Obstacle Detection System

Abstract

To confirm that an obstacle sensor is functioning normally while avoiding deterioration in work efficiency by execution of travelling control based on the detection by the obstacle sensor for detecting an obstacle in a direction opposite to a work vehicle travelling direction.SOLUTION: When an obstacle is detected by a front obstacle sensor 86 or a rear obstacle sensor 87 whose obstacle detection range corresponds to a travelling direction of a work vehicle in an obstacle detection system, a control unit 23 causes an obstacle detection position to be displayed in a display unit, and executes collision avoidance control according to the obstacle detection position. When an obstacle is detected by the front obstacle sensor 86 or the rear obstacle sensor 87 whose obstacle detection range does not correspond to the travelling direction of the work vehicle, the control unit causes an obstacle detection position to be displayed in the display unit without executing the collision avoidance control according to the obstacle detection position.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an obstacle detection system provided in a work vehicle such as a tractor or a riding grass cutter. [Background technology]

[0002] An example of such an obstacle detection system includes a front obstacle sensor (front lidar sensor) that uses laser light to measure in three dimensions the distance to a measurement object located in front of the work vehicle, a rear obstacle sensor (rear lidar sensor) that uses laser light to measure in three dimensions the distance to a measurement object located in the rear of the work vehicle, an obstacle detection unit that detects obstacles based on measurement information from the front and rear obstacle sensors, and a collision avoidance control unit that performs collision avoidance control to avoid the work vehicle colliding with an obstacle detected by the obstacle detection unit, etc. In this obstacle detection system, when the work vehicle travels forward, measurement is performed by the front obstacle sensor and the obstacle detection unit is switched to a forward detection state in which it detects an obstacle based on measurement information from the front obstacle sensor, and when the work vehicle travels backward, measurement is performed by the rear obstacle sensor and the obstacle detection unit is switched to a backward detection state in which it detects an obstacle based on measurement information from the rear obstacle sensor (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-168888 A Summary of the Invention [Problem to be solved by the invention]

[0004] That is, in the technology described in Patent Document 1, when the traveling direction of the work vehicle is the forward direction, obstacle detection based on the measurement information of the rear obstacle sensor, whose obstacle detection range is set in the opposite direction (reverse direction), is stopped, and when the traveling direction of the work vehicle is the reverse direction, obstacle detection based on the measurement information of the front obstacle sensor, whose obstacle detection range is set in the opposite direction (forward direction), is stopped. This makes it possible to avoid a decrease in work efficiency caused by the collision avoidance control unit performing collision avoidance control for obstacles that are not at risk of colliding with the work vehicle, based on the measurement information of either the front or rear obstacle sensor that measures the opposite direction from the traveling direction of the work vehicle.

[0005] On the other hand, in the technology described in Patent Document 1, for example, when a work vehicle is traveling forward and an obstacle such as a person is present near the rear of the work vehicle, the obstacle is not detected based on the measurement information of the rear obstacle sensor, and the user is not notified of the presence of the obstacle, which may lead the user to suspect that the rear obstacle sensor may not be functioning properly.

[0006] In view of this situation, the main objective of the present invention is to provide an obstacle detection system that can easily confirm that obstacle sensors that do not correspond to the work vehicle's traveling direction are functioning normally when an obstacle is present in the opposite direction to the work vehicle's traveling direction, while avoiding the aforementioned decrease in work efficiency. [Means for solving the problem]

[0007] A first characteristic configuration of the present invention is an obstacle detection system, a front obstacle sensor having an obstacle detection range set to the front side of the work vehicle; a rear obstacle sensor, the detection range of which is set to the rear side of the work vehicle; a display unit that displays the positions of the obstacles detected by the front obstacle sensor and the rear obstacle sensor; a control unit that determines a traveling direction of the work vehicle and controls the obstacle including the display on the display unit based on the determination result and the detection information of the front obstacle sensor and the rear obstacle sensor, when the obstacle is detected by the front obstacle sensor or the rear obstacle sensor, the detection range of which corresponds to the traveling direction of the work vehicle, the control unit displays the detected position of the obstacle on the display unit and executes collision avoidance control according to the detected position of the obstacle, When an obstacle is detected by the front obstacle sensor or the rear obstacle sensor, whose detection range does not correspond to the travel direction of the work vehicle, the control unit does not execute the collision avoidance control, but displays the detected position of the obstacle on the display unit.

[0008] According to this configuration, when an obstacle is detected by either the front or rear obstacle sensor, whose obstacle detection range corresponds to the direction of travel of the work vehicle, the detected position of the obstacle at that time is displayed on the display unit and collision avoidance control is executed according to the detected position of the obstacle, so that the user can be informed of the detected position of the obstacle and the risk of the work vehicle colliding with an obstacle that exists in the direction of travel of the work vehicle can be avoided.

[0009] On the other hand, if an obstacle is detected by either the front or rear obstacle sensor, whose detection range does not correspond to the direction of travel of the work vehicle, the detection position of the obstacle at that time is simply displayed on the display unit, and collision avoidance control is not executed according to the detection position of the obstacle. Therefore, the detection position of the obstacle can be notified to the user while avoiding control of the work vehicle's travel, etc. according to the detection position of an obstacle that is located in the opposite direction to the work vehicle's direction of travel and therefore is not at risk of colliding with.

[0010] As a result, when an obstacle is present in the opposite direction to the work vehicle's travel direction, it is possible to provide an obstacle detection system that allows the user to easily confirm that either the front or rear obstacle sensor, whose obstacle detection range does not correspond to the work vehicle's travel direction, is functioning normally, while avoiding a decrease in work efficiency caused by collision avoidance control being executed according to the detected position of an obstacle with which the work vehicle is not likely to collide.

[0011] The second characteristic configuration of the present invention is as follows: The control unit is included in an automatic driving unit that enables automatic driving of the work vehicle, The display unit is provided in a wireless communication device that is set to be able to wirelessly communicate with the automatic driving unit.

[0012] According to this configuration, when an obstacle is present in the traveling direction of the automatically traveling work vehicle, the obstacle is detected by either the front or rear obstacle sensor whose obstacle detection range corresponds to the traveling direction of the work vehicle, and the detection position of the obstacle by either the front or rear obstacle sensor is displayed on the display unit of the wireless communication device. Also, when an obstacle is present in the opposite direction to the traveling direction of the automatically traveling work vehicle, the obstacle is detected by either the front or rear obstacle sensor whose obstacle detection range does not correspond to the traveling direction of the work vehicle, and the detection position of the obstacle by either the front or rear obstacle sensor is displayed on the display unit of the wireless communication device.

[0013] As a result, while enabling the work vehicle to travel automatically, the user monitoring the work vehicle's automatic travel can easily confirm that the front and rear obstacle sensors are functioning normally.

[0014] The third characteristic configuration of the present invention is as follows: If there is a following work vehicle following the work vehicle while the work vehicle is traveling forward, when the following work vehicle enters the detection range of the rear obstacle sensor, the rear obstacle sensor detects the following work vehicle as an obstacle.

[0015] According to this configuration, during accompanying work in which a following work vehicle is present, for example, if the following work vehicle is driven within the detection range of the rear obstacle sensor at a certain distance from the leading work vehicle, the detection position of the following work vehicle by the rear obstacle sensor at this time will be displayed on the display unit.

[0016] Furthermore, since the detection range of the rear obstacle sensor at this time does not correspond to the direction of travel of the work vehicle, collision avoidance control according to the detected position of the pursuing work vehicle is not executed based on the detection information of the rear obstacle sensor at this time.

[0017] As a result, a user monitoring the travel of the work vehicle and the pursuing work vehicle can easily grasp the position of the pursuing work vehicle relative to the work vehicle, while avoiding a decrease in work efficiency caused by collision avoidance control being performed based on the detected position of the pursuing work vehicle, and can easily confirm that the rear obstacle sensor is functioning normally. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an automatic driving system for a work vehicle. [Diagram 2] A plan view of the tractor showing the imaging range of each camera. [Diagram 3] A side view of the tractor showing the measurement range of each obstacle sensor. [Figure 4] A plan view of the tractor showing the measurement range of each obstacle sensor. [Diagram 5] FIG. 1 is a plan view showing an example of a target route for automatic driving; [Figure 6] A block diagram showing the schematic configuration of an automatic driving system for a work vehicle. [Figure 7] Block diagram showing the schematic configuration of the obstacle detection system, etc. [Figure 8] FIG. 13 is a diagram showing an obstacle detection range and a non-detection range in a distance image of a front obstacle sensor; [Figure 9] FIG. 13 is a diagram showing an obstacle detection range and a non-detection range in a distance image of a rear obstacle sensor when the work implement is in a lowered state; [Figure 10] FIG. 13 is a diagram showing an obstacle detection range and a non-detection range in a distance image of a rear obstacle sensor when the working implement is in a raised state; [Figure 11] FIG. 13 is a diagram showing the display state of the display unit when no obstacle is detected by each obstacle sensor. [Figure 12] FIG. 13 is a diagram showing a display state of the display unit when an obstacle is detected by the front obstacle sensor within the deceleration control range of the first detection range. [Figure 13] FIG. 13 is a diagram showing a display state of the display unit when an obstacle is detected by the front obstacle sensor within the stop control range of the first detection range. [Figure 14] FIG. 13 is a diagram showing the display state of the display unit when an obstacle is detected in the third detection range by the lateral obstacle sensor; [Figure 15] FIG. 13 is a diagram showing a display state of the display unit when dirt or the like is attached to the sensor surface of the front obstacle sensor or the rear obstacle sensor; [Figure 16] FIG. 13 is a diagram showing a display state of the display unit when the first detection range of the front obstacle sensor is set to an obstacle detection prohibited range. [Figure 17] FIG. 13 shows a display state of the display unit when detection information from each obstacle sensor cannot be received. [Figure 18] Flowchart showing the control operation of the automatic driving control unit in obstacle display control [Figure 19] Flowchart showing the control operation of the automatic driving control unit in obstacle display control [Figure 20] A flowchart showing the control operation of the automatic driving control unit in collision avoidance control. [Figure 21] A flowchart showing the control operation of the automatic driving control unit in the first collision avoidance process of the collision avoidance control. [Figure 22] A flowchart showing the control operation of the automatic driving control unit in the second collision avoidance process of the collision avoidance control. [Diagram 23] Flowchart showing the control operation of the automatic driving control unit in the dirt driving control [Figure 24] A flowchart showing the control operation of the automatic driving control unit in the detection status display control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, as one example of a mode for carrying out the present invention, an embodiment in which an obstacle detection system according to the present invention is applied to a tractor, which is an example of a work vehicle, will be described with reference to the drawings.

[0020] Furthermore, the obstacle detection system of the present invention can be applied to automatically-driving ride-on work vehicles other than tractors, such as ride-on cultivation machines, ride-on lawn mowers, ride-on rice transplanters, combines, snowplows, wheel loaders, and transporters, as well as unmanned work vehicles such as unmanned tillers and unmanned lawn mowers.

[0021] 1 to 4, the tractor 1 illustrated in this embodiment is connected to a rotary tilling device 3, which is an example of a working device, via a link mechanism 2 provided at the rear of the tractor 1 so that the rotary tilling device 3 can be raised, lowered, and rolled. As a result, the tractor 1 is configured with rotary tilling specifications that enable tilling work to be performed using the rotary tilling device 3.

[0022] Incidentally, the working implement connected to the rear of the tractor 1 may be, other than the rotary tilling implement 3, for example, a plow, a disc harrow, a cultivator, a subsoiler, a seeding implement, a spreading implement, a grass cutting implement, a harvesting implement, and the like.

[0023] By using an automatic driving system for work vehicles, the tractor 1 can be made to automatically travel in a field A, which is an example of a work site shown in Fig. 5. As shown in Figs. 1 and 6, the automatic driving system for work vehicles includes an automatic driving unit 4 mounted on the tractor 1, and a mobile communication terminal 5, which is an example of a wireless communication device set to be able to wirelessly communicate with the automatic driving unit 4. The mobile communication terminal 5 is equipped with a multi-touch display device (an example of a display unit) 50 that allows various information related to automatic driving to be displayed and input operations to be performed.

[0024] A tablet-type personal computer, a smartphone, or the like can be used as the mobile communication terminal 5. For wireless communication, a wireless LAN (Local Area Network) such as Wi-Fi (registered trademark) or a short-distance wireless communication such as Bluetooth (registered trademark) can be used.

[0025] 1 to 3 and 6, the tractor 1 is equipped with left and right front wheels 10 that can be driven and steered, left and right rear wheels 11 that can be driven, a cabin 13 forming a riding driver's section 12, an electronically controlled diesel engine (hereinafter referred to as the engine) 14 having a common rail system, a bonnet 15 that covers the engine 14 and the like, and a speed change unit 16 that changes the speed of the power from the engine 14. Note that an electronically controlled gasoline engine having an electronic governor or the like may be used as the engine 14.

[0026] As shown in Fig. 6, the tractor 1 is equipped with a fully hydraulic power steering unit 17 for steering the left and right front wheels 10, a brake unit 18 for braking the left and right rear wheels 11, an electronically controlled working clutch unit 19 for connecting and disconnecting power transmission to the rotary tilling device 3, an electronically controlled lifting drive unit 20 for lifting and lowering the rotary tilling device 3, an electronically controlled rolling unit 21 for driving the rotary tilling device 3 in the roll direction, a vehicle state detection device 22 including various sensors and switches for detecting various settings and operating states of each part of the tractor 1, and an on-board control unit 23 having various control parts. Note that the power steering unit 17 may be an electric type having an electric motor for steering.

[0027] 1 and 3, the driving section 12 is equipped with a steering wheel 25 for manual steering, a seat 26 for a passenger, and an operation terminal 27 that enables various information displays and input operations. Although not shown, the driving section 12 is equipped with operation levers such as an accelerator lever and a gear lever, and operation pedals such as an accelerator pedal and a clutch pedal. A multi-touch liquid crystal monitor or an ISOBUS-compatible virtual terminal can be used as the operation terminal 27.

[0028] Although not shown, the transmission unit 16 includes an electronically controlled continuously variable transmission that changes the speed of the power from the engine 14, and an electronically controlled forward / reverse switching device that switches the power after the speed change by the continuously variable transmission between forward and reverse. The continuously variable transmission employs an I-HMT (Integrated Hydro-static Mechanical Transmission), which is an example of a hydromechanical continuously variable transmission with higher transmission efficiency than a hydrostatic continuously variable transmission (HST: Hydro Static Transmission). The forward / reverse switching device includes a hydraulic clutch for interrupting forward power, a hydraulic clutch for interrupting reverse power, and an electromagnetic valve for controlling the flow of oil to these.

[0029] Instead of the I-HMT, the continuously variable transmission may be an HMT (Hydraulic Mechanical Transmission), which is an example of a hydromechanical continuously variable transmission, a hydrostatic continuously variable transmission, or a belt type continuously variable transmission. Also, instead of the continuously variable transmission, the transmission unit 16 may include an electronically controlled stepped transmission having a plurality of hydraulic clutches for shifting and a plurality of electromagnetic valves for controlling the flow of oil to the clutches.

[0030] Although not shown in the figure, the brake unit 18 includes left and right brakes that brake the left and right rear wheels 11 individually, a foot brake system that activates the left and right brakes in conjunction with depressing the left and right brake pedals provided on the driver's unit 12, a parking brake system that activates the left and right brakes in conjunction with operating a parking lever provided on the driver's unit 12, and a turning brake system that activates the brakes on the inside of a turn in conjunction with steering the left and right front wheels 10 beyond a set angle.

[0031] The vehicle condition detection device 22 is a collective term for various sensors, switches, etc. provided in various parts of the tractor 1. As shown in Fig. 7, the vehicle condition detection device 22 includes a vehicle speed sensor 22A that detects the vehicle speed of the tractor 1, a reverser sensor 22B that detects the operating position of a reverser lever for switching between forward and reverse, and a steering angle sensor 22C that detects the steering angle of the front wheels 10. In addition, although not shown, the vehicle condition detection device 22 also includes a rotation sensor that detects the output speed of the engine 14, an accelerator sensor that detects the operating position of an accelerator lever, and a gear shift sensor that detects the operating position of a gear shift lever.

[0032] As shown in Figs. 6-7, the vehicle-mounted control unit 23 includes an engine control unit 23A that controls the engine 14, a transmission unit control unit 23B that controls the transmission unit 16 such as the vehicle speed of the tractor 1 and switching between forward and reverse, a steering control unit 23C that controls steering, an implement control unit 23D that controls implements such as the rotary tiller 3, a display control unit 23E that controls display and notification on the operation terminal 27, an automatic driving control unit 23F that controls automatic driving, and a non-volatile vehicle-mounted storage unit 23G that stores a target route P for automatic driving (see Fig. 5) generated according to the field A. Each of the control units 23A-23F is constructed by an electronic control unit in which a microcontroller or the like is integrated, various control programs, and the like. Each of the control units 23A-23F is connected to be able to communicate with each other via a CAN (Controller Area Network).

[0033] For the mutual communication between the control units 23A to 23F, a communication standard other than CAN or a next-generation communication standard, such as in-vehicle Ethernet or CAN-FD (CAN with Flexible Data rate), may be adopted.

[0034] The engine control unit 23A executes engine speed maintenance control for maintaining the engine speed at a speed corresponding to the operating position of the accelerator lever, based on detection information from the accelerator sensor and detection information from the rotation sensor.

[0035] The speed change unit control section 23B executes vehicle speed control for controlling the operation of the continuously variable transmission so that the vehicle speed of the tractor 1 is changed to a speed corresponding to the operating position of the speed change lever based on detection information from the speed change sensor and vehicle speed sensor 22A, and forward / reverse switching control for switching the transmission state of the forward / reverse switching device based on detection information from the reverser sensor 22B. The vehicle speed control includes a deceleration / stop process for decelerating the continuously variable transmission to a zero speed state and stopping the travel of the tractor 1 when the speed change lever is operated to the zero speed position.

[0036] The working device control section 23D executes a work clutch control for controlling the operation of the work clutch unit 19 based on the operation of a PTO switch provided in the driving section 12, a lift control for controlling the operation of the lift drive unit 20 based on the operation of a lift switch provided in the driving section 12 and the setting value of a height setting dial, and a rolling control for controlling the operation of the rolling unit 21 based on the setting value of a roll angle setting dial provided in the driving section 12. The PTO switch, the lift switch, the height setting dial, and the roll angle setting dial are included in the vehicle state detection device 22.

[0037] As shown in FIG. 6, the tractor 1 is provided with a positioning unit 30 that measures the position and orientation of the tractor 1. The positioning unit 30 includes a satellite navigation device 31 that measures the position and orientation of the tractor 1 using a global navigation satellite system (GNSS), which is an example of a satellite positioning system, and an inertial measurement unit (IMU) 32 that has a three-axis gyroscope and a three-directional acceleration sensor and measures the attitude and orientation of the tractor 1. Positioning methods using the GNSS include DGNSS (Differential GNSS: relative positioning method) and RTK-GNSS (Real Time Kinematic GNSS: interferometric positioning method). In this embodiment, RTK-GNSS, which is suitable for positioning a moving object, is adopted. Therefore, as shown in FIG. 1, a base station 6 that enables positioning by RTK-GNSS is installed at a known position around the field.

[0038] As shown in Fig. 1 and Fig. 6, the tractor 1 and the base station 6 are each provided with a GNSS antenna 33, 60 for receiving radio waves transmitted from a positioning satellite 7 (see Fig. 1), and a communication module 34, 61 for enabling wireless communication of information including positioning information between the tractor 1 and the base station 6. This allows the satellite navigation device 31 of the positioning unit 30 to measure the position and orientation of the tractor 1 with high accuracy based on the positioning information obtained by the GNSS antenna 33 of the tractor 1 receiving radio waves from the positioning satellite 7 and the positioning information obtained by the GNSS antenna 60 of the base station 6 receiving radio waves from the positioning satellite 7. In addition, the positioning unit 30 has the satellite navigation device 31 and the inertial measurement unit 32, and thus can measure the position, orientation, and attitude angles (yaw angle, roll angle, and pitch angle) of the tractor 1 with high accuracy.

[0039] In this tractor 1, the inertial measurement unit 32, the GNSS antenna 33, and the communication module 34 of the positioning unit 30 are included in an antenna unit 35 shown in Fig. 1. The antenna unit 35 is disposed in the center of the upper left and right sides on the front side of the cabin 13.

[0040] Although not shown in the figure, the vehicle body position is set to the rear axle center position when identifying the position of the tractor 1. The vehicle body position can be obtained from positioning information from the positioning unit 42 and vehicle body information including the positional relationship between the mounting position of the GNSS antenna 45 in the tractor 1 and the rear axle center position.

[0041] 6, the mobile communication terminal 5 includes an electronic control unit in which a microcontroller and the like are integrated, a terminal control unit 51 having various control programs, and the like. The terminal control unit 51 includes a display control unit 51A that controls display and notification on the display device 50 and the like, a target route generating unit 51B that generates a target route P for automatic driving, and a non-volatile terminal storage unit 51C that stores the target route P generated by the target route generating unit 51B, and the like. The terminal storage unit 51C stores various information used in generating the target route P, such as vehicle body information such as the turning radius of the tractor 1 and the working width or number of working rows of a working implement such as the rotary tilling implement 3, and field information obtained from the positioning information described above. The field information includes four corner points Cp1 to Cp4 (see Figure 5), which are multiple shape identification points (shape identification coordinates) in field A obtained using GNSS when tractor 1 is driven along the outer edge of field A to identify the shape, size, etc. of field A, and a rectangular shape identification line SL (see Figure 5) that connects these corner points Cp1 to Cp4 and identifies the shape, size, etc. of field A.

[0042] As shown in Fig. 6, the tractor 1 and the mobile communication terminal 5 are provided with communication modules 28, 52 that enable wireless communication of various information including positioning information between the on-board control unit 23 and the terminal control unit 51. When Wi-Fi is adopted for wireless communication with the mobile communication terminal 5, the communication module 28 of the tractor 1 functions as a converter that converts communication information in both directions between CAN and Wi-Fi. The terminal control unit 51 can acquire various information related to the tractor 1 including the position and direction of the tractor 1 through wireless communication with the on-board control unit 23. This allows the display device 50 of the mobile communication terminal 5 to display various information including the position and direction of the tractor 1 relative to the target route P.

[0043] The target route generating unit 51B generates a target route P based on the turning radius of the tractor 1, the working width or number of working furrows of the working implement, which are included in the vehicle body information, and the shape and size of the field A, which are included in the field information.

[0044] For example, as shown in Figure 5, when a start position p1 and end position p2 of automatic driving are set in a rectangular field A, and the work driving direction of the tractor 1 is set to be along the short side of the field A, the target path generating unit 51B first divides the field A into a margin area A1 adjacent to the outer periphery of the field A and a workable area A2 located inside the margin area A1 based on the four corner points Cp1 to Cp4 described above and the rectangular shape specification line SL.

[0045] Next, the target path generating unit 51B divides the workable area A2 into a pair of end areas A2a set at the ends of each long side of the workable area A2 and a central area A2b set between the pair of end areas A2a based on the turning radius of the tractor 1 and the working width or number of working ridges of the working equipment. After that, the target path generating unit 51B generates a plurality of parallel paths P1 in the central area A2b that are arranged in parallel at predetermined intervals according to the working width or the number of working ridges in the direction along the long side of the field A. The target path generating unit 51B also generates a plurality of connecting paths P2 in each end area A2a that connect the plurality of parallel paths P1 in the traveling order of the tractor 1.

[0046] This enables the target route generating unit 51B to generate a target route P along which the tractor 1 can automatically travel from the start position p1 to the end position p2 of the automatic travel set in the field A shown in FIG.

[0047] In the field A shown in Fig. 5, a margin area A1 is an area secured between the outer edge of the field A and the workable area A2 to prevent the working equipment, etc. from contacting other objects such as ridges and fences adjacent to the field A when the tractor 1 automatically travels along the edge of the workable area A2. Each edge area A2a is a direction change area when the tractor 1 changes direction and moves from the currently traveling parallel path P1 to the next parallel path P1 along the connecting path P2. The central area A2b is a working area where the tractor 1 automatically travels in a working state along each parallel path P1.

[0048] In the target route P shown in FIG. 5, each parallel route P1 is a work route along which the tractor 1 automatically travels while performing work using the work implement such as the rotary tiller 3. Each connecting route P2 is a non-work route along which the tractor 1 automatically travels without performing work using the work implement. The start position p3 of each parallel route P1 is a work start position where the tractor 1 starts work using the work implement. The end position p4 of each parallel route P1 is a work stop position where the tractor 1 stops work using the work implement. Among the start positions p3 of each parallel route P1, the start position p3 of the parallel route P1 whose travel order of the tractor 1 is set first is the start position p1 of the automatic travel. And the start position p3 of the remaining parallel route P1 is a connection position with the end position of the connecting route P2. Also, the end position p4 of the parallel route P1 whose travel order of the tractor 1 is set last is the end position p2 of the automatic travel. The end position p4 of the remaining parallel path P1 is the connection position with the start position of the connection path P2.

[0049] Each connecting path P2 includes a direction change path that changes the direction of the tractor 1 from the currently traveling parallel path P1 to the next parallel path P1. Depending on the relationship between the turning radius of the tractor 1 and the working width or number of working furrows of a working implement such as the rotary tilling implement 3, a U-shaped turning path that changes the direction of the tractor 1 in a U-shape and a switchback turning path that uses a switchback to change the direction of the tractor 1 in a fishtail shape can be used as the direction change path.

[0050] Note that the target route P shown in Figure 5 is merely an example, and the target route generating unit 51B can generate various target routes P suitable for the various conditions based on vehicle body information, which differs depending on the model of the tractor 1 and the type of work implement, and field information, such as the shape and size of the field A, which differs depending on the field A.

[0051] The target route P is stored in the terminal storage unit 51C in a state associated with vehicle body information, farm field information, etc., and can be displayed on the display device 50 of the mobile communication terminal 5. The target route P includes various information related to automatic driving, such as the traveling direction (forward or reverse direction) of the tractor 1 set on each parallel route P1, each connecting route P2, etc., the target vehicle speed, and the front wheel steering angle.

[0052] In response to a transmission request command from the on-vehicle control unit 23, the terminal control unit 51 transmits the field information, the target route P, and the like stored in the terminal storage unit 51C to the on-vehicle control unit 23. The on-vehicle control unit 23 stores the received field information, the target route P, and the like in the on-vehicle storage unit 23G. Regarding the transmission of the target route P, for example, the terminal control unit 51 may transmit all of the target route P from the terminal storage unit 51C to the on-vehicle control unit 23 at once at a stage before the tractor 1 starts automatic traveling. Alternatively, the terminal control unit 51 may divide the target route P into a plurality of divided route information for each predetermined distance, and sequentially transmit a predetermined number of divided route information according to the traveling order of the tractor 1 from the terminal storage unit 51C to the on-vehicle control unit 23 each time the traveling distance of the tractor 1 reaches a predetermined distance from a stage before the tractor 1 starts automatic traveling.

[0053] Detection information from various sensors and switches included in the vehicle state detection device 22 is input to the automatic driving control unit 23F via the transmission unit control unit 23B, the steering control unit 23C, etc. This allows the automatic driving control unit 23F to monitor various setting states and the operating states of each unit in the tractor 1.

[0054] When a user such as a passenger or manager performs various manual setting operations to enable automatic driving of the tractor 1 and switches the driving mode of the tractor 1 from manual driving mode to automatic driving mode, and the display device 50 of the mobile communication terminal 5 is operated to instruct the start of automatic driving, the automatic driving control unit 23F starts automatic driving control to cause the tractor 1 to automatically drive according to the target route P while acquiring the position, direction, etc. of the tractor 1 using the positioning unit 30.

[0055] During execution of the automatic driving control, for example, if a user operates the display device 50 of the mobile communication terminal 5 to instruct the end of automatic driving, or if a user in the driver's unit 12 operates a manual operating tool such as the steering wheel 25 or accelerator pedal, the automatic driving control unit 23F terminates the automatic driving control and switches the driving mode from the automatic driving mode to the manual driving mode.

[0056] The automatic driving control by the automatic driving control unit 23F includes an automatic engine control process that sends control commands for automatic driving related to the engine 14 to the engine control unit 23A, an automatic vehicle speed control process that sends control commands for automatic driving related to the vehicle speed and forward / reverse switching of the tractor 1 to the transmission unit control unit 23B, an automatic steering control process that sends control commands for automatic driving related to the steering control unit 23C, and an automatic work control process that sends control commands for automatic driving related to work implements such as the rotary tiller 3 to the work implement control unit 23D.

[0057] In the automatic engine control process, the automatic driving control unit 23F transmits to the engine control unit 23A an engine speed change command that instructs changing the engine speed based on a set speed included in the target route P. The engine control unit 23A executes engine speed change control that automatically changes the engine speed in response to various control commands related to the engine 14 transmitted from the automatic driving control unit 23F.

[0058] In the automatic vehicle speed control process, the automatic travel control unit 23F transmits to the transmission unit control unit 23B a speed change operation command that instructs the speed change operation of the continuously variable transmission based on the target vehicle speed included in the target route P, and a forward / reverse switching command that instructs the forward / reverse switching operation of the forward / reverse switching device based on the traveling direction of the tractor 1 included in the target route P. The transmission unit control unit 23B executes an automobile speed control that automatically controls the operation of the continuously variable transmission, and an automatic forward / reverse switching control that automatically controls the operation of the forward / reverse switching device, in response to various control commands related to the continuously variable transmission and the forward / reverse switching device transmitted from the automatic travel control unit 23F. The automobile speed control includes, for example, an automatic deceleration and stop process that stops the traveling of the tractor 1 by controlling the continuously variable transmission to a zero speed state when the target vehicle speed included in the target route P is zero speed.

[0059] In the automatic control process for steering, the automatic driving control unit 23F transmits to the steering control unit 23C steering commands instructing the steering of the left and right front wheels 10 based on the front wheel steering angle included in the target route P, etc. In response to the steering commands transmitted from the automatic driving control unit 23F, the steering control unit 23C executes automatic steering control for controlling the operation of the power steering unit 17 to steer the left and right front wheels 10, and automatic brake turning control for operating the brake unit 18 to apply the brakes on the inside of the turn when the left and right front wheels 10 are steered beyond a set angle.

[0060] In the automatic control process for work, the automatic travel control unit 23F transmits to the work equipment control unit 23D a work start command that instructs switching of the work equipment, such as the rotary tiller 3, to a working state based on the tractor 1 reaching each work start position (start end position p3 of each parallel path P1) included in the target route P, and a work stop command that instructs switching of the work equipment to a non-working state based on the tractor 1 reaching each work stop position (end position p4 of each parallel path P1) included in the target route P. The work equipment control unit 23D controls the operation of the lift drive unit 20 etc. in response to various control commands related to the work equipment transmitted from the automatic travel control unit 23F to execute automatic work start control that lowers the work equipment to a working height and makes it work, and automatic work stop control that raises the work equipment to a non-working height and makes it wait.

[0061] That is, the aforementioned automatic driving unit 4 includes a power steering unit 17, a brake unit 18, a working clutch unit 19, a lifting drive unit 20, a rolling unit 21, a vehicle state detection device 22, an on-board control unit 23, a positioning unit 30, and communication modules 28, 34. By properly operating these components, the tractor 1 can be automatically driven with high accuracy along the target route P, and the rotary tilling implement 3 and other working implements can be operated properly.

[0062] As shown in Figures 6 to 7, the tractor 1 is equipped with a surrounding condition acquisition system 8 that acquires the surrounding conditions of the tractor 1. As shown in Figure 7, the surrounding condition acquisition system 8 includes an imaging unit 80 that captures images of the surroundings of the tractor 1 to acquire image information, and an obstacle detection unit 85 that detects obstacles present around the tractor 1. Obstacles detected by the obstacle detection unit 85 include people such as workers working in the field A, other work vehicles, and electric poles, trees, and the like existing in the field A.

[0063] As shown in Figures 1 to 3 and 7, the imaging unit 80 includes a front camera 81 whose imaging range is set to a first imaging range Ri1 forward from the cabin 13, a rear camera 82 whose imaging range is set to a second imaging range Ri2 rearward from the cabin 13, and an image processing device 83 (see Figure 7) that processes image information from the front and rear cameras 81, 82.

[0064] As shown in FIG. 2, the front camera 81 and the rear camera 82 are disposed on the left-right center line of the tractor 1. The front camera 81 is disposed in a left-right center position at the upper part of the front end side of the cabin 13, in a front-down position looking down on the front side of the tractor 1 from an obliquely upward direction. As a result, for the front camera 81, a predetermined range on the front side of the vehicle body with the left-right center line of the tractor 1 as the axis of symmetry is set as a first imaging range Ri1. The rear camera 82 is disposed in a left-right center position at the upper part of the rear end side of the cabin 13, in a rear-down position looking down on the rear side of the tractor 1 from an obliquely upward direction. As a result, for the rear camera 82, a predetermined range on the rear side of the vehicle body with the left-right center line of the tractor 1 as the axis of symmetry is set as a second imaging range Ri2.

[0065] 7, the image processing device 83 is constructed by an electronic control unit in which a microcontroller and the like are integrated, various control programs, etc. The image processing device 83 is connected to the in-vehicle control unit 23 and the like via a CAN so as to be able to communicate with each other.

[0066] The image processing device 83 performs image generation processing and the like for generating front and rear images of the tractor 1 corresponding to the imaging ranges of the cameras 81, 82 for the image information sequentially transmitted from the front and rear cameras 81, 82. Then, it performs image transmission processing for transmitting each generated image to the display control unit 23E of the on-vehicle control unit 23. The display control unit 23E transmits each image from the image processing device 83 to the operation terminal 27 via the CAN, and also transmits each image to the display control unit 5A of the mobile communication terminal 5 via the communication modules 28, 52.

[0067] This allows the front side image and rear side image of the tractor 1 generated by the image processing device 83 to be displayed on the operation terminal 27 of the tractor 1, the display device 50 of the mobile communication terminal 5, etc. This display allows the user to easily grasp the situations in front and rear of the tractor 1.

[0068] In addition to the front camera 81, the rear camera 82, and the image processing device 83, the imaging unit 80 may include a right camera having a third imaging range set to the right of the cabin 13 as an imaging range, and a left camera having a fourth imaging range set to the left of the cabin 13 as an imaging range. In this case, the image processing device 83 may perform an image generation process for generating front, rear, left, and right images corresponding to the imaging ranges of each camera, and a panoramic image generation process for generating a panoramic image (for example, a surround view) of the tractor 1 by synthesizing the image information from all the cameras, for example. Each image and the panoramic image generated by the image processing device 83 may be transmitted to the operation terminal 27 of the tractor 1 or the display control unit 5A of the mobile communication terminal 5, and displayed on the display device 50 of the operation terminal 27 or the mobile communication terminal 5.

[0069] As shown in Fig. 1, Fig. 3-4, and Fig. 7, the obstacle detection unit 85 includes a front obstacle sensor 86 whose obstacle detection range is set to the front side of the tractor 1, a rear obstacle sensor 87 whose obstacle detection range is set to the rear side of the tractor 1, and a lateral obstacle sensor 88 whose obstacle detection range is set to both the left and right sides of the tractor 1. The front obstacle sensor 86 and the rear obstacle sensor 87 employ lidar sensors that use pulsed near-infrared laser light to detect obstacles. The lateral obstacle sensor 88 employs sonar that uses ultrasonic waves to detect obstacles.

[0070] 1 to 4 and 7, the front obstacle sensor 86 and the rear obstacle sensor 87 have measurement units 86A, 87A that use near-infrared laser light to measure the distance to each distance measurement point (measurement object) present within the measurement range, and control units 86B, 87B that perform operations such as generating a distance image based on measurement information from the measurement units 86A, 87A. The side obstacle sensor 88 has a right ultrasonic sensor 88A and a left ultrasonic sensor 88B that transmit and receive ultrasonic waves, and a single control unit 88C that measures the distance to a measurement object present within the measurement range based on the transmission and reception of ultrasonic waves by each ultrasonic sensor 88A, 88B.

[0071] The control units 86B, 87B, 88C of the obstacle sensors 86 to 88 are constructed by electronic control units integrating microcontrollers and the like, various control programs, etc. The control units 86B, 87B, 88C are connected to the vehicle-mounted control unit 23 and the like via the CAN so as to be able to communicate with each other.

[0072] 3 and 4, the front obstacle sensor 86 has a measurement range set to a first measurement range Rm1 forward from the cabin 13. The rear obstacle sensor 87 has a measurement range set to a second measurement range Rm2 rearward from the cabin 13. The lateral obstacle sensor 88 has a measurement range set to a third measurement range Rm3 to the right side from the cabin 13 and a fourth measurement range Rm4 to the left side from the cabin 13.

[0073] As shown in FIG. 1, 3 and 4, the front obstacle sensor 86 and the rear obstacle sensor 87 are disposed on the left-right center line of the tractor 1, like the front camera 81 and the rear camera 82. The front obstacle sensor 86 is disposed in a left-right center position at the upper part of the front end side of the cabin 13, in a front-down position looking down on the front side of the tractor 1 from an obliquely upward direction. As a result, the front obstacle sensor 86 is set as a first measurement range Rm1 by the measurement unit 86A in a predetermined range on the front side of the vehicle body with the left-right center line of the tractor 1 as an axis of symmetry. The rear obstacle sensor 87 is disposed in a left-right center position at the upper part of the rear end side of the cabin 13, in a rear-down position looking down on the rear side of the tractor 1 from an obliquely upward direction. As a result, the rear obstacle sensor 87 is set as a second measurement range Rm2 by the measurement unit 87A in a predetermined range on the rear side of the vehicle body with the left-right center line of the tractor 1 as an axis of symmetry.

[0074] As shown in Fig. 2, the right ultrasonic sensor 88A is attached to the right boarding / alighting step 24 located between the right front wheel 10 and the right rear wheel 11 in a position facing outward to the right of the vehicle body. As a result, the predetermined range on the right outer side of the vehicle body of the right ultrasonic sensor 88A is set to a third measurement range Rm3. As shown in Figs. 1 to 3, the left ultrasonic sensor 88B is attached to the left boarding / alighting step 24 located between the left front wheel 10 and the left rear wheel 11 in a position facing outward to the left of the vehicle body. As a result, the predetermined range on the left outer side of the vehicle body of the left ultrasonic sensor 88B is set to a fourth measurement range Rm4.

[0075] 3-4 and 7, the measurement units 86A, 87A of the front obstacle sensor 86 and the rear obstacle sensor 87 measure the distance from each of the measurement units 86A, 87A to each of the distance measurement points in the first measurement range Rm1 or the second measurement range Rm2 by a TOF (Time Of Flight) method that measures the distance to a distance measurement point based on the round-trip time it takes for an irradiated near-infrared laser light to reach the distance measurement point and return. Each of the measurement units 86A, 87A performs three-dimensional measurement in the first measurement range Rm1 or the second measurement range Rm2 by scanning the near-infrared laser light vertically and horizontally at high speed over the entire first measurement range Rm1 or the second measurement range Rm2 to sequentially measure the distance to the distance measurement point for each scanning angle (coordinate). Each of the measuring units 86A, 87A sequentially measures the intensity of reflected light (hereinafter referred to as reflection intensity) from each distance measurement point obtained when the near-infrared laser light is scanned vertically and horizontally at high speed over the entire first measurement range Rm1 or the second measurement range Rm2. Each of the measuring units 86A, 87A repeatedly measures the distance to each distance measurement point in the first measurement range Rm1 or the second measurement range Rm2, each reflection intensity, etc. in real time.

[0076] The control units 86B, 87B of the front obstacle sensor 86 and the rear obstacle sensor 87 generate a distance image and extract a group of ranging points that are estimated to be obstacles from measurement information such as the distance to each ranging point measured by each measurement unit 86A, 87A and the scanning angle (coordinates) for each ranging point, and transmit the measurement information regarding the extracted group of ranging points to the on-board control unit 23 as measurement information regarding the obstacle.

[0077] The control units 86B, 87B of the front obstacle sensor 86 and the rear obstacle sensor 87 determine whether the distance values ​​of each ranging point measured by each measurement unit 86A, 87A meet the invalid condition, and transmit the distance values ​​that meet the invalid condition to the on-board control unit 23 as invalid values.

[0078] Specifically, each of the control units 86B, 87B invalidates the distance value of the ranging point having the characteristic of the dirt on the sensor surface being located at a close distance from the front obstacle sensor 86 or the rear obstacle sensor 87. This prevents the distance value of the ranging point related to the dirt on the sensor surface from being used as measurement information related to the obstacle in the vehicle control unit 23.

[0079] Furthermore, each of the control units 86B, 87B invalidates the distance value of the ranging point having the characteristic of floating objects such as dust and fog, which have very weak reflection intensity even though they are close to the front obstacle sensor 86 or the rear obstacle sensor 87. This prevents the in-vehicle control unit 23 from using the distance value of the ranging point related to the floating objects as measurement information related to the obstacle.

[0080] 3-4 and 7, the control unit 88C of the lateral obstacle sensor 88 determines the presence or absence of a measurement object in the third measurement range Rm3 or the fourth measurement range Rm4 based on the transmission and reception of ultrasonic waves by the left and right ultrasonic sensors 88A, 88B. The control unit 88C measures the distance from each ultrasonic sensor 88A, 88B to the measurement object using a TOF (Time Of Flight) method that measures the distance to a ranging point based on the round-trip time it takes for an emitted ultrasonic wave to reach the ranging point and return, and transmits the measured distance to the measurement object and the direction of the measurement object to the in-vehicle control unit 23 as measurement information related to the obstacle.

[0081] As shown in Fig. 4 and Fig. 8 to 10, the control units 86B, 87B of the front obstacle sensor 86 and the rear obstacle sensor 87 perform cutting and masking processes based on vehicle body information and the like on the measurement ranges Rm1, Rm2 of the measurement units 86A, 87A to limit the obstacle detection ranges of the front obstacle sensor 86 and the rear obstacle sensor 87 to a first detection range Rd1 set on the forward side of the tractor 1 and a second detection range Rd2 set on the reverse side of the tractor 1. As shown in Fig. 4, in the lateral obstacle sensor 88, the third measurement range Rm3 and the fourth measurement range Rm4 are set to the third detection range Rd3 and the fourth detection range Rd4.

[0082] In the cutting process, the control units 86B, 87B of the front obstacle sensor 86 and the rear obstacle sensor 87 obtain the maximum left-right width of the vehicle body including the working implement (the left-right width of the rotary tilling implement 3 in this embodiment) by communicating with the on-vehicle control unit 23, and set the detection target width Wd of the obstacle by adding a predetermined safety band to this maximum left-right width of the vehicle body. Then, in the first measurement range Rm1 and the second measurement range Rm2, the left and right ranges outside the detection target width Wd are set as first non-detection ranges Rnd1 by the cutting process and are excluded from each detection range Rd1, Rd2.

[0083] In the masking process, each control unit 86B, 87B sets the range in which the front end of the tractor 1 enters into the first measurement range Rm1 and the range in which the rear end of the implement enters into the second measurement range Rm2 plus a predetermined safety band as a second non-detection range Rnd2 by masking process, and excludes this range from each detection range Rd1, Rd2.

[0084] By limiting the obstacle detection range to the first detection range Rd1 and the second detection range Rd2 in this manner, an increase in the detection load caused by the front obstacle sensor 86 and the rear obstacle sensor 87 detecting an obstacle that is outside the detection target width Wd and is not at risk of colliding with the tractor 1, and the risk of mistakenly detecting the front end of the tractor 1 or the rear end of the implement that is within the first measurement range Rm1 or the second measurement range Rm2 as an obstacle are avoided.

[0085] The second non-detection range Rnd2 shown in Fig. 8 is an example of a non-detection range suitable for the front side of the vehicle body where the left and right front wheels 10 and the bonnet 15 are located. The second non-detection range Rnd2 shown in Fig. 9 is an example of a non-detection range suitable for a working state where the rotary tilling device 3 is lowered to the working height on the rear side of the vehicle body. The second non-detection range Rnd2 shown in Fig. 10 is an example of a non-detection range suitable for a non-working state where the rotary tilling device 3 is raised to the retraction height on the rear side of the vehicle body. The second non-detection range Rnd2 on the rear side of the vehicle body switches appropriately in conjunction with the raising and lowering of the rotary tilling device 3.

[0086] Information regarding the first detection range Rd1, the second detection range Rd2, the first non-detection range Rnd1, and the second non-detection range Rnd2 is included in the above-mentioned distance image and is transmitted to the in-vehicle control unit 23 together with the above-mentioned distance image.

[0087] As shown in FIG. 4, the detection ranges Rd1, Rd2 of the front obstacle sensor 86 and the rear obstacle sensor 87 are divided into a stop control range Rsc, a deceleration control range Rdc, and a notification control range Rnc based on the collision determination process in which the collision prediction time is a set time (for example, 3 seconds). The stop control range Rsc is set to a range from the front obstacle sensor 86 or the rear obstacle sensor 87 to a determination reference position of the collision determination process. The deceleration control range Rdc is set to a range from the determination reference position to the deceleration start position. The notification control range Rnc is set to a range from the deceleration start position to the measurement limit position of the front obstacle sensor 86 or the rear obstacle sensor 87. Each determination reference position is set at a position spaced a certain distance L (for example, 2000 mm) from the front end or rear end of the vehicle body including the rotary tilling device 3 in the vehicle front-rear direction. The third detection range Rd3 and the fourth detection range Rd4 of the lateral obstacle sensor 88 are set to the stop control range.

[0088] The settings of the detection ranges Rd1-Rd4 of the obstacle sensors 86-88 and the control ranges Rsc, Rdc, Rnc in the first detection range Rd1 of the front obstacle sensor 86 and the second detection range Rd2 of the rear obstacle sensor 87 can be changed in various ways depending on the type or model of the work vehicle or the work content, etc. Furthermore, the measurement ranges Rm1, Rm2 of the front obstacle sensor 86 and the rear obstacle sensor 87 may not be cut.

[0089] The display screens displayed on the display device 50 of the portable communication terminal 5 include a route generation screen for generating a target route, a work screen 70 for automatic driving shown in Figs. 11 to 17, etc. The display control unit 51A of the portable communication terminal 5 switches the display screen of the display device 50 to the work screen 70 when an operation for displaying the work screen is performed on the display device 50.

[0090] As shown in Figures 11 to 17, the work screen 70 displays a driving instruction button 71 for instructing the start or pause of automatic driving of the tractor 1, an emergency stop button 72 for instructing an emergency stop of the tractor 1 during automatic driving, an image display section 73 for displaying front and rear images of the tractor 1 from the imaging unit 80, an information display section 74 for displaying various types of information, and an obstacle information display button 75 for instructing the display of detection information from the obstacle detection unit 85 on the information display section 74.

[0091] When the display control unit 51A of the mobile communication terminal 5 detects that the tractor 1 is stopped by communication with the in-vehicle control unit 23 or the like, it switches the driving instruction button 71 to a start button that instructs the tractor 1 to start driving. In addition, when the display control unit 51A of the mobile communication terminal 5 detects that the tractor 1 is in an automatic driving state, it switches the driving instruction button 71 to a pause button that instructs the tractor 1 to pause.

[0092] In response to operation of the obstacle information display button 75, the display control unit 51A switches the display state of the information display unit 74 from a work information display state, which displays the progress of the work, etc., to an obstacle information display state, which displays the positions of obstacles detected by the obstacle sensors 86-88 of the obstacle detection unit 85. In this way, the information display unit 74 functions as an obstacle information display unit that displays the positions of obstacles detected by the obstacle sensors 86-88. Figures 11-17 show examples of the obstacle information display state of the information display unit 74 (hereinafter referred to as the obstacle information display unit 74) in which the information display unit 74 functions as the obstacle information display unit.

[0093] As shown in Figures 11 to 17, the obstacle information display unit 74 displays a first display area D1 that displays the obstacle detection state by the front obstacle sensor 86, a second display area D2 that displays the obstacle detection state by the rear obstacle sensor 87, and a third display area D3 and a fourth display area D4 that display the obstacle detection state by the lateral obstacle sensor 88.

[0094] In this tractor 1, the on-board control unit 23 having an automatic driving control unit 23F etc., the display device 50 of the mobile communication terminal 5, and each obstacle sensor 86 to 88 function as an obstacle detection system that detects obstacles present around the tractor 1, displays the position of the detected obstacle, and controls the driving of the tractor 1 according to the detected position of the obstacle.

[0095] The automatic driving control unit 23F performs a traveling direction determination process to determine the current traveling direction of the tractor 1 based on the position of the tractor 1 acquired by the positioning unit 30 and the traveling direction of the tractor 1 included in the target route P. The automatic driving control unit 23F performs obstacle display control to control the display on the display device 50 of the mobile communication terminal 5 to notify the presence and position of an obstacle, and collision avoidance control to control the traveling of the tractor 1 to avoid a collision with an obstacle, based on the determination result of the traveling direction determination process and the detection information of each obstacle sensor 86-88 transmitted to the in-vehicle control unit 23.

[0096] In obstacle display control, the automatic driving control unit 23F controls the display on the display device 50 of the mobile communication terminal 5 by instructing the display control unit 51A of the mobile communication terminal 5 to execute each obstacle information display process according to the detection information of each obstacle sensor 86 to 88.

[0097] Hereinafter, the control operation of the automatic driving control unit 23F in the obstacle display control will be described based on the detection ranges Rd1-Rd4 of the obstacle sensors 86-88 shown in Fig. 4 and the flowcharts shown in Figs. 18-19. Also, various obstacle information display processes executed by the display control unit 51A of the mobile communication terminal 5 in response to the control operation of the automatic driving control unit 23F in the obstacle display control will be described based on the work screen 70 of the display device 50 shown in Figs. 11-17.

[0098] The automatic traveling control unit 23F performs a first determination process (step #1) to determine whether or not an obstacle is detected in a forward speed control range including the deceleration control range Rdc and the stop control range Rsc of the first detection range Rd1 based on the detection information of the front obstacle sensor 86. Then, if an obstacle is detected in the first determination process, the automatic traveling control unit 23F performs a second determination process (step #2) to determine whether or not the detected position of the obstacle is in the deceleration control range Rdc of the forward speed control range.

[0099] When no obstacle is detected in the first determination process, the automatic traveling control unit 23F performs a first display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a first obstacle information display process (step #3). In the first obstacle information display process, the display control unit 51A of the mobile communication terminal 5 displays the first display area D1 of the obstacle information display unit 74 in a first notification color (e.g., green) that notifies that no obstacle is detected within the forward speed control range (see FIG. 11 and FIGS. 14 to 17).

[0100] When the detected position of the obstacle is within the deceleration control range Rdc of the forward speed control range in the second determination process, the automatic driving control unit 23F performs a second display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a second obstacle information display process (step #4). In the second obstacle information display process, the display control unit 51A of the mobile communication terminal 5 displays the first display area D1 of the obstacle information display unit 74 in a second notification color (e.g., yellow) that indicates that an obstacle has been detected within the deceleration control range Rdc of the forward speed control range, and displays the detected position of the obstacle in the first display area D1 with an x ​​mark (see FIG. 12).

[0101] If the detected position of the obstacle is not in the deceleration control range Rdc of the forward speed control range in the second determination process, the automatic driving control unit 23F performs a third display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a third obstacle information display process since the detected position of the obstacle is in the stop control range Rsc of the forward speed control range (step #5). In the third obstacle information display process, the display control unit 51A of the mobile communication terminal 5 displays the first display area D1 of the obstacle information display unit 74 in a third notification color (e.g., red) that notifies that an obstacle has been detected in the stop control range Rsc of the forward speed control range, and displays the detected position of the obstacle in the first display area D1 with an x ​​mark (see FIG. 13).

[0102] The automatic traveling control unit 23F performs a third determination process (step #6) to determine whether or not an obstacle is detected in the reverse speed control range including the deceleration control range Rdc and the stop control range Rsc of the second detection range Rd2 based on the detection information of the rear obstacle sensor 87. If an obstacle is detected in the third determination process, the automatic traveling control unit 23F performs a fourth determination process (step #7) to determine whether or not the detected position of the obstacle is in the deceleration control range Rdc of the reverse speed control range.

[0103] When no obstacle is detected in the third determination process, the automatic traveling control unit 23F performs a fourth display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a fourth obstacle information display process (step #8). In the fourth obstacle information display process, the display control unit 51A of the mobile communication terminal 5 displays the second display area D2 of the obstacle information display unit 74 in a first notification color that notifies that no obstacle is detected in the reverse speed control range (see FIGS. 11 to 17).

[0104] If the detected position of the obstacle is within the deceleration control range Rdc of the reverse speed control range in the fourth determination process, the automatic driving control unit 23F performs a fifth display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a fifth obstacle information display process (step #9). In the fifth obstacle information display process, the display control unit 51A of the mobile communication terminal 5 displays the second display area D2 of the obstacle information display unit 74 in a second notification color that notifies the user that an obstacle has been detected within the deceleration control range Rdc of the reverse speed control range, and displays the detected position of the obstacle in the second display area D2 with an x ​​mark.

[0105] If the detected position of the obstacle is not in the deceleration control range Rdc of the reverse speed control range in the fourth determination process, the automatic traveling control unit 23F performs a sixth display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a sixth obstacle information display process since the detected position of the obstacle is in the stop control range Rsc of the reverse speed control range (step #10). In the sixth obstacle information display process, the display control unit 51A of the mobile communication terminal 5 displays the second display area D2 of the obstacle information display unit 74 in a third notification color that notifies that an obstacle has been detected in the stop control range Rsc of the reverse speed control range, and displays the detected position of the obstacle in the second display area D2 with an x ​​mark.

[0106] The automatic driving control unit 23F performs a fifth determination process to determine whether or not an obstacle has been detected within the third detection range Rd3, based on the detection information from the lateral obstacle sensor 88 (step #11).

[0107] When no obstacle is detected in the fifth determination process, the automatic driving control unit 23F performs a seventh display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a seventh obstacle information display process (step #12). In the seventh obstacle information display process, the display control unit 51A of the mobile communication terminal 5 displays the third display area D3 of the obstacle information display unit 74 in a first notification color that notifies that no obstacle is detected in the third detection range Rd3 (see FIGS. 11 to 13 and 15 to 17).

[0108] When an obstacle is detected in the fifth determination process, the automatic driving control unit 23F performs an eighth display instruction process that instructs the display control unit 51A of the mobile communication terminal 5 to execute an eighth obstacle information display process (step #13). In the eighth obstacle information display process, the display control unit 51A of the mobile communication terminal 5 displays the third display area D3 of the obstacle information display unit 74 in a third notification color that notifies that an obstacle has been detected in the third detection range Rd3 (see FIG. 14).

[0109] The automatic driving control unit 23F performs a sixth determination process to determine whether or not an obstacle has been detected in the fourth detection range Rd4, based on the detection information of the lateral obstacle sensor 88 (step #14).

[0110] When no obstacle is detected in the sixth determination process, the automatic driving control unit 23F performs a ninth display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a ninth obstacle information display process (step #15). In the ninth obstacle information display process, the display control unit 51A of the mobile communication terminal 5 displays the fourth display area D4 of the obstacle information display unit 74 in a first notification color that notifies that no obstacle is detected in the fourth detection range Rd4 (see FIGS. 11 to 17).

[0111] When an obstacle is detected in the sixth determination process, the automatic driving control unit 23F performs a tenth display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a tenth obstacle information display process (step #16). In the tenth obstacle information display process, the display control unit 51A of the mobile communication terminal 5 displays the fourth display area D4 of the obstacle information display unit 74 in a third notification color that notifies that an obstacle has been detected in the fourth detection range Rd4.

[0112] That is, when no obstacle is detected in any of the forward speed control range of the first detection range Rd1, the reverse speed control range of the second detection range Rd2, the third detection range Rd3, and the fourth detection range Rd4, the display state of the obstacle information display unit 74 on the display device 50 of the mobile communication terminal 5 is controlled to a non-detection display state. When an obstacle is detected in any of the forward speed control range of the first detection range Rd1, the reverse speed control range of the second detection range Rd2, the third detection range Rd3, and the fourth detection range Rd4, the display state of the obstacle information display unit 74 is controlled to a detection display state according to the position of the detected obstacle. This allows the user to easily grasp the position of the detected obstacle by visually checking the obstacle information display unit 74, and to confirm that each of the obstacle sensors 86 to 88 is functioning normally.

[0113] In collision avoidance control, the automatic driving control unit 23F controls the driving of the tractor 1 by instructing the transmission unit control unit 23B to execute driving control for avoiding each collision according to the detection information of each obstacle sensor 86-88, etc.

[0114] Hereinafter, the control operation of the automatic driving control unit 23F in collision avoidance control will be described based on the detection ranges Rd1 to Rd4 of the obstacle sensors 86 to 88 shown in Fig. 4 and the flowcharts shown in Fig. 20 to 22. Also, each collision avoidance driving control executed by the gear change unit control unit 23B in response to the control operation of the automatic driving control unit 23F in collision avoidance control will be described.

[0115] The automatic travel control unit 23F performs the first determination process described above based on the detection information of the front obstacle sensor 86 (step #21). Then, if an obstacle is detected within the forward speed control range in the first determination process of step #21, the automatic travel control unit 23F performs a seventh determination process (step #22) to determine whether or not the first detection range Rd1 of the front obstacle sensor 86 in which the obstacle is detected corresponds to the traveling direction of the tractor 1 based on the determination result of the traveling direction determination process described above. In the seventh determination process, when the traveling direction of the tractor 1 is the forward direction, the automatic traveling control unit 23F determines that the first detection range Rd1 of the front obstacle sensor 86 corresponds to the traveling direction of the tractor 1. In addition, when the traveling direction of the tractor 1 is the reverse direction, the automatic traveling control unit 23F determines that the first detection range Rd1 of the front obstacle sensor 86 does not correspond to the traveling direction of the tractor 1.

[0116] The automatic traveling control unit 23F performs a first collision avoidance process (step #23) when the first detection range Rd1 of the front obstacle sensor 86 corresponds to the traveling direction of the tractor 1 in the seventh determination process. When the first detection range Rd1 does not correspond to the traveling direction of the tractor 1, the detection information of the front obstacle sensor 86 is ignored, thereby avoiding the transmission unit control unit 23B from performing a control process for collision avoidance according to the detection information of the front obstacle sensor 86.

[0117] If no obstacle is detected in the first determination process of step #21, the automatic travel control unit 23F performs the third determination process described above based on the detection information of the rear obstacle sensor 87 (step #24). Then, if an obstacle is detected in the reverse speed control range in the third determination process of step #24, the automatic travel control unit 23F performs an eighth determination process (step #25) to determine whether or not the second detection range Rd2 of the rear obstacle sensor 87 in which the obstacle is detected corresponds to the traveling direction of the tractor 1 based on the determination result of the traveling direction determination process described above. In the eighth determination process, when the traveling direction of the tractor 1 is the reverse direction, the automatic traveling control unit 23F determines that the second detection range Rd2 of the rear obstacle sensor 87 corresponds to the traveling direction of the tractor 1. In addition, when the traveling direction of the tractor 1 is the forward direction, the automatic traveling control unit 23F determines that the second detection range Rd2 of the rear obstacle sensor 87 does not correspond to the traveling direction of the tractor 1.

[0118] The automatic traveling control unit 23F performs a second collision avoidance process (step #26) when the second detection range Rd2 of the rear obstacle sensor 87 corresponds to the traveling direction of the tractor 1 in the eighth determination process. On the other hand, when the second detection range Rd2 does not correspond to the traveling direction of the tractor 1, the detection information of the rear obstacle sensor 87 is ignored, thereby preventing the transmission unit control unit 23B from performing a control process for collision avoidance according to the detection information of the rear obstacle sensor 87.

[0119] If no obstacle is detected in the third judgment process, the automatic driving control unit 23F performs a ninth judgment process to determine whether or not an obstacle is detected in the third detection range Rd3 or the fourth detection range Rd4 based on the detection information of the lateral obstacle sensor 88 (step #27).

[0120] When an obstacle is detected in the ninth determination process, the automatic driving control unit 23F performs a travel stop instruction process to instruct the transmission unit control unit 23B to execute a travel stop control for collision avoidance (step #28). In the travel stop control for collision avoidance, the transmission unit control unit 23B performs a deceleration operation of the continuously variable transmission, etc., to stop the travel of the tractor 1 so that the tractor 1 does not come into contact with an obstacle located in the third detection range Rd3 or the fourth detection range Rd4.

[0121] If no obstacle is detected in the ninth determination process, the automatic driving control unit 23F returns to the first determination process in step #21.

[0122] The automatic travel control unit 23F performs the second determination process described above in the first collision avoidance process (see FIG. 21) (step #31). If the detected position of the obstacle is within the deceleration control range Rdc of the forward speed control range in the second determination process in step #31, the automatic travel control unit 23F performs a forward deceleration instruction process to instruct the transmission unit control unit 23B to execute forward deceleration control for collision avoidance (step #32). In the forward deceleration control for collision avoidance, the transmission unit control unit 23B performs a deceleration operation of the continuously variable transmission to reduce the forward speed of the tractor 1 as the distance to the obstacle located within the deceleration control range Rdc of the forward speed control range becomes closer.

[0123] After performing the forward deceleration instruction process, the automatic traveling control unit 23F performs the first determination process described above (step #33). Then, if an obstacle is detected within the forward speed control range in the first determination process of step #33, the automatic traveling control unit 23F returns to the second determination process of step #31.

[0124] If no obstacle is detected within the forward speed control range in the first determination process of step #33, the automatic driving control unit 23F performs a forward speed return instruction process that instructs the transmission unit control unit 23B to execute forward speed return control (step #34). In the forward speed return control, the transmission unit control unit 23B increases the forward speed of the tractor 1 to a target vehicle speed that corresponds to the current position of the tractor 1 included in the target route P by performing an accelerating operation of the continuously variable transmission.

[0125] If the detected position of the obstacle is not within the deceleration control range Rdc of the forward speed control range in the second determination process of step #31, the automatic traveling control unit 23F performs a forward stop instruction process to instruct the transmission unit control unit 23B to execute forward stop control for collision avoidance (step #35) since the detected position of the obstacle is within the stop control range Rsc of the forward speed control range. In the forward stop control for collision avoidance, the transmission unit control unit 23B performs a deceleration operation of the continuously variable transmission, etc., to stop the forward traveling of the tractor 1 until the tractor 1 comes into contact with an obstacle located within the stop control range Rsc of the forward speed control range.

[0126] The automatic travel control unit 23F performs the fourth judgment process described above in the second collision avoidance process (see FIG. 22) (step #41). If the detected position of the obstacle is within the deceleration control range Rdc of the reverse speed control range in the fourth judgment process in step #41, the automatic travel control unit 23F performs a reverse deceleration instruction process to instruct the transmission unit control unit 23B to execute reverse deceleration control for collision avoidance (step #42). In the reverse deceleration control for collision avoidance, the transmission unit control unit 23B performs a deceleration operation of the continuously variable transmission to reduce the reverse speed of the tractor 1 as the distance to the obstacle located within the deceleration control range Rdc of the reverse speed control range becomes closer.

[0127] After performing the reverse deceleration instruction process, the automatic traveling control unit 23F performs the third determination process described above (step #43). Then, if an obstacle is detected within the reverse speed control range in the third determination process of step #43, the automatic traveling control unit 23F returns to the fourth determination process of step #41.

[0128] If no obstacle is detected within the reverse speed control range in the third determination process of step #43, the automatic traveling control unit 23F performs a reverse speed return instruction process to instruct the transmission unit control unit 23B to execute reverse speed return control (step #44). In the reverse speed return control, the transmission unit control unit 23B increases the reverse speed of the tractor 1 to a target speed corresponding to the current position of the tractor 1 included in the target route P by performing a speed increase operation of the continuously variable transmission.

[0129] If the detected position of the obstacle is not within the deceleration control range Rdc of the reverse speed control range in the fourth determination process of step #41, the automatic traveling control unit 23F performs a reverse stop instruction process to instruct the transmission unit control unit 23B to execute reverse stop control for collision avoidance (step #45) since the detected position of the obstacle is within the stop control range Rsc of the reverse speed control range. In the reverse stop control for collision avoidance, the transmission unit control unit 23B performs a deceleration operation of the continuously variable transmission, etc., to stop the reverse traveling of the tractor 1 until the tractor 1 comes into contact with an obstacle located within the stop control range Rsc of the reverse speed control range.

[0130] That is, when an obstacle is detected in the forward speed control range or the reverse speed control range by the front obstacle sensor 86 or the rear obstacle sensor 87, whose detection ranges Rd1, Rd2 correspond to the traveling direction of the tractor 1, or when an obstacle is detected in the third detection range Rd3 or the fourth detection range Rd4 by the lateral obstacle sensor 88, the automatic traveling control unit 23F performs obstacle display control to display the position of the detected obstacle on the display device 50 of the mobile communication terminal 5. In addition, collision avoidance control is performed to control the traveling of the tractor 1 according to the position of the detected obstacle.

[0131] On the other hand, when an obstacle is detected by the front obstacle sensor 86 or the rear obstacle sensor 87 whose detection ranges Rd1, Rd2 do not correspond to the direction of travel of the tractor 1, the automatic driving control unit 23F performs obstacle display control without performing collision avoidance control based on the detection information of the front obstacle sensor 86 or the rear obstacle sensor 87.

[0132] In this way, when an obstacle is detected by any of the obstacle sensors 86-88 set in the detection ranges Rd1-Rd4 in the travel direction or left / right direction of the tractor 1, the automatic driving control unit 23F controls the travel of the tractor 1 by instructing the transmission unit control unit 23B to execute driving control for collision avoidance in accordance with the detection information based on the detection information of the obstacle sensor 86-88 that detected the obstacle, thereby preventing the tractor 1 from colliding with an obstacle present in the travel direction or left / right direction of the tractor 1.

[0133] In addition, when an obstacle is detected by the front obstacle sensor 86 or the rear obstacle sensor 87, whose detection ranges Rd1, Rd2 are set in the opposite direction that does not correspond to the traveling direction of the tractor 1, the automatic driving control unit 23F does not instruct the transmission unit control unit 23B to execute driving control for collision avoidance, thereby avoiding a decrease in work efficiency caused by performing driving control for collision avoidance for an obstacle that is not at risk of collision.

[0134] Then, when an obstacle is detected by any of the obstacle sensors 86-88, the automatic driving control unit 23F instructs the display control unit 51A of the mobile communication terminal 5 to execute an obstacle information display process corresponding to the detection information based on the detection information of the obstacle sensor 86-88 that detected the obstacle, and displays the detected position of the obstacle on the display device 50 of the mobile communication terminal 5, thereby allowing the user to grasp the position of the detected obstacle and to confirm that each of the obstacle sensors 86-88 is functioning normally.

[0135] In addition, when the tractor 1 is stopped from traveling based on the above-mentioned collision avoidance control, the display control unit 51A of the mobile communication terminal 5 displays a message on the display device 50 of the mobile communication terminal 5 informing the user that the tractor 1 will be stopped from traveling due to collision avoidance control.

[0136] 11 to 17, when the tractor 1 stops traveling based on the collision avoidance control, a notification section 76 that notifies the user that the tractor 1 has stopped traveling based on the collision avoidance control is displayed on the work screen 70 displayed on the display device 50 of the mobile communication terminal 5. When the display control section 51A of the mobile communication terminal 5 detects that the tractor 1 has stopped traveling based on the collision avoidance control, the display control section 51A switches the display state of the notification section 76 from a normal non-notification display state (e.g., a state in which the notification section 76 is displayed in green: see Figs. 11 to 12 and Figs. 15 to 17) to a notification display state that notifies the user that the tractor 1 has stopped traveling based on the collision avoidance control (e.g., a state in which the notification section 76 is displayed in red: see Figs. 13 to 14).

[0137] As a result, when the tractor 1 stops traveling, the user can easily understand by visually checking the notification unit 76 whether or not the stop of the tractor 1 is based on collision avoidance control.

[0138] The rear obstacle sensor 87 is set so that if there is a following work vehicle (not shown) following the tractor 1 while the tractor 1 is traveling forward, the rear obstacle sensor 87 detects the following work vehicle as an obstacle when the following work vehicle enters the reverse speed control range.

[0139] As a result, during accompanying work in which a following work vehicle is present, for example, if the following work vehicle is driven within the reverse speed control range of the rear obstacle sensor 87 at a certain distance from the leading tractor 1, then based on the detection information from the rear obstacle sensor 87 at this time, the automatic driving control unit 23F instructs the display control unit 51A of the mobile communication terminal 5 to execute display switching processing in accordance with the detection information, and displays the detected position of the following work vehicle on the display device 50 of the mobile communication terminal 5.

[0140] As a result, the user can grasp the position of the following work vehicle relative to the tractor 1, and can also confirm that the rear obstacle sensor 87 is functioning normally.

[0141] At this time, the second detection range Rd2 of the rear obstacle sensor 87 does not correspond to the traveling direction of the tractor 1, so the automatic driving control unit 23F does not instruct the transmission unit control unit 23B to execute driving control for collision avoidance based on the detection information of the rear obstacle sensor 87. As a result, it is possible to avoid a decrease in work efficiency caused by the driving control for collision avoidance being executed for the following work vehicle.

[0142] Although not shown in the figure, if the pursuit work vehicle is, for example, a work vehicle in which a user boards and drives, the boarding section of the pursuit work vehicle is equipped with an installation section that enables the mobile communication terminal 5 to be installed in an appropriate position that makes it easy for the user to view the mobile communication terminal 5 while driving.

[0143] Even when the tractor 1 is stopped on the target route P, the automatic driving control unit 23F performs the above-mentioned traveling direction determination process to acquire the traveling direction of the tractor 1 set at the traveling stop position of the tractor 1 on the target route P. Then, based on the acquired traveling direction of the tractor 1 and the detection information of each of the obstacle sensors 86 to 88, the automatic driving control unit 23F performs a condition satisfaction determination process to determine whether or not a condition related to an obstacle for permitting automatic driving of the tractor 1 is satisfied.

[0144] Regarding the process of determining whether the conditions are satisfied, if an obstacle is detected in the forward speed control range of the first detection range Rd1 corresponding to the traveling direction of the tractor 1 or in the reverse speed control range of the second detection range Rd2, the third detection range Rd3, or the fourth detection range Rd4, the automatic driving control unit 23F determines that the conditions for allowing the automatic driving of the tractor 1 are not satisfied and prohibits the automatic driving of the tractor 1.

[0145] If an obstacle is not detected in any of the forward speed control range, reverse speed control range, third detection range Rd3, and fourth detection range Rd4, or if an obstacle is detected only in the forward speed control range or reverse speed control range that does not correspond to the traveling direction of the tractor 1, the automatic driving control unit 23F determines that the conditions for permitting automatic driving of the tractor 1 are met and permits automatic driving of the tractor 1.

[0146] This makes it possible to avoid a decrease in work efficiency caused by the prohibition of the start of automatic driving when the tractor 1 starts to drive automatically due to an obstacle that is located in the opposite direction to the tractor 1's traveling direction at that time and is therefore not likely to collide with, while also avoiding the risk of the tractor 1 colliding with an obstacle that is located in the direction of travel or to the left or right of the tractor 1.

[0147] The automatic driving control unit 23F performs the above-mentioned obstacle display control, even when the tractor 1 is stopped on the target route P, making it possible to display the presence or absence and position of obstacles on the display device 50 of the mobile communication terminal 5.

[0148] As a result, when the tractor 1 is stopped on the target route P, by operating the display device 50 of the mobile communication terminal 5 to display the presence and position of obstacles on the display device 50, it is possible to easily check whether each of the obstacle sensors 86 to 88 is functioning normally.

[0149] The automatic driving control unit 23F determines whether dirt or the like has adhered to the sensor surface of the front obstacle sensor 86 or the rear obstacle sensor 87, and executes dirt-responsive driving control that controls the driving of the tractor 1 depending on the determined adhesion status of dirt or the like.

[0150] In the dirt-adaptive driving control, the automatic driving control unit 23F controls the driving of the tractor 1 by instructing the transmission unit control unit 23B to execute various driving controls according to the determined status of adhesion of dirt or the like.

[0151] Below, based on the flowchart shown in Figure 23, we will explain the control operation of the automatic driving control unit 23F in the dirt-resistant driving control, as well as the various driving controls performed by the gear change unit control unit 23B in response to the control operation of the automatic driving control unit 23F in the dirt-resistant driving control. In this example, a case where adhesion of dirt or the like to the sensor surface of the front obstacle sensor 86 is determined will be described.

[0152] The automatic driving control unit 23F performs a tenth judgment process to determine whether the proportion of invalid values ​​caused by measurement obstructions such as dirt and floating objects contained in the measurement information of the front obstacle sensor 86 is equal to or greater than a predetermined value (e.g., 50%) for the first measurement range Rm1 of the front obstacle sensor 86 (step #51).

[0153] When the ratio of invalid values ​​in the tenth determination process is equal to or greater than a predetermined value, the automatic driving control unit 23F performs a creep deceleration instruction process to instruct the transmission unit control unit 23B to execute creep deceleration control (step #52). In the creep deceleration control, the transmission unit control unit 23B reduces the vehicle speed of the tractor 1 to an extremely low speed for creep driving.

[0154] When the ratio of invalid values ​​is not equal to or greater than a predetermined value in the tenth determination process, the automatic driving control unit 23F performs a vehicle speed maintenance instruction process that instructs the transmission unit control unit 23B to execute vehicle speed maintenance control (step #53). In the vehicle speed maintenance control, the transmission unit control unit 23B maintains the vehicle speed of the tractor 1 at a current set speed (a set speed corresponding to the current position of the tractor 1 included in the target route P).

[0155] After performing the creep deceleration instruction processing, the automatic driving control unit 23F performs an eleventh judgment processing to determine whether or not the ultra-low speed driving state for creep driving has continued for a predetermined time, and also performs the aforementioned tenth judgment processing until the predetermined time has elapsed (steps #54 to #55).

[0156] If the ratio of invalid values ​​falls below a predetermined value in the tenth determination process of step #55, the automatic driving control unit 23F determines that dirt or the like is not adhering to the sensor surface of the front obstacle sensor 86, but that dust, mist, or other floating objects are simply floating around the front obstacle sensor 86, and performs a vehicle speed return instruction process to instruct the transmission unit control unit 23B to execute vehicle speed return control (step #56), and then returns to the tenth determination process of step #51. In the vehicle speed return control, the transmission unit control unit 23B returns the vehicle speed of the tractor 1 to a set speed corresponding to the current position of the tractor 1 included in the target route P.

[0157] If the creeping traveling state at an extremely low speed continues for a predetermined time in the eleventh determination process, the automatic traveling control unit 23F determines that dirt or the like is attached to the sensor surface of the front obstacle sensor 86, and performs an emergency stop instruction process to instruct the gear change unit control unit 23B to execute a dirt countermeasure travel stop control (step #57). In the dirt countermeasure travel stop control, the gear change unit control unit 23B immediately stops the tractor 1.

[0158] In this way, when the proportion of invalid values ​​in the first measurement range Rm1 of the front obstacle sensor 86 becomes equal to or exceeds a predetermined value during automatic driving of the tractor 1, the vehicle speed of the tractor 1 is reduced to an ultra-low speed for creep driving and is maintained in a driving state at an ultra-low speed. Therefore, compared to when the tractor 1 is driven at a low speed, it is possible to make it longer to determine whether the cause of the invalid value is dirt or other adhesions on the sensor surface of the front obstacle sensor 86 or the rear obstacle sensor 87, or floating objects such as dust or dirt that have been stirred up around the front obstacle sensor 86 or the rear obstacle sensor 87.

[0159] By lengthening the determination time in this way, it becomes easier to determine whether the cause of the invalid value is an attached object or a floating object, and this makes it possible to suppress a decrease in work efficiency caused by the tractor 1 stopping its travel due to the floating object when the invalid value is caused by the attached object. It also makes it possible to suppress the occurrence of an inconvenience in which the tractor 1 collides with an obstacle while determining whether the cause of the invalid value is an attached object or a floating object.

[0160] 11 to 17, the obstacle information display button 75 of the display device 50 in the mobile communication terminal 5 includes a detection status display section 75A that displays the detection status of each of the obstacle sensors 86 to 88. The automatic traveling control section 23F executes detection status display control that notifies the user of the detection status of each of the obstacle sensors 86 to 88 by controlling the display in the detection status display section 75A based on the detection information of each of the obstacle sensors 86 to 88, etc.

[0161] In the detection status display control, the automatic driving control unit 23F controls the display of the detection status display unit 75A on the display device 50 of the mobile communication terminal 5 by instructing the display control unit 51A of the mobile communication terminal 5 to execute each detection status display process according to the detection status of each obstacle sensor 86 to 88.

[0162] Hereinafter, the control operation of the automatic driving control unit 23F in the detection status display control will be described based on the detection ranges Rd1-Rd4 of the obstacle sensors 86-88 shown in Fig. 4 and the flowchart shown in Fig. 24. Also, various detection status display processes executed by the display control unit 51A of the mobile communication terminal 5 in response to the control operation of the automatic driving control unit 23F in the detection status display control will be described based on the work screen 70 of the display device 50 shown in Figs. 11-17.

[0163] The automatic driving control unit 23F performs a twelfth determination process to determine whether or not an abnormality due to adhesion of dirt or the like has occurred on the sensor surface of the front obstacle sensor 86 or the rear obstacle sensor 87 based on the dirt determination result in the dirt-adaptive driving control described above (step #61). If no abnormality has occurred in the twelfth determination process, the automatic driving control unit 23F performs a thirteenth determination process to determine whether or not an obstacle has been detected in any of the forward speed control range, the reverse speed control range, the third detection range Rd3, and the fourth detection range Rd4 based on the detection information of each of the obstacle sensors 86-88 (step #62).

[0164] When no obstacle is detected in the thirteenth determination process, the automatic driving control unit 23F performs an eleventh display instruction process that instructs the display control unit 51A of the mobile communication terminal 5 to execute a first detection status display process (step #63). In the first detection status display process, the display control unit 51A of the mobile communication terminal 5 displays the detection status display unit 75A in a first notification color (e.g., green) that notifies that no obstacle is detected in any of the forward speed control range, the reverse speed control range, the third detection range Rd3, and the fourth detection range Rd4 (see FIG. 11).

[0165] If an obstacle is detected in the 13th judgment process, the automatic driving control unit 23F performs a 14th judgment process to determine whether the detection position of the obstacle is within the deceleration control range Rdc of the forward speed control range or the reverse speed control range (step #64).

[0166] If the detected position of the obstacle is within the deceleration control range Rdc of the forward speed control range or the reverse speed control range in the 14th determination process, the automatic driving control unit 23F performs a 12th display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a second detection status display process (step #65). In the second detection status display process, the display control unit 51A of the mobile communication terminal 5 displays the detection status display unit 75A in a second notification color (e.g., yellow) that notifies the user that an obstacle has been detected within the deceleration control range Rdc of the forward speed control range or the reverse speed control range (see FIG. 12).

[0167] When the detected position of the obstacle is not in the deceleration control range Rdc of the forward speed control range or the reverse speed control range in the 14th determination process, the automatic traveling control unit 23F performs a 13th display instruction process to instruct the display control unit 51A of the mobile communication terminal 5 to execute a third detection status display process (step #66) since the detected position of the obstacle is in the stop control range Rsc of the forward speed control range or the reverse speed control range, or the third detection range Rd3 or the fourth detection range Rd4. In the third detection status display process, the display control unit 51A of the mobile communication terminal 5 displays the detection status display unit 75A in a third notification color (e.g., red) that notifies that an obstacle is detected in the stop control range Rsc of the forward speed control range or the reverse speed control range, or the third detection range Rd3 or the fourth detection range Rd4 (see Figs. 13 to 14).

[0168] When an abnormality occurs due to the adhesion of dirt or the like on the sensor surface in the 12th determination process, the automatic driving control unit 23F performs a 14th display instruction process that instructs the display control unit 51A of the mobile communication terminal 5 to execute a fourth detection status display process (step #67). In the fourth detection status display process, the display control unit 51A of the mobile communication terminal 5 displays the detection status display unit 75A in an abnormality notification state (for example, a state in which an exclamation mark is added to a red display color) that notifies that an abnormality occurs due to the adhesion of dirt or the like on the sensor surface of the front obstacle sensor 86 or the rear obstacle sensor 87 (see FIG. 15).

[0169] When any of the detection ranges Rd1 to Rd4 of the obstacle sensors 86 to 88 is set as an obstacle detection prohibited range by operation of the display device 50, the display control unit 51A of the mobile communication terminal 5 displays the detection status display unit 75A of the display device 50 in a detection prohibited state (for example, a yellow display color with an exclamation mark added) indicating that any of the detection ranges Rd1 to Rd4 has been set as an obstacle detection prohibited range, as shown in FIG. 16, and displays the display areas D1 to D4 (first display area D1 in FIG. 16) corresponding to the detection ranges Rd1 to Rd4 set as detection prohibited ranges in the obstacle information display unit 74 of the display device 50 in a detection prohibited color (for example, gray) to notify that they have been set as obstacle detection prohibited ranges.

[0170] When the display control unit 51A of the mobile communication terminal 5 is unable to receive detection information from each of the obstacle sensors 86-88 due to poor CAN communication in the tractor 1 or poor communication with the on-board control unit 23, it displays the detection status display unit 75A of the obstacle information display button 75 on the display device 50 in a fourth alert color (e.g., gray) as shown in FIG. 17, indicating that the detection information from each of the obstacle sensors 86-88 cannot be properly received.

[0171] As described above, in the display device 50 of the mobile communication terminal 5, the display of the obstacle information display button 75 on the detection status display section 75A is controlled according to the detection status of each obstacle sensor 86-88, so that the user can easily grasp the detection status of each obstacle sensor 86-88 by visually checking the detection status display section 75A.

[0172] 11 to 17, the image display section 73 displayed on the display device 50 of the mobile communication terminal 5 is partitioned vertically into a front image display area 73A that displays a front image of the tractor 1 captured by the imaging unit 80, and a rear image display area 73B that displays a rear image. The image display section 73 is set to have its upper, lower, left, and right edges 73a to 73c function as detection direction display sections that indicate the detection direction of an obstacle.

[0173] When the display control unit 51A of the mobile communication terminal 5 detects, through communication with the in-vehicle control unit 23 (instructions from the automatic driving control unit 23F), that an obstacle has been detected by the front obstacle sensor 86 within the deceleration control range Rdc or stop control range Rsc of the first detection range Rd1, it displays the upper edge 73a of the image display unit 73 in a detection notification color (e.g., red) to notify of the detection of an obstacle (see Figure 12).

[0174] When the display control unit 51A of the mobile communication terminal 5 detects the detection of an obstacle within the deceleration control range Rdc or the stop control range Rsc of the second detection range Rd2 by the rear obstacle sensor 87, it displays the lower edge 73b of the image display unit 73 in a detection notification color to notify the detection of an obstacle.

[0175] When the display control unit 51A of the mobile communication terminal 5 detects that an obstacle has been detected in the third detection range Rd3 by the lateral obstacle sensor 88, it displays the right edge 73c of the image display unit 73 in a detection notification color to indicate the detection of an obstacle (see Figure 14).

[0176] When the display control unit 51A of the mobile communication terminal 5 detects that an obstacle has been detected in the fourth detection range Rd4 by the lateral obstacle sensor 88, it displays the left edge 73d of the image display unit 73 in a detection notification color to notify the user of the detection of an obstacle.

[0177] As a result, even if the user is visually viewing the front image or rear image of the tractor 1 displayed on the image display section 73 of the display device 50 in the mobile communication terminal 5, if an obstacle is detected by any of the obstacle sensors 86 to 88, the user can easily grasp the direction in which the obstacle is detected relative to the tractor 1.

[0178] [Another embodiment] Another embodiment of the present invention will now be described. The configurations of the respective alternative embodiments described below are not limited to being applied alone, but may also be applied in combination with the configurations of other alternative embodiments.

[0179] (1) The configuration of the work vehicle 1 can be modified in various ways. For example, the work vehicle 1 may be configured as a semi-crawler vehicle in which left and right crawlers are provided instead of the left and right rear wheels 11. For example, the work vehicle 1 may be configured as a full crawler vehicle in which left and right crawlers are provided in place of the left and right front wheels 10 and the left and right rear wheels 11. For example, the work vehicle 1 may be configured as an electrically powered vehicle equipped with an electric motor instead of the engine 14. For example, the work vehicle 1 may be configured as a hybrid vehicle equipped with an engine 14 and an electric motor. For example, the work vehicle 1 may be configured to allow only manual driving, and may be configured to allow the control unit 23 to control the driving of the work vehicle 1 in accordance with the position of an obstacle detected by the front obstacle sensor 86 or the rear obstacle sensor 87.

[0180] (2) The obstacle detection system may be configured to have, in addition to the front obstacle sensor 86 and the rear obstacle sensor 87, a lateral obstacle sensor 88 including a right lidar sensor set in an obstacle detection range Rd1 on the right side of the work vehicle 1, and a left lidar sensor set in an obstacle detection range Rd1 on the left side of the work vehicle 1. Also, the obstacle detection system may be configured to have only the front obstacle sensor 86 and the rear obstacle sensor 87 without including the lateral obstacle sensor 88.

[0181] (3) The display device provided on the operation terminal 27 of the driving unit 12 may be configured to function as a display unit that displays the position of an obstacle detected by the front obstacle sensor 86 and the rear obstacle sensor 87, similar to the display device 50 of the mobile communication terminal (wireless communication device) 5.

[0182] (4) The control unit 23 (automatic driving control unit 23F) may be configured to determine the direction of travel of the work vehicle 1 based on detection information from a reverser sensor 22B that detects the operating position of a reverse lever for switching between forward and reverse, or a sensor that detects the transmission state of the forward / reverse switching device.

[0183] (5) The control unit 23 (automatic driving control unit 23F) may be configured to perform driving control for steering the front wheels 10 to avoid an obstacle as driving control of the work vehicle 1 according to the detected position of the obstacle.

[0184] (6) In the first and third judgment processes of the obstacle display control, the control unit 23 (automatic driving control unit 23F) may be configured to determine whether an obstacle is detected in the first detection range Rd1 or the second detection range Rd2, instead of determining whether an obstacle is detected in a forward speed control range including the deceleration control range Rdc and the stop control range Rsc of the first detection range Rd1 or the second detection range Rd2, and in the second and fourth judgment processes of the obstacle display control, instead of determining whether the detection position of the obstacle is in the deceleration control range Rdc of the forward speed control range, determine whether the detection position of the obstacle is in the notification control range Rnc, the deceleration control range Rdc, or the stop control range Rsc of the first detection range Rd1 or the second detection range Rd2. In this configuration, when an obstacle is detected within the notification control range Rnc of the obstacle sensor 86, 87, either at the front or rear, whose obstacle detection range Rd1, Rd2 corresponds to the travel direction of the work vehicle 1, an alarm buzzer provided on the work vehicle 1 or the wireless communication device 5 is activated to notify the user of the presence of an obstacle in the travel direction of the work vehicle 1, and when an obstacle is detected within the notification control range Rnc of the obstacle sensor 86, 87, either at the front or rear, whose obstacle detection range Rd1, Rd2 does not correspond to the travel direction of the work vehicle 1, the above-mentioned alarm buzzer is not activated, thereby avoiding the risk of causing discomfort to the user due to unnecessary activation of the alarm buzzer in response to the detection of an obstacle that is located in the opposite direction to the travel direction of the work vehicle 1 and therefore is not likely to cause a collision with the work vehicle 1.

[0185] (7) The imaging unit 80 may be subjected to a learning process for recognizing people such as workers working in field A, other work vehicles such as following work vehicles, and existing utility poles, trees, and the like in field A as obstacles, so that the front camera 81 is included in the front obstacle sensor 86 and the rear camera 82 is included in the rear obstacle sensor 87. In this case, it becomes possible to detect obstacles with higher accuracy based on measurement information from the front and rear LIDAR sensors, which have high distance measurement accuracy, and information from the imaging unit 80, which has high object discrimination accuracy. [Explanation of symbols]

[0186] 1 Work vehicle 4. Autonomous Driving Unit 5. Wireless communication devices 23 Control Unit 50 Display section 86 Front Obstacle Sensor 87 Rear Obstacle Sensor Rd1 Obstacle detection range Rd2 Obstacle detection range

Claims

1. a front obstacle sensor having an obstacle detection range set to the front side of the work vehicle; a rear obstacle sensor, the detection range of which is set to the rear side of the work vehicle; a display unit that displays the positions of the obstacles detected by the front obstacle sensor and the rear obstacle sensor; a control unit that determines a traveling direction of the work vehicle and controls the obstacle including the display on the display unit based on the determination result and the detection information of the front obstacle sensor and the rear obstacle sensor, the control unit changes processing for detection results of the front obstacle sensor and the rear obstacle sensor according to a traveling direction of the work vehicle; when the obstacle is detected by the front obstacle sensor or the rear obstacle sensor, the detection range of which corresponds to the traveling direction of the work vehicle, the control unit displays the detected position of the obstacle on the display unit and performs a process of executing a collision avoidance control according to the detected position of the obstacle, The control unit is an obstacle detection system that, when an obstacle is detected by the front obstacle sensor or the rear obstacle sensor, whose detection range does not correspond to the direction of travel of the work vehicle, performs a process to display the detected position of the obstacle on the display unit without executing the collision avoidance control.

2. The control unit is included in an automatic driving unit that enables automatic driving of the work vehicle, The obstacle detection system according to claim 1 , wherein the display unit is provided in a wireless communication device that is set to be able to wirelessly communicate with the automatic driving unit.

3. 3. An obstacle detection system as described in claim 1 or 2, wherein when there is a following work vehicle following the work vehicle while the work vehicle is traveling forward, the rear obstacle sensor detects the following work vehicle as the obstacle when the following work vehicle enters the detection range of the rear obstacle sensor.

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