automatic driving, an operation for starting automatic driving is performed again (step S130).

[0077] In this way, when the travel control unit 701 acquires a signal from the operation device 73 operated by the user (step S120), it can execute control to cancel the driving for danger avoidance and return the vehicle body 11 to a state where normal running is possible. That is, when safety is confirmed, based on the operation of the user, the work vehicle 10 returns to the state before it was determined to be dangerous.

[0078] As described above, the work vehicle 10 of the present embodiment has a detection device 80 that detects the running state of the vehicle body 11. The control device 70 included in the work vehicle 10 can execute a travel control process for controlling the running of the vehicle body 11, a determination process for estimating the danger (abnormality) of the vehicle body 11 based on the detection information of the detection device 80, and a valve control process for executing control to close the safety valve 60 when it is estimated to be dangerous by the determination process.

[0079] The travel control process is executed by the travel control unit 701. The determination process is executed by the determination unit 702. The valve control process is executed by the valve control unit 703. The travel control unit 701 can execute control for automatic driving of the vehicle body 11 based on information from a sensor device mounted on the vehicle body 11. In the case of the present embodiment, the sensor device is a camera 81 and a LiDAR sensor 82. The sensor device (camera 81 and LiDAR sensor 82) for this automatic driving functions as the detection device 80 and outputs detection information to the determination unit 702.

[0080] The camera 81 and the LiDAR sensor 82 (sensor device) used for autonomous driving detect the surrounding obstacles and the vehicle state of the vehicle body 11 as the driving situation of the vehicle body 11. The determination unit 702 estimates the risk of the vehicle body 11 based on the detection information of the sensor device composed of the camera 81 and the LiDAR sensor 82. That is, for risk estimation, the sensor device for autonomous driving is utilized as the detection device 80. There is no need to separately provide a dedicated sensor for risk estimation.

[0081] Note that the sensor device may include at least one of the camera 81, the LiDAR sensor 82, the millimeter-wave radar 84, the ultrasonic sensor 85, and the microphone sensor 83. The sensor device functioning as the detection device 80 can detect the obstacles around the vehicle body 11 as the driving situation. As described above, when an obstacle is detected and the possibility of a collision with the obstacle is estimated while the vehicle body 11 is traveling by autonomous driving, the safety valve 60 is closed and the supply of hydrogen gas from the tank 13 is shut off.

[0082] When the sensor device mounted on the vehicle body 11 includes one or both of a gyro sensor and an acceleration sensor, that is, when the sensor device is the inertial measurement device 77, the sensor device (inertial measurement device 77) functioning as the detection device 80 can detect at least one of the posture, vibration, and acceleration of the vehicle body 11 as the driving situation. As described above, when the vehicle body is traveling by autonomous driving and, for example, the vehicle body 11 is greatly tilted and the possibility of tipping over is estimated, the safety valve 60 is closed and the supply of hydrogen gas from the tank 13 is shut off.

[0083] And in the case of this embodiment, when the determination unit 702 estimates a risk, the driving control unit 701 can execute driving control for risk avoidance (stopping of driving, stopping of autonomous driving). When danger is estimated, the hydrogen supplied from the tank 13 to the fuel cell 24 is shut off, and as an operation for avoiding danger, for example, the work vehicle 10 can make an emergency stop. Therefore, it is possible to avoid a collision with an obstacle or to avoid the work vehicle 10 from falling even if it tries to fall.

[0084] 〔Automatic driving of the work vehicle 10〕 A specific example of automatic driving will be described. The work vehicle 10 requires a target route for automatic driving. The target route is generated before the automatic driving is started. The target route is generated by the control device 70 of the work vehicle 10. Alternatively, a computer of a management device other than the work vehicle 10 may generate the target route. In this case, the work vehicle 10 acquires the information of the target route through the communication device.

[0085] FIG. 6 is an explanatory diagram showing a state in which the work vehicle 10 travels on the road 8 outside the farm field 7 by automatic driving. When the work vehicle 10 travels on the road 8 by automatic driving, the work vehicle 10 requires information on the environmental map. The environmental map is map information of the environment in which the work vehicle 10 moves, and includes map information such as the farm field 7 and the road 8 for moving between the farm fields 7. The target route G is generated based on the map information. That is, when the arrival destination is set in the map information, a route from the current position of the work vehicle 10 to the destination is generated as the target route G. In the case of FIG. 6, the target route G along the road 8 is generated. The information of the target route G is stored in the storage device of the control device 70 together with the map information.

[0086] FIG. 7 is an explanatory diagram of the target route G when automatic driving is performed in the farm field 7. The farm field 7 includes a work area 7a where the work vehicle 10 performs work and a headland 7b located near the outer periphery of the farm field 7. Which area of the farm field 7 corresponds to the work area 7a or the headland 7b is set by the user. The target path G in the field 7 includes a plurality of parallel main paths P1 and a turning path P2 connecting two main paths P1. The main path P1 is located in the working area 7a, and the turning path P2 is located in the headland 74. Although the main path P1 shown in FIG. 7 is linear, the main path P1 may include a curved portion.

[0087] The interval between the dashed lines in FIG. 7 represents the working width of the working machine (implement) 50. The working width is preset and stored in the storage device of the control device 70. The working width is input to the control device 70 by the user (driver) operating the operating device in the cabin 16. The working width may be automatically recognized and input to the control device 70 when the working machine 50 is connected to the work vehicle 10. The interval between adjacent main paths P1 is set according to the working width. The target path G is created so as to pass through (cover) the entire working area 7a. The work vehicle 10 automatically travels along the target path G, repeating a round trip from the start point S of the work to the end point G of the work.

[0088] When the target path G for the outside of the field 7 or the inside of the field 7 is generated, automatic driving becomes possible. FIG. 8 is a flowchart showing an example of control for automatic driving. The travel control unit 701 (see FIG. 4) performs automatic steering by executing the processes from steps S201 to S205 shown in FIG. 8 during the travel of the work vehicle 10. The travel speed of the work vehicle 10 is maintained at a preset value, but may be automatically changed during the journey.

[0089] The travel control unit 701 acquires the position information of the work vehicle 10 obtained by the positioning device 76 during the travel of the work vehicle 10 (step S201). The position information is information indicating the current position of the work vehicle 10. The travel control unit 701 obtains the deviation E between the current position of the work vehicle 10 and the target path G (step S202). FIG. 9 is an explanatory diagram of a work vehicle 10 traveling by automatic driving. Deviation E is the difference between the current position of the work vehicle 10 and the target route G, and is, for example, a distance. The travel control unit 701 determines whether or not the deviation E exceeds a threshold value (step S203 in FIG. 8).

[0090] When the deviation E exceeds the threshold value (in the case of “Yes” in step S203), the travel control unit 701 outputs a command signal to the control unit of the steering device 39 (see FIG. 2) in order to reduce the deviation E. When receiving the command signal, the steering device 39 changes the steering angle (step S204). The steering angle is changed until the deviation E becomes equal to or less than the threshold value. In step S203, when the deviation E is equal to or less than the threshold value, step S204 is skipped.

[0091] In the case of the present embodiment (see FIG. 9), the steering device 39 is controlled based on the deviation E between the current position of the work vehicle 10 and the target route G, but control may be performed by further adding the deviation in azimuth. For example, the travel control unit 701 determines whether or not an angular difference between the direction of the work vehicle 10 specified by one or both of the positioning device 76 and the inertial measurement device 77 and the direction of the target route G exceeds a preset threshold value. Note that the angular difference is the deviation in azimuth. When the angular difference exceeds the threshold value, the control parameter (for example, the steering angle) of the steering device 39 is changed according to the deviation.

[0092] Step S205 in FIG. 8 is a step of determining whether or not the travel control unit 701 has received a command to end the operation. The command to end the operation is issued, for example, in the following cases. 1) The administrator (user) instructs the stop of the automatic driving by, for example, remote operation 2) The work vehicle 10 reaches the destination (end position)

[0093] When the travel control unit 701 does not receive the command to end the operation (in the case of “No” in step S205), it returns to step S201 and executes the following similar processing. The travel control unit 701 repeats the operations from steps S201 to S205 until it receives the command to end the operation.

[0094] When the traveling control unit 701 detects an obstacle by the detection device 80 during any step in the processes from steps S201 to S205 for automatic driving as described above, it can execute avoidance driving to avoid the obstacle. That is, while the work vehicle 10 is traveling, the camera 81 which is the detection device 80 captures the surrounding environment, and the LiDAR sensor 82 which is the detection device 80 senses the surrounding objects. Based on the detection information of the detection device 80, a danger avoidance operation can be executed (step S50 in FIG. 5). Further, the safety valve 60 is closed (step S60 in FIG. 5).

[0095] [Others] The above-described embodiments are illustrative in all respects and not restrictive. The scope of the rights of the present invention is indicated by the claims rather than the above-described embodiments, and includes all modifications within the scope equivalent to the configurations described in the claims.

Explanation of Reference Numerals

[0096] 10 Work vehicle (working machine) 11 Vehicle body 13 Tank 21 Tank unit 24 Fuel cell 60 Safety valve (valve) 70 Control device 73 Operating device 80 Detection device 82 LiDAR sensor 84 Millimeter-wave radar 85 Ultrasonic sensor 211 Support member

Claims

1. A vehicle body capable of traveling, a tank mounted on the vehicle body, a fuel cell, a valve capable of shutting off a supply path from the tank to the fuel cell, a detection device provided on the vehicle body, and having, the vehicle body travels based on detection information of the detection device, the valve is closed when it is determined that the traveling state of the vehicle body obtained from the detection information is dangerous, a working machine.

2. The detection device can detect obstacles around the vehicle body, when the position between the obstacle detected by the detection device and the vehicle body is equal to or less than a predetermined distance, the vehicle body executes an operation to avoid the obstacle or an operation to stop the traveling, the valve is closed assuming that the traveling state is dangerous when the position between the obstacle and the vehicle body is equal to or less than a predetermined distance, The working machine according to claim 1.

3. The detection device includes at least one of a LiDAR sensor, a millimeter-wave radar, and an ultrasonic sensor, the valve is closed based on the detection information detected by at least one of the LiDAR sensor, the millimeter-wave radar, and the ultrasonic sensor, The working machine according to claim 1.

4. When acquiring a signal from an operating device operated by a user, the valve switches from a closed state to an open state, The working machine according to claim 1.

5. When the valve switches from a closed state to an open state, the vehicle body stops an operation to avoid the obstacle or an operation to stop the traveling, The working machine according to claim 4.

6. having a tank unit having the tank and a support member supporting the tank, the valve is provided in the tank unit, The working machine according to claim 1.

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