Autonomous driving system for work vehicles

Abstract

To provide an automatic travel system of a work vehicle capable of appropriately performing elevation and lowering of a work part and disconnection and connection of a work clutch at the time of automatic traveling of the work vehicle.SOLUTION: An automatic travel system of a rice transplanter 1 (work vehicle) can cause the rice transplanter 1 (work vehicle) including a planting part 14 (work part) to automatically travel. When the rice transplanter 1 (work vehicle) automatically travels, the automatic travel system performs work part automatic control of automatically performing elevation and lowering control of the planting part 14 (work part) at the time of turning of the rice transplanter 1 (work vehicle) or disconnection and connection control of a work clutch before automatic traveling of the rice transplanter 1 (work vehicle) is started, irrespective of whether execution or non-execution of the work part automatic control.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an automatic driving system for a work vehicle. [Background technology]

[0002] Conventionally, there has been known a work vehicle equipped with a working section for performing work and a work clutch for switching between transmitting and disconnecting a driving force to the working section, and the working section is configured to be raised and lowered. Some of these work vehicles automatically control the raising and lowering of the working section and the disconnection of the work clutch when turning in order to reduce the user's effort in operation. Patent Document 1 discloses a rice transplanter, which is a work vehicle of this type.

[0003] The rice transplanter of Patent Document 1 includes a planting unit, a planting clutch, and a control unit. The control unit can execute the following control (automatic lift control during turning). That is, when the rice transplanter starts turning, the control unit raises the planting unit and disconnects the planting clutch to stop the planting of seedlings by the planting unit, etc. When the rice transplanter finishes turning, the control unit lowers the planting unit and connects the planting clutch to start the planting of seedlings by the planting unit.

[0004] In the rice transplanter of Patent Document 1, the lifting and lowering of the planting part and the connection and disconnection of the planting clutch during turning can also be performed manually. In this rice transplanter, the user can select whether to manually or automatically lift and lower the planting part and connect and disconnect the planting clutch during turning. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-235702 A Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, a work vehicle capable of automatic travel along a predetermined travel route has been developed. However, the configuration of Patent Document 1 does not take into consideration how to raise and lower the planting part and how to connect and disconnect the planting clutch when the rice transplanter is automatically traveled along a predetermined travel route.

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an automatic driving system for a work vehicle that is capable of appropriately raising and lowering a working unit and engaging and disengaging a work clutch when the work vehicle is automatically traveling.

[0008] The problem to be solved by the present invention has been described above. Next, the means for solving this problem and the effects thereof will be described.

[0009] According to an aspect of the present invention, an automatic driving system for a work vehicle is capable of automatically driving a work vehicle along a driving route having a plurality of work routes along which work is performed by a working unit, and a turning route connecting adjacent work routes among the plurality of work routes. The automatic driving system for a work vehicle includes an operation unit. The operation unit is capable of selecting whether to execute or not execute automatic control of the work unit. The automatic control of the work unit detects the start of turning of the work vehicle, and automatically raises the work unit and disengages the work clutch of the work unit, and detects the end of turning of the work vehicle, and automatically lowers the work unit and engages the work clutch. When the start of turning is detected while the work vehicle is automatically traveling along the turning route, the automatic control of the work unit is executed regardless of whether the operation unit selects to execute or not execute the automatic control of the work unit.

[0010] As a result, when the work vehicle is automatically traveling, the automatic control of the working unit is executed regardless of whether the operation unit selects to execute or not execute the automatic control of the working unit, thereby reducing the burden on the user.

[0011] The automatic driving system for a work vehicle is preferably configured as follows: In other words, when automatic driving is cancelled during automatic driving of the work vehicle along the turning path, if non-execution of the automatic control of the working unit is selected by the operation unit, the automatic driving system for a work vehicle terminates the automatic control of the working unit, whereas if execution of the automatic control of the working unit is selected by the operation unit, the automatic control of the working unit is continued.

[0012] As a result, when the automatic driving of the work vehicle is cancelled and the work vehicle is shifted to manual driving, the automatic control of the working unit is in an execution state or a non-execution state according to the selection state of the operation unit. Therefore, for example, when the user wishes to turn by manual operation in the middle of turning on the turning path, the user's wish can be appropriately reflected as to whether or not to execute the lifting and lowering control of the working unit.

[0013] The automatic driving system for a work vehicle is preferably configured as follows. That is, the work vehicle is equipped with a vehicle speed operation unit that operates the vehicle speed of the work vehicle. The work vehicle is configured to set the vehicle speed of the work vehicle during automatic driving in response to the operation of the vehicle speed operation unit. The automatic driving system for a work vehicle is configured to be capable of executing vehicle speed maintenance control that maintains the vehicle speed of the work vehicle corresponding to a predetermined operation position of the vehicle speed operation unit on the work route, while being unable to execute the vehicle speed maintenance control on the turning route. When the vehicle speed maintenance control and the automatic control of the working unit are being executed, upon reaching a predetermined point a predetermined distance before the end point of the work route, the vehicle speed maintenance control is terminated, while the automatic control of the working unit is maintained.

[0014] As a result, the vehicle speed maintenance control is prohibited on the turning route and ends before the turning route is reached, but the automatic control of the working unit does not end. Therefore, after the end of the vehicle speed maintenance control, the lifting and lowering control of the working unit is automatically performed as the work vehicle turns on the turning route. This makes it possible to improve workability while ensuring careful turning. [Brief description of the drawings]

[0015] [Figure 1] 1 is a side view of a rice transplanter used in an automatic driving system for a work vehicle according to one embodiment of the present invention. [Diagram 2] Plan view of the rice transplanter. [Diagram 3] A skeleton diagram showing the power transmission configuration of a rice transplanter. [Figure 4] FIG. 2 is a functional block diagram of the rice transplanter and the wireless communication terminal. [Diagram 5] FIG. 4 is a diagram showing an example of an automatic driving route generated by a route generating unit of the wireless communication terminal. [Figure 6] 6 is a flowchart showing a process for determining whether or not to execute automatic control of the working unit. [Figure 7] 4 is a flowchart of automatic control of the working unit. [Figure 8] FIG. [Figure 9] 5 is a flowchart showing a process for determining whether or not to execute auto-cruise control. [Figure 10] 4 is a flowchart of vehicle speed control including auto-cruise control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Next, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side view of a rice transplanter 1. Fig. 2 is a plan view of the rice transplanter 1.

[0017] The automatic driving system for a work vehicle according to one embodiment of the present invention includes a rice transplanter 1 shown in Fig. 1 as an automatically driving work vehicle. In this embodiment, a rice transplanter is used as the work vehicle, but this is not limited thereto, and for example, a tractor or a combine harvester can be used.

[0018] The automatic driving system includes a wireless communication terminal 3 capable of remotely operating the rice transplanter 1. In this embodiment, the wireless communication terminal 3 is attached to an appropriate position on the rice transplanter 1 so that the user can operate it while riding on the rice transplanter 1. However, the wireless communication terminal 3 can also be removed from the rice transplanter 1 and carried by the user.

[0019] The rice transplanter 1 can perform planting work of seedlings in a field. As shown in Figures 1 and 2, the rice transplanter 1 is equipped with a vehicle body section 11, front wheels 12, rear wheels 13, and a planting section (working section) 14. The front wheels 12 and the rear wheels 13 are provided in pairs on the left and right sides of the vehicle body section 11.

[0020] The vehicle body 11 is configured as a traveling body of the rice transplanter 1. The vehicle body 11 is provided with an engine 22 and a transmission case 23. The engine 22 is supported at the front of the vehicle body 11. The transmission case 23 is attached to the lower part of the vehicle body 11.

[0021] The driving force of the engine 22 is changed in speed by a transmission case 23 and transmitted to the front wheels 12 and the rear wheels 13. The driving force of the engine 22 is also transmitted to the planting section 14 via the transmission case 23 and a PTO shaft 24 disposed at the rear of the vehicle body section 11.

[0022] The vehicle body 11 can travel in a field or the like by transmitting the driving force of the engine 22 to the front wheels 12 and the rear wheels 13. The planting unit 14 can perform the task of planting seedlings in the field by transmitting the driving force of the engine 22.

[0023] A driver's seat 25 and a plurality of operating members are provided in the vehicle body 11. The driver's seat 25 is disposed between the front wheels 12 and the rear wheels 13 in the front-rear direction of the vehicle body 11. A user can sit in the driver's seat 25.

[0024] The multiple operating members include a steering handle 26, a speed change pedal (vehicle speed operating unit) 27, a planting lift lever 28, a work unit automatic control on / off switch (operating unit) 69 described below, and an auto-cruise lever (vehicle speed maintenance operating unit) 68.

[0025] The steering wheel 26 is attached to a steering column disposed in front of the driver's seat 25. A user of the rice transplanter 1 can instruct the vehicle body 11 (rice transplanter 1) to move straight or turn by gripping and turning the steering wheel 26 with his or her hands.

[0026] The speed change pedal 27 is provided so as to protrude upward from the floor in front of the driver's seat 25. The speed change pedal 27 is rotatably supported at an appropriate location on the vehicle body 11. A user can operate the speed change pedal 27 by stepping on it with his / her foot. A return spring (not shown) is attached to the speed change pedal 27 to return the speed change pedal 27 when the user releases the pedal.

[0027] The user can instruct the vehicle body 11 (rice transplanter 1) to travel by depressing the speed change pedal 27. The user can instruct the vehicle body 11 to accelerate / decelerate (instruct the vehicle speed) by changing the depth to which the user depresses the speed change pedal 27 with his / her foot. By removing the foot from 27, the rice transplanter 1 can be instructed to stop moving.

[0028] A pedal sensor 29 capable of detecting the operation position of the speed change pedal 27 is provided at an appropriate location in the vehicle body 11 relative to the speed change pedal 27. The pedal sensor 29 can be configured as, for example, a potentiometer.

[0029] As shown in FIG. 1 etc., the planting unit 14 is disposed behind the vehicle body unit 11. The planting unit 14 can plant seedlings in a field. The planting unit 14 is connected to the vehicle body unit 11 via a lifting link mechanism 31.

[0030] A lifting cylinder 32 is provided between the vehicle body 11 and the planting unit 14. The lifting cylinder 32 is driven to extend and retract, thereby allowing the planting unit 14 to be raised and lowered up and down relative to the vehicle body 11. The planting unit 14 may be raised and lowered by an actuator other than a cylinder.

[0031] The planting unit 14 can be raised and lowered between a lowered position for planting and an elevated position for not planting. The lowered position is a position where the planting claws 43 described below are ready to plant seedlings in the field. The elevated position is a position where the lifting cylinder 32 has raised the planting unit 14 sufficiently relative to the vehicle body 11.

[0032] The planting section 14 includes a planting input case section 33, a plurality of planting units 34, a seedling carrying table 35, and a plurality of floats 36. The planting section 14 sequentially supplies seedlings from the seedling carrying table 35 to each planting unit 34, allowing the seedlings to be planted continuously.

[0033] Each planting unit 34 has a planting transmission case portion 41 and a rotating case portion 42. Power is transmitted to the planting transmission case portion 41 via the PTO shaft 24 and the planting input case portion 33.

[0034] The rotating case portion 42 is rotatably attached to the planting transmission case portion 41. The rotating case portion 42 is disposed on both sides in the vehicle width direction of the planting transmission case portion 41. Two planting claws 43 are attached to one side of each rotating case portion 42.

[0035] The two planting claws 43 are displaced with the rotation of the rotating case part 42. As the two planting claws 43 are displaced, one row of seedlings is planted.

[0036] The seedling carrier 35 is disposed above and in front of the multiple planting units 34. A seedling mat can be placed on the seedling carrier 35. The seedling carrier 35 can supply the seedlings of the seedling mat placed on the seedling carrier 35 to each planting unit 34.

[0037] Specifically, the seedling carrier 35 is configured to be capable of moving laterally (sliding laterally) so as to reciprocate in the width direction of the vehicle. Also, the seedling carrier 35 is configured so that the seedling mat can be intermittently transported vertically downward at the end of the reciprocating movement of the seedling carrier 35.

[0038] The float 36 is provided to be able to swing at the bottom of the planting unit 14. The bottom surface of the float 36 can be brought into contact with the surface of the field in order to stabilize the planting posture of the planting unit 14 with respect to the surface of the field.

[0039] The float 36 is provided with a float sensor 37 that detects the attitude of the float 36. The float sensor 37 can be configured as, for example, a potentiometer.

[0040] The spare seedling trays 38 are provided in a pair on the left and right sides of the vehicle body 11. The spare seedling trays 38 are arranged on the outer side in the vehicle width direction of the bonnet 21. The spare seedling trays 38 can carry seedling boxes containing spare mat seedlings.

[0041] The upper parts of the left and right spare seedling tables 38 are connected to each other by a connecting frame 48 extending in the vertical direction and the vehicle width direction. A communication housing 49 is provided in the center of the connecting frame 48 in the vehicle width direction. A positioning antenna 91 and a wireless communication antenna 92, which will be described later, are provided inside the communication housing 49.

[0042] Next, the drive transmission path in the rice transplanter 1 will be described with reference to Fig. 3. Fig. 3 is a skeleton diagram showing the power transmission configuration of the rice transplanter 1.

[0043] 3, the driving force of the engine 22 is input to the transmission case 23 via a drive transmission belt 50. A hydrostatic mechanical continuously variable transmission (HMT) 51 is provided inside the transmission case 23, and the driving force of the engine 22 is continuously changed by this hydrostatic mechanical continuously variable transmission 51. The user can change the gear ratio of the hydrostatic mechanical continuously variable transmission 51 by operating the speed change pedal 27.

[0044] The output of the hydromechanical continuously variable transmission 51 is taken out from the transmission case 23 via a main clutch 52. The output of the hydromechanical continuously variable transmission 51 is transmitted to the front wheels 12. In addition, the output of the hydromechanical continuously variable transmission 51 is transmitted to the rear wheels 13 via a propeller shaft 53. In this way, the front wheels 12 and the rear wheels 13 are driven.

[0045] A left side clutch 55L is provided on the drive transmission path from the propeller shaft 53 to the left rear axle 54L. Also, a right side clutch 55R is provided on the drive transmission path from the propeller shaft 53 to the right rear axle 54R.

[0046] The left and right side clutches 55L, 55R are configured to be independently connected / disconnected by the control unit 30. That is, in this embodiment, the rice transplanter 1 can individually switch between the transmission of driving force to the left and right rear wheels 13, 13.

[0047] The left and right side clutches 55L and 55R are provided with left and right side clutch sensors, respectively. The detection results of the left and right side clutch sensors can be used to detect the engagement / disengagement of the left and right side clutches 55L and 55R.

[0048] The output of the hydromechanical continuously variable transmission 51 is taken out from the transmission case 23 and transmitted to the PTO shaft 24 via the planting drive transmission shaft 61 and the planting speed change section 62. The planting section 14 is driven by the driving force of this PTO shaft 24.

[0049] The power of the PTO shaft 24 is input to the planting input case 33 of the planting unit 14. The driving force input to the planting input case 33 is transmitted to the drive shaft of the rotating case 42 via a plurality of transmission shafts and a plurality of transmission gears, etc.

[0050] As a result, the rotating case portion 42 can be rotated by the power of the engine 22. Therefore, seedlings can be planted by the planting unit 34 configured as a rotary planting device.

[0051] As shown in Fig. 3, the planting speed-changing unit 62 is provided with a speed-changing device consisting of multiple gears. This speed-changing device can change the speed at which the rotating case unit 42 of the planting unit 14 is driven to rotate. This makes it possible to change the interval at which the planting unit 14 plants seedlings in the field (the distance between seedlings).

[0052] The planting speed change unit 62 is provided with a planting clutch (work clutch) 63. By connecting the planting clutch 63, the planting unit 14 can be driven. By disconnecting the planting clutch 63, the planting unit 14 can be stopped from being driven.

[0053] The planting clutch 63 can be switched between connected and disconnected by the control unit 30. The planting clutch 63 can also be switched between connected and disconnected by the user operating a not-shown operating member (a planting clutch operating lever).

[0054] The planting clutch 63 is provided with a planting clutch sensor 64. The detection result of the planting clutch sensor 64 can be used to detect whether the planting clutch 63 is engaged / disengaged.

[0055] Next, the control unit 30 provided in the rice transplanter 1 of this embodiment will be described with reference to Fig. 4. Fig. 4 is a functional block diagram of the rice transplanter 1 and the wireless communication terminal 3.

[0056] The control unit 30 is configured as a known computer and includes a CPU, ROM, RAM, input / output units, etc. (not shown). The CPU can read out and execute various programs, etc. from the ROM. Various programs and data are stored in the ROM. As shown in FIG. 4, the control unit 30 includes an automatic driving control unit 71, and can operate as the automatic driving control unit 71 through cooperation between the hardware and software described above.

[0057] The control unit 30 is electrically connected to a sensor group 72. The sensor group 72 includes the pedal sensor 29, the float sensor 37, the left and right side clutch sensors, and the planting clutch sensor 64. The sensor group 72 also includes a vehicle speed sensor 73, a working unit automatic control on / off switch 69, an operation detection switch for the auto-cruise lever 68, and the like, which will be described later.

[0058] The control unit 30 can detect the operation position (depression amount) of the speed change pedal 27 based on the detection result of the pedal sensor 29. The control unit 30 can set the gear ratio of the hydromechanical continuously variable transmission 51 according to the operation position of the speed change pedal 27.

[0059] The control unit 30 can detect the raised and lowered positions of the planting unit 14 based on the detection results of the float sensor 37. For example, the control unit 30 can detect a change of the planting unit 14 from the lowered position to the raised position, and a change from the raised position to the lowered position.

[0060] The control unit 30 can obtain the connection / disconnection state of the left and right side clutches 55L, 55R based on the detection results of the left and right side clutch sensors. This allows the control unit 30 to detect the start / end of turning of the vehicle body unit 11 (rice transplanter 1).

[0061] The control unit 30 can obtain the connected / disconnected state of the planting clutch 63 based on the detection result of the planting clutch sensor 64. This allows the control unit 30 to detect the driven state / driven stop state.

[0062] The control unit 30 can acquire the vehicle speed and travel distance of the rice transplanter 1 based on the detection result of the vehicle speed sensor 73. The vehicle speed sensor 73 is provided on the axle of the front wheel 12 so as to detect the rotation of the axle. The vehicle speed sensor 73 can also be provided at another appropriate position of the rice transplanter 1.

[0063] The control unit 30 is electrically connected to a plurality of controllers for controlling each component (e.g., the engine 22, etc.) of the rice transplanter 1. In this embodiment, the plurality of controllers include an engine controller 81, a vehicle speed controller (vehicle speed control unit) 82, a work unit controller 83, and a steering controller 84.

[0064] The engine controller 81 controls the rotation speed of the engine 22. The engine 22 is provided with a governor device 86 having an actuator (not shown) that changes the rotation speed of the engine 22. The engine controller 81 controls the governor device 86 based on a control signal input from the control unit 30, thereby controlling the rotation speed of the engine 22.

[0065] The vehicle speed controller 82 controls the vehicle speed of the rice transplanter 1. The vehicle speed controller 82 changes the angle of the movable swash plate of the hydromechanical continuously variable transmission 51 by an actuator (not shown) based on a control signal input from the control unit 30, thereby changing the gear ratio of the hydromechanical continuously variable transmission 51, thereby realizing a vehicle speed desired by the user.

[0066] The control of the vehicle speed by the vehicle speed controller 82 includes auto-cruise control (vehicle speed maintenance control). The auto-cruise control is a control that makes the rice transplanter 1 travel at a predetermined vehicle speed even when the foot is released from the speed change pedal 27.

[0067] The auto-cruise control is started by operating the auto-cruise lever 68 shown in Fig. 2 while the rice transplanter 1 is traveling. The auto-cruise lever 68 can be operated to the ON side or the OFF side. The auto-cruise lever 68 is provided with a return spring (not shown), and when no operating force is applied to the auto-cruise lever 68, the auto-cruise lever 68 is in an intermediate position that is neither the ON side nor the OFF side.

[0068] The vehicle speed during auto-cruise control is set based on the operating position of the gear shift pedal 27 at the time the auto-cruise lever 68 is operated to the ON side. The auto-cruise control can be ended by operating the auto-cruise lever 68 to the OFF side. The auto-cruise control also ends automatically when the gear shift pedal 27 is depressed.

[0069] The working unit controller 83 controls the lifting and lowering of the planting unit 14. The working unit controller 83 drives the lifting cylinder 32 to extend and retract based on a control signal input from the control unit 30, thereby appropriately lifting and lowering the planting unit 14. The working unit controller 83 can change the lifting position (height position) of the planting unit 14 to the lowered position, the raised position, or the like.

[0070] In addition, the working unit controller 83 controls the left and right tilt posture of the planting unit 14. The working unit controller 83 can operate the tilt actuator 88 based on a control signal input from the control unit 30 to control the planting unit 14 horizontally.

[0071] The steering controller 84 can control the steering angle of the front wheels 12. In this embodiment, the steering controller 84 drives the steering actuator 87 based on a control signal input from the control unit 30 to control the rotation angle of the steering handle 26 and, ultimately, the steering angle of the front wheels 12.

[0072] More specifically, a steering actuator 87 is provided in the middle of the steering shaft of the steering handle 26. In this configuration, when the rice transplanter 1 travels along a predetermined route, the control unit 30 calculates an appropriate rotation angle of the steering handle 26 so that the rice transplanter 1 travels along the route, and outputs a control signal to the steering controller 84. Then, the steering controller 84 changes the rotation angle of the steering handle 26 by the steering actuator 87 to control the steering angle of the front wheels 12.

[0073] The steering controller 84 is also configured to be able to control the rotation of the PTO shaft 24. The steering controller 84 switches the connection / disconnection state of the planting clutch 63 of the planting speed change unit 62 based on a control signal input from the control unit 30. As a result, it is possible to control the transmission / disconnection of power to the PTO shaft 24 and drive or stop the planting unit 14.

[0074] In addition, the above-mentioned multiple controllers such as the engine controller 81 control each part such as the engine 22 based on a signal input from the control unit 30. Therefore, it can be said that the control unit 30 substantially controls each configuration of the rice transplanter 1.

[0075] The control unit 30 is configured to select whether or not to execute automatic control of the working unit with respect to the planting unit 14 by operating the automatic control on / off switch 69. The automatic control of the working unit is to detect the start of turning of the rice transplanter 1 (disconnected state of the left or right side clutch 55L or 55R) and automatically raise the planting unit 14 and disconnect the planting clutch 63, and to detect the end of turning of the rice transplanter 1 (transition of the side clutch 55L or 55R from the disconnected state to the connected state) and automatically lower the planting unit 14 and connect the planting clutch 63. This makes it possible to omit a series of operations when turning the vehicle between works, thereby improving user convenience.

[0076] The working unit automatic control on / off switch 69 can be alternately switched between an ON state and an OFF state by the user pressing it with his / her finger. In this embodiment, the working unit automatic control on / off switch 69 is provided near the steering handle 26, as shown in FIG.

[0077] The control unit 30 executes the automatic control of the working unit when the working unit automatic control on / off switch 69 is in the ON state. The control unit 30 does not execute the automatic control of the working unit when the working unit automatic control on / off switch 69 is in the OFF state.

[0078] In this way, the rice transplanter 1 equipped with the control unit 30 as described above can control each part (such as the planting unit 14) of the rice transplanter 1 by the control unit 30 by a user riding on the vehicle body unit 11 and performing various operations, and can perform planting work using the planting unit 14 while traveling within a farm field. In addition, the rice transplanter 1 can automatically travel and work based on a predetermined control signal output by the wireless communication terminal 3.

[0079] Specifically, as shown in Fig. 4, the rice transplanter 1 has various configurations for enabling automatic travel. For example, the rice transplanter 1 has an automatic travel control unit 71 of the control unit 30, as well as configurations such as an antenna required for acquiring its own position information based on a positioning system. With such a configuration, the rice transplanter 1 is capable of automatically traveling in a farm field while acquiring its own position information using the positioning system.

[0080] Next, a detailed description will be given of the configuration for enabling the rice transplanter 1 to travel automatically. As shown in Fig. 2 and Fig. 4, the rice transplanter 1 includes a positioning antenna 91, a wireless communication antenna 92, and a storage unit 93. In addition to these, the rice transplanter 1 may include an inertial measurement unit (IMU) capable of acquiring the attitude (roll angle, pitch angle, yaw angle) of the vehicle body unit 11.

[0081] The positioning antenna 91 can receive signals from positioning satellites constituting a positioning system such as a Global Navigation Satellite System (GNSS). The positioning signals received by the positioning antenna 91 are input to a position information calculation unit 95 shown in FIG. 4. The position information calculation unit 95 calculates the position information of the rice transplanter 1 as, for example, latitude and longitude information. The position information calculated by the position information calculation unit 95 is input to the control unit 30 and used for the automatic driving of the rice transplanter 1 by the automatic driving control unit 71.

[0082] In this embodiment, a highly accurate satellite positioning system using the GNSS-RTK method is used as the positioning system, but the present invention is not limited to this, and other positioning systems may be used as long as they can obtain highly accurate position coordinates. For example, a differential GPS (DGPS) or a satellite-based augmentation system (SBAS) may be used as the positioning system.

[0083] The wireless communication antenna 92 ​​can receive signals from the wireless communication terminal 3 operated by the user and transmit signals to the wireless communication terminal 3. The signal from the wireless communication terminal 3 received by the wireless communication antenna 92 ​​is processed by a wireless communication unit 96 shown in FIG. 4 and then input to the control unit 30. In addition, a signal transmitted from the control unit 30 to the wireless communication terminal 3 is processed by the wireless communication unit 96 and then transmitted from the wireless communication antenna 92 ​​and received by the wireless communication terminal 3.

[0084] The memory unit 93 can store the travel route (path) along which the rice transplanter 1 automatically travels among the routes traveled by the rice transplanter 1, and can store the change in the position (travel trajectory) of the rice transplanter 1 while traveling. In addition, the memory unit 93 stores various information necessary for the rice transplanter 1 to automatically travel and operate. The memory unit 93 is composed of a non-volatile memory such as a flash memory or a hard disk, for example.

[0085] The wireless communication terminal 3 is configured as a computer that the user can carry around, for example, a tablet-type personal computer. The user can check information about the rice transplanter 1 by referring to the information displayed on the display unit (display) 101 of the wireless communication terminal 3. The user can also operate an operation unit (for example, a touch panel provided on the display unit 101) of the wireless communication terminal 3 to transmit a control signal for controlling the rice transplanter 1 to the control unit 30 of the rice transplanter 1. As this control signal, for example, a signal instructing the rice transplanter 1 to start or end automatic traveling can be considered.

[0086] The rice transplanter 1 configured in this manner is controlled based on instructions from a user using the wireless communication terminal 3, and can perform planting work using the planting unit 14 while automatically traveling along a travel path in the field.

[0087] Next, the configuration of the wireless communication terminal 3 will be described with reference to FIG.

[0088] As shown in FIG. 4, the wireless communication terminal 3 includes, in addition to the display unit 101 described above, a communication unit 122, an automatic driving operation unit 123, a control unit 124, and a route generation unit 125.

[0089] The communication unit 122 is configured as, for example, a wireless communication module. The communication unit 122 is electrically connected to a communication antenna 127. The communication antenna 127 has a short-range communication antenna for wireless communication with the rice transplanter 1, and a mobile communication antenna for communication using a mobile phone line and the Internet. The communication unit 122 can transmit and receive data between the rice transplanter 1 or other devices by performing modulation or demodulation processing in an appropriate manner.

[0090] The automatic travel operation unit 123 is configured as, for example, a touch panel, and is included in the operation unit of the wireless communication terminal 3. The automatic travel operation unit 123 can instruct the automatic travel control unit 71 (control unit 30) in the rice transplanter 1 to start and end automatic travel.

[0091] The wireless communication terminal 3 is configured as a known computer, and includes a CPU, a ROM, a RAM, an input / output unit, and the like (not shown). The CPU can read out and execute various programs and the like from the ROM. In addition, the ROM stores various programs and data. Then, the wireless communication terminal 3 can operate as the control unit 124, the route generating unit 125, and the like by cooperation between the above-mentioned software and hardware.

[0092] The control unit 124 can transmit information on the automatic travel route generated by the route generation unit 125 to the rice transplanter 1 by communicating with the control unit 30 of the rice transplanter 1 via the communication unit 122. In addition, the control unit 124 can transmit commands from the automatic travel operation unit 123 to the automatic travel control unit 71 in the rice transplanter 1 via the communication unit 122. Furthermore, when the rice transplanter 1 is traveling automatically, the control unit 124 can receive the status (position, vehicle speed, etc.) of the rice transplanter 1 from the rice transplanter 1 and display it on the display unit 101.

[0093] The route generating unit 125 can generate a travel route (automatic travel route) along which the rice transplanter 1 travels automatically, based on the field information, the machine information, and the like. The field information includes information on the shape of the field, information on the automatic travel start position, and information on the automatic travel direction. The information on the shape of the field is specified, for example, based on a movement trajectory when the user manually operates the rice transplanter 1 to travel along the periphery of the field before the rice transplanter 1 starts automatic travel. Hereinafter, the above travel may be referred to as a field shape specific travel. The information on the automatic travel start position and the information on the automatic travel direction are specified by the user when the automatic travel route is generated using the wireless communication terminal 3. The method of specification is not particularly limited, but as the automatic travel start position, for example, in a state where the movement trajectory of the field shape specific travel is displayed on the display unit 101, the user can specify any position on the trajectory. Furthermore, the automatic travel direction can be specified as the direction of a straight line connecting any two points on the movement trajectory of the field shape specific travel displayed on the display unit 101 by the user.

[0094] The machine information includes, for example, the front-rear vehicle length and left-right vehicle width of the entire rice transplanter 1 including the vehicle body section 11 and the planting section 14, the distance from the positioning antenna 91 in the positioning system to the work center of the planting section 14, the turning radius of the rice transplanter 1, and information indicating the maximum number of planting rows by the planting section 14. Then, the automatic travel route generated by the route generation section 125 of the wireless communication terminal 3 is input (transferred) to the memory section 93 of the rice transplanter 1. At this time, information on the positional relationship between the positioning antenna 91 and the work center of the planting section 14 is also transmitted from the wireless communication terminal 3 to the rice transplanter 1. As a result, the control section 30 (automatic travel control section 71) of the rice transplanter 1 can grasp the work center position of the planting section 14.

[0095] Fig. 5 shows an example of an automatic driving route generated by the route generating unit 125. As shown in Fig. 5, the field 130 can be considered as being divided into a central region 131 and an outer periphery region 132 surrounding the periphery of the central region 131. The width of the outer periphery region 132 is determined based on the above-mentioned field information and machine information.

[0096] In the central region 131 of the field 130, a round-trip path along which the planting work is performed by the planting unit 14 is generated. The round-trip path has a plurality of work paths 136. Each work path 136 extends in a straight line so that the rice transplanter 1 travels straight ahead.

[0097] In the outer circumferential area 132 of the field 130, a turning path 137 is generated that connects an end point (terminal end) E1 of one of the multiple work paths 136 adjacent to each other and a starting point (starting end) S1 of the other work path 136.

[0098] In this way, the automatic driving route generated by the route generation unit 125 has a plurality of work routes 136 and a plurality of turning routes 137, and appropriate work routes 136 and turning routes 137 are alternately connected.

[0099] Next, the processing when the rice transplanter 1 performs automatic travel will be described with reference to Figs. 6 to 10. Fig. 6 is a flowchart showing the processing for determining whether or not to execute automatic control of the working unit. Fig. 7 is a flowchart of the automatic control of the working unit. Fig. 8 is a diagram showing a part of the automatic travel route. Fig. 9 is a flowchart showing the processing for determining whether or not to execute auto-cruise control. Fig. 10 is a flowchart of vehicle speed control including auto-cruise control.

[0100] In this embodiment, the rice transplanter 1 starts automatic traveling when the wireless communication terminal 3 instructs the rice transplanter 1 to start automatic traveling.

[0101] However, before the automatic driving control unit 71 actually starts the automatic driving, it determines whether or not a predetermined automatic driving start condition is satisfied. The automatic driving start condition is satisfied when all of the following conditions are satisfied. (1) Path search is complete. (2) The steering angle is within a specified range with respect to the working direction of the rice transplanter 1. (3) The running gear of the rice transplanter 1 is in neutral. (4) The parking brake of rice transplanter 1 is OFF. (5) The steering operation flag is OFF. (6) The speed fix flag is OFF. (7) No abnormalities have occurred with regard to automatic planting. However, this is merely an example, and some conditions may be omitted or other conditions may be added.

[0102] Here, "path search is completed" means that the rice transplanter 1 has specified one of the work paths 136 as an automatic travel start target path. For example, the rice transplanter 1 specifies the work path 136 to which the start point S1 closest to the position of the rice transplanter 1 belongs among the start points S1 of the work paths 136 as an automatic travel start target path.

[0103] "The traveling part of the rice transplanter 1 is in neutral" means that the main clutch 52 shown in Fig. 3 is disengaged. For example, in the rice transplanter 1, when the main shift lever (not shown) is operated to the neutral position by the user, the main clutch 52 is disengaged and the traveling part of the rice transplanter 1 is in neutral.

[0104] "The steering operation flag is OFF" means that the steering wheel 26 is not being manually operated by the user. The steering operation flag is data stored in the control unit 30, and indicates whether the steering wheel 26 is being manually operated or not. When the steering operation flag is ON, it means that the steering wheel 26 is being manually operated, and when the steering operation flag is OFF, it means that the steering wheel 26 is not being manually operated. The state of the steering operation flag is updated at any time.

[0105] "The speed fix flag being OFF" means that the auto-cruise control described above is not being executed. The speed fix flag is data stored in the control unit 30, and indicates whether or not auto-cruise control is being executed. When the speed fix flag is ON, it means that auto-cruise control is being executed, and when the speed fix flag is OFF, it means that auto-cruise control is not being executed. The state of the speed fix flag is changed at any time, as described below.

[0106] "No abnormality related to automatic planting" means that no abnormality has occurred that would impede the lifting and lowering of the planting unit 14 or the connection / disconnection of the planting clutch 63 of the planting speed change unit 62. If there is a malfunction of the lifting cylinder 32 or a malfunction of the planting clutch 63, the rice transplanter 1 is not permitted to automatically travel. Even if there is an abnormality related to the horizontal control of the planting unit 14 by the working unit controller 83, the planting unit 14 can be leveled by the spring mechanism provided in the rice transplanter 1, so in this case, the rice transplanter 1 is permitted to automatically travel (it is treated as if no abnormality related to automatic planting has occurred).

[0107] When the automatic travel control unit 71 determines that the above automatic travel start conditions are satisfied, it starts automatic travel of the rice transplanter 1. After the automatic travel of the rice transplanter 1 starts, the automatic travel control unit 71 causes the rice transplanter 1 to automatically travel along the travel route generated by the route generation unit 125.

[0108] The automatic travel control unit 71 turns on an automatic travel flag when causing the rice transplanter 1 to start automatic travel. The automatic travel flag is data stored in the control unit 30, and indicates whether the rice transplanter 1 is automatically travelling or not. When the automatic travel flag is ON, it means that the rice transplanter 1 is automatically travelling, and when it is OFF, it means that the rice transplanter 1 is not automatically travelling.

[0109] The automatic driving control by the automatic driving control unit 71 is executed by the automatic driving control unit 71 outputting a control signal to the steering controller 84 so that the rice transplanter 1 drives along the automatic driving path 135, and the steering controller 84 controlling the steering angle based on the control signal.

[0110] While the automatic travel control is being executed, the vehicle speed of the rice transplanter 1 is instructed, in principle, by manual operation of the user. Specifically, the vehicle speed during automatic travel of the rice transplanter 1 is controlled by the vehicle speed controller 82 based on the operation of the speed change pedal 27.

[0111] The automatic driving control unit 71 monitors whether or not a predetermined automatic driving end condition is satisfied during automatic driving. There are various possible automatic driving end conditions, and one example is when the wireless communication terminal 3 instructs the rice transplanter 1 to end automatic driving. In addition, the automatic driving end condition is satisfied when a situation occurs in which it is undesirable to continue automatic driving, such as when the steering operation flag is turned ON or when the rice transplanter 1 deviates from the automatic driving route 135 by a predetermined deviation or more.

[0112] When the automatic driving control unit 71 determines that the above-mentioned automatic driving end condition is satisfied, it ends the automatic driving of the rice transplanter 1. The method of ending the automatic driving differs depending on the situation. For example, when the driving of the rice transplanter 1 should be immediately stopped due to a communication interruption of the wireless communication terminal 3, detection of an obstacle by an obstacle sensor (not shown), etc., the automatic driving control unit 71 controls the engine 22 to immediately stop, and then ends the automatic driving. On the other hand, when there is an instruction from the user to end the automatic driving, the automatic driving control unit 71 ends the automatic driving after performing deceleration control by the vehicle speed controller 82 to smoothly decelerate the vehicle so that the vehicle speed becomes zero. After ending the automatic driving of the rice transplanter 1, the automatic driving control unit 71 turns off the automatic driving flag.

[0113] Next, the automatic control of the working unit will be described.

[0114] As described above, the automatic working unit control is a series of controls related to the planting unit 14 when the rice transplanter 1 is turned between tasks. Whether or not this automatic working unit control is performed is determined according to the state of the automatic working unit control flag, which is data stored in the control unit 30. If the automatic working unit control flag is ON, the automatic working unit control is performed, and if it is OFF, the automatic working unit control is not performed.

[0115] In principle, the state of the working unit automatic control flag can be switched by the user operating the working unit automatic control on / off switch 69 to the ON or OFF state. However, even if the working unit automatic control on / off switch 69 is in the OFF state, the automatic travel control unit 71 forcibly changes the working unit automatic control flag to ON during automatic travel of the rice transplanter 1. In other words, during automatic travel of the rice transplanter 1, the working unit automatic control is executed regardless of whether the working unit automatic control on / off switch 69 is in the ON state or the OFF state.

[0116] In addition, even if the working unit automatic control on / off switch 69 is in the ON state and the automatic running of the rice transplanter 1 is started, and then the working unit automatic control on / off switch 69 is switched to the OFF state, the working unit automatic control flag is maintained as ON.

[0117] A specific process will be described with reference to the flowchart in Fig. 6. When the process in Fig. 6 is started, the automatic travel control unit 71 judges whether or not the rice transplanter 1 is currently automatically traveling (step S101). This judgment can be made based on the automatic travel flag described above. If the rice transplanter 1 is automatically traveling, the automatic travel control unit 71 sets the working unit automatic control flag to ON (step S102). After that, the process returns to step S101.

[0118] If it is determined in step S101 that the vehicle is not in automatic driving, the automatic driving control unit 71 determines whether the working unit automatic control on / off switch is ON or not (step S103). If it is ON, the automatic driving control unit 71 sets the working unit automatic control flag to ON (step S102). If not, the automatic driving control unit 71 sets the working unit automatic control flag to OFF (step S104). In either case, the process returns to step S101.

[0119] Next, the actual automatic control of the working unit will be described with reference to the flow chart of FIG.

[0120] The process of Fig. 7 is executed in parallel with the process of Fig. 6. When the process of Fig. 7 is started, the control unit 30 judges whether or not the working unit automatic control flag is ON (step S201). If the working unit automatic control flag is OFF, the process returns to step S201 (therefore, the processes of steps S202 to S205 are not performed).

[0121] When the working unit automatic control flag is ON in the determination in step S201, the control unit 30 determines whether the rice transplanter 1 has started turning (step S202). There are various methods for this determination, but for example, it is considered to determine that turning has started when one of the side clutches 55L, 55R provided on the left and right rear wheels 13, 13 is disengaged. According to this determination method, the point at which the start of turning is detected is approximately point Q1 in FIG. 8.

[0122] If it is determined in step S202 that the rice transplanter 1 has started turning, the control unit 30 causes the working unit controller 83 to raise the planting unit 14 to the raised position, and causes the steering controller 84 to disengage the planting clutch 63 (step S203). The timing of raising the planting unit 14 and disengaging the planting clutch 63 can be changed as appropriate. If it is determined in step S202 that the rice transplanter 1 has not started turning, the processing of step S203 is skipped.

[0123] Next, the control unit 30 judges whether the rice transplanter 1 has finished turning (step S204). There are various methods for this judgment, but it is possible to judge that the turning has finished when the travel distance during turning exceeds a predetermined distance and one of the side clutches 55L and 55R that was disconnected is reconnected. According to this judgment method, the point at which the turning end is detected is approximately the point Q2 in FIG. 8.

[0124] If it is determined in step S204 that the rice transplanter 1 has finished turning, the control unit 30 causes the working unit controller 83 to lower the planting unit 14 to the lowered position, and causes the steering controller 84 to connect the planting clutch 63 (step S204). The order of the timing between the lowering of the planting unit 14 and the connection of the planting clutch 63 can be changed as appropriate. If it is determined in step S204 that the rice transplanter 1 has not finished turning, the process of step S205 is skipped. Then, the process returns to step S201.

[0125] Next, vehicle speed control including auto-cruise control will be described.

[0126] As described above, the auto-cruise control is a control in which the vehicle speed controller 82 maintains the traveling of the rice transplanter 1 at a speed corresponding to the operation position of the speed change pedal 27 when the auto-cruise lever 68 was previously operated to the ON side, even if no operating force is applied to the speed change pedal 27. Whether or not to perform this auto-cruise control is determined according to the state of the speed fixing flag, which is the stored content of the control unit 30. If the speed fixing flag is ON, the auto-cruise control is performed, and if it is OFF, the auto-cruise control is not performed.

[0127] In principle, the speed fix flag can be switched ON / OFF by the user operating the auto-cruise lever 68 to the ON side or OFF side. However, even if the speed fix flag is ON, the automatic travel control unit 71 forcibly changes the speed fix flag to OFF during automatic travel of the rice transplanter 1 under a predetermined condition, such as when the rice transplanter 1 is traveling on the turning path 137. Therefore, when the rice transplanter 1 is automatically traveling on the turning path 137 shown in FIG. 8, the auto-cruise control is prohibited. When the rice transplanter 1 is automatically traveling, the auto-cruise control is permitted substantially only when the rice transplanter 1 is traveling on the work path 136.

[0128] Strictly speaking, when considering a case where the rice transplanter 1 is automatically traveling along the work path 136 on the left side of Fig. 8, the section for which the automatic traveling control unit 71 permits the execution of the auto-cruise control is not the entire section from the start point S1 to the end point E1 of the work path 136. The section for which the auto-cruise control is permitted is the section from the start point S1 of the work path 136 to an intermediate point P1 close to the end point E1 (a specified point a specified distance before the end point E1). This intermediate point P1 and the end point E1 are separated by a specified distance (first specified distance L1).

[0129] On the working path 136, execution of auto-cruise control is prohibited in the section from intermediate point P1 to end point E1. Also, execution of auto-cruise control is prohibited in the entire section of the turning path 137. In this way, in the section immediately before turning and in the section where turning is performed, the vehicle speed is controlled according to the operating position of the speed change pedal 27. This allows for agile and careful gear change operation at the user's discretion.

[0130] However, among the work path 136 and the turning path 137 that constitute the automatic travel path 135, during automatic travel on the turning path 137, a predetermined upper limit is set for the vehicle speed based on the amount of operation of the speed change pedal 27 during automatic travel. Therefore, the rice transplanter 1 cannot automatically travel on the turning path 137 at a vehicle speed that exceeds the upper limit vehicle speed, regardless of the amount of operation of the speed change pedal 27. As a result, the vehicle speed of the rice transplanter 1 is limited to be equal to or lower than the upper limit vehicle speed, so that a stable ride comfort can be achieved when turning.

[0131] In addition, in this embodiment, restraining control is performed with respect to the vehicle speed when the rice transplanter 1 transitions from the turning path 137 to the working path 136 during automatic traveling.

[0132] For example, consider a case where the user depresses the speed change pedal 27 to the maximum while the rice transplanter 1 is traveling on the turning path 137. Due to the above-mentioned control, the vehicle speed of the rice transplanter 1 traveling on the turning path 137 becomes a predetermined upper limit value. Then, consider a case where the rice transplanter 1 moves to the work path 136 while the user maintains the operating position of the speed change pedal 27. At this time, if the upper limit of the vehicle speed is released, there is a risk that the rice transplanter 1 will accelerate against the user's intention.

[0133] In consideration of the above, in this embodiment, even if the rice transplanter 1 during automatic traveling finishes traveling on the turning path 137 and starts traveling on the working path 136, the upper limit control of the vehicle speed performed on the turning path 137 is maintained (restraint control) unless the user operates the speed change pedal 27 to the deceleration side by a predetermined amount. This allows acceleration to be performed based on the explicit operation of the user releasing and then re-depressing the speed change pedal 27, thereby increasing the user's sense of security.

[0134] A specific process will be described with reference to the flowchart of Fig. 9. When the process of Fig. 9 is started, the control unit 30 determines whether or not the rice transplanter 1 is currently automatically traveling (step S301).

[0135] When the rice transplanter 1 is not automatically traveling, the control unit 30 judges whether the auto-cruise lever 68 has been operated to the OFF side (step S302). When the auto-cruise lever 68 has been operated to the OFF side, the control unit 30 changes the speed fixing flag to OFF if it is ON (step S303). After that, the process returns to step S301.

[0136] In the above step S302, it is actually determined whether or not the auto-cruise lever 68 has been operated to the OFF side, as well as whether or not another operation that should automatically end the auto-cruise control (specifically, depression of the speed change pedal 27) has been performed. Even if the auto-cruise lever 68 has not been operated to the OFF side, if the speed change pedal 27 has been depressed, the speed fix flag is changed from ON to OFF in step S303.

[0137] In the above step S302, it is actually determined whether not only the auto-cruise lever 68 has been operated to the OFF side, but also whether any other operation that should automatically end the auto-cruise control (specifically, depression of the shift pedal 27) has been performed.

[0138] If it is determined in step S302 that the auto-cruise lever 68 has not been operated to the OFF side, the control unit 30 determines whether or not the auto-cruise lever 68 has been operated to the ON side (step S304). If the auto-cruise lever 68 has been operated to the ON side, the control unit 30 changes the speed fixing flag, if OFF, to ON (step S305). If the auto-cruise lever 68 has not been operated to the ON side, the process of step S305 is skipped. After that, the process returns to step S301.

[0139] If it is determined in step S301 that the rice transplanter 1 is automatically traveling, the automatic traveling control unit 71 determines whether or not the rice transplanter 1 is on the work path 136 (step S306). This determination can be made based on the work center position of the planting unit 14 calculated from the current position of the rice transplanter 1. If the rice transplanter 1 is not on the work path 136 (i.e., on the turning path 137), the automatic traveling control unit 71 turns the speed fixing flag OFF if it is ON (step S303). After that, the process returns to step S301.

[0140] If it is determined in step S306 that the rice transplanter 1 is on the work path 136, the automatic driving control unit 71 determines whether or not the rice transplanter 1 is before the midway point P1 on the work path 136 (step S307). This determination can be made based on the work center position of the planting unit 14, as described above. If the rice transplanter 1 is not before the midway point P1 (i.e., it is traveling beyond the point P1), the automatic driving control unit 71 turns the speed fixation flag OFF if it is ON (step S303). After that, the process returns to step S301.

[0141] As shown in the flowchart of Fig. 9, when the rice transplanter 1 is automatically traveling on the turning path 137, or when the rice transplanter 1 is automatically traveling on the side closer to the end point than the intermediate point P1 of the work path 136, the speed fixing flag is turned OFF. In the above cases, the operation of the auto-cruise lever 68 to the ON side is disabled. This realizes the prohibition of the auto-cruise control.

[0142] 9, even if the user operates the wireless communication terminal 3 to instruct the end of the automatic driving, the speed fixation flag is changed to OFF if it is ON. As a result, the auto-cruise control is automatically released.

[0143] Next, the actual vehicle speed control will be described with reference to the flowchart of FIG.

[0144] The process of Fig. 10 is executed in parallel with the process of Fig. 9. When the process of Fig. 10 starts, the control unit 30 determines whether or not the speed fixing flag is ON (step S401).

[0145] When the speed fixing flag is ON, the control unit 30 sets the target vehicle speed based on the operation amount of the speed change pedal 27 at the time when the auto-cruise lever 68 is operated to the ON side (step S402). Next, the control unit 30 (vehicle speed controller 82) controls the vehicle speed of the rice transplanter 1 so as to approach the target vehicle speed (step S403). After that, the process returns to step S401.

[0146] If it is determined in step S401 that the speed fixing flag is OFF, the control unit 30 sets a target vehicle speed based on the current amount of operation of the shift pedal 27 (step S404).

[0147] After that, the control unit 30 judges whether the rice transplanter 1 is currently automatically traveling (step S405). If the rice transplanter 1 is currently automatically traveling, the automatic traveling control unit 71 changes the target vehicle speed to the upper limit value when the rice transplanter 1 is on the turning path 137 and the target vehicle speed set in step S404 exceeds the upper limit value (step S406). This makes it possible to prevent turning at an excessively high speed during automatic traveling. In addition, after the rice transplanter 1 shifts from the turning path 137 to the working path 136, when the stepping on the speed change pedal 27 is not released and the target vehicle speed set in step S404 exceeds the upper limit value, the automatic traveling control unit 71 changes the target vehicle speed to the upper limit value (step S407). This realizes the above-mentioned check control. If it is determined in step S405 that the rice transplanter 1 is not currently automatically traveling, the processing of the above steps S406 and S407 is skipped.

[0148] Next, the control unit 30 controls the vehicle speed of the rice transplanter 1 so as to approach the target vehicle speed (step S403). After that, the process returns to step S401.

[0149] Next, the notification control will be described.

[0150] In this embodiment, when the position of the rice transplanter 1 (the work center position of the planting unit 14) reaches a point R1 slightly before the end point E1 of the work path 136 during automatic travel, a notification is given to inform the user that the transition to travel on the turning path 137 is imminent. The notification can be made, for example, by a display with a lamp or a sound. The notification to the user may be made on the rice transplanter 1 side or on the wireless communication terminal 3 side. This allows the user to know that the traveling direction of the rice transplanter 1 will soon be changed, so that the user can prepare for the shaking that accompanies the turning of the rice transplanter 1 by, for example, sitting deeply in the driver's seat 25. This notification control can be realized by a simple process of monitoring the current position of the rice transplanter 1, so a flowchart will be omitted.

[0151] Next, an example will be given to explain how the rice transplanter 1 operates during automatic travel under the above control.

[0152] After getting on the stopped rice transplanter 1, the user operates the wireless communication terminal 3 to instruct the start of automatic travel. In this explanation, when the start of automatic travel is instructed, the working unit automatic control on / off switch 69 of the rice transplanter 1 is in the OFF state. In addition, the speed change pedal 27 is released, and the auto cruise control ON operation by the auto cruise lever 68 has not been performed.

[0153] Based on the above instruction, automatic travel of the rice transplanter 1 is started. Since the speed fixing flag is initially OFF, the actual movement of the rice transplanter 1 is started when the user depresses the speed change pedal 27.

[0154] However, the position of the rice transplanter 1 when the user instructs the start of automatic travel (strictly speaking, the position of the work center of the planting unit 14) does not necessarily match the position of the start point of the above-mentioned automatic travel start target route. Therefore, before travel along the above-mentioned automatic travel route 135 is performed, the automatic travel control unit 71 travels the rice transplanter 1 by automatic steering so that the position of the work center of the planting unit 14 matches the point where automatic travel is scheduled to start along the automatic travel route 135 (pre-travel).

[0155] Here, if automatic driving could be started while driving under auto-cruise control, the rice transplanter 1 would turn at high speed and change course at the moment the user instructs the start of automatic driving. However, in this embodiment, as described above, automatic driving by the automatic driving control unit 71 would not start unless the auto-cruise control by the vehicle speed controller 82 is released. Therefore, the vehicle speed of the rice transplanter 1 during the above-mentioned pre-driving would necessarily follow the user's operation of the speed change pedal 27. As a result, the user can confidently instruct the start of automatic driving.

[0156] After the rice transplanter 1 moves to a predetermined position by the pre-travel, the rice transplanter 1 travels according to the automatic travel route 135 shown in Fig. 5. Specifically, the automatic travel control unit 71 performs automatic steering so as to realize travel along the automatic travel route 135. The vehicle speed of the rice transplanter 1 at this time is controlled so as to correspond to the amount by which the user depresses the speed change pedal 27. When the rice transplanter 1 travels along the work route 136, the planting unit 14 is in the lowered position and the planting clutch 63 is connected, so that the seedling planting work is performed.

[0157] Consider the case where the rice transplanter 1 is in the position shown in Fig. 8, for example, and the user operates the auto-cruise lever 68 to the ON side while depressing the speed change pedal 27 by a desired amount. In this case, the speed fixing flag is changed from OFF to ON. After that, even if the user releases the operating force on the speed change pedal 27, the vehicle speed controller 82 controls the traveling speed of the rice transplanter 1 so as to maintain the vehicle speed at the time when the auto-cruise lever 68 was operated to the ON side (auto-cruise control).

[0158] Thereafter, when the rice transplanter 1 traveling on the work path 136 approaches a predetermined intermediate point P1, the auto-cruise control is prohibited, and the speed fixing flag is automatically changed from ON to OFF. As a result, the vehicle speed of the rice transplanter 1 is controlled to a vehicle speed according to the current amount of depression of the speed change pedal 27. During the auto-cruise control, the user does not depress the speed change pedal 27. Therefore, by changing the speed fixing flag from ON to OFF, the vehicle speed controller 82 controls the rice transplanter 1 to start decelerating from the above-mentioned point P1. If the state in which the speed change pedal 27 is not depressed is maintained, the rice transplanter 1 stops at a point (for example, point R1) a little further ahead from the point P1. The position of the stopping point changes depending on the vehicle speed during the auto-cruise control, but the position of the point P1 where the auto-cruise control is prohibited is set so that the stopping point is before the end point E1 of the work path 136 even if the auto-cruise control is performed at the maximum vehicle speed.

[0159] After that, the user depresses the speed change pedal 27 by a desired amount. This causes the rice transplanter 1 to start traveling again. Immediately, the rice transplanter 1 shifts from the work path 136 to the turning path 137.

[0160] As described above, the working unit automatic control on / off switch 69 is in the OFF state, but during automatic travel, the working unit automatic control flag is forcibly set to ON. Therefore, the working unit automatic control is performed on the turning path 137. Specifically, when the rice transplanter 1 reaches point Q1 where the side clutch 55R on the inside of the turning is in the disconnected state, the planting unit 14 rises to the raised position and the planting clutch 63 is in the disconnected state. After that, when the rice transplanter 1 reaches point Q2 where the side clutch on the inside of the turning (side clutch 55R in the case of FIG. 8) is in the connected state, the planting unit 14 descends to the lowered position and the planting clutch 63 is in the connected state.

[0161] When a user desires automatic travel of the rice transplanter 1 along the automatic travel route 135, it is generally considered that the user also desires lifting and lowering control of the planting unit 14 when turning between tasks, and connection and disconnection control of the planting clutch 63. Therefore, by performing automatic control of the working unit even when the working unit automatic control on / off switch 69 is in the OFF state, the user's effort can be reduced.

[0162] However, it is conceivable that for some reason the user wishes to switch from automatic driving to manual driving midway. In this case, for example, the user manually operates the steering handle 26, which automatically cancels automatic driving. As a result, the working unit automatic control flag is released from being forced to be ON, and thereafter the state of the working unit automatic control flag follows the state of the working unit automatic control on / off switch 69 operated by the user. Therefore, after automatic driving is canceled, the user's intention as to whether or not to execute the working unit automatic control can be reliably reflected.

[0163] When the rice transplanter 1 is traveling on the turning path 137, the auto-cruise control is prohibited. Therefore, even if the user operates the auto-cruise lever 68 to the ON side, the auto-cruise control is not performed on the turning path 137. As a result, during automatic traveling on the turning path 137, the vehicle speed of the rice transplanter 1 is controlled based on the amount by which the user actually depresses the speed change pedal 27. Also, even if the user depresses the speed change pedal 27 greatly, the rice transplanter 1 does not turn at an excessive speed due to the above-mentioned upper limit control of the vehicle speed.

[0164] After that, the rice transplanter 1 moves to the work path 136. When the rice transplanter 1 enters the work path 136 from the turning path 137 at a speed equal to or higher than a predetermined speed, the upper limit control of the vehicle speed is not released even on the work path 136 unless the user releases the pressure on the speed change pedal 27 at least to a certain extent (the above-mentioned check control). To release the check control, the user releases the pressure on the speed change pedal 27 once and then presses it again. This allows the rice transplanter 1 to travel at a speed higher than the above-mentioned upper limit speed on the work path 136. Since the auto-cruise control is permitted again on the work path 136, the user can start the auto-cruise control using the auto-cruise lever 68 in the same manner as described above.

[0165] In addition, at point P2 before the end of the auto-cruise control at the above-mentioned intermediate point P1, a notification control may be performed to notify the user that the auto-cruise control will be terminated. The point P1 where the auto-cruise control ends and the point P2 where the notification is made are separated by an appropriate distance (a second predetermined distance L2). By receiving this notification and quickly terminating the auto-cruise control (specifically, by depressing the speed change pedal 27), the rice transplanter 1 can be shifted from the work path 136 to the turning path 137 without stopping. As a result, the work can be smoothly performed by automatic traveling. When the rice transplanter 1 enters the turning path 137 from the work path 136 without stopping, the above-mentioned notification control that notifies the user of this immediately before the transition to the turning path 137 is more preferable.

[0166] As described above, the automatic travel system of the work vehicle of this embodiment is capable of automatically traveling the rice transplanter 1 along the automatic travel path 135 having a plurality of work paths 136 along which planting work is performed by the planting unit 14, and a turning path 137 connecting adjacent work paths 136 among the plurality of work paths 136. This automatic travel system of the work vehicle is equipped with a work unit automatic control on / off switch 69. The work unit automatic control on / off switch 69 can select whether to execute the work unit automatic control. This work unit automatic control is a control that detects the start of turning of the rice transplanter 1, automatically raises the planting unit 14 and disconnects the planting clutch 63 of the planting unit 14, and detects the end of turning of the rice transplanter 1, automatically lowers the planting unit 14 and connects the planting clutch 63. When the rice transplanter 1 is automatically traveling along the turning path 137 and the start of turning is detected, the automatic control of the working unit is executed regardless of whether the automatic control of the working unit is executed or not, as selected by the automatic control on / off switch 69.

[0167] As a result, during automatic travel of the rice transplanter 1, the automatic control of the working unit is executed regardless of whether execution or non-execution of the automatic control of the working unit is selected by the automatic control on / off switch 69, so the burden on the user can be reduced. As a result, the lifting and lowering of the planting unit 14 and the connection and disconnection of the planting clutch 63 can be appropriately executed during automatic travel of the rice transplanter 1.

[0168] In addition, in the automatic driving system of the work vehicle of this embodiment, when automatic driving is released (terminated) while the rice transplanter 1 is automatically driving along the turning path 137, if the automatic control on / off switch 69 has selected not to execute the automatic control of the work unit, the automatic control of the work unit is terminated, whereas if the automatic control on / off switch 69 has selected to execute the automatic control of the work unit, the automatic control of the work unit is continued.

[0169] As a result, when the automatic travel of the rice transplanter 1 is cancelled and the rice transplanter 1 is shifted to manual travel, the presence or absence of automatic control of the working unit is determined according to the selected state of the automatic control on / off switch 69. Therefore, for example, when the user wishes to turn manually while turning on a turning path in automatic travel, the user's wish can be appropriately reflected as to whether or not to perform lifting and lowering control of the planting unit 14.

[0170] In the automatic driving system of the work vehicle of this embodiment, the rice transplanter 1 is provided with a speed change pedal 27 for setting and operating the vehicle speed. The rice transplanter 1 is configured to set the vehicle speed of the rice transplanter 1 during automatic driving in response to the operation of the speed change pedal 27. This automatic driving system of the work vehicle is capable of executing auto-cruise control for maintaining the vehicle speed of the rice transplanter 1 corresponding to a predetermined operating position of the speed change pedal 27 on the work path 136, while being configured to be unable to execute auto-cruise control on the turning path 137. When the auto-cruise control and the automatic control of the working unit are being executed, when the rice transplanter 1 reaches a point P1 that is a first predetermined distance L1 before the end point E1 of the work path 136, the auto-cruise control is terminated, while the automatic control of the working unit is maintained.

[0171] As a result, the auto-cruise control is prohibited on the turning path 137 and ends before reaching the turning path 137 (a first predetermined distance L1 before the end point E1 of the work path 136), but the automatic control of the working unit does not end. Therefore, after the auto-cruise control ends, as the rice transplanter 1 turns on the turning path 137 at the vehicle speed instructed by manual operation of the speed change pedal 27, the lifting and lowering control of the planting unit 14 and the connection and disconnection control of the planting clutch 63 are automatically performed. This makes it possible to improve workability while ensuring careful turning.

[0172] Although the preferred embodiment of the present invention has been described above, the above configuration can be modified, for example, as follows.

[0173] In the above embodiment, when the auto-cruise control is being executed during automatic travel on the work path 136, the auto-cruise control ends at a point P1 that is a first predetermined distance L1 before the end point E1 of the work path 136. In addition, the auto-cruise control is prohibited on the turning path 137. However, the auto-cruise control may be permitted during automatic travel on the turning path 137. For example, when the vehicle speed (vehicle speed based on the operation amount of the gear shift pedal 27) of the rice transplanter 1 during automatic travel along the work path 136 exceeds the upper limit vehicle speed associated with the turning path 137, it is considered that the rice transplanter 1 automatically decelerates to the upper limit vehicle speed and continues automatic travel on the turning path 137 while maintaining the auto-cruise control. In addition, when the current vehicle speed is less than the upper limit vehicle speed associated with the turning path 137, it is considered that the automatic travel on the turning path 137 is continued at the same vehicle speed or at a vehicle speed multiplied by a predetermined rate and while maintaining the auto-cruise control. After transitioning from the turning path 137 to the working path 136, automatic cruise control can be performed on the new working path 136 at the same vehicle speed as the auto-cruise control performed on the previous working path 136, thereby allowing automatic driving to be continued.

[0174] Regarding the vehicle speed of the rice transplanter 1, a first vehicle speed during auto-cruise control on the work path 136 and a second vehicle speed during auto-cruise control on the turning path may be set in advance, and the vehicle speed may be decelerated from the first vehicle speed to the second vehicle speed when transitioning from the work path 136 to the turning path 137, and may be accelerated from the second vehicle speed to the first vehicle speed when transitioning from the turning path 137 to the work path 136. In this case, the first vehicle speed is greater than the second vehicle speed. At this time, it is considered that the deceleration of the vehicle speed when transitioning from the work path 136 to the turning path 137 starts after the work center of the planting unit 14 reaches the end point E1 of the work path 136. In addition, it is considered that the acceleration when transitioning from the turning path 137 to the work path 136 starts before the work center of the planting unit 14 reaches the start point S1 of the work path 136, and the acceleration is completed at the timing when the start point S1 is reached.

[0175] The start / end of turning of the rice transplanter 1 may be detected based on position information of the rice transplanter 1.

[0176] In this embodiment, the connected / disconnected state of the left side clutch 55L or the right side clutch 55R is switched to turn the rice transplanter 1, and such switching may be performed in conjunction with the operation of the steering handle 26, or may be performed based on the detection results of a steering angle sensor provided in the rice transplanter 1.

[0177] The wireless communication terminal 3 may be removed from the rice transplanter 1, and the operator may operate the wireless communication terminal 3 without being on the rice transplanter 1, causing the unmanned rice transplanter 1 to travel automatically.

[0178] The rice transplanter 1 may have a function equivalent to the wireless communication terminal 3. In this case, even if the wireless communication terminal 3 is not provided, the rice transplanter 1 can realize an automatic driving system for a work vehicle.

[0179] Obviously many modifications and variations of the present invention are possible in light of the above teachings, and it is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. [Explanation of symbols]

[0180] 1 Rice transplanter (work vehicle) 14 Planting Department (Working Department) 27 Gear shift pedal (vehicle speed control unit) 63 Planting clutch (work clutch) 69 Work section automatic control on / off switch (operation section) 135 Travel Route 136 Work Path 137 Turning Path E1 End Point

Claims

1. An automatic driving system for a work vehicle capable of automatically driving a work vehicle having a working unit, An automatic driving system for a work vehicle, characterized in that when the work vehicle is driving automatically, the automatic control of the working unit is executed, regardless of whether the automatic control of the working unit, which automatically controls the lifting and lowering of the working unit or the connection and disconnection of the work clutch when the work vehicle turns, is set to be executed or not before the automatic driving of the work vehicle begins.

2. An operation unit capable of selecting whether to execute the automatic control of the working unit, The automatic driving system for a work vehicle as described in claim 1, characterized in that when the automatic driving of the work vehicle is canceled and transitions to manual driving, the automatic control of the working unit is executed or not executed depending on the selection state of the operation unit.

3. When a condition for starting automatic driving is satisfied, automatic driving of the work vehicle can be started, 3. The automatic driving system for a work vehicle according to claim 1, wherein the start condition includes a state in which the automatic control of the work unit is normally executed.

4. An automatic driving system for a work vehicle capable of automatically driving a work vehicle having a working unit, An automatic driving system characterized in that, regardless of whether automatic control of a working unit, which automatically controls the lifting of the working unit or the disengagement of the work clutch when the work vehicle turns, is set to be executed or not executed before the work vehicle starts to drive automatically, when the work vehicle is driving automatically.

5. An automatic driving system for a work vehicle capable of automatically driving a work vehicle having a working unit, An automatic driving system characterized in that, regardless of whether automatic control of a working unit, which automatically controls the lowering of the working unit or the connection of the work clutch when the work vehicle turns, is set to be executed or not executed before the work vehicle starts to drive automatically, when the work vehicle is driving automatically.

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