Field work vehicle

Abstract

To provide a field work vehicle capable of performing further control while holding an automatic control state of a steering control part.SOLUTION: A field work vehicle comprises: a travel machine body comprising, steering wheels 5A, a steering mechanism 3 capable of steering the steering wheels 5A, and a steering drive unit 31 for driving so as to operate the steering mechanism 3; a path setting part 13 for setting a target path GL; a first steering control part 11 which can be changed between an automatic control state for controlling drive of the steering drive unit 31 so as to travel along the target path GL, and a non-control state not for controlling the drive of the steering drive unit 31; and a second steering control part 12 for holding the automatic control state when the first steering control part 11 is in the automatic control state, and controlling the drive of the steering drive unit 31 separately from the first steering control part 11.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a field work vehicle.

Background Art

[0002] For example, in the field work vehicle (referred to as "work vehicle" in the document) disclosed in Patent Document 1, a steering control unit (referred to as "steering control unit" in the document) capable of traveling along a target path (referred to as "target movement path" in the document) is provided. The steering control unit controls the drive of the steering drive device (referred to as "steering motor" in the document) so as to travel along the target path in the automatic control state (referred to as "automatic entry mode" in the document).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the field work vehicle disclosed in Patent Document 1, the steering control unit controls the drive of the steering drive device so as to travel along the target path. However, it is conceivable that traveling along the target path may not be appropriately performed only by the control of the steering control unit. In such a case, means for controlling the drive of the steering drive device other than the control of the steering control unit is considered necessary. However, in the case of the field work vehicle disclosed in Patent Document 1, it is necessary to manually control the drive of the steering drive device by changing the state of the steering control unit to a non-control state (referred to as "automatic cut mode" in the document). Therefore, the operator is forced to perform troublesome work in order to return the steering control unit to the automatic control state.

[0005] An object of the present invention is to provide a field work vehicle capable of performing further control while maintaining the automatic control state of the steering control unit.

Means for Solving the Problems

[0006] The field working vehicle according to the present invention includes a traveling body having a steering wheel, a steering mechanism capable of steering the steering wheel, and a steering drive device capable of driving the steering mechanism, a route setting unit for setting a target route, an automatic control state for controlling the drive of the steering drive device to travel along the target route, and a first steering control unit capable of changing the state to a non-control state in which the drive of the steering drive device is not controlled. separate from the first steering control unit, it is possible to control the drive of the steering drive device, When the first steering control unit is in the automatic control state, while maintaining the automatic control state, the first steering control unit prioritizing over It is characterized in that a second steering control unit capable of controlling the drive of the steering drive device is provided.

[0007] According to the present invention, in addition to the first steering control unit capable of controlling the drive of the steering drive device to travel along the target route, a second steering control unit is provided. The second steering control unit is configured to be able to control the drive of the steering drive device separately from the first steering control unit while maintaining the automatic control state of the first steering control unit. Therefore, even when traveling along the target route cannot be appropriately performed only by the control of the first steering control unit, the second steering control unit can separately control the drive of the steering drive device as necessary. At this time, since the automatic control state of the first steering control unit is maintained, when the field working vehicle returns to a state of appropriately traveling along the target route based on the control of the second steering control unit, the control of the first steering control unit based on the automatic control state can be continued as it is. Thus, according to the present invention, a field working vehicle capable of performing further control while maintaining the automatic control state of the steering control unit is realized.

[0008] In the present invention, it is preferable that the first steering control unit is configured to output a first target command value calculated to travel along the target route to the steering drive device in the automatic control state, and the second steering control unit is configured to output a second target command value obtained by adding or subtracting a preset command value to or from the first target command value to the steering drive device.

[0009] According to this configuration, the first steering control unit outputs a target command value to the steering drive device. Therefore, the second steering control unit can control the steering drive device as necessary by simply calculating a target command value obtained by adding or subtracting based on the target command value output by the first steering control unit.

[0010] In the present invention, it is preferable that the steering drive device is an electric motor, and each of the first target command value and the second target command value is a current value.

[0011] With this configuration, the steering drive device is an electric motor, and the first steering control unit outputs a current value as a target command value to the electric motor. Therefore, the second steering control unit can control the electric motor as necessary by simply calculating a current value obtained by adding or subtracting based on the current value output by the first steering control unit.

[0012] In the present invention, it is preferable that the second steering control unit is configured to be able to control the drive of the steering drive device when the working device is mounted on the traveling body, and is configured to be unable to control the drive of the steering drive device when the working device is not mounted on the traveling body.

[0013] Due to the operation of the working device, it is conceivable that traveling along the target path cannot be appropriately performed only by the control of the first steering control unit. With this configuration, the control by the second steering control unit can be performed only when the working device is mounted. Thereby, it is possible to limit the control by the second steering control unit to necessary scenes. In addition, the possibility that the steering control becomes unstable due to the control by the second steering control unit being unexpectedly performed in an unnecessary scene is avoided.

[0014] In the present invention, it is preferable that a determination unit for determining whether or not the working device is mounted on the traveling body is provided, and the determination unit is configured to be able to automatically detect the working device.

[0015] With this configuration, when the working device is attached to the traveling body, the control of the second steering control unit is enabled, and when the working device is not attached to the traveling body, the control of the second steering control unit is disabled. This configuration can be easily realized by automatically detecting the working device.

[0016] In the present invention, it is preferable that an input unit that accepts a manual operation and a determination unit that determines whether or not the working device is attached to the traveling body are provided, and the determination unit is configured to detect the working device based on information input to the input unit by the manual operation.

[0017] With this configuration, when the working device is attached to the traveling body, the control of the second steering control unit is enabled, and when the working device is not attached to the traveling body, the control of the second steering control unit is disabled. This configuration can be easily realized only by a manual operation on the input unit.

[0018] In the present invention, it is preferable that the working device is a plow.

[0019] When the working device is a plow, when the plow tills the field surface, the plow receives a reaction force in one left - right direction from the field surface with respect to the traveling direction of the field working vehicle. For this reason, the field working vehicle tends to slip in the left - right direction. With this configuration, even when traveling along the target path cannot be appropriately performed only by the control of the first steering control unit, the second steering control unit can perform control corresponding to the slip as needed, for example.

[0020] In the present invention a field working vehicle according to , a traveling body having a steering wheel, a steering mechanism capable of steering the steering wheel, and a steering drive device capable of driving the steering mechanism to operate; a path setting unit for setting a target path; an automatic control state for controlling the drive of the steering drive device to travel along the target path; and a first steering control unit capable of changing the state to a non-control state in which the drive of the steering drive device is not controlled; and a second steering control unit capable of controlling the drive of the steering drive device separately from the first steering control unit while maintaining the automatic control state when the first steering control unit is in the automatic control state. a control tool that accepts a manual operation and is provided, and when the control tool is operated when the first steering control unit is in the automatic control state, the second steering control unit is configured to control the drive of the steering drive device with priority over the first steering control unit. characterized by .

[0021] According to the present invention, in addition to the first steering control unit capable of controlling the drive of the steering drive device to travel along the target path, a second steering control unit is provided. The second steering control unit is configured to be able to control the drive of the steering drive device separately from the first steering control unit while maintaining the automatic control state of the first steering control unit. Therefore, even when traveling along the target path cannot be appropriately performed only by the control of the first steering control unit, the second steering control unit can separately control the drive of the steering drive device as necessary. At this time, since the automatic control state of the first steering control unit is maintained, when the field working vehicle returns to a state where it appropriately travels along the target path based on the control of the second steering control unit, the control of the first steering control unit based on the automatic control state can be continued as it is. Also, With this configuration, when the operator determines that the control by the second steering control unit is necessary, the control by the second steering control unit can be realized simply by operating the operating tool. As a result, the operator can easily perform necessary control separately while maintaining the automatic control state of the first steering control unit. In this way, according to the present invention, a field working vehicle capable of executing further control while maintaining the automatic control state of the steering control unit is realized.

[0022] In the present invention, when the operating tool is not operated when the first steering control unit is in the automatic control state, it is preferable that the second steering control unit does not control the driving of the steering drive device, and the first steering control unit is configured to control the driving of the steering drive device.

[0023] With this configuration, when the operator determines that the control by the second steering control unit is not necessary, if the operating tool is not operated, the control by the first steering control unit is performed as it is. Thereby, the possibility that the steering control becomes unstable due to the control by the second steering control unit being unexpectedly performed in an unnecessary situation is avoided.

[0024] In the present invention, it is preferable that the second steering control unit is configured to control the driving of the steering drive device prior to the first steering control unit when the operating tool is operated for a period longer than a preset first set time.

[0025] With this configuration, when the operator long-presses the operating tool for a time equal to or longer than the first set time, the control by the second steering control unit is performed. Therefore, with respect to whether to perform the control by the second steering control unit, it is possible to confirm the intention of the operator by long-pressing the operating tool.

[0026] In the present invention, when the operating tool is operated for a period longer than a second set time set longer than the first set time, it is preferable that the second steering control unit does not control the driving of the steering drive device, and the first steering control unit is configured to control the driving of the steering drive device.

[0027] When the operating tool is pressed for a long time and the control by the second steering control unit is performed for a long time, there is a possibility that the field working vehicle may turn excessively and the steering control may become unstable. With this configuration, when the operating tool is operated for a second set time or longer, the control of the second steering control unit ends. Thereby, the possibility that the steering control becomes unstable is reduced.

[0028] In the present invention, when the operating tool is operated for a short time equal to or less than the first set time, the second steering control unit does not control the driving of the steering drive device, and the path setting unit changes the extension direction of the target path. It is preferable that the target path is displaced to one of the left and right without changing the direction.

[0029] With this configuration, the operating tool is used as both an operating tool for displacing the target path and an operating tool for control by the second steering control unit.

[0030] In the present invention, the operating tool has a first operation unit and a second operation unit, and when the first operation unit is operated, the second steering control unit controls the steering drive device so that the steering wheel turns to one of the left and right with respect to the steering direction based on the control of the first steering control unit. When the second operation unit is operated, it is preferable to control the driving of the steering drive device so that the steering wheel turns to the other side of the left and right with respect to the steering direction based on the control of the first steering control unit.

[0031] With this configuration, when the operator wants to adjust the steering direction to either the left or the right, the operator can quickly adjust the traveling direction of the field working vehicle by operating either the first operation unit or the second operation unit.

Brief Description of the Drawings

[0032]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0033] 〔Basic Configuration of Steering Control Device〕 Based on FIG. 1, the steering control device 1 mounted on the field work vehicle will be described. The steering control device 1 may be a physical device such as a microcomputer, or a combination of a device and software. Although not shown, the steering control device 1 is provided with a storage device. This storage device is, for example, a non-volatile memory (such as a flash memory) or a ROM such as an EEPROM. The storage device stores the data generated by each functional unit in the steering control device 1 temporarily or permanently.

[0034] The steering control device 1 is provided with a first steering control unit 11, a second steering control unit 12, a path setting unit 13, and a determination unit 14. The path setting unit 13 sets a target path GL that is the target for work travel in the field. Work travel means performing work on the field with a work device attached to the traveling body while traveling. In the present embodiment, the target path GL is a straight path as shown in FIGS. 3 and 5. Note that the target path GL may be a path including a curve.

[0035] The detection value from the current sensor 32, the calculated value from the steering angle calculation unit 34, the positioning signal from the dead reckoning positioning device 35, and the detection value from the inertial measurement device 36 are input to the first steering control unit 11. Also, a target current value (target command value) is output from the first steering control unit 11 to the electric motor 31. The electric motor 31 is an example of an actuator for steering and corresponds to the 'Steering Drive Device' of the present invention. The target current value output from the first steering control unit 11 to the electric motor 31 is referred to as the 'first target current value' in the present embodiment. The first target current value is an example of the 'first target command value' of the present invention. The second steering control unit 12 will be described later.

[0036] The electric motor 31 is interlocked and connected with the steering mechanism 3, and when the electric motor 31 is driven, the steering mechanism 3 is driven. Further, the steering mechanism 3 is provided with a steering wheel 3A, and the steering wheel 3A receives the steering operation of the operator.

[0037] The current sensor 32 detects the actual current value in the electric motor 31. The motor encoder 33 detects the rotation angle of the electric motor 31. The motor encoder 33 is configured to be able to detect the rotation angle of the electric motor 31, for example, in the range of -10800 degrees to +10800 degrees. The motor encoder 33 may be, for example, a resolver type encoder or an optical encoder.

[0038] The steering angle calculation unit 34 is configured to calculate the steering angular velocity of the steering wheel 5A (wheel, crawler, etc.) in the field working vehicle based on the detection value of the motor encoder 33. In addition, the steering angle calculation unit 34 is configured to calculate the steering angular velocity of the steering wheel 5A in the field working vehicle based on the change amount per unit time of the detection value of the motor encoder 33. The steering angular velocity of the steering wheel 5A means the speed at which the direction (steering angle) of the steering wheel 5A changes. The larger the steering angular velocity, the steeper the change in the steering angle of the steering wheel 5A.

[0039] The navigation positioning device 35 receives a positioning signal from an artificial satellite (not shown) used in GNSS (Global Satellite Navigation System, for example, GPS, GLONASS, Galileo, QZSS, BeiDou, etc.). In the present embodiment, the navigation positioning device 35 uses DGPS (Differential GPS: relative positioning method), but it is also possible to use RTK-GPS (Real Time Kinematic GPS: interference positioning method).

[0040] The inertial measurement device 36 is, for example, a gyro acceleration sensor or a magnetic azimuth sensor, and detects the angular velocity of the yaw angle of the field working vehicle and the accelerations in three mutually perpendicular axial directions over time. The inertial measurement device 36 can calculate the azimuth change angle of the field working vehicle by integrating the angular velocity. From this, the measurement data measured by the inertial measurement device 36 includes data indicating the azimuth (direction) of the field working vehicle. Although not described in detail, the inertial measurement device 36 can also measure, in addition to the angular velocity of the turning angle of the field working vehicle, the left-right inclination angle of the field working vehicle, and the angular velocity of the front-rear inclination angle of the field working vehicle. Thus, the inertial measurement device 36 detects the orientation of the body of the field working vehicle.

[0041] The first steering control unit 11 calculates the position coordinates of the field working vehicle over time based on the positioning data output by the navigation positioning device 35. Thereby, the first steering control unit 11 acquires the position coordinates of the field working vehicle. Further, the first steering control unit 11 calculates the attitude azimuth of the field working vehicle based on the position coordinates of the field working vehicle and the detection values by the inertial measurement device 36. Note that the attitude azimuth of the field working vehicle is the azimuth when the field working vehicle moves forward or backward while moving straight.

[0042] Referring to FIG. 3, first, during the running of the tractor 5, which is an example of the field working vehicle, based on the current position coordinates of the tractor 5 and the position coordinates of the tractor 5 at the point where it was running immediately before, the first steering control unit 11 calculates the initial attitude azimuth. Next, when the tractor 5 runs for a certain period of time after the initial attitude azimuth is calculated, the first steering control unit 11 calculates the amount of change in azimuth by integrating the angular velocity detected by the inertial measurement device 36 during that certain period of running.

[0043] Then, by adding the amount of change in azimuth calculated in this way to the initial attitude azimuth, the first steering control unit 11 updates the calculation result of the azimuth. After that, every certain period of time, the amount of change in the attitude azimuth is similarly calculated, and sequentially, the calculation result of the attitude azimuth is updated. With the above configuration, the first steering control unit 11 calculates the azimuth of the tractor 5.

[0044] In the form shown in FIG. 3, the steering mechanism 3 shown in FIG. 1 is a mechanism for steering the steering wheel 5A of the tractor 5. The first steering control unit 11 is configured to be able to execute automatic steering that controls the steering mechanism 3 to automatically run the tractor 5 along the target path GL. As a control method of the first steering control unit 11 for the steering mechanism 3, for example, known PID control is used.

[0045] The first steering control unit 11 has a plurality of control modes for controlling the steering mechanism 3. This control mode can be switched between a plurality of modes including a manual steering mode which is a mode in which automatic steering is not executed and an automatic steering mode which is a mode in which automatic steering can be executed. This control mode may be configured to be switchable by manual operation (artificial operation) or may be configured to be automatically switchable. When the control mode of the first steering control unit 11 is the automatic steering mode, if the operator operates the steering wheel 3A, the control mode of the first steering control unit 11 switches to the manual steering mode.

[0046] When the control mode of the first steering control unit 11 is the manual steering mode, the first steering control unit 11 does not output the first target current value to the electric motor 31. At this time, the wheels and crawlers of the field working vehicle are steered according to the manual operation of the steering wheel 3A in the steering mechanism 3. Therefore, when the control mode of the first steering control unit 11 is the manual steering mode, the state of the first steering control unit 11 is a non-control state in which automatic steering is not performed.

[0047] When the control mode of the first steering control unit 11 is the automatic steering mode, the first steering control unit 11 is configured to be able to control the steering of the field working vehicle so that the field working vehicle performs automatic steering travel along the target path GL based on the positioning data output by the navigation positioning device 35 and the detection value by the inertial measurement device 36.

[0048] When the control mode of the first steering control unit 11 is the automatic steering mode, the state of the first steering control unit 11 is an automatic control state in which automatic steering is performed. Therefore, when in the automatic control state, the first steering control unit 11 outputs a first target current value for the field work vehicle to travel along the target path GL to the electric motor 31.

[0049] In this way, the steering control device 1 is configured to be able to change its state between a non-control state in which automatic steering is not performed and an automatic control state in which automatic steering is performed.

[0050] 〔Regarding the control of the second steering control unit〕 As described above, when in the automatic control state, the first steering control unit 11 outputs a first target current value for the field work vehicle to travel along the target path GL to the electric motor 31. However, if the steering wheels 5A of the tractor 5 slip, etc., there is a possibility that the traveling direction of the tractor 5 will change greatly contrary to intention. In particular, when the working device is the plow 6 (see FIGS. 3 and 5), when the plow 6 tills the field surface, the plow 6 receives a reaction force in one left-right direction from the field surface with respect to the traveling direction of the tractor 5. For this reason, the tractor 5 is likely to slip in the left-right direction. Also, when the first steering control unit 11 outputs the first target current value to the electric motor 31, in order to prevent the tractor 5 from making a sharp turn, the control gain of the first steering control unit 11 is likely to be set gently. In this state, for example, if the steering wheels 5A of the tractor 5 get stuck in the groove of the plowed soil A1 (see FIGS. 3 and 5), it may take time to return only by the automatic steering of the first steering control unit 11.

[0051] To avoid such inconveniences, it is conceivable that the operator operates the steering wheel 3A to return the tractor 5 onto the target path GL before the steering wheels 5A, etc. get stuck in the groove of the plowed soil A1. However, as described above, when the operator operates the steering wheel 3A when the first steering control unit 11 is in the automatic control state, the first steering control unit 11 changes its state from the automatic control state to the non-control state. When this happens, the operator is forced to perform cumbersome work to return the state of the first steering control unit 11 to the automatic control state.

[0052] In order to solve such problems, in this embodiment, the second steering control unit 12 is configured to be able to control the drive of the electric motor 31 separately from the first steering control unit 11 while maintaining the automatic control state of the first steering control unit 11 when the first steering control unit 11 is in the automatic control state.

[0053] The second steering control unit 12 is configured to be able to add or subtract a preset current value to or from the first target current value output from the first steering control unit 11. The target current value obtained by adding or subtracting to or from the first target current value output from the first steering control unit 11 is referred to as the "second target current value" in this embodiment. The second target current value is an example of the "second target command value" of the present invention. The determination result of the determination unit 14 and the signal from the operating tool 38 are input to the second steering control unit 12.

[0054] An input signal from the input unit 37 is input to the determination unit 14. A three-point link mechanism (not shown) is provided at the rear of the traveling body of the tractor 5. The input unit 37 is configured to be able to receive input of information regarding a working device attached to the three-point link mechanism. The determination unit 14 is configured to determine whether or not the working device is attached to the traveling body of the tractor 5 based on the information input to the input unit 37.

[0055] The input unit 37 may be, for example, a communication port based on the ISOBUS standard (International Standard ISO11783). In this case, the determination unit 14 is configured to be able to automatically detect the working device.

[0056] Further, the input unit 37 may be, for example, a touch panel type operation screen display device attached to the tractor 5, and the operator may operate the operation screen display device to input the type of the working device. In this case, the determination unit 14 is configured to detect the working device based on the information input to the input unit 37 by manual operation.

[0057] The operating tool 38 is provided with a left operation button 38L and a right operation button 38R. Each of the left operation button 38L and the right operation button 38R is, for example, a seesaw-type push button switch biased to a neutral position. The condition for the second steering control unit 12 to output the second target current value includes the operation of the left operation button 38L or the right operation button 38R. That is, when at least one of the left operation button 38L and the right operation button 38R is operated while the first steering control unit 11 is in the automatic control state, the second steering control unit 12 is configured to control the driving of the electric motor 31 prior to the first steering control unit 11. In other words, when neither the left operation button 38L nor the right operation button 38R is operated while the first steering control unit 11 is in the automatic control state, the second steering control unit 12 does not control the driving of the electric motor 31, and the first steering control unit 11 is configured to control the driving of the electric motor 31. The left operation button 38L is an example of the 'first operation unit' of the present invention. The right operation button 38R is an example of the'second operation unit' of the present invention.

[0058] Based on the processes of the flowcharts shown in FIGS. 2 and 4, the second steering control unit 12 outputs the second target current value to the electric motor 31. FIG. 2 shows a flowchart when the left operation button 38L is operated. FIG. 4 shows a flowchart when the right operation button 38R is operated.

[0059] Explanation will be made based on the flowchart of FIG. 2. When the operator presses the left operation button 38L, first, the steering control device 1 determines whether the first steering control unit 11 is in the automatic control state (step #01). If the first steering control unit 11 is in the non-control state (manual steering mode) (step #01: No), the process based on the flowchart of FIG. 2 ends as it is. Then, the first steering control unit 11 continuously outputs the first target current value to the electric motor 31.

[0060] If the first steering control unit 11 is in the automatic control state (autopilot mode) (step #01: Yes), the steering control device 1 determines whether the left operation button 38L has been continuously pressed for 0.5 seconds or more (step #02). If the left operation button 38L has not been continuously pressed for 0.5 seconds or more (step #02: No), the steering control device 1 determines whether the left operation button 38L has stopped being pressed (step #03). 0.5 seconds is an example of the "first set time" of the present invention.

[0061] When the left operation button 38L stops being pressed within a time less than 0.5 seconds (step #03: Yes), the route setting unit 13 displaces the target route GL leftward by, for example, 5 to 10 centimeters without changing the extending direction of the target route GL (step #04). When the navigation and positioning device 35 uses the above-described DGPS, the positioning error increases with the passage of time, and it is conceivable that the target route GL shifts rightward by the amount of the positioning error. By the route setting unit 13 shifting the target route GL leftward in step #04, the positional deviation of the target route GL in the left-right direction is eliminated. Thus, when the left operation button 38L is operated briefly for less than 0.5 seconds, the second steering control unit 12 does not control the drive of the electric motor 31, and the route setting unit 13 is configured to displace the target route GL leftward without changing the extending direction of the target route GL. Then, the process based on the flowchart of FIG. 2 ends as it is, and the first steering control unit 11 continues to output the first target current value to the electric motor 31.

[0062] If the left operation button 38L has not been continuously pressed for 0.5 seconds or more (step #02: No) and the left operation button 38L continues to be pressed (step #03: No), the processes of step #02 and step #03 are repeated.

[0063] When the left operation button 38L is continuously pressed for 0.5 seconds or more (Step #02: Yes), the steering control device 1 determines whether the plow 6 is attached to the traveling body of the tractor 5 based on the determination result of the determination unit 14 (Step #05). If the plow 6 is not attached to the traveling body of the tractor 5 (Step #05: No), the processing based on the flowchart of FIG. 2 ends as it is. Then, the first steering control unit 11 continuously outputs the first target current value to the electric motor 31. That is, the second steering control unit 12 is configured to be able to control the drive of the electric motor 31 when the plow 6 is attached to the traveling body of the tractor 5, and is configured not to be able to control the drive of the electric motor 31 when the plow 6 is not attached to the traveling body of the tractor 5.

[0064] If the plow 6 is attached to the traveling body of the tractor 5 (Step #05: Yes), the steering control device 1 determines whether the left operation button 38L is continuously pressed for 3 seconds or more (Step #06). If the left operation button 38L is not continuously pressed for 3 seconds or more (Step #06: No), the second steering control unit 12 executes the current value addition process for left turning (Step #07). In Step #07, the second steering control unit 12 outputs the second target current value to the electric motor 31 prior to the first steering control unit 11. At this time, the first steering control unit 11 does not output the first target current value to the electric motor 31, and only the second target current value is output to the electric motor 31. That is, the second steering control unit 12 is configured to control the drive of the electric motor 31 prior to the first steering control unit 11 when the left operation button 38L is operated for 0.5 seconds or more. At this time, the second steering control unit 12 controls the drive of the electric motor 31 so that the steering wheel 5A faces left with respect to the steering direction based on the control of the first steering control unit 11. Regarding the "current value addition process for left turning", when the right turning side is defined as addition and the left turning side is defined as subtraction, the "current value addition process" may be rephrased as the "current value subtraction process".

[0065] FIG. 3 shows the state in which the plow 6 tills the field surface while the tractor 5 moves forward. In the example shown in FIG. 3, the field surface after the plow 6 tills is shown as the plowed soil A1, and the field surface before the plow 6 tills is shown as the unplowed soil A2. The first steering control unit 11 outputs a first target current value to the electric motor 31 so that the tractor 5 travels along the target path GL. However, as described above, since the plow 6 receives a reaction force in one left - right direction from the field surface, in the example shown in FIG. 3, as shown by the travel locus FP, the tractor 5 slips in the right direction (the side where the plowed soil A1 is located). Then, the operator operates the left operation button 38L at the point P1, and the second steering control unit 12 executes a current value addition process for left - hand rotation. As a result, even when the control gain of the first steering control unit 11 is set gently, the steering wheel 5A of the tractor 5 can quickly return in the direction along the target path GL.

[0066] When the left operation button 38L is no longer pressed (step #08: Yes), the process based on the flowchart of FIG. 2 ends as it is. Then, again, the first steering control unit 11 outputs the first target current value to the electric motor 31. If the left operation button 38L continues to be pressed while 3 seconds have not elapsed since the left operation button 38L was pressed (step #08: No), steps #06, #07, and #08 are repeated.

[0067] If the left operation button 38L continues to be pressed continuously for 3 seconds or more (step #06: Yes), there is a risk that the tractor 5 will turn excessively. Also in this case, the process based on the flowchart of FIG. 2 ends as it is. Then, again, the first steering control unit 11 outputs the first target current value to the electric motor 31. That is, when the left operation button 38L is operated for a long time of 3 seconds or more, the second steering control unit 12 does not control the drive of the electric motor 31, and the first steering control unit 11 is configured to control the drive of the electric motor 31. 3 seconds is an example of the 'second set time' of the present invention.

[0068] The flowchart of FIG. 4 is a flowchart when the operator operates the right operation button 38R. Therefore, except for the difference between whether it is the left operation button 38L or the right operation button 38R, and the difference between left and right, the processing of each step shown in the flowchart of FIG. 4 is the same as the processing of each step shown in FIG. 2.

[0069] Regarding the flowchart of FIG. 4, as a supplement, in step #14, the path setting unit 13 displaces the target path GL, for example, 5 to 10 centimeters to the right. Thereby, for example, when the target path GL is displaced to the left by the amount of the positioning error of the navigation positioning device 35, the positional deviation in the left - right direction of the target path GL is eliminated. In this way, when the right operation button 38R is operated briefly for less than 0.5 seconds, the second steering control unit 12 does not control the drive of the electric motor 31, and the path setting unit 13 is configured to displace the target path GL to the right without changing the extending direction of the target path GL.

[0070] Regarding the flowchart of FIG. 4, as a supplement, in step #17, the second steering control unit 12 executes a current value addition process for right - hand rotation. In step #17, the second steering control unit 12 outputs a second target current value to the electric motor 31 prior to the first steering control unit 11. That is, when the right operation button 38R is operated for a long time of 0.5 seconds or more, the second steering control unit 12 is configured to control the drive of the electric motor 31 prior to the first steering control unit 11. At this time, the second steering control unit 12 controls the drive of the electric motor 31 so that the steering wheel 5A faces to the right with respect to the steering direction based on the control of the first steering control unit 11. In addition, in step #17, the first steering control unit 11 does not output the first target current value to the electric motor 31, and only the second target current value is output to the electric motor 31. Also, as shown in step #16, when the right operation button 38R is operated for a long time of 3 seconds or more, the second steering control unit 12 does not control the drive of the electric motor 31, and the first steering control unit 11 is configured to control the drive of the electric motor 31. Regarding the "current value addition process for right - hand rotation", when the left - hand rotation side is defined as addition and the right - hand rotation side is defined as subtraction, the "current value addition process" may be rephrased as the "current value subtraction process".

[0071] Figure 5 shows the state where the plow 6 tills the field surface while the tractor 5 moves forward. In the example shown in Figure 5, the field surface after the plow 6 tills is shown as the cultivated soil A1, and the field surface before the plow 6 tills is shown as the uncultivated soil A2. In the example shown in Figure 5, the first steering control unit 11 outputs the first target current value to the electric motor 31 so that the tractor 5 travels along the target path GL. However, as shown by the travel locus FP, the tractor 5 slips in the left direction (the side where the cultivated soil A1 is located). At this time, the operator operates the right operation button 38R at the point P1, and the second steering control unit 12 executes the current value addition process for right turning. As a result, the steering wheel 5A of the tractor 5 is steered further to the right, and even when the control gain of the first steering control unit 11 is set gently, it can quickly return in the direction along the target path GL.

[0072] In this way, for example, when the tractor 5 is about to slip and get stuck in the groove on the cultivated soil A1 side, the operator steers the steering wheel 5A to the uncultivated soil A2 side by operating the left operation button 38L or the right operation button 38R. From this, for example, even when the tractor 5 is about to deviate greatly from the target path GL due to slipping, the operator can quickly return the tractor 5 onto the target path GL by operating the left operation button 38L or the right operation button 38R.

[0073] Also, as described above, when the operator operates the steering wheel 3A when the first steering control unit 11 is in the automatic control state, the first steering control unit 11 changes its state from the automatic control state to the non-control state. In this embodiment, the operator can quickly return the tractor 5 onto the target path GL only by operating the left operation button 38L or the right operation button 38R without operating the steering wheel 3A. Then, the automatic control state of the first steering control unit 11 continues as it is, and the tractor 5 travels along the target path GL.

[0074] Furthermore, as shown in FIGS. 2 and 4, in the present embodiment, the operating tool 38 is also used for both the displacement of the target path GL and the control by the second steering control unit 12.

[0075] 〔Alternative Embodiment〕 The present invention is not limited to the configurations exemplified in the above-described embodiments. Hereinafter, representative alternative embodiments of the present invention will be exemplified.

[0076] (1) As the “steering drive device” of the present invention, an electric motor 31 is shown. The steering drive device is not limited to the electric actuator exemplified by the electric motor 31, and may be, for example, a hydraulic actuator such as a hydraulic motor or a hydraulic cylinder, or a hybrid actuator. The hybrid actuator is, for example, a hydraulic actuator that drives a hydraulic pump with an electric servo motor. When the steering drive device is a hydraulic motor, a hydraulic cylinder, or the like, the target command values (the first target command value and the second target command value) of the present invention may include, for example, the opening degree of a hydraulic valve for the hydraulic motor, the hydraulic cylinder, or the like. In this case, the first target command value and the second target command value are command values related to the opening degree of the hydraulic valve. That is, the first steering control unit 11 is configured to output the first target command value calculated to travel along the target path GL to the steering drive device in the automatic control state, and the second steering control unit 12 may be configured to output the second target command value obtained by adding or subtracting a preset command value to or from the first target command value to the steering drive device.

[0077] (2) In the above-described embodiment, the first set time is set to 0.5 seconds and the second set time is set to 3 seconds. However, the present invention is not limited to this embodiment, and the first set time and the second set time can be appropriately set and changed.

[0078] (3) Each of the left operation button 38L and the right operation button 38R may be, for example, a lever or a soft button displayed on a touch panel type operation screen display device. Also, the right operation button 38R may be the first operation unit, and the left operation button 38L may be the second operation unit. In short, when the first operation unit is operated, the second steering control unit 12 controls the drive of the electric motor 31 (steering drive device) so that the steering wheel 5A turns to one side of the left and right with respect to the steering direction based on the control of the first steering control unit 11, and when the second operation unit is operated, the second steering control unit 12 controls the drive of the electric motor 31 (steering drive device) so that the steering wheel 5A turns to the other side of the left and right with respect to the steering direction based on the control of the first steering control unit 11.

[0079] (4) In the above-described embodiment, the operating tool 38 is also used for each of the displacement of the target path GL and the control by the second steering control unit 12. However, the present invention is not limited to this embodiment. For example, the displacement of the target path GL may be configured to be possible by operating another operation button. In this case, when the operating tool 38 is operated, the second steering control unit 12 may be configured to output a second target current value (second target command value) to the electric motor 31 (steering drive device) immediately without waiting for a long press of 0.5 seconds (first set time). Alternatively, when the operating tool 38 is operated, the second steering control unit 12 may be configured to output a second target current value (second target command value) to the electric motor 31 (steering drive device) for a preset fixed time from the timing when the operator starts pressing the operating tool 38 regardless of whether the operator long presses the operating tool 38.

[0080] (5) In the current value addition process (step #07, step #17) shown in FIGS. 2 and 4, the second steering control unit 12 outputs a second target current value (second target command value) to the electric motor 31 (steering drive device) prior to the first steering control unit 11. Without being limited to this embodiment, the second steering control unit 12 may be configured to output a current value to the electric motor 31 (steering drive device) in parallel with the first steering control unit 11. In this case, the second target current value (second target command value) may be a preset addition value or subtraction value. And a configuration may be adopted in which the sum of the first target current value (first target command value) calculated by the first steering control unit 11 and the second target current value (second target command value) which is an addition value or subtraction value is output to the electric motor 31 (steering drive device).

[0081] (6) The first steering control unit 11 controls the driving of the electric motor 31 (steering drive device). Without being limited to this, for example, the first steering control unit 11 may be configured to also control the vehicle speed of the tractor 5. The field working vehicle may be configured to enable not only automatic steering but also automatic control of the vehicle speed (including vehicle speed control linked to the control of the working device), automatic control of the working device, automatic turning control of the vehicle, automatic stop control of the vehicle, and the like. The automatic control of the working device includes, for example, automatic lifting control of the working device, automatic control of the angle (roll angle) of the working device, automatic control of the working width, automatic control of the working depth, automatic control of the spraying amount, automatic control of the seeding amount, automatic control of the fertilizing amount, and the like.

[0082] (7) In the above-described embodiment, the plow 6 is exemplified as the working device. Without being limited to this embodiment, the working device may be, for example, a mowing device (boom mower, chopper, etc.), a multi-cultivator, a stone picker, a seeding device, a rake, a tedder, a towed harvesting and sorting device, a pinching device, a tillage management device, and the like.

[0083] (8) In the above-described embodiment, the tractor 5 is exemplified as the field working vehicle, but the field working vehicle may be a rice transplanter, a harvester, a sprayer, a mower, a tillage management machine, or the like.

[0084] In addition, the configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction. Also, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope not departing from the object of the present invention.

Industrial Applicability

[0085] The present invention is applicable to field working vehicles.

Explanation of Signs

[0086] 3: Steering mechanism 5A: Steering wheel 6: Plow (working device) 11: First steering control unit 12: Second steering control unit 13: Route setting unit 14: Determination unit 31: Electric motor (steering drive device) 37: Input unit 38: Operating tool 38L: Left operation button (first operation unit) 38R: Right operation button (second operation unit) GL: Target route

Claims

1. A traveling vehicle having a steering wheel, a steering mechanism capable of steering the steering wheel, and a steering drive device capable of driving the steering mechanism to operate; A path setting unit for setting a target path; A first steering control unit capable of changing the state between an automatic control state in which the drive of the steering drive device is controlled to travel along the target path and a non-control state in which the drive of the steering drive device is not controlled; A second steering control unit that is separate from the first steering control unit and is capable of controlling the drive of the steering drive device, and when the first steering control unit is in the automatic control state, can control the drive of the steering drive device prior to the first steering control unit while maintaining the automatic control state. A field working vehicle equipped with such a unit.

2. A traveling vehicle having a steering wheel, a steering mechanism capable of steering the steering wheel, and a steering drive device capable of driving the steering mechanism to operate; A path setting unit for setting a target path; A first steering control unit capable of changing the state between an automatic control state in which the drive of the steering drive device is controlled to travel along the target path and a non-control state in which the drive of the steering drive device is not controlled; A second steering control unit that is separate from the first steering control unit and is capable of controlling the drive of the steering drive device when the first steering control unit is in the automatic control state while maintaining the automatic control state; An operating tool for receiving a manual operation; A field working vehicle configured such that when the operating tool is operated when the first steering control unit is in the automatic control state, the second steering control unit controls the drive of the steering drive device prior to the first steering control unit.

3. The field working vehicle according to claim 2, wherein when the operating tool is not operated when the first steering control unit is in the automatic control state, the second steering control unit does not control the drive of the steering drive device, and the first steering control unit controls the drive of the steering drive device.

4. The field working vehicle according to claim 2, wherein the second steering control unit is configured to control the drive of the steering drive device prior to the first steering control unit when the operating tool is operated for a period longer than a preset first setting time.

5. When the operating tool is operated for a second set time that is longer than the first set time and longer than or equal to the second set time, the second steering control unit does not control the driving of the steering drive device, and the first steering control unit is configured to control the driving of the steering drive device. The field working vehicle according to claim 4.

6. When the operating tool is operated for a short time equal to or less than the first set time, the second steering control unit does not control the driving of the steering drive device, and the path setting unit is configured to displace the target path to one side (left or right) without changing the extending direction of the target path. The field working vehicle according to claim 4 or 5.

7. The operating tool has a first operation unit and a second operation unit. When the first operation unit is operated, the second steering control unit controls the driving of the steering drive device so that the steering wheel turns to one side (left or right) with respect to the steering direction based on the control of the first steering control unit. When the second operation unit is operated, the second steering control unit controls the driving of the steering drive device so that the steering wheel turns to the other side (left or right) with respect to the steering direction based on the control of the first steering control unit. The field working vehicle according to any one of claims 2 to 5.

8. The steering drive device is an electric motor. The first steering control unit is configured to output a first target command value calculated to travel along the target path to the steering drive device in the automatic control state. The second steering control unit is configured to output a second target command value obtained by adding or subtracting a preset command value to or from the first target command value to the steering drive device. The field working vehicle according to claim 1 or 2.

9. In the field working vehicle according to claim 8, each of the first target command value and the second target command value is a current value.

10. The second steering control unit is configured to be able to control the driving of the steering drive device when the working device is mounted on the traveling body, and is configured not to be able to control the driving of the steering drive device when the working device is not mounted on the traveling body. The field working vehicle according to claim 1 or 2.

11. A determination unit for determining whether or not the working device is mounted on the traveling body is provided. The determination unit is configured to be able to automatically detect the working device. The field working vehicle according to claim 10.

12. An input unit for receiving a manual operation, A determination unit for determining whether or not the working device is mounted on the traveling body are provided. The field working vehicle according to claim 10, wherein the determination unit is configured to detect the working device based on information input to the input unit by the manual operation.

13. The field working vehicle according to claim 10, wherein the working device is a plow.

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