Automatic travel system for work vehicle

Abstract

In an automatic driving system for a work vehicle, the automatic driving control unit executes a first automatic driving control that automatically drives the work vehicle (1) along the parallel path (P1) in a working state when the condition determination unit determines that the condition for starting the first automatic driving control is established at the time when the work vehicle (1) reaches the entry area (Aa) for the parallel path (P1), and executes an automatic turnback driving control that turns the work vehicle (1) in a turnback driving state by a combined operation of forward / reverse switching operation and steering operation of the work vehicle (1) so that the condition for starting the first automatic driving control is established.

Description

Technology Field

[0001] The present invention relates to an automatic driving system for work vehicles that enables automatic driving of work vehicles such as tractors or combines. Background Technology

[0002] An automatic driving system for a work vehicle as described above comprises a control unit that automatically drives a work vehicle according to a work path generated according to a work area, a position detection unit that detects the position of the work vehicle, and an azimuth detection unit that detects the azimuth of the work vehicle. Furthermore, the control unit is configured to automatically drive the work vehicle from the driving start position on the immersion set around the work area to the work start position on the work path when work is initiated while the work vehicle is located at the driving start position on the immersion set around the work area, while controlling the driving of the work vehicle so that the deviation between the extension line of the work path and the position of the work vehicle is reduced (see, for example, Patent Document 1). Prior art literature

[0003] Japanese Patent Publication No. 2017-162373 The problem to be solved

[0004] The technology described in Patent Document 1 is such that, while the work vehicle is automatically driving from a driving start position on the immersion to a working start position on the working path, the control unit controls the driving of the work vehicle so that the deviation between the extension line of the working path and the position of the work vehicle is reduced. Therefore, the longer the distance from the driving start position on the immersion to the working start position on the working path, the smaller the deviation between the extension line of the working path and the position of the work vehicle can be. By doing so, the work vehicle can be automatically driven with high precision along the working path in the work area, and the working precision of the work vehicle can be increased.

[0005] On the other hand, in order to increase the distance from the starting position of the drive on the immersion to the starting position of the work path, the immersion becomes wider and the work area becomes narrower; for example, if the work area is a field farming area, the cropping area becomes smaller, and the crop yield decreases. In addition, if the work area is a reciprocal work area where the work vehicle travels back and forth and the immersion is a circular work area where the work vehicle travels around, the number of times the work vehicle travels around the immersion increases, and work efficiency decreases. In particular, when the circular movement of the work vehicle is performed by manual driving, the burden placed on the user increases.

[0006] If the immersion area is narrowed to avoid such reductions in yield or decreased work efficiency, the distance from the starting position on the immersion to the starting position of the work path becomes shorter as the immersion narrows, and the deviation between the extension of the work path and the position of the work vehicle at the time it reaches the starting position of the work path increases. In this state, if the control unit switches the work vehicle to the working state and drives it automatically along the work path, the greater the deviation, the more unstable the vehicle begins automatic driving, swaying significantly from side to side relative to the work path, and the driving distance required to stabilize this swaying also increases. Consequently, the work track left after the work vehicle passes remains uneven for a long period, with the amplitude of lateral swaying relative to the work path increasing the closer it is to the starting position of the work path.

[0007] Taking this situation into account, the main objective of the present invention is to increase the work precision of a work vehicle through automatic driving without causing a decrease in yield or a decline in work efficiency. means of solving the problem

[0008] The first feature configuration of the present invention is an automatic driving system for a work vehicle, wherein

[0009] An entry area setting unit for setting an entry area for a work vehicle for a plurality of parallel paths arranged at predetermined intervals, and

[0010] A positioning unit for measuring the position and orientation of the above-mentioned work vehicle, and

[0011] An automatic driving control unit that executes a first automatic driving control to automatically drive the work vehicle in a working state along the parallel path based on the parallel path and positioning information from the positioning unit, and

[0012] A deviation detection unit that detects the angular deviation and lateral deviation of the work vehicle with respect to the parallel path at the time when the work vehicle reaches the entry area based on the parallel path and positioning information from the positioning unit, and

[0013] When the above-mentioned work vehicle reaches the above-mentioned entry area, the condition determination unit determines whether the initiation condition of the first automatic driving control is established based on detection information from the deviation detection unit, and

[0014] The above condition determination unit determines that the initiation condition of the first automatic driving control is established when the angle deviation is less than a predetermined angle and the lateral deviation is less than a predetermined value, and

[0015] The above automatic driving control unit has the advantage that, at the time when the work vehicle reaches the entry area, if the condition determination unit determines that the initiation condition of the first automatic driving control is established, it executes the first automatic driving control, and if the condition determination unit determines that the initiation condition of the first automatic driving control is not established, it executes automatic turnback driving control that drives the work vehicle in a turnback manner through a combined operation of forward / reverse switching operation and steering operation of the work vehicle so that the initiation condition of the first automatic driving control is established.

[0016] According to this configuration, the work precision of the work vehicle can be increased through automatic driving without causing a decrease in yield or a decline in work efficiency. Brief explanation of the drawing

[0017] Figure 1 is a diagram showing the schematic configuration of an automatic driving system for a work vehicle. Figure 2 is a block diagram showing the schematic configuration of an automatic driving system for a work vehicle. Figure 3 is a schematic diagram showing the electric power configuration of a tractor. Figure 4 is a plan view showing an example of a target path for automatic driving. Figure 5 is a block diagram showing the schematic configuration of an obstacle detection unit. FIG. 6 is an explanatory diagram showing the state in which the tractor is located in the entry area of ​​a parallel path when the initiation condition of the first automatic driving control is established. FIG. 7 is an explanatory diagram showing the state in which a tractor turns back in a drivable area where the entry area and the upper area of ​​the driving direction are selected. FIG. 8 is an explanatory diagram showing the forward state when a tractor turns back in a drivable area where the entry area and the lower area of ​​the driving direction are selected. FIG. 9 is an explanatory diagram showing the reverse state when a tractor turns back in a drivable area where the entry area and the lower area of ​​the driving direction are selected. Figure 10 is a flowchart of the driving control switching process. Specific details for implementing the invention

[0018] Hereinafter, as an example of a form for carrying out the present invention, an embodiment in which an automatic driving system for a work vehicle 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. In addition, the automatic driving system for a work vehicle according to the present invention can be applied to, in addition to a tractor, to, for example, ride-on work vehicles such as a ride-on brush cutter, ride-on electric shaving machine, combine harvester, transport vehicle, snowplow, wheel loader, etc., and to unmanned work vehicles such as an unmanned brush cutter.

[0019] As shown in FIG. 1, the tractor (1) exemplified in this embodiment has a rotary light-wheel device (3), which is an example of a work device, connected to its rear portion via a three-point linkage mechanism (2) so as to be vertically movable and also rollable. By doing so, the tractor (1) functions as a work vehicle with rotary light-wheel specifications. By using an automatic driving system for work vehicles, the tractor (1) can drive automatically on a pavement (A), which is an example of a work site shown in FIG. 4.

[0020] In addition, instead of a rotary light-powered device (3) at the rear of the tractor (1), a rear-mounted work device such as a plow, disc harrow, tiller, subsoiler, seeding device, spraying device, offset mower, or harvesting device can be connected. In addition, a front-mounted work device such as a front loader or front mower conditioner can be connected to the front of the tractor (1).

[0021] As shown in FIGS. 1 and 2, the automatic driving system includes an automatic driving unit (4) mounted on a tractor (1), and a portable communication terminal (5), which is an example of a wireless communication device configured to communicate wirelessly with the automatic driving unit (4). The portable communication terminal (5) is equipped with a multi-touch display device (e.g., a liquid crystal panel) (50) that enables various information display or input operations regarding automatic driving.

[0022] In addition, the mobile communication terminal (5) may be a tablet-type personal computer or a smartphone. In addition, wireless communication may be a wireless LAN (Local Area Network) such as Wi-Fi (registered trademark) or short-range wireless communication such as Bluetooth (registered trademark).

[0023] As shown in FIGS. 1 and 3, the tractor (1) is equipped with left and right front wheels (10) that are drivable and steerable, left and right rear wheels (11) that are drivable, a cabin (13) forming a driver's seat (12), an electronically controlled diesel engine (hereinafter referred to as the engine) (14) having a common rail system, a bonnet (15) covering the engine (14), and a transmission unit (16) that transmits power from the engine (14). By this, the tractor (1) is configured with a four-wheel driveable front-wheel steering specification. Additionally, the engine (14) may be an electronically controlled gasoline engine having an electronic governor.

[0024] As shown in FIG. 2, the tractor (1) is equipped with an all-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 electro-hydraulic control work clutch unit (19) for controlling the transmission to a driving work device such as a rotary light-wheel drive unit (3), an electro-hydraulic control lifting drive unit (20) for lifting and lowering the rotary light-wheel drive unit (3), an electro-hydraulic control rolling unit (21) for driving the rotary light-wheel drive unit (3) in the rolling direction, a vehicle state detection device (22) including various sensors and switches for detecting various setting states or operating states of each part in the tractor (1), and a vehicle control unit (23) having various control sections. Additionally, the power steering unit (17) may be an electric type having an electric motor for steering.

[0025] As shown in FIGS. 1 and 2, the driving unit (12) is equipped with a steering wheel (25) for manual steering, a seat (26) for passengers, and an operating terminal (27) that enables various information display and input operations. Although not shown, the driving unit (12) is equipped with operating levers such as an accelerator lever and a main speed lever, and operating pedals such as an accelerator pedal and a clutch pedal. The operating terminal (27) may employ a multi-touch liquid crystal monitor or an ISOBUS-compatible virtual terminal.

[0026] As shown in FIG. 3, the transmission unit (16) is equipped with a driving transmission system (16A) that shifts power from the engine (14) for driving and a work transmission system (16B) that shifts power for work. Then, the power after shifting by the driving transmission system (16A) is transmitted to the left and right front wheels (10) through a front wheel drive shaft (28) and a front wheel differential (30) built into the front axle case (29). In addition, the power after shifting by the work transmission system (16B) is transmitted to the rotary light transmission device (3). The transmission unit (16) is equipped with left and right brakes (31) that individually brake the left and right rear wheels (11).

[0027] The driving transmission system (16A) includes an electronically controlled main transmission unit (32) for shifting power from the engine (14), an electronically hydraulically controlled forward / reverse switching unit (33) for switching power from the main transmission unit (32) for forward and reverse, a gear-type auxiliary transmission unit (34) for shifting power for forward or reverse from the forward / reverse switching unit (33) to high and low two stages, a gear-type creep transmission unit (35) for shifting power for forward or reverse from the forward / reverse switching unit (33) to an ultra-low speed stage, a rear wheel differential unit (36) for distributing power from the auxiliary transmission unit (34) or the creep transmission unit (35) to the left and right rear wheels (11), left and right reduction units (37) for reducing power from the rear wheel differential unit (36) and transmitting it to the left and right rear wheels (11), and power transmission from the auxiliary transmission unit (34) or the creep transmission unit (35) to the left and right front wheels (10). It includes an electronic hydraulic control type electric switching device (38) that switches.

[0028] The work transmission system (16B) includes a hydraulic work clutch (39) that controls power from the engine (14), a work transmission device (40) that switches power passing through the work clutch (39) to a forward 3rd gear and a reverse 1st gear, and a PTO shaft (41) that outputs power from the work transmission device (40) for work. Power extracted from the PTO shaft (41) is transmitted to the work device through an external transmission shaft (not shown), etc., when a driving work device, such as a rotary light transmission device (3), is connected to the rear of the tractor (1).

[0029] The main transmission unit (32) employs an I-HMT (Integrated Hydro-Static Mechanical Transmission), which is an example of a hydraulic mechanical stepless transmission with higher transmission efficiency than a hydrostatic transmission (HST).

[0030] In addition, instead of the I-HMT, the main transmission unit (32) may employ a stepless transmission such as an HMT (Hydraulic Mechanical Transmission), which is an example of a hydraulic mechanical stepless transmission, a hydrostatic stepless transmission, or a belt-type stepless transmission. In addition, instead of a stepless transmission, an electro-hydraulic controlled stepless transmission having a plurality of hydraulic shift clutches and a plurality of electronic shift valves that control the flow of oil thereto may be employed.

[0031] The electric switching device (38) switches the electric power state to the left and right front wheels (10) to an electric power cutoff state that cuts off electric power to the left and right front wheels (10), a constant speed electric power state that drives electric power to the left and right front wheels (10) so that the main speed of the left and right front wheels (10) becomes equal to the main speed of the left and right rear wheels (11), and a speed-adjusted electric power state that drives electric power to the left and right front wheels (10) so that the main speed of the left and right front wheels (10) becomes approximately twice the main speed of the left and right rear wheels (11). By doing so, this tractor (1) is configured to be able to switch between a two-wheel drive state, a four-wheel drive state, and a front-wheel speed-adjusted state.

[0032] Although the city is omitted, the brake unit (18) includes left and right brakes (31), a foot brake system that operates the left and right brakes (31) in conjunction with the operation of the left and right brake pedals provided in the driving unit (12), a parking brake system that operates the left and right brakes (31) in conjunction with the operation of the parking lever provided in the driving unit (12), and a turning brake system that operates the inner turning brake (31) in conjunction with steering of the left and right front wheels (10) at a set angle or greater.

[0033] The vehicle condition detection device (22) is a general term for various sensors or switches provided in each part of the tractor (1). Although not explicitly shown, the vehicle condition detection device (22) includes an accelerator sensor that detects the operating position of the accelerator lever, a transmission sensor that detects the operating position of the main speed lever, a reverser sensor that detects the operating position of the reverser lever for forward / reverse switching, a rotation sensor that detects the output rotational speed of the engine (14), a vehicle speed sensor that detects the vehicle speed of the tractor (1), and a steering angle sensor that detects the steering angle of the front wheel (10).

[0034] As shown in FIG. 2, the vehicle control unit (23) includes an engine control unit (23A) that performs control regarding the engine (14), a transmission unit control unit (23B) that performs control regarding the transmission unit (16) such as the vehicle speed or forward / reverse switching of the tractor (1), a steering control unit (23C) that performs control regarding steering, a work device control unit (23D) that performs control regarding a work device such as a rotary light-wheeling device (3), a display control unit (23E) that performs control regarding display or notification to an operation terminal (27), an automatic driving control unit (23F) that performs control regarding automatic driving, and a non-volatile vehicle memory unit (23G) that stores a target path (P) for automatic driving (see FIG. 4) generated according to a driving area divided within the packaging. Each control unit (23A to 23F) is constructed by an electronic control unit in which a microcontroller is integrated or by various control programs. Each control unit (23A to 23F) is connected to communicate with each other via a CAN (Controller Area Network).

[0035] In addition, for mutual communication between each control unit (23A to 23F), communication standards other than CAN or next-generation communication standards, such as onboard Ethernet or CAN-FD (CAN with flexible data rate), may be adopted.

[0036] The engine control unit (23A) performs engine rotation speed maintenance control, such as maintaining the engine rotation speed at the rotation 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.

[0037] The transmission unit control unit (23B) performs speed control, which controls the operation of the main speed device (32) so that the vehicle speed of the tractor (1) changes to a speed according to the operating position of the main speed lever based on detection information from the transmission sensor and detection information from the vehicle speed sensor, and forward / reverse switching control, which switches the electric state of the forward / reverse switching device based on detection information from the reverser sensor. The speed control includes deceleration stop processing, which controls the main speed device (32) to decelerate to the 0th speed state and stops the driving of the tractor (1) when the transmission lever is operated to the 0th speed position.

[0038] The work device control unit (23D) performs work clutch control, which controls the operation of the work clutch unit (19) based on the operation of the PTO switch provided in the driving unit (12); lifting control, which controls the operation of the lifting drive unit (20) based on the operation of the lifting switch provided in the driving unit (12) or the setting value of the height setting dial; and rolling control, which controls the operation of the rolling unit (21) based on the setting value of the roll angle setting dial provided in the driving unit (12). The PTO switch, lifting switch, height setting dial, and roll angle setting dial are included in the vehicle state detection device (22).

[0039] As shown in FIG. 2, the tractor (1) is equipped with a positioning unit (an example of a positioning unit) (42) for measuring the position and orientation of the tractor (1). The positioning unit (42) includes a satellite navigation device (43) that measures the position and orientation of the tractor (1) using a GNSS (Global Navigation Satellite System), which is an example of a satellite positioning system, and an inertial measurement unit (IMU) (44) that measures the attitude and orientation of the tractor (1) using a 3-axis gyroscope and a 3-directional acceleration sensor. Positioning methods using GNSS include DGNSS (Differential GNSS: relative positioning method) and RTK-GNSS (Real Time Kinematic GNSS: interferential positioning method). In this embodiment, RTK-GNSS suitable for positioning a moving body is adopted. For this reason, as shown in Fig. 1, a base station (6) that enables positioning by RTK-GNSS is installed at the base station location around the packaging.

[0040] As shown in FIGS. 1 and 2, each of the tractor (1) and the base station (6) is equipped with a GNSS antenna (45, 60) that receives radio waves transmitted from a positioning satellite (7) (see FIG. 1), and a communication module (46, 61) that enables wireless communication of information including positioning information between the tractor (1) and the base station (6). By this, the satellite navigation device (43) of the positioning unit (42) can measure the position and bearing of the tractor (1) with high precision based on the positioning information obtained by the GNSS antenna (45) on the tractor side receiving radio waves from the positioning satellite (7) and the positioning information obtained by the GNSS antenna (60) on the base station side receiving radio waves from the positioning satellite (7). In addition, the positioning unit (42) has a satellite navigation device (43) and an inertial measurement device (44), so that the position, bearing, and attitude angle (yaw angle, roll angle, pitch angle) of the tractor (1) can be measured with high precision.

[0041] In this tractor (1), the inertial measurement device (44) of the positioning unit (42), the GNSS antenna (45), and the communication module (46) are included in the antenna unit (47) shown in FIG. 1. The antenna unit (47) is positioned at the upper left and right center of the front side of the cabin (13).

[0042] As shown in FIGS. 6 to 9, the vehicle body position (Vp) when determining the position of the tractor (1) is set to the center position of the rear axle. The vehicle body position (Vp) can be obtained from positioning information from the positioning unit (42) and from vehicle body information including the positional relationship between the attachment position of the GNSS antenna (45) on the tractor (1) and the center position of the rear axle.

[0043] As shown in FIG. 2, the mobile communication terminal (5) is equipped with an electronic control unit, such as a microcontroller, and a terminal control unit (51) having various control programs. The terminal control unit (51) includes a display control unit (51A) that performs control regarding display or notification to a display device (50), a target path generation unit (51B) that generates a target path (P) for automatic driving, and a non-volatile terminal memory unit (51C) that stores the target path (P) generated by the target path generation unit (51B). The terminal memory unit (51C) stores various information used to generate the target path (P), such as vehicle body information including the turning radius of the tractor (1) and the working width of the rotary light-wheeling device (3), and pavement information obtained from the positioning information described above. The pavement information includes, in order to specify the shape or size of the pavement (A), four corner points (Pa to Pd) (see FIG. 4) that are multiple shape-specific points (shape-specific coordinates) in the pavement (A) obtained using GNSS when the tractor (1) is driven along the outer edge of the pavement (A), and a rectangular shape-specific line (SL) (see FIG. 4) that connects these corner points (Pa to Pd) to specify the shape or size of the pavement (A).

[0044] As shown in FIG. 2, the tractor (1) and the mobile communication terminal (5) are equipped with communication modules (48, 52) that enable wireless communication of various information, including positioning information, between the vehicle control unit (23) and the terminal control unit (51). When Wi-Fi is used for wireless communication with the mobile communication terminal (5), the communication module (48) of the tractor (1) functions as a converter that converts communication information into bidirectional CAN and Wi-Fi. The terminal control unit (51) can acquire various information regarding the tractor (1), including the position and orientation of the tractor (1), through wireless communication with the vehicle control unit (23). By doing so, various information, including the position and orientation of the tractor (1) regarding the target path (P), can be displayed on the display device (50) of the mobile communication terminal (5).

[0045] The target path generation unit (51B) generates a target path (P) based on the turning radius of the tractor (1) included in the vehicle body information, the working width of the rotary light device (3), and the shape or size of the pavement (A) included in the pavement information.

[0046] For example, as shown in FIG. 4, in a rectangular pavement (A), the starting position (p1) and ending position (p2) of automatic driving are set, and the working driving direction of the tractor (1) is set to follow the short side of the pavement (A). In this case, the target path generation unit (51B) first divides the pavement (A) into a margin area (A1) adjacent to the outer edge of the pavement (A) and a driving area (A2) located inside the margin area (A1), based on the four corner points (Pa~Pd) described above and a rectangular shape specific line (SL).

[0047] Next, the target path generation unit (51B) divides the driving area (A2) into a pair of immersion areas (A2a) set at the edge of the ridge on each long side of the driving area (A2) and a central area (A2b) set between the pair of immersion areas (A2a), based on the turning radius of the tractor (1) or the working width of the rotary light-powered device (3). After that, the target path generation unit (51B) generates a plurality of parallel paths (P1) arranged in parallel at a predetermined interval according to the working width in the direction following the long side of the pavement (A) in the central area (A2b). In addition, the target path generation unit (51B) generates a plurality of connecting paths (P2) that connect the plurality of parallel paths (P1) in each immersion area (A2a) in the driving order of the tractor (1).

[0048] By this, the target path generation unit (51B) can generate a target path (P) that enables the tractor (1) to automatically drive from the starting position (p1) to the ending position (p2) of the automatic driving set on the pavement (A) shown in FIG. 4.

[0049] In the pavement (A) shown in FIG. 4, the margin area (A1) is an area secured between the outer edge of the pavement (A) and the driving area (A2) to prevent the rotary light-powering device (3), etc., from coming into contact with other objects such as the ridge adjacent to the pavement (A) when the tractor (1) automatically drives along the ridge of the driving area (A2). Each immersion area (A2a) is a turning area when the tractor (1) turns along the connecting path (P2) from the parallel path (P1) currently being driven toward the next parallel path (P1). The central area (A2b) is a working area where the tractor (1) automatically drives in a working state along each parallel path (P1).

[0050] In the target path (P) shown in FIG. 4, each parallel path (P1) is a work path in which the tractor (1) automatically drives while performing light-turning work by the rotary light-turning device (3). Each connecting path (P2) is a non-work path in which the tractor (1) automatically drives without performing light-turning work by the rotary light-turning device (3). The starting position (p3) of each parallel path (P1) is the work start position where the tractor (1) starts light-turning work by the rotary light-turning device (3). The ending position (p4) of each parallel path (P1) is the work stop position where the tractor (1) stops light-turning work by the rotary light-turning device (3). Among the starting positions (p3) of each parallel path (P1), the starting position (p3) of the parallel path (P1) in which the driving order of the tractor (1) is set first is the starting position (p1) of automatic driving. And, the starting position (p3) of the remaining parallel path (P1) is the connection position with the ending position of the connecting path (P2). Also, the ending position (p4) of the parallel path (P1) where the driving order of the tractor (1) is set last is the end position (p2) of the automatic driving.

[0051] In addition, the target path (P) shown in FIG. 4 is merely an example, and the target path generation unit (51B) can generate various target paths (P) suitable for them based on different vehicle body information depending on the type of tractor (1) or the type of work device, and different paving information such as the shape or size of the paving (A) depending on the paving (A).

[0052] Additionally, in the target path (P) shown in FIG. 4, when the tractor (1) performs harrowing work using a harrowing device, each parallel path (P1) and each connecting path (P2) are used as work paths.

[0053] The target path (P) is stored in the terminal memory unit (51C) in a state related to body information or packaging information, etc., and can be displayed on the display device (50) of the mobile communication terminal (5). The target path (P) includes the above-described work start position (p3) and work stop position (p4), as well as the azimuth of each parallel path (P1), the target vehicle speed of the tractor (1) in each parallel path (P1), the target vehicle speed of the tractor (1) in each connecting path (P2b), the front wheel steering angle in each parallel path (P1), and the front wheel steering angle in each connecting path (P2b).

[0054] The terminal control unit (51) transmits packaging information or a target route (P), etc., stored in the terminal memory unit (51C) to the vehicle control unit (23) in response to a transmission request command from the vehicle control unit (23). The vehicle control unit (23) stores the received packaging information or a target route (P), etc., in the vehicle memory unit (23G). Regarding the transmission of the target route (P), for example, the terminal control unit (51) may transmit the entire target route (P) from the terminal memory unit (51C) to the vehicle control unit (23) all at once at a stage before the tractor (1) begins automatic driving. Additionally, the terminal control unit (51) may divide the target path (P) into multiple divided path information at predetermined distances, and sequentially transmit a predetermined number of divided path information according to the driving order of the tractor (1) from the terminal memory unit (51C) to the vehicle control unit (23) whenever the driving distance of the tractor (1) reaches a predetermined distance from the stage before the tractor (1) starts automatic driving.

[0055] In the vehicle control unit (23), detection information from various sensors or switches included in the vehicle state detection device (22) is input to the automatic driving control unit (23F) through the transmission unit control unit (23B) or steering control unit (23C). By this, the automatic driving control unit (23F) can monitor various setting states and operating states of each part in the tractor (1).

[0056] The automatic driving control unit (23F) initiates automatic driving control to drive the tractor (1) automatically along the target path (P) while acquiring the position and orientation of the tractor (1) using the positioning unit (42), when the tractor (1) is moved to the automatic driving start position (p1) by manual driving by a user such as a passenger or manager, and manual operation is performed to satisfy various automatic driving start conditions and the driving mode of the tractor (1) is switched to the automatic driving mode, and the display device (50) of the portable communication terminal (5) is operated to command the start of automatic driving.

[0057] 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 when, during the execution of automatic driving control, for example, the display device (50) of the mobile communication terminal (5) is operated by a user to command the termination of automatic driving, or when a manual operating device such as the steering wheel (25) or accelerator pedal is operated by a user riding in the driving unit (12). When resuming automatic driving control after the automatic driving control has been terminated, first, the user rides in the driving unit (12) and switches the driving mode of the tractor (1) from the automatic driving mode to the manual driving mode. Next, after performing manual operations to satisfy various automatic driving start conditions, the driving mode of the tractor (1) is switched from the manual driving mode to the automatic driving mode. Then, in this state, the automatic driving control can be resumed by operating the display device (50) of the mobile communication terminal (5) to command the start of automatic driving.

[0058] The automatic driving control by the automatic driving control unit (23F) includes an automatic driving control process for the engine that transmits an automatic driving control command regarding the engine (14) to the engine control unit (23A), an automatic driving control process for the vehicle speed that transmits an automatic driving control command regarding the vehicle speed or forward / reverse switching of the tractor (1) to the transmission unit control unit (23B), an automatic driving control process for the steering that transmits an automatic driving control command regarding the steering to the steering control unit (23C), and an automatic driving control process for the work device that transmits an automatic driving control command regarding the work device such as the rotary light electric device (3) to the work device control unit (23D).

[0059] In the automatic driving control unit (23F), for automatic control processing for the engine, the automatic driving control unit (23F) transmits an engine speed change command, etc., to the engine control unit (23A), which instructs the engine speed change based on the set speed of the engine included in the target path (P). The engine control unit (23A) executes engine speed change control, etc., which automatically changes the engine speed according to various control commands regarding the engine (14) transmitted from the automatic driving control unit (23F).

[0060] In the automatic driving control unit (23F) for automatic control processing for vehicle speed, it transmits to the transmission unit control unit (23B) a transmission operation command that instructs the transmission operation of the main transmission device (32) based on the target vehicle speed included in the target path (P), and a forward / reverse switching command that instructs the forward / reverse switching operation of the forward / reverse switching device (33) based on the direction of travel of the tractor (1) included in the target path (P). The transmission unit control unit (23B) executes automatic vehicle speed control that automatically controls the operation of the main transmission device (32) and automatic forward / reverse switching control that automatically controls the operation of the forward / reverse switching device (33) according to various control commands regarding the main transmission device (32) or the forward / reverse switching device (33) transmitted from the automatic driving control unit (23F). Automatic vehicle speed control includes, for example, an automatic deceleration stop process that controls the main speed device (32) to decelerate to a 0-speed state and stops the driving of the tractor (1) when the target vehicle speed included in the target path (P) is 0 speed.

[0061] In the automatic driving control unit (23F), for automatic control processing for steering, the steering command, etc., which instructs steering of the left and right front wheels (10) based on the front wheel steering angle included in the target path (P), is transmitted to the steering control unit (23C). The steering control unit (23C) performs automatic steering control, which controls the operation of the power steering unit (17) to steer the left and right front wheels (10) according to the steering command transmitted from the automatic driving control unit (23F), and automatic brake turning control, which operates the brake unit (18) to operate the brake (31) on the inner side of the turning when the left and right front wheels (10) are steered beyond a set angle.

[0062] In the automatic driving control unit (23F), for automatic control processing for work, the automatic driving control unit (23F) transmits to the work device control unit (23D) a work start command that instructs the rotary light device (3) to switch to a work state based on a work start position (p3) included in the target path (P), and a work stop command that instructs the rotary light device (3) to switch to a non-work state based on a work stop position (p4) included in the target path (P). The work device control unit (23D) executes automatic work start control, which controls the operation of the work clutch unit (19) and the lifting drive unit (20) to drive the rotary light device (3) by lowering it to a work height, and automatic work stop control, which stops the rotary light device (3) and raises it to a non-work height, in accordance with the various control commands regarding the rotary light device (3) transmitted from the automatic driving control unit (23F).

[0063] Additionally, the above-described automatic driving unit (4) includes a power steering unit (17), a brake unit (18), a work clutch unit (19), a lifting drive unit (20), a rolling unit (21), a vehicle status detector (22), a vehicle control unit (23), a positioning unit (42), and communication modules (46, 48). By operating these properly, the tractor (1) can be driven automatically with high precision along a target path (P), and a rotary light-turning device (3) can be properly operated.

[0064] As shown in FIGS. 2 and 5, the tractor (1) is equipped with an obstacle detection unit (80) that monitors the surroundings of the tractor (1) and detects obstacles present in the surroundings. The obstacles detected by the obstacle detection unit (80) include people such as workers working on the pavement (A), other work vehicles, and existing utility poles or trees on the pavement (A).

[0065] As shown in FIGS. 1 and 5, the obstacle detection unit (80) includes an imaging unit (80A) that captures images of the surroundings of the tractor (1), an active sensor unit (80B) that measures the distance to a measurement target existing around the tractor (1), and an information integration processing unit (80C) that integrates and processes information from the imaging unit (80A) and measurement information from the active sensor unit (80B).

[0066] The imaging unit (80A) includes a front camera (81) with a predetermined range of the front from the cabin (13) set as the imaging range, a rear camera (82) with a predetermined range of the rear from the cabin (13) set as the imaging range, a right camera (83) with a predetermined range of the right from the cabin (13) set as the imaging range, a left camera (84) with a predetermined range of the left from the cabin (13) set as the imaging range, and an image processing device (85) for processing images from each camera (81 to 84).

[0067] The active sensor unit (80B) includes a front lidar sensor (86) with a predetermined range forward from the cabin (13) set as the measurement range, a rear lidar sensor (87) with a predetermined range rearward from the cabin (13) set as the measurement range, and a sonar (88) with a predetermined range to the right and a predetermined range to the left from the cabin (13) set as the measurement range. Each lidar sensor (86, 87) includes a measurement unit (86A, 87A) that performs measurement within the measurement range using a laser light (e.g., pulsed near-infrared laser light) which is an example of measurement light, and a lidar control unit (86B, 87B) that performs the generation of a distance image based on measurement information from the measurement unit (86A, 87A). The sonar (88) includes a right ultrasonic sensor (88A), a left ultrasonic sensor (88B), and a single sonar control unit (88C).

[0068] The information integration processing unit (80C), image processing device (85), each lidar control unit (86B, 87B), and sonar control unit (88C) are constructed by an electronic control unit with integrated microcontrollers or various control programs. The information integration processing unit (80C), image processing device (85), each lidar control unit (86B, 87B), and sonar control unit (88C) are connected to the vehicle control unit (23) so as to communicate with each other via CAN.

[0069] The front camera (81) and the rear camera (82) are positioned on the left and right centerlines of the tractor (1). The front camera (81) is positioned at the upper left and right center point on the front side of the cabin (13) in a downward-facing position, looking down at the front side of the tractor (1) from an oblique upward angle. By this, the front camera (81) has a predetermined range on the front side of the vehicle body with the left and right centerlines of the tractor (1) as the axis of symmetry set as the imaging range. The rear camera (82) is positioned at the upper left and right center point on the rear side of the cabin (13) in a downward-facing position, looking down at the rear side of the tractor (1) from an oblique upward angle. By this, the rear camera (82) has a predetermined range on the rear side of the vehicle body with the left and right centerlines of the tractor (1) as the axis of symmetry set as the imaging range. The right camera (83) is positioned at the upper front-rear center of the right end of the cabin (13) in a downward-facing position, looking down obliquely from the upper side at the right side of the tractor (1). By this, the right camera (83) has a predetermined range of the right side of the vehicle body set as its imaging range. The left camera (84) is positioned at the upper front-rear center of the left end of the cabin (13) in a downward-facing position, looking down obliquely from the upper side at the left side of the tractor (1). By this, the left camera (84) has a predetermined range of the left side of the vehicle body set as its imaging range.

[0070] In each LiDAR sensor (86, 87), each measuring unit (86A, 87A) measures the distance to each measuring point in the measurement range from each measuring unit (86A, 87A) by the Time Of Flight (TOF) method, which measures the distance to the measuring point based on the round-trip time from when the irradiated laser light reaches the measuring point and returns. Each measuring unit (86A, 87A) performs three-dimensional measurement in each measurement range by scanning the laser light at high speed in the vertical and horizontal directions over the entire measurement range and sequentially measuring the distance to the measuring point for each scanning angle (coordinate). Each measuring unit (86A, 87A) sequentially measures the intensity of the reflected light from each measuring point (hereinafter referred to as reflection intensity) obtained when the laser light is scanned at high speed in the vertical and horizontal directions over the entire measurement range. Each measuring unit (86A, 87A) repeatedly measures the distance to each measuring point in the measurement range and each reflection intensity in real time. Each rider control unit (86B, 87B) generates a distance image from measurement information, such as the distance to each measurement point or the scanning angle (coordinates) for each measurement point, measured by each measurement unit (86A, 87A), and extracts a group of measurement points presumed to be obstacles, and transmits the measurement information regarding the extracted group of measurement points to the information integration processing unit (80C) as measurement information regarding obstacle candidates.

[0071] The front lidar sensor (86) and the rear lidar sensor (87) are positioned on the left and right centerlines of the tractor (1), just like the front camera (81) and the rear camera (82). The front lidar sensor (86) is positioned at the upper left and right center point on the front side of the cabin (13) in a downward-facing position, looking down at the front side of the tractor (1) from an oblique upward direction. By this, the front lidar sensor (86) sets a predetermined range on the front side of the vehicle body, with the left and right centerlines of the tractor (1) as the axis of symmetry, as the measurement range by the measuring unit (86A). The rear lidar sensor (87) is positioned at the upper left and right center point on the rear side of the cabin (13) in a downward-facing position, looking down at the rear side of the tractor (1) from an oblique upward direction. By this, the rear rider sensor (87) is set to a predetermined range on the rear side of the vehicle body, with the left and right centerlines of the tractor (1) as the axis of symmetry, as the measurement range by the measuring unit (87A).

[0072] In the sonar (88), the sonar control unit (88C) determines the presence or absence of a measurement target within the measurement range based on the transmission and reception of ultrasound by the left and right ultrasound sensors (88A, 88B). The sonar control unit (88C) measures the distance to the measurement target from each ultrasound sensor (88A, 88B) by the Time Of Flight (TOF) method, which measures the distance to the measurement point based on the round-trip time from when the transmitted ultrasound reaches the measurement point and returns, and transmits the measured distance to the measurement target and the direction of the measurement target to the information integration processing unit (80C) as measurement information regarding obstacle candidates.

[0073] Although the city is omitted, the right ultrasonic sensor (88A) is attached to the right lifting step positioned between the right front wheel (10) and the right rear wheel (11) in a rightward-facing position of the vehicle body. By this, the right ultrasonic sensor (88A) has a predetermined range on the right outer side of the vehicle body set as the measurement range. As shown in FIG. 1, the left ultrasonic sensor (88B) is attached to the left lifting step (24) positioned between the left front wheel (10) and the left rear wheel (11) in a leftward-facing position of the vehicle body. By this, the left ultrasonic sensor (88B) has a predetermined range on the left outer side of the vehicle body set as the measurement range.

[0074] The image processing device (85) performs image processing on images transmitted sequentially from each camera (81-84). The image processing device (85) is equipped with learning processing to recognize people, such as workers working on the packaging (A), other work vehicles, and existing utility poles or trees on the packaging (A) as obstacles.

[0075] The image processing device (85) synthesizes images sequentially transmitted from each camera (81 to 84) to generate an overall surrounding image of the tractor (1) (e.g., a surround view), and transmits the generated overall surrounding image or images from each camera (81 to 84) to the display control unit (23E) of the tractor (1) or the display control unit (51A) of the mobile communication terminal (5).

[0076] By this, the entire surrounding image generated by the image processing device (85) or the image of the tractor (1)'s driving direction can be displayed on the tractor (1)'s operating terminal (27) or the display device (50) of the mobile communication terminal (5). And, through this display, the user can be made aware of the surrounding conditions of the tractor (1) or the conditions of the driving direction.

[0077] The image processing device (85) determines whether there is an obstacle affecting the driving of the tractor (1) in the imaging range of any one of the cameras (81 to 84) based on images sequentially transmitted from each camera (81 to 84). If an obstacle is present, the image processing device (85) obtains the coordinates of the obstacle on the image where the obstacle is present, and converts the obtained coordinates of the obstacle into coordinates based on the vehicle body coordinate origin, based on the mounting position or mounting angle of each camera (81 to 84). Then, the straight-line distance between the converted coordinates and a preset distance calculation reference point is obtained as the distance from the distance calculation reference point to the obstacle, and the converted coordinates and the obtained distance to the obstacle are transmitted to the information integration processing unit (80C) as information regarding the obstacle. Meanwhile, if no obstacle is present, the fact that the obstacle was not detected is transmitted to the information integration processing unit (80C).

[0078] Thus, when an obstacle exists in any of the imaging ranges of each camera (81-84), the image processing device (85) transmits information regarding the obstacle to the information integration processing unit (80C). By receiving the information regarding the obstacle, the information integration processing unit (80C) can identify that an obstacle exists in the imaging range of any of the cameras (81-84), and can also obtain the location of the obstacle and the distance to the obstacle. Additionally, when no obstacle exists anywhere in the imaging ranges of each camera (81-84), the image processing device (85) transmits the non-detection of the obstacle to the information integration processing unit (80C). In this way, the information integration processing unit (80C) can identify that no obstacle exists anywhere in the imaging ranges of each camera (81-84).

[0079] When the information integration processing unit (80C) matches information regarding an obstacle from an imaging unit (80A) with high object discrimination precision with measurement information regarding an obstacle candidate from an active sensor unit (80B) with high distance measurement precision, it adopts the distance to the obstacle candidate obtained from the active sensor unit (80B) as the distance to the obstacle. By doing so, the obstacle detection unit (80) can acquire information regarding an obstacle with high object discrimination precision and distance measurement precision from the information integration processing unit (80C). The obstacle detection unit (80) transmits the information regarding the obstacle acquired from the information integration processing unit (80C) to the automatic driving control unit (23F).

[0080] The automatic driving control unit (23F) executes collision avoidance control to avoid collision with an obstacle based on information regarding an obstacle from the obstacle detection unit (80). In collision avoidance control, the automatic driving control unit (23F) is configured to appropriately perform various collision avoidance processes, such as obtaining the distance to the obstacle based on information regarding the obstacle from the obstacle detection unit (80), and, according to the obtained distance to the obstacle, an alarm such as a notification buzzer or notification lamp equipped on the tractor (1) and the portable communication terminal (5), an automatic deceleration process to automatically reduce the vehicle speed of the tractor (1), and an automatic driving stop process to automatically stop the driving of the tractor (1).

[0081] The automatic driving control unit (23F) initiates automatic driving control to drive the tractor (1) automatically along a target path (P) when the tractor (1) is positioned at the starting position (p1) for automatic driving and the start of automatic driving is commanded. The automatic driving control includes a first automatic driving control to drive the tractor (1) automatically along the parallel path (P1) in a working state based on the parallel path (P1) of the target path (P) and positioning information from the positioning unit (42), and a second automatic driving control to drive the tractor (1) automatically along the connected path (P2) in a non-working state based on the connected path (P2) of the target path (P) and positioning information from the positioning unit (42).

[0082] As shown in FIG. 2, the automatic driving control unit (23F) includes an entry area setting unit (23Fa) for setting an entry area (Aa) (see FIG. 4) of the tractor (1) for each parallel path (P1), a deviation detection unit (23Fb) for detecting the angular deviation (Δθ) (see FIG. 6-8) and lateral deviation (Δd) (see FIG. 6-8) of the tractor (1) in the yaw direction relative to the parallel path (P1) at the time when the tractor (1) reaches the entry area (Aa) based on the parallel path (P1) and the positioning unit (42), and a condition determination unit (23Fc) for determining whether the initiation condition of the first automatic driving control is established based on the detection information from the deviation detection unit (23Fb) when the tractor (1) reaches the entry area (Aa).

[0083] As shown in FIGS. 4, 6 to 9, the entry area setting unit (23Fa) sets a predetermined area including the starting position (p3) of each parallel path (P1) as the entry area (Aa) for each parallel path (P1). As shown in FIG. 6, the condition determination unit (23Fc) determines that the initiation condition for the first automatic driving control is established when the aforementioned angle deviation (Δθ) is less than a predetermined angle (θ) (e.g., 10 degrees) and the aforementioned lateral deviation (Δd) is less than a predetermined value (L) (5 cm). As shown in FIGS. 7 to 8, the condition determination unit (23Fc) determines that the initiation condition for the first automatic driving control is not established when the aforementioned angle deviation (Δθ) is greater than or equal to the predetermined angle (θ) or when the aforementioned lateral deviation (Δd) is greater than or equal to the predetermined value (L).

[0084] The automatic driving control unit (23F) executes the first automatic driving control when the condition determination unit (23Fc) determines that the starting condition for the first automatic driving control is established at the time when the tractor (1) reaches the entry area (Aa) through manual driving by a user or automatic driving by the second automatic driving control (see FIG. 6). In addition, when the condition determination unit (23Fc) determines that the starting condition for the first automatic driving control is not established, it executes automatic turnback driving control to turn the tractor (1) back by a combined operation of forward / reverse switching operation and steering operation so that the starting condition for the first automatic driving control is established (see FIG. 7-9).

[0085] Additionally, the automatic driving control unit (23F) performs a driving control switching process that switches the driving control executed based on the determination of the condition determination unit (23Fc) to the first automatic driving control and the automatic turnback driving control when the tractor (1) reaches the entry area (Aa) through manual driving by a user or automatic driving by the second automatic driving control.

[0086] And, as shown in the flowchart of FIG. 10, in this driving control switching process, first, when the tractor (1) reaches the entry area (Aa) described above, the automatic driving control unit (23F) performs a determination process to determine whether the condition for starting the first automatic driving control is established in the condition determination unit (23Fc) (Step #1).

[0087] And, as shown in FIG. 6, when the tractor (1) reaches the aforementioned entry area (Aa), if the aforementioned angle deviation (Δθ) is less than a predetermined angle (θ) and the aforementioned lateral deviation (Δd) is less than a predetermined value (L), in the judgment process, the condition judgment unit (23Fc) determines that the initiation condition for the first automatic driving control is established, and the automatic driving control unit (23F) executes the first automatic driving control and drives the tractor (1) automatically along the parallel path (P1) in a working state (Step #2). By doing so, the tractor (1) can perform work while performing high-precision automatic driving with a small amplitude of shaking along the parallel path (P1) from the step of starting automatic driving by the first automatic driving control.

[0088] Meanwhile, as shown in FIGS. 7 to 9, when the tractor (1) reaches the aforementioned entry area (Aa), if the aforementioned angle deviation (Δθ) is greater than or equal to a predetermined angle (θ) or the aforementioned lateral deviation (Δd) is greater than or equal to a predetermined value (L), in the determination process, the automatic driving control unit (23F) does not execute the first automatic driving control and executes automatic turnback driving control (Step #3) in the case where the condition determination unit (23Fc) determines that the initiation condition for the first automatic driving control is not established, and also performs the aforementioned determination process (Step #1).

[0089] By this, when the above-described angle deviation (Δθ) is greater than a predetermined angle (θ) or when the above-described lateral deviation (Δd) is greater than a predetermined value (L), the first automatic driving control is executed, which causes the amplitude of shaking of the tractor (1) on the parallel path (P1) to increase and requires a long distance to be stopped, thereby preventing the occurrence of a problem in which the work precision is reduced during this time.

[0090] In addition, the automatic driving control unit (23F) does not need to create a long travel path on the extension line of the starting position (p3) in each parallel path (P1) in order to make it easier to establish the starting condition of the first automatic driving control by the turnback driving of the tractor (1). As a result, as the travel path in the pavement (A) becomes longer, the parallel path (P1) that automatically drives the tractor (1) in a working state becomes shorter and the immersion area (A2a) becomes wider. For example, when the immersion area (A2a) is a circulating work area where the tractor (1) is driven around, the number of times the tractor (1) runs around in the circulating work area increases, thereby preventing the occurrence of problems such as reduced work efficiency.

[0091] As shown in FIGS. 2 and FIGS. 7-8, the automatic driving control unit (23F) includes a driving area selection unit (23Fd) that selects a driving area (A3) of the tractor (1) in automatic turnback driving control from the aforementioned entry area (Aa), and from a predetermined driving direction upper area (Ab) and driving direction lower area (Ac) with the entry area (Aa) in between in each parallel path (P1) of the tractor (1). The driving area selection unit (23Fd) selects the driving area (A3) of the tractor (1) based on the width of the immersion area (A2a) set by the user or the type of work device (3) when the target path (P) is generated by the target path generation unit (51B).

[0092] Specifically, the driving area selection section (23Fd) is configured such that, for example, the immersion width (W) (see FIG. 4) extending from the shape-specific line (SL) in the immersion area (A2a) to the central area (A2b) is set wider than the working width of the work device (3), and in the case where the upper area (Ab) of the driving direction of the entry area (Aa) is wide, even if the tractor (1) performs a turnback drive in the upper area (Ab) of the driving direction, there is no risk of the work device (3) connected to the tractor (1) coming into contact with other objects such as a ridge adjacent to the pavement (A), so the upper area (Ab) of the driving direction can be selected as a driving area (A3) in addition to the entry area (Aa).

[0093] For example, the driving area selection section (23Fd) is set so that the immersion width (W) of the immersion area (A2a) is narrow enough to allow turning driving at the minimum turning radius of the tractor (1), and the upper driving area (Ab) of the entry area (Aa) is narrow. In this case, if the tractor (1) performs a turnback driving in the upper driving area (Ab), the upper driving area (Ab) cannot be selected as a driving area (A3) because there is a risk that the work device (3) connected to the tractor (1) will come into contact with a ridge, etc.

[0094] The driving area selection unit (23Fd) allows the driving area (Ac) to be selected as a driving area (A3) in addition to the entry area (Aa) in the case where the type of work device (3) is, for example, a rotary light-powered device (see FIG. 1) or a plow (not shown), and the tractor (1) enters the driving direction lower area (Ac) and turns back, making it difficult to be affected in subsequent work in the driving direction lower area (Ac).

[0095] The driving area selection unit (23Fd) makes the driving area (Ac) unselectable as a driving area (A3) when, for example, the type of work device (3) is a sowing device (not shown) or a harvesting device (not shown), and when the tractor (1) enters the driving direction lower area (Ac) and turns back, the subsequent work in the driving direction lower area (Ac) is likely to be affected.

[0096] The driving area selection unit (23Fd) selects the driving area (Aa) and the driving direction upper area (Ab) and the driving direction lower area (Ac) as driving areas (A3) in addition to the entry area (Aa), and in the case where the driving direction upper area (Ab) is selected as a driving area (A3) in addition to the entry area (Aa), the entry area (Aa) and the driving direction upper area (Ab) are selected as driving areas (A3). By doing so, the driving area (A3) where the turnback driving is performed can be widened while avoiding the tractor (1) entering the driving direction lower area (Ac) during turnback driving. As a result, it is possible to easily establish the initiation condition for the first automatic driving control while avoiding the risk of causing interference with the work by the subsequent work device (3) due to the tractor (1) entering the driving direction lower area (Ac).

[0097] In addition, the automatic driving control unit (23F) controls the automatic turnback driving when the entry area (Aa) and the upper driving direction area (Ab) are selected as the driving area (A3). As shown in FIG. 7, in the driving area (A3) including the entry area (Aa) and the upper driving direction area (Ab), the tractor (1) is moved forward and backward while steering the left and right front wheels (10) so that the angle deviation (Δθ) described above becomes less than a predetermined angle (θ), and the lateral deviation (Δd) described above becomes less than a predetermined value (L).

[0098] The driving area selection unit (23Fd) selects the entry area (Aa) and the driving direction lower area (Ac) as the driving area (A3) when the driving direction lower area (Ac) can be selected as the driving area (A3) in addition to the entry area (Aa). By doing so, the driving area (A3) where the turnback driving is performed can be widened while avoiding the tractor (1) entering the driving direction upper area (Ab) during turnback driving. As a result, it is possible to easily establish the initiation condition for the first automatic driving control while avoiding the risk of the work device (3) connected to the tractor (1) coming into contact with other objects such as a ridge due to the tractor (1) entering the driving direction upper area (Ab).

[0099] In addition, the automatic driving control unit (23F) controls the automatic turnback driving when the entry area (Aa) and the lower driving direction area (Ac) are selected as the driving area (A3). As shown in FIGS. 8 and 9, in the driving area (A3) including the entry area (Aa) and the lower driving direction area (Ac), the tractor (1) is moved forward and backward while steering the left and right front wheels (10) so that the angle deviation (Δθ) described above becomes less than a predetermined angle (θ), and the lateral deviation (Δd) described above becomes less than a predetermined value (L).

[0100] The driving area selection unit (23Fd) selects only the entry area (Aa) as the driving area (A3) when only the entry area (Aa) can be selected as the driving area (A3). By doing so, the driving area (A3) where the turnback driving is performed can be secured while avoiding the tractor (1) entering the upper driving area (Ab) and the lower driving area (Ac) during the turnback driving. As a result, the initiation condition for the first automatic driving control can be established while avoiding the risk of the work device (3) connected to the tractor (1) coming into contact with other objects such as a ridge due to the tractor (1) entering the upper driving area (Ab), and the risk of causing interference with the subsequent work by the work device (3) due to the tractor (1) entering the lower driving area (Ac).

[0101] In the automatic turnback driving control, the tractor (1) is configured to perform multiple turnback drives in the driving area (A3). By doing so, for example, even when only the entry area (Aa) is selected as the driving area (A3) in the driving area selection unit (23Fd) and the driving area (A3) becomes narrow, the conditions for initiating the first automatic driving control can be reliably established by the turnback driving of the tractor (1) in the driving area (A3).

[0102] The automatic driving control unit (23F) transitions from the automatic turning back driving control to the first automatic driving control when the condition determination unit (23Fc) determines that the starting condition for the first automatic driving control is established during the turning back driving of the tractor (1) by the automatic turning back driving control. By doing so, when the starting condition for the first automatic driving control is established by the turning back driving of the tractor (1) by the automatic turning back driving control, the tractor (1) immediately performs work while driving automatically along the parallel path (P1) in a state of high precision with a small amplitude of shaking relative to the parallel path (P1), in accordance with the establishment of the starting condition. As a result, work efficiency can be improved while work precision can be improved.

[0103] As shown in FIG. 4, the target path (P) can be generated to include a travel path (Rm) (the path indicated by the dashed line in FIG. 4) extending from the waiting position (p0) of the tractor (1) away from each parallel path (P1) and the starting position (p3) of the parallel path (P1) where the driving order of the tractor (1) is set first. In FIG. 4, the waiting position (p0) is set near the entrance of the tractor (1) to the pavement (A). The setting of the waiting position (p0) can be changed in various ways depending on the shape of the pavement, etc.

[0104] When the automatic driving control unit (23F) includes a travel path (Rm) in the target path (P), it is possible to execute automatic movement control in which the tractor (1) is automatically driven in a non-working state according to the travel path (Rm) based on the travel path (Rm) and the positioning information from the positioning unit (42).

[0105] In automatic movement control, the entry area setting unit (23Fa) sets a predetermined area as the entry area (Aa) that includes the starting position (p3) of the first parallel path (P1), which is the connection position between the first parallel path (P1) and the movement path (Rm) where the driving order of the tractor (1) is set first.

[0106] By this, when automatic driving is initiated after the tractor (1) is positioned at the standby position (p0), the automatic driving control unit (23F) executes automatic movement control to automatically drive the tractor (1) in a non-working state from the standby position (p0) toward the entry area (Aa) along the movement path (Rm). Then, when the tractor (1) reaches the entry area (Aa) during this automatic driving, if the initiation condition for the first automatic driving control is established, the automatic driving control unit (23F) executes the first automatic driving control to automatically drive the tractor (1) in a working state along the parallel path (P1). Furthermore, if the initiation condition for the first automatic driving control is not established, the automatic driving control unit (23F) does not execute the first automatic driving control but executes automatic turnback driving control to drive the tractor (1) in a turnback state. And, when the initiation condition for the first automatic driving control is established by this turnback driving, the automatic driving control unit (23F) executes the first automatic driving control and drives the tractor (1) automatically along the parallel path (P1) in a working state.

[0107] That is, if the target path (P) includes a travel path (Rm), the tractor (1) can be driven automatically with high precision over the entire length of the target path (P) including the travel path (Rm). By doing so, the user does not need to manually drive the tractor (1) to the starting position (p3) of the parallel path (P1) where the driving priority of the tractor (1) is set first, thereby reducing the burden placed on the user.

[0108] [Separate embodiment]

[0109] Separate embodiments of the present invention will be described. Furthermore, the configurations of each separate embodiment described below are not limited to being applied individually, but may also be applied in combination with the configurations of other separate embodiments.

[0110] (1) Representative separate embodiments regarding the configuration of the work vehicle (1) are as follows. For example, the work vehicle (1) may be configured as a semi-crawler specification having left and right crawlers instead of left and right rear wheels (11). For example, the work vehicle (1) may be configured as a full crawler specification having left and right crawlers instead of left and right front wheels (10) and left and right rear wheels (11). For example, the work vehicle (1) may be configured as a rear-wheel steering specification in which the left and right rear wheels (11) function as steering wheels. For example, the work vehicle (1) may be configured as an electric specification having an electric motor instead of an engine (14). For example, the work vehicle (1) may be configured as a hybrid specification having an engine (14) and an electric motor.

[0111] (2) As an automatic driving system for a work vehicle, the automatic driving control unit (23F) may execute the first automatic driving control and automatic turnback driving control described above, and the turning movement to move the work vehicle (1) from the current parallel path (P1) to the next parallel path (P1) may be configured to be performed by manual driving by a user.

[0112] (3) The entry area setting unit (23Fa) may be configured to set a predetermined area (e.g., the area indicated by the dashed line in FIG. 4) that includes the position where the work is stopped (e.g., the position indicated by the symbol p5 in FIG. 4) in the parallel path (P1) at that time, when the work vehicle (1) is a harvesting work vehicle such as a combine and the first automatic driving control is executed and the harvest is full and it is necessary to stop the first automatic driving control, the entry area (Aa) for the parallel path (P1) may be configured to include the position where the work is stopped (e.g., the position indicated by the symbol p5 in FIG. 4).

[0113] (4) The entry area setting unit (23Fa) may be configured such that, for example, the work vehicle (1) is a work vehicle for supplying agricultural materials such as seeds or seedlings to a package, such as a planter or a planter, and when the remaining amount of agricultural materials reaches a lower limit value during the execution of the first automatic driving control and is detected by a remaining amount sensor and it becomes necessary to stop the first automatic driving control, a predetermined area including the position of the work stoppage in the parallel path (P1) at that time is set as the entry area (Aa) for the parallel path (P1).

[0114] [Invention Note]

[0115] The first feature configuration of the present invention is an automatic driving system for a work vehicle, wherein

[0116] An entry area setting unit for setting an entry area for a work vehicle for a plurality of parallel paths arranged at predetermined intervals, and

[0117] A positioning unit for measuring the position and orientation of the above-mentioned work vehicle, and

[0118] An automatic driving control unit that executes a first automatic driving control to automatically drive the work vehicle in a working state along the parallel path based on the parallel path and positioning information from the positioning unit, and

[0119] A deviation detection unit that detects the angular deviation and lateral deviation of the work vehicle with respect to the parallel path at the time when the work vehicle reaches the entry area based on the parallel path and positioning information from the positioning unit, and

[0120] When the above-mentioned work vehicle reaches the above-mentioned entry area, the condition determination unit determines whether the initiation condition of the first automatic driving control is established based on detection information from the deviation detection unit, and

[0121] The above condition determination unit determines that the initiation condition of the first automatic driving control is established when the angle deviation is less than a predetermined angle and the lateral deviation is less than a predetermined value, and

[0122] The above automatic driving control unit has the advantage that, at the time when the work vehicle reaches the entry area, if the condition determination unit determines that the initiation condition of the first automatic driving control is established, it executes the first automatic driving control, and if the condition determination unit determines that the initiation condition of the first automatic driving control is not established, it executes automatic turnback driving control that drives the work vehicle in a turnback manner through a combined operation of forward / reverse switching operation and steering operation of the work vehicle so that the initiation condition of the first automatic driving control is established.

[0123] According to the present configuration, when the work vehicle reaches the aforementioned entry area, if the aforementioned angle deviation is less than a predetermined angle and the aforementioned lateral deviation is less than a predetermined value, the automatic driving control unit executes the first automatic driving control to drive the work vehicle automatically along a parallel path in a working state. By doing so, the work vehicle can perform work while performing high-precision automatic driving with a small amplitude of shaking along the parallel path from the stage where automatic driving is initiated.

[0124] Meanwhile, when the work vehicle reaches the aforementioned entry area, if the aforementioned angle deviation is greater than a predetermined angle or the aforementioned lateral deviation is greater than a predetermined value, the automatic driving control unit does not execute the first automatic driving control and executes automatic turnback driving control. By doing so, it is possible to prevent the occurrence of a problem in which the work vehicle starts automatic driving with low precision where the amplitude of shaking along the parallel path increases due to the execution of the first automatic driving control when the aforementioned angle deviation is greater than a predetermined angle or when the aforementioned lateral deviation is greater than a predetermined value, and the work precision decreases during this time because it takes a long distance for the shaking to be stabilized.

[0125] In addition, the automatic driving control unit reduces the aforementioned angular deviation and lateral deviation in both forward and reverse directions by the turnback driving of the work vehicle, thereby establishing the initiation condition for the first automatic driving control. This eliminates the need to generate a long travel path on the extension of the parallel path in order to make it easier to establish the initiation condition for the first automatic driving control. In particular, for agricultural work vehicles, which are often configured with front-wheel steering specifications, it is suitable for shortening the aforementioned travel path because it is easier to perform position alignment operations of the work vehicle relative to the parallel path during reverse driving than during forward driving.

[0126] By doing so, as the movement path in the work area is lengthened, the parallel path that automatically drives the work vehicle into a working state is shortened. Consequently, problems such as a decrease in crop yield due to a narrowed cropping area when, for example, the area where the parallel path is generated (work area) is a field farming area, or a decrease in work efficiency due to an increased number of rotations of the work vehicle in the rotation work area when the area where the parallel path is generated is a round-trip work area where the work vehicle travels back and forth and the area where the movement path is generated is a circular work area where the work vehicle travels around, can be prevented.

[0127] As a result, work vehicles can be automatically driven with high precision along a parallel path in a working state without causing a decrease in yield or a decline in work efficiency, and the work precision of the work vehicles can be increased through automatic driving.

[0128] The second feature configuration of the present invention is,

[0129] The above automatic turnback driving control has a driving area selection unit that selects a driving area of ​​the above work vehicle from the above entry area and a driving direction upper area and a driving direction lower area with the above entry area in between in the driving direction of the above work vehicle in the above parallel path.

[0130] According to the present configuration, for example, if the entry area is a predetermined area including the starting position of a parallel path, the upper area in the driving direction is included in the immersion area above the starting position of the parallel path in the driving direction, and the lower area in the driving direction is included in the work area where the parallel path is arranged.

[0131] In this case, if the work of the work vehicle is light work that is difficult to affect in the subsequent work in the lower area of ​​the driving direction even if the work vehicle enters the lower area of ​​the driving direction and turns back, at least the lower area of ​​the driving direction can be selected as a drivable area in addition to the entry area. By doing so, the drivable area can be widened to make it easier to perform a turnback of the work vehicle in the drivable area, and it can be easier to establish the initiation condition of the first automatic driving control in the drivable area.

[0132] Conversely, if the work of the work vehicle is a sowing or seedling transplanting operation that is susceptible to being affected by the subsequent work in the lower area of ​​the driving direction when the work vehicle enters the lower area of ​​the driving direction and turns back, the entry area and the upper area of ​​the driving direction can be selected as the drivable area and the lower area of ​​the driving direction can be excluded from the drivable area. By doing so, while avoiding a decrease in work precision caused by the work vehicle turning back in the lower area of ​​the driving direction, the drivable area can be widened to make it easier to perform the turnback of the work vehicle in the drivable area, and it can be easier to establish the initiation condition of the first automatic driving control in the drivable area.

[0133] Meanwhile, for example, if the entry area is a predetermined area including the stop position of the first automatic driving control in a parallel path, the area above the driving direction is included in the work area above the stop position in the driving direction, and the area below the driving direction is included in the unwork area below the stop position in the driving direction.

[0134] In this case, if the work of the work vehicle is a harvesting operation, the entry area and the upper area of ​​the driving direction can be selected as the drivable area, and the lower area of ​​the driving direction can be excluded from the drivable area. By doing so, the problem of unharvested materials being trampled and knocked over by the work vehicle turning back in the lower area of ​​the driving direction can be avoided, and the drivable area can be widened to make it easier to perform a turnback of the work vehicle in the drivable area, and it can be easier to establish the initiation condition of the first automatic driving control in the drivable area.

[0135] In addition, if the work content of the work vehicle is light work, the entry area and the area below the driving direction can be selected as the drivable area, and the area above the driving direction can be excluded from the drivable area. By doing so, while avoiding the problem of the work site being trampled and ruined by the work vehicle turning back in the area above the driving direction, the drivable area can be widened to make it easier to perform the turnback of the work vehicle in the drivable area, and it can be easier to establish the initiation condition of the first automatic driving control in the drivable area.

[0136] That is, a driving range suitable for the work content of the work vehicle can be set, and by doing so, it is possible to easily perform turnback driving of the work vehicle in the driving range without causing interference with the work by the work vehicle, and it is possible to easily establish the initiation condition of the first automatic driving control.

[0137] The third feature configuration of the present invention is,

[0138] The above automatic turnback driving control is configured to allow multiple turnback drives of the work vehicle in the driving area.

[0139] According to the present configuration, even when the driving area is narrowed because only the entry area is selected as the driving area, the initiation condition for the first automatic driving control can be reliably established by the turnback driving of the work vehicle in the driving area.

[0140] The fourth characteristic configuration of the present invention is,

[0141] The above automatic driving control unit has the advantage of transitioning from the automatic turnback driving control to the first automatic driving control when the condition determination unit determines that the initiation condition of the first automatic driving control is established in the turnback driving of the work vehicle by the above automatic turnback driving control.

[0142] According to the present configuration, when the initiation condition for the first automatic driving control is established by the turnback driving of the work vehicle by the automatic turnback driving control, the work vehicle immediately performs work while automatically driving along the parallel path in a state of high precision with a small amplitude of shaking along the parallel path, in accordance with the establishment of the initiation condition. As a result, it is possible to improve work efficiency and improve work precision.

[0143] The fifth feature configuration of the present invention is,

[0144] The above automatic driving control unit executes automatic movement control to automatically drive the work vehicle in a non-working state according to a movement path spanning the waiting position of the work vehicle deviating from the parallel path and the starting position of the parallel path among the plurality of parallel paths where the driving priority of the work vehicle is set first.

[0145] The above entry area setting unit has in that, in the above automatic movement control, a predetermined area including the above time position is set as the entry area for the first parallel path.

[0146] According to the present configuration, when automatic driving is initiated after the work vehicle is positioned at a waiting position, the automatic driving control unit executes automatic movement control to automatically drive the work vehicle from the waiting position toward the entry area in a non-working state along the movement path. Furthermore, at the time when the work vehicle reaches the entry area during this automatic driving, if the initiation condition for the first automatic driving control is met, the automatic driving control unit executes the first automatic driving control to automatically drive the work vehicle in a working state along a parallel path. In addition, if the initiation condition for the first automatic driving control is not met, the automatic driving control unit does not execute the first automatic driving control but executes automatic turnback driving control to drive the work vehicle in a turnback state. Furthermore, if the initiation condition for the first automatic driving control is met through this turnback driving, the automatic driving control unit executes the first automatic driving control to automatically drive the work vehicle in a working state along a parallel path.

[0147] In other words, in addition to the parallel path, the work vehicle can be automatically driven with high precision along the movement path from the waiting position to the starting position of the parallel path. As a result, the user no longer needs to manually drive the work vehicle from the waiting position to the starting position of the parallel path, thereby reducing the burden placed on the user.

[0148] The sixth feature configuration of the present invention is,

[0149] The above automatic driving control unit executes a second automatic driving control that automatically drives the work vehicle according to a connection path that connects a plurality of the above parallel paths in the driving order of the work vehicle, and

[0150] The above entry area setting unit is in that, in the second automatic driving control, a predetermined area including the time unit of a parallel path connected to the connection path is set as the entry area.

[0151] According to the present configuration, when the work vehicle reaches an entry area via automatic driving by the second automatic driving control, if the initiation condition for the first automatic driving control is established, the automatic driving control executes the first automatic driving control to automatically drive the work vehicle along a parallel path in a working state. Additionally, if the initiation condition for the first automatic driving control is not established, the automatic driving control does not execute the first automatic driving control but executes automatic turnback driving control to drive the work vehicle in a turnback state. Furthermore, if the initiation condition for the first automatic driving control is established through this turnback driving, the automatic driving control executes the first automatic driving control to automatically drive the work vehicle along a parallel path in a working state.

[0152] In other words, the work vehicle can be automatically driven smoothly along multiple parallel paths connected in driving order through each connecting path, with high precision and a small amplitude of shaking for each parallel path. As a result, the user does not need to manually drive the work vehicle from the end position of a parallel path to the beginning position of the next parallel path, thereby reducing the burden placed on the user.

[0153] The seventh feature configuration of the present invention is,

[0154] The above entry area setting unit has the advantage of setting a predetermined area including the interruption position of the first automatic driving control in the parallel path as the entry area when the first automatic driving control is interrupted.

[0155] According to the present configuration, for example, if the work vehicle is a harvesting work vehicle such as a combine, when the harvest is full, the first automatic driving control is stopped, the work vehicle is moved to a predetermined discharge position to discharge the harvest, and then the work vehicle is moved to an entry area including the stop position of the first automatic driving control to resume automatic driving. At this point, if the initiation condition of the first automatic driving control is established, the automatic driving control unit executes the first automatic driving control and automatically drives the work vehicle along a parallel path in a working state from the stop position of the first automatic driving control. Furthermore, if the initiation condition of the first automatic driving control is not established, the automatic driving control unit executes automatic turnback driving control and drives the work vehicle back in the entry area including the stop position. Then, if the initiation condition of the first automatic driving control is established by this turnback driving, the automatic driving control unit executes the first automatic driving control and drives the work vehicle along a parallel path in a working state.

[0156] That is, even when the work vehicle is returned to the interrupted position of the first automatic driving control to resume automatic driving of the work vehicle, automatic driving can be resumed well with high precision and a small amplitude of shaking in the parallel path.

Claims

Claim 1 An automatic driving system for a work vehicle that, when starting automatic driving of a work vehicle along a target path, if the angular deviation of the work vehicle with respect to the target path is greater than a predetermined angle, performs automatic turnback driving control by combining forward / reverse switching control and steering control on the work vehicle to reduce the angular deviation of the work vehicle with respect to a single work path. Claim 2 An automatic driving system for a work vehicle that performs automatic turnback driving control by combining forward / reverse switching control and steering control to reduce the lateral deviation of the work vehicle with respect to a single work path when the work vehicle starts automatic driving on a target path and the lateral deviation of the work vehicle with respect to the target path is greater than or equal to a predetermined value. Claim 3 An automatic driving system for a work vehicle according to claim 1, wherein when the angle deviation of the work vehicle relative to the target path becomes less than the predetermined angle by performing the automatic turnback driving control, the work vehicle starts automatic driving along the target path. Claim 4 An automatic driving system for a work vehicle according to claim 2, wherein when the lateral deviation of the work vehicle relative to the target path becomes less than the predetermined value by performing the automatic turnback driving control, the work vehicle starts automatic driving along the target path. Claim 5 A control method for a work vehicle that performs automatic turnback driving control by combining forward / reverse switching control and steering control to reduce the angle deviation of the work vehicle with respect to a single work path when starting automatic driving of the work vehicle along a target path, and when the angle deviation of the work vehicle with respect to the target path is greater than a predetermined angle. Claim 6 A control method for a work vehicle that performs automatic turnback driving control by combining forward / reverse switching control and steering control to reduce the lateral deviation of the work vehicle with respect to a single work path when the work vehicle starts automatic driving on a target path, and the lateral deviation of the work vehicle with respect to the target path is greater than or equal to a predetermined value. Claim 7 An automatic driving system for a work vehicle that performs automatic turnback driving control by combining forward / reverse switching control and steering control to reduce the angle deviation of the work vehicle with respect to the one work path when the work vehicle enters one of a plurality of work paths for automatic driving of the work vehicle, and the angle deviation of the work vehicle with respect to the one work path is greater than a predetermined angle. Claim 8 An automatic driving system for a work vehicle according to claim 7, wherein when the work vehicle enters the work path from a connecting path connecting the work paths, if the angle deviation of the work vehicle with respect to the work path is greater than or equal to the predetermined angle, the automatic turnback driving control is performed to reduce the angle deviation of the work vehicle with respect to the work path. Claim 9 An automatic driving system for a work vehicle that performs automatic turnback driving control by combining forward / reverse switching control and steering control to reduce the lateral deviation of the work vehicle with respect to the one work path when the work vehicle enters one of a plurality of work paths for automatic driving of the work vehicle, and the lateral deviation of the work vehicle with respect to the one work path is greater than or equal to a predetermined value. Claim 10 An automatic driving system for a work vehicle according to claim 9, wherein when the work vehicle enters the work path from a connecting path connecting the work paths, if the lateral deviation of the work vehicle with respect to the work path is greater than or equal to the predetermined value, the automatic turnback driving control is performed to reduce the lateral deviation of the work vehicle with respect to the work path. Claim 11 A control method for a work vehicle that performs automatic turnback driving control by combining forward / reverse switching control and steering control to reduce the angle deviation of the work vehicle with respect to the one work path when the work vehicle enters one of a plurality of work paths for automatic driving of the work vehicle, and the angle deviation of the work vehicle with respect to the one work path is greater than a predetermined angle. Claim 12 A control method for a work vehicle that performs automatic turnback driving control by combining forward / reverse switching control and steering control to reduce the lateral deviation of the work vehicle with respect to the one work path when the work vehicle enters one of a plurality of work paths for automatic driving of the work vehicle, and the lateral deviation of the work vehicle with respect to the one work path is greater than or equal to a predetermined value.

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