Field working vehicle

Abstract

To provide a farm field work vehicle designed to take account of an operator who operates a steering tool.SOLUTION: A farm field work vehicle capable of automatic steering along a target path, comprises: a steering wheel; a steering mechanism 3 having a steering tool 3A configured to receive a human operation and configured to perform a steering operation of the steering wheel; an automatic steering control device 1 configured to allow a change in a state between a non-control state in which the automatic steering is not performed and an automatic control state in which the automatic steering is performed and configured to output a target steering parameter for traveling along the target path in the automatic control state; and a steering drive device 31 configured to execute drive control on the steering mechanism 3, based on the target steering parameter, when the automatic steering control device 1 is in the automatic control state. The steering tool 3A is configured to change an amount of steering in conjunction with the drive control executed by the steering drive device 31. The automatic steering control device 1 is configured to execute a restraint process for restraining the target steering parameter when the state is changed from the non-control state to the automatic control state.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] For example, in the field working vehicle (referred to as "tractor" in the literature) disclosed in Patent Document 1, an automatic steering device (referred to as "control device" in the literature) is provided. This automatic steering device is configured to be able to change its state between a non-control state (referred to as "manual steering mode" in the literature) in which automatic steering (referred to as "automatic steering control" in the literature) is not performed and an automatic control state (referred to as "automatic steering mode" in the literature) in which automatic steering is performed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the automatic steering by the automatic steering control device is started, the steering mechanism is automatically driven. Also, the steering wheel that receives manual operation often operates in conjunction with the steering mechanism. At this time, depending on the steering angle of the steered wheels, it is conceivable that the steering mechanism is driven at high speed at the start of automatic steering and the steering wheel operates steeply. For this reason, there is room for improvement regarding the operation of the steering wheel so as not to give the operator a sense of discomfort.

[0005] An object of the present invention is to provide a field working vehicle that takes into consideration the operator who operates the steering wheel.

Means for Solving the Problems

[0006] The present invention relates to a field work vehicle capable of automatic steering along a target path, having a steering wheel and a steering device for receiving a manual operation, a steering mechanism for steering the steering wheel, configured to be capable of changing states between a non-control state in which the automatic steering is not performed and an automatic control state in which the automatic steering is performed, an automatic steering control device that outputs target steering parameters for traveling along the target path in the automatic control state, and a steering drive device that drives and controls the steering mechanism based on the target steering parameters when the automatic steering control device is in the automatic control state. The steering device is configured such that the steering amount changes in conjunction with the drive control by the steering drive device, and the automatic steering control device is configured to execute a suppression process for suppressing the target steering parameters when changing the state from the non-control state to the automatic control state.

[0007] According to the present invention, the automatic steering control device executes a suppression process when changing the state from the non-control state to the automatic control state. Therefore, at the start of automatic control, the target steering parameters for the steering drive device are suppressed, and the drive control for the steering mechanism also becomes a suppressing one. Further, the steering device is configured such that the steering amount changes in conjunction with the drive control by the steering drive device. Therefore, the change in the steering amount in the steering device also becomes a suppressing one. As a result, the movement of the steering device at the start of automatic control becomes gentle, and the operator can monitor the movement of the steering device with a natural feeling. The present invention realizes a field work vehicle that takes into consideration the operator who operates the steering device.

[0008] In the field work vehicle of the present invention, it is preferable that the steering drive device is an electric motor, the target steering parameters include a current value for the electric motor, and the automatic steering control device is configured to suppress the current value when executing the suppression process.

[0009] With this configuration, the electric motor starts to drive slowly at the start of automatic control. Therefore, the movement of the steering device at the start of automatic control becomes gentle.

[0010] In the field working vehicle of the present invention, a steering angle calculation unit that calculates the steering angle of the steering wheel is provided, the target steering parameter includes a first angular velocity that is the target change amount of the steering angle per unit time, and it is preferable that the automatic steering control device is configured to suppress the first angular velocity when executing the suppression process.

[0011] With this configuration, the target change amount of the steering angle per unit time is suppressed at the start of automatic control. For this reason, at the start of automatic control, the steering angle of the steering wheel does not change significantly, and the movement of the steering device becomes gentle.

[0012] In the field working vehicle of the present invention, it is preferable to be provided with a first detection unit capable of detecting at least one of the drive amount of the steering drive device and the steering amount of the steering device, and the steering angle calculation unit is configured to calculate the steering angle based on the detection value of the first detection unit.

[0013] With this configuration, the steering angle calculation unit can calculate the steering angle based on at least one of the drive amount of the steering drive device and the steering amount of the steering device.

[0014] In the field working vehicle of the present invention, a second detection unit that detects the orientation of the vehicle body is provided, the target steering parameter includes a second angular velocity that is the target change amount of the orientation of the vehicle body per unit time, and it is preferable that the automatic steering control device is configured to suppress the second angular velocity when executing the suppression process.

[0015] With this configuration, the target change amount of the orientation of the vehicle body per unit time is suppressed at the start of automatic control. For this reason, at the start of automatic control, the orientation of the vehicle body does not change significantly, and the steering angle of the steering wheel also does not change significantly. As a result, the movement of the steering device becomes gentle.

[0016] In the field work vehicle of the present invention, when the automatic steering control device changes the state from the non-control state to the automatic control state, it is preferable that the automatic steering control device is configured to output the target steering parameter so that the change amount of the steering amount of the steering tool per unit time is less than a preset threshold value.

[0017] With this configuration, at the start of automatic control, the movement of the steering tool becomes gentle.

[0018] In the field work vehicle of the present invention, the automatic steering control device is configured to execute the suppression process from the start timing at which the execution of the suppression process is started to the end timing at which a preset time has elapsed from the start timing. The automatic steering control device is configured to set the target steering parameter to a first parameter at the start timing, and to set the target steering parameter to a second parameter larger than the first parameter at the end timing. This is preferable.

[0019] According to this configuration, at the start of automatic control, the target steering parameter is set to the first parameter, and at the time when a preset time has elapsed from the start of automatic control, the target steering parameter is set to a second parameter larger than the first parameter. For this reason, at the start of automatic control, the movement of the steering tool becomes gentle, and as time passes, the movement of the steering tool becomes faster than at the start. As a result, the operator can monitor the movement of the steering tool in a natural sense, and it becomes easier for the automatic steering control device to perform steering control along the target path when performing automatic steering.

[0020] In the field work vehicle of the present invention, it is preferable that the automatic steering control device is configured to hold the target steering parameter at the first parameter for at least a preset time from the start timing to the end timing.

[0021] With this configuration, the target steering parameter is held at the first parameter for a preset time from the start timing. Therefore, a gentle time for the movement of the steering device is ensured for a certain period of time at the start of automatic steering.

[0022] In the field work vehicle of the present invention, it is preferable that the automatic steering control device is configured to change the setting of the target steering parameter so as to approach the second parameter as time elapses for at least a preset time until the end timing from the start timing.

[0023] With this configuration, since the target steering parameter is first set to the first parameter and moves backward toward the second parameter as time passes, the speed of movement of the steering device changes smoothly and continuously. As a result, the operator can monitor the movement of the steering device without feeling unnaturalness in the movement of the steering device.

[0024] In the field work vehicle of the present invention, it is preferable that the automatic steering control device is configured to be able to change the state to the automatic control state when the vehicle travels in the same direction for a preset distance or time based on the manual operation of the steering device in the non-control state.

[0025] With this configuration, when the field work vehicle travels in the same direction, automatic steering is disclosed as it is. As a result, even if the movement of the steering device is gentle at the start of automatic steering, the automatic steering control device can perform automatic steering smoothly without the field work vehicle deviating from the target path.

Brief Description of Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0027] 〔Basic Configuration of Steering Control Device and Notification Control Device〕 Based on FIG. 1, the steering control device 1 and the notification control device 2 mounted on the field work vehicle will be described. The steering control device 1 and the notification control device 2 may be physical devices such as microcomputers, or may be a combination of a device and software. Although not shown, each of the steering control device 1 and the notification control device 2 includes a storage device. These storage devices are, for example, ROMs such as non-volatile memories (e.g., flash memories) and EEPROMs. The storage device stores the data generated by each functional unit in each of the steering control device 1 and the notification control device 2 temporarily or permanently. The steering control device 1 corresponds to the 'automatic steering control device' of the present invention.

[0028] The detection value from the current sensor 32, the calculated value from the steering angle calculation unit 34, the positioning signal from the navigation positioning device 35, and the detection value from the inertial measurement device 36 are input to the steering control device 1. Further, an instruction current value is output from the steering control device 1 to the electric motor 31. In addition, a notification signal is output from the steering control device 1 to the notification control device 2. The notification signal from the steering control device 1 to the notification control device 2 may be, for example, a signal for interrupt control or a status signal for transmitting the control mode of the steering control device 1. The electric motor 31 corresponds to the “steering drive device” of the present invention.

[0029] The notification control device 2 is configured to be able to notify an operator or the like of information related to automatic steering by controlling each of the buzzer 41, the speaker 42, and the display device 43 based on the notification signal from the steering control device 1. The buzzer 41 outputs a buzzing sound. The speaker 42 outputs voice guidance. Voice guidance means the voice of natural language. The display device 43 is, for example, a touch panel display (liquid crystal display device or OLED display device) provided in a portable information terminal or an in-vehicle device, and is configured to be able to display notification information. The portable information terminal or the in-vehicle device may be configured to also serve as the buzzer 41, the speaker 42, and the display device 43. In addition, the buzzer 41, the speaker 42, and the display device 43 may be an integrated unit (for example, a display panel having a function of emitting sound).

[0030] The electric motor 31 is interlocked and connected to the steering mechanism 3, and when the electric motor 31 is driven, the steering mechanism 3 is driven. Further, the steering wheel 3A is provided in the steering mechanism 3, and the steering wheel 3A receives the steering operation of the operator. The steering wheel 3A corresponds to the “steering tool” of the present invention.

[0031] 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 in the range of -10,800 degrees to +10,800 degrees, for example. The motor encoder 33 may be, for example, a resolver-type encoder or an optical encoder. The motor encoder 33 corresponds to the 'first detection unit' of the present invention.

[0032] The steering angle calculation unit 34 is configured to calculate the steering angular velocity of the steering wheel (such as a wheel or a crawler) 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 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 means the speed at which the direction of the steering wheel (the cut angle of the steering wheel) changes. The larger the steering angular velocity, the steeper the change in the cut angle of the steering wheel.

[0033] The navigation positioning device 35 receives a positioning signal from an artificial satellite (not shown) used in GNSS (Global Navigation Satellite System, such as GPS, GLONASS, Galileo, QZSS, BeiDou, etc.).

[0034] 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 orthogonal 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. Therefore, 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. In this way, the inertial measurement device 36 detects the direction of the vehicle body of the field working vehicle. The inertial measurement device 36 corresponds to the'second detection unit' of the present invention.

[0035] Based on the positioning data output by the navigation positioning device 35, the steering control device 1 calculates the position coordinates of the field working vehicle over time. Thereby, the steering control device 1 acquires the position coordinates of the field working vehicle. Further, the steering control device 1 calculates the attitude azimuth of the field working vehicle based on the position coordinates of the field working vehicle and the detection value by the inertial measurement device 36. Note that the attitude azimuth of the field working vehicle is the azimuth in which the field working vehicle moves forward or backward while going straight.

[0036] Referring to FIG. 3, first, while the tractor 5, which is an example of a field working vehicle, is running, 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 steering control device 1 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 steering control device 1 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.

[0037] Then, by adding the amount of change in azimuth calculated in this way to the initial attitude azimuth, the steering control device 1 updates the calculation result of the azimuth. After that, every certain period of time, the amount of change in the attitude azimuth is calculated in the same way, and sequentially, the calculation result of the attitude azimuth is updated. With the above configuration, the steering control device 1 calculates the azimuth of the tractor 5.

[0038] The steering mechanism 3 shown in FIG. 1 is a mechanism for steering the front wheels of the tractor 5 in the form shown in FIG. 3. The steering control device 1 is configured to be able to execute automatic steering to control the steering mechanism 3 to automatically run the tractor 5 along the automatic steering target line GL.

[0039] 〔Regarding automatic steering control〕 As shown in FIG. 2, the steering control device 1 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. The switching operation tool 37 shown in FIG. 1 receives a manual operation (artificial operation) for switching the control mode of the steering control device 1.

[0040] When the control mode of the steering control device 1 is the manual steering mode, the steering control device 1 does not output an instruction current value to the electric motor 31. At this time, the wheels and crawlers of the field working vehicle are steered in response to the manual operation of the steering wheel 3A in the steering mechanism 3. Therefore, when the control mode of the steering control device 1 is the manual steering mode, the state of the steering control device 1 is a non-control state in which automatic steering is not performed. In this case, the steering control device 1 outputs various notification signals to the notification control device 2 based on the detection value from the current sensor 32, the calculated value from the steering angle calculation unit 34, the positioning signal from the navigation positioning device 35, and the detection value from the inertial measurement device 36.

[0041] When the control mode of the steering control device 1 is the automatic steering mode, the steering control device 1 is configured to be able to control the steering of the field working vehicle so that the field working vehicle automatically steers and travels along the automatic steering target line GL (see FIG. 3) based on the positioning data output by the navigation positioning device 35 and the detection value by the inertial measurement device 36. The automatic steering target line GL corresponds to the 'target path' of the present invention.

[0042] The steering control device 1 is configured to be able to switch the control mode based on the operation signal from the switching operation tool 37 and the state of the field working vehicle. As described above, the switching operation tool 37 receives a manual operation for switching the control mode of the steering control device 1 to the automatic steering mode. The operation on the switching operation tool 37 is shown as 'Operation #01' in FIG. 2. When Operation #01 is performed, the steering control device 1 switches the control mode from the manual steering mode to the preparation mode.

[0043] When the steering control device 1 switches the control mode from the manual steering mode to the preparation mode, it outputs a notification signal to the notification control device 2. Then, based on the notification signal from the steering control device 1, the notification control device 2 notifies the operator of the start of the preparation for shifting to the automatic steering mode. That is, based on the notification signal from the steering control device 1, the notification control device 2 causes the buzzer 41 to output a beeping sound, causes the speaker 42 to output voice guidance, and causes the display device 43 to display notification information.

[0044] The preparation mode is a control mode for preparing to start automatic steering, and manual steering by the operator continues in this preparation mode. Therefore, when the control mode of the steering control device 1 is the preparation mode, the state of the steering control device 1 is a non-control state where automatic steering is not performed. When operation #01 is performed while the control mode of the steering control device 1 is in the preparation mode, the steering control device 1 switches the control mode of the steering control device 1 from the preparation mode to the manual steering mode.

[0045] When in the preparation mode, the steering control device 1 determines whether condition #01 for shifting to the automatic steering mode is satisfied. At this time, the operator manually operates the field working vehicle to adjust the conditions for shifting to the automatic steering mode. That is, based on the preparation mode, the operator performs manual steering so that the attitude azimuth of the field working vehicle matches a preset reference azimuth. The preset reference azimuth is, for example, an azimuth set based on two points, the starting point and the ending point, in teaching travel.

[0046] Figure 3 shows a state where operation #01 is performed at point P1, the control mode of the steering control device 1 is switched from the manual steering mode to the preparation mode, and the tractor 5 is traveling between point P1 and point P2 based on manual steering.

[0047] The conditions #01 for shifting from the preparation mode to the automatic steering mode are, for example, that the main transmission lever (not shown) operated by the operator is set to the forward position, the clutch (not shown, for example, the PTO clutch) for power transmission to the working device (not shown) of the field working vehicle is in the power transmission state, the difference between the attitude azimuth of the field working vehicle and a preset reference azimuth is within a preset angle (for example, 3 degrees), and so on.

[0048] When in the preparation mode, the steering control device 1 outputs a notification signal to the notification control device 2. Then, based on the notification signal from the steering control device 1, the notification control device 2 notifies the operator of the guidance information for satisfying the condition #01. That is, based on the notification signal from the steering control device 1, the notification control device 2 causes the buzzer 41 to output a beeping sound, causes the speaker 42 to output the operation content necessary for satisfying the condition #01, and causes the display device 43 to display the operation content necessary for satisfying the condition #01.

[0049] When the control mode is in the preparation mode and the items necessary as the condition #01 are satisfied, it becomes possible to switch to the automatic steering mode. In this state, as shown in FIG. 3, when the field working vehicle travels a predetermined distance D1, the steering control device 1 generates an automatic steering target line GL, and the control mode shifts from the preparation mode to the automatic steering mode. The automatic steering target line GL extends along a preset reference azimuth.

[0050] FIG. 3 shows a state where the condition #01 is satisfied at the point P2 and the tractor 5 travels a predetermined distance D1 between the point P2 and the point P3. The predetermined distance D1 is not particularly limited, and may be, for example, 1 meter.

[0051] While the field operation vehicle travels a predetermined distance D1, the steering control device 1 outputs a notification signal to the notification control device 2. Then, the notification control device 2 notifies the operator of the start of automatic steering. At this time, based on the notification signal from the steering control device 1, the notification control device 2 causes the buzzer 41 to output a beeping sound, causes the speaker 42 to output voice guidance saying "Automatic steering will start soon", and causes the display device 43 to display notification information. With this configuration, the operator can grasp the timing to release the hand from the steering wheel 3A.

[0052] As described above, when in the non-control state, when the steering control device 1 travels in the same direction over a predetermined distance D1 set in advance based on the manual operation of the steering wheel 3A, it is configured to be able to change the state to the automatic control state. Note that when in the non-control state, the steering control device 1 may be configured to be able to change the state to the automatic control state when traveling in the same direction over a preset time (for example, 3 to 5 seconds) based on the manual operation of the steering wheel 3A.

[0053] When the control mode of the steering control device 1 is the automatic steering mode, the state of the steering control device 1 is the automatic control state for performing automatic steering. Therefore, when in the automatic control state, the steering control device 1 outputs an instruction current value for the field operation vehicle to travel along the automatic steering target line GL to the electric motor 31.

[0054] A method for canceling the automatic steering mode will be described. When the "Condition #02" shown in FIG. 2 is detected during the execution of automatic steering, the steering control device 1 ends the automatic steering. "Condition #02" is a condition related to the stop of work. Condition #02 is, for example, the operator operates to an operation position other than the forward position of the main transmission lever, the clutch for power transmission to the working device of the field operation vehicle becomes in a power non-transmission state, the steering wheel 3A is manually operated in the left-right direction by more than a preset operation amount, and so on.

[0055] If any of the items listed as condition #02 is met, the automatic steering is released, and the control mode of the steering control device 1 shifts from the automatic steering mode to the preparation mode. At this time, the steering control device 1 outputs a notification signal to the notification control device 2. Then, based on the notification signal from the steering control device 1, the notification control device 2 causes the buzzer 41 to output a beeping sound, the speaker 42 to output voice guidance, and the display device 43 to display notification information, thereby notifying the operator of the end of the automatic steering.

[0056] Even if any of the items listed as condition #02 is met and the automatic steering ends, the control mode of the steering control device 1 shifts to the preparation mode and does not return to the manual steering mode. Therefore, when the above-mentioned condition #01 is satisfied, the resumption of the automatic steering is possible. From this, for example, if the operator performs an operation corresponding to condition #02 at the edge of the field, then turns the field working vehicle by 90 degrees or 180 degrees and drives it along the preset reference azimuth, it becomes possible to satisfy the above-mentioned condition #01. As a result, the automatic steering resumes as it is.

[0057] In this way, the steering control device 1 is configured to be able to change its state between a non-control state where it does not perform automatic steering and an automatic control state where it performs automatic steering.

[0058] Note that when the control mode of the steering control device 1 is the automatic steering mode and during automatic steering, if the operator presses the switching operation tool 37 (operation #01), the steering control device 1 switches the control mode of the steering control device 1 from the automatic steering mode to the manual steering mode, and the automatic steering of the steering control device 1 ends. When the automatic steering is released, the indicated current value output from the steering control device 1 to the electric motor 31 becomes zero.

[0059] Based on FIG. 4, the automatic steering control in this embodiment will be described. The steering control device 1 has a plurality of modules. The steering control device 1 is provided with a vehicle position PI control module 11, a heading angle PI control module 12, a heading angular velocity PI control module 13, a steering angular velocity PI control module 14, a current PI control module 15, and a current value suppression processing module 16.

[0060] The vehicle position PI control module 11 calculates a position deviation amount, which is the difference between the target position of the field working vehicle to travel along the automatic steering target line GL and the actual position coordinates of the field working vehicle based on the positioning signal from the navigation positioning device 35. The position deviation amount means the amount of position deviation to the right or left in the traveling direction with respect to the automatic steering target line GL. Then, the vehicle position PI control module 11 calculates a target heading for the field working vehicle to travel along the automatic steering target line GL based on the position deviation amount.

[0061] The heading angle PI control module 12 calculates a heading deviation amount, which is the difference between the target heading calculated by the vehicle position PI control module 11 and the actual heading of the field working vehicle measured by the inertial measurement device 36. Then, the heading angle PI control module 12 calculates a target heading angular velocity for aligning the heading of the field working vehicle with the target heading based on the heading deviation amount. The target heading angular velocity for aligning the heading of the field working vehicle with the target heading is the target change amount per unit time of the orientation of the vehicle body of the field working vehicle.

[0062] The heading angular velocity PI control module 13 calculates a heading angular velocity deviation amount, which is the difference between the target heading angular velocity calculated by the heading angle PI control module 12 and the actual heading angular velocity measured by the inertial measurement device 36. Then, the heading angular velocity PI control module 13 calculates a target steering angular velocity of the steering wheel for turning the field working vehicle along the target heading angular velocity based on the heading angular velocity deviation amount. The target steering angular velocity of the steering wheel is the target change amount per unit time of the steering angle of the steering wheel.

[0063] The steering angular velocity PI control module 14 calculates the deviation amount of the steering angular velocity, which is the difference between the target steering angular velocity calculated by the azimuth angular velocity PI control module 13 and the actual steering angular velocity of the steering wheel calculated by the steering angle calculation unit 34. Then, the steering angular velocity PI control module 14 calculates the target current value for the electric motor 31 based on the deviation amount of the steering angular velocity.

[0064] The current PI control module 15 calculates the deviation amount of the current value, which is the difference between the target current value calculated by the steering angular velocity PI control module 14 and the actual current value of the electric motor 31 detected by the current sensor 32. Then, the current PI control module 15 adjusts the above-mentioned target current value based on the deviation amount of the current value and outputs a more appropriate commanded current value to the electric motor 31. With this configuration, when the steering control device 1 is in the automatic control state, the electric motor 31 drives and controls the steering mechanism 3 based on the commanded current value. When the field working vehicle is the tractor 5 shown in FIG. 3, the front wheels of the tractor 5 are steered by the drive of the steering mechanism 3. Then, the steering angle of the steering wheel is adjusted, and the field working vehicle travels along the automatic steering target line GL. The commanded current value corresponds to the 'target steering parameter' of the present invention. In other words, the commanded current value for the electric motor 31 is included in the target steering parameter of the present invention.

[0065] The steering control device 1 in the present embodiment does not directly output the commanded current value calculated by the current PI control module 15 at the start timing of the automatic steering control. Instead, the current value suppression processing module 16 weakly sets the commanded current value and outputs it to the electric motor 31. Hereinafter, the suppression processing of the commanded current value at the start of automatic steering will be described.

[0066] 〔Suppression Processing of Commanded Current Value at Start of Automatic Steering〕 When the control mode of the steering control device 1 switches from the manual steering mode to the automatic steering mode via the preparation mode, the steering control device 1 starts the automatic steering control of the field working vehicle. When the steering control device 1 starts the automatic steering control of the field working vehicle, depending on the steering angle of the steering wheel, it is conceivable that a large indicated current value is output from the steering control device 1 and the steering mechanism 3 is driven at high speed.

[0067] The steering wheel 3A rotates in response to the drive of the steering mechanism 3. In other words, the steering wheel 3A is configured such that the steering amount changes in conjunction with the drive control of the steering mechanism 3 by the electric motor 31. For this reason, when the steering mechanism 3 is driven at high speed, the steering wheel 3A rotates at high speed. In this case, at the timing of starting the automatic steering control, it is conceivable that the steering wheel 3A suddenly rotates steeply, and the operator may be surprised or feel uncomfortable.

[0068] In order to avoid such inconveniences, in the present embodiment, the current value suppression processing module 16 executes processing for suppressing the steep operation of the steering wheel 3A at the timing of starting the automatic steering control. In other words, the steering control device 1 is configured to execute a suppression process for suppressing the indicated current value for the electric motor 31 when changing the state from the non-control state to the automatic control state. More specifically, the steering control device 1 is configured to output the indicated current value for the electric motor 31 such that the change amount of the steering amount of the steering wheel 3A per unit time is less than a preset threshold value when changing the state from the non-control state to the automatic control state.

[0069] Figures 5 to 7 show examples of suppression processing for suppressing the commanded current value for the electric motor 31. In the present embodiment, a magnification factor K for the commanded current value is provided. The current value suppression processing module 16 sets the magnification factor K within the range from the first parameter to the second parameter, and multiplies the commanded current value calculated by the current PI control module 15 by the magnification factor K. In the examples shown in Figures 5 to 7, 0.5 is shown as the first parameter of the magnification factor K, and 1.0 is shown as the second parameter of the magnification factor K. The magnification factor K corresponds to the 'target steering parameter' of the present invention. In other words, the target steering parameter of the present invention includes the magnification factor K.

[0070] When the magnification factor K is 1.0, the current value suppression processing module 16 outputs the commanded current value calculated by the current PI control module 15 as it is to the electric motor 31. When the magnification factor K is 0.5, the current value suppression processing module 16 suppresses the commanded current value calculated by the current PI control module 15 to half of the current value and outputs it to the electric motor 31.

[0071] In the example shown in Figure 5, the current value suppression processing module 16 sets the magnification factor K to 0.5 (first parameter) until a preset set time T1 elapses from the start timing of the automatic steering control. The set time T1 is set to, for example, 5 seconds. The timing of the set time T1 shown in Figure 5 is the end timing of the suppression processing. That is, the steering control device 1 is configured to execute the suppression processing from the start timing of starting the execution of the suppression processing to the end timing at the timing when the preset set time T1 has elapsed from the start timing.

[0072] Until the preset set time T1 has elapsed since the start timing of the automatic steering control, the current value suppression processing module 16 suppresses the commanded current value calculated by the current PI control module 15 to half the current value and outputs it to the electric motor 31. That is, the current value suppression processing module 16 of the steering control device 1 is configured to hold the magnification factor K at 0.5 (first parameter) for the time from the start timing to the set time T1. Then, at the timing when the set time T1 has elapsed, the current value suppression processing module 16 changes the magnification factor K stepwise from 0.5 (first parameter) to 1.0 (second parameter). After that, the current value suppression processing module 16 outputs the commanded current value calculated by the current PI control module 15 to the electric motor 31 as it is.

[0073] In the example shown in FIG. 6, the current value suppression processing module 16 sets the magnification factor K to 0.5 (first parameter) at the start timing of the automatic steering control. The timing of the set time T5 shown in FIG. 6 is the end timing of the suppression processing. The current value suppression processing module 16 changes the magnification factor K stepwise in a plurality of steps within the range from 0.5 (first parameter) to 1.0 (second parameter) until the preset set time T5 has elapsed since the start timing of the automatic steering control. In the example shown in FIG. 6, the magnification factor K changes in five steps. Note that in the example shown in FIG. 6, the magnification factor K is not limited to five steps and can be appropriately changed to any number of steps of two or more.

[0074] In the example shown in FIG. 6, until a preset setting time T1 elapses from the start timing of the automatic steering control, the current value suppression processing module 16 sets the magnification factor K to 0.5 (first parameter). As a result, the commanded current value calculated by the current PI control module 15 is suppressed to half the current value. Then, the current value suppression processing module 16 increases the magnification factor K by, for example, 0.1 at the timings of the respective setting times T1, T2, T3, T4, and T5. At the timing of the setting time T5, the magnification factor K reaches 1.0 (second parameter). That is, the current value suppression processing module 16 of the steering control device 1 is configured to stepwise change the setting of the magnification factor K so as to approach 1.0 (second parameter) over the time from the start timing of the automatic steering control to the setting time T5. After the setting time T5 has elapsed, the current value suppression processing module 16 outputs the commanded current value calculated by the current PI control module 15 as it is to the electric motor 31.

[0075] In the example shown in FIG. 7, the current value suppression processing module 16 sets the magnification factor K to 0.5 (first parameter) at the start timing of the automatic steering control. The current value suppression processing module 16 proportionally changes the magnification factor K in the range from 0.5 (first parameter) to 1.0 (second parameter) until a preset setting time T1 elapses from the start timing of the automatic steering control. The setting time T1 is set to, for example, 5 seconds. The timing of the setting time T1 shown in FIG. 7 is the end timing of the suppression processing. That is, the current value suppression processing module 16 of the steering control device 1 is configured to change the setting of the magnification factor K so as to approach 1.0 (second parameter) as time elapses over the time from the start timing of the automatic steering control to the setting time T1. After the setting time T1 has elapsed, the current value suppression processing module 16 outputs the commanded current value calculated by the current PI control module 15 as it is to the electric motor 31.

[0076] In this way, the steering control device 1 is configured to set the magnification K as the first parameter at the start timing of the automatic steering control, and to set the magnification K to a second parameter larger than the first parameter at the end timing when the set time T1 (set time T5 in FIG. 6) has elapsed. With this configuration, at the start timing of the automatic steering control, the amount of steering change per unit time of the steering wheel 3A becomes smaller compared to the configuration where the suppression process is not executed, and the steering wheel 3A starts to rotate slowly. As a result, when the steering control device 1 changes the state from the non-control state to the automatic control state, the steering control device 1 is configured to output an instruction current value for the electric motor 31 so that the change amount of the steering amount of the steering wheel 3A per unit time is less than a preset threshold value.

[0077] 〔Notification by the Notification Control Device〕 The notification control device 2, buzzer 41, speaker 42, and display device 43 shown in FIG. 1 are configured to be able to notify an operator of various information related to automatic steering according to the control mode of the steering control device 1. Various information related to automatic steering is, for example, information that prompts the operator to pay attention, guidance information that conveys the operation method to the operator, information that conveys the state of the equipment in the field work vehicle to the operator, and the like. The notification control device 2 is, for example, a voice synthesis LSI and is arranged separately from the buzzer 41, speaker 42, and display device 43. The buzzer 41, speaker 42, and display device 43 are arranged at appropriate positions in the cockpit of the field work vehicle and are connected by wiring to the notification control device 2.

[0078] The notification control device 2 is configured to enable control of each of the buzzer 41, speaker 42, and display device 43. The operator can recognize various information related to automatic steering based on the sounds and display items output from each of the buzzer 41, speaker 42, and display device 43.

[0079] When the operator manually operates the field work vehicle, the operator often finely adjusts the position and speed of the field work vehicle while visually checking the surrounding conditions in the field and the position of the crops. Therefore, when the operator tries to start the automatic steering of the field work vehicle, it is conceivable that the operator cannot visually check the display device 43 while visually checking the surrounding conditions in the field and the position of the crops. In particular, when the operator is unfamiliar with switching the control mode of the steering control device 1 to the automatic steering mode, it may be difficult for the operator to grasp what should be done to start the automatic steering of the field work vehicle while visually checking the surrounding conditions in the field and the position of the crops. In such a case, the automatic steering function of the field work vehicle becomes difficult for the operator to handle.

[0080] In the present embodiment, various types of information related to automatic steering are output from the speaker 42 in natural language voice. For this reason, the operator can grasp at an appropriate timing what should be done to start the automatic steering of the field work vehicle while visually checking the surrounding conditions in the field and the position of the crops. In other words, the operator can perform an operation to start the automatic steering of the field work vehicle according to the voice guidance output from the speaker 42 while visually checking the surrounding conditions in the field and the position of the crops without looking at the display device 43. Thereby, the operator can concentrate on checking the surrounding conditions in the field and the position of the crops.

[0081] Also, even when the operator is unfamiliar with switching the control mode of the steering control device 1 to the automatic steering mode, it becomes easy to start the automatic steering of the field work vehicle according to the voice guidance output from the speaker 42. Thereby, the automatic steering function of the field work vehicle becomes easy for the operator to handle.

[0082] The voice guidance output from the speaker 42 includes messages such as "Please set to the automatic steering mode", "It is warming up", "Please register the starting point (or the ending point)", "Please sit on the seat", "Please turn the aircraft to the left (or right)", "A failure has been detected", "The positioning level has dropped", "Automatic steering will start soon", and "Thank you for your hard work".

[0083] As described above, the notification control device 2 is configured to be able to notify an operator or the like of information related to automatic steering by controlling each of the buzzer 41, the speaker 42, and the display device 43 based on a notification signal from the steering control device 1.

[0084] FIG. 8 shows a first notification signal as an example of the notification signal. As shown in FIG. 8, when the notification control device 2 receives a notification signal from the steering control device 1, it executes control for each of the buzzer 41 and the speaker 42. At that time, the notification control device 2 is configured to first execute a first control for outputting a buzzing sound to the buzzer 41, and after the buzzer 41 finishes outputting the buzzing sound, execute a second control for outputting voice guidance to the speaker 42.

[0085] That is, the buzzing sound from the buzzer 41 and the voice guidance from the speaker 42 do not overlap, and the voice guidance is output from the speaker 42 after the buzzing sound from the buzzer 41 stops. Thereby, it becomes easier for the operator to hear the voice guidance from the speaker 42.

[0086] Also, the display of the notification information by the display device 43 is linked to each of the output of the buzzing sound from the buzzer 41 and the output of the voice guidance from the speaker 42. The notification control device 2 is configured to display the notification information on the display device 43 simultaneously with outputting the buzzing sound to the buzzer 41 when executing the first control for outputting the buzzing sound to the buzzer 41 first. That is, the display device 43 starts displaying the notification information simultaneously with the start of the output of the buzzing sound from the buzzer 41.

[0087] When the display device 43 displays the notification information, it is configured to continue displaying the notification information until the speaker 42 finishes outputting the voice guidance. The notification control device 2 causes the display device 43 to display the same display content as the content of the voice guidance from the speaker 42. That is, the content of the notification information displayed on the display device 43 is linked to the content of the voice guidance from the speaker 42. At the timing when the voice guidance by the speaker 42 ends, the display device 43 ends the display of the notification information related to the automatic steering and switches to another screen. That is, the display device 43 ends the display of the notification information simultaneously with the end of the output of the voice guidance from the speaker 42.

[0088] As notification signals output from the steering control device 1, there are a plurality of types of notification signals. The types of notification signals are classified according to the priority order. That is, the notification signals that the steering control device 1 can output include a plurality of notification signals according to the priority order.

[0089] In the example shown in FIG. 9, as the plurality of notification signals, a first notification signal and a second notification signal are shown. The second notification signal has a higher priority than the first notification signal. That is, in the present embodiment, the plurality of notification signals include a first notification signal and a second notification signal having a higher priority than the first notification signal.

[0090] In the example shown in FIG. 9, after the first notification signal is output, the notification control device 2 first executes a first control to cause the buzzer 41 to output a buzzing sound based on the first notification signal. Then, after the buzzer 41 finishes outputting the buzzing sound, the notification control device 2 executes a second control to cause the speaker 42 to output voice guidance based on the first notification signal. However, in the example shown in FIG. 9, before the notification control device 2 finishes executing the second control based on the first notification signal, a second notification signal having a higher priority than the first notification signal is output. In this case, the notification control device 2 is configured to abort the execution of the first control and the second control based on the first notification signal. And the notification control device 2 is configured to execute the first control and the second control based on the second notification signal.

[0091] In the example shown in FIG. 9, at the timing when the second notification signal is output, the notification control device 2 has completed the first control based on the first notification signal, and the buzzer 41 has finished sounding. However, for example, if the second notification signal is output before the notification control device 2 completes the execution of the first control based on the first notification signal, the notification control device 2 immediately stops the execution of the first control based on the first notification signal. Then, the sounding of the buzzer 41 based on the first notification signal stops midway. That is, the buzzer 41 is configured to output the sounding based on the second notification signal without waiting for the completion of the output of the sounding based on the first notification signal when the second notification signal is output.

[0092] In the example shown in FIG. 9, immediately before the second notification signal is output, the notification control device 2 is in the middle of executing the second control based on the first notification signal, and the speaker 42 is in the middle of outputting voice guidance. At the timing when the second notification signal is output, the notification control device 2 immediately stops the execution of the second control based on the first notification signal. Then, the voice guidance of the speaker 42 based on the second notification signal stops midway. That is, the speaker 42 is configured to immediately stop the output of the voice guidance based on the first notification signal when the second notification signal is output, and after the buzzer 41 finishes outputting the sounding based on the second notification signal, output the voice guidance based on the second notification signal.

[0093] In the example shown in FIG. 9, immediately before the second notification signal is output, the notification control device 2 executes the control to display the notification information on the display device 43 based on the first notification information, and the display device 43 displays the notification information based on the first notification information. At the timing when the second notification signal is output, the notification control device 2 immediately stops the control of the display device 43 based on the first notification signal and executes the control of the display device 43 based on the second notification signal. Then, the display of the display device 43 switches from the display based on the first notification signal to the display based on the second notification signal. In addition, the display device 43 ends the display of the notification information based on the second notification signal simultaneously with the end of the output of the voice guidance based on the second notification signal from the speaker 42.

[0094] In the example shown in FIG. 10, as a plurality of notification signals, a first notification signal and a third notification signal are shown. The third notification signal has the same priority as the first notification signal or a lower priority than the first notification signal. That is, in the present embodiment, the plurality of notification signals include a first notification signal and a third notification signal having the same priority as the first notification signal or a lower priority than the first notification signal.

[0095] In the example shown in FIG. 10, after the first notification signal is output, the notification control device 2 first executes a first control to output a buzzing sound to the buzzer 41 based on the first notification signal. Then, after the buzzer 41 finishes outputting the buzzing sound, the notification control device 2 executes a second control to output a voice guidance to the speaker 42 based on the first notification signal. In the example shown in FIG. 10, the third notification signal is output before the notification control device 2 completes the execution of the second control based on the first notification signal. In this case, the notification control device 2 is configured to continue executing the first control and the second control based on the first notification signal as it is. Then, after the notification control device 2 completes the execution of the first control and the second control based on the first notification signal, it is configured to execute the first control and the second control based on the third notification signal.

[0096] In the example shown in FIG. 10, at the timing when the third notification signal is output, the notification control device 2 completes the first control based on the first notification signal, and the buzzing of the buzzer 41 is completed. For example, even if the third notification signal is output before the notification control device 2 completes the execution of the first control based on the first notification signal, the notification control device 2 continues to execute the first control based on the first notification signal as it is. That is, the buzzer 41 is configured to output a buzzing sound based on the third notification signal after finishing outputting the buzzing sound based on the first notification signal and after the speaker 42 finishes outputting the voice guidance based on the first notification signal.

[0097] In the example shown in FIG. 10, immediately before the third notification signal is output, the notification control device 2 is in the middle of executing the second control based on the first notification signal, and the speaker 42 is in the middle of outputting voice guidance. At the timing when the third notification signal is output, the notification control device 2 continues to execute the second control based on the first notification signal as it is. That is, when the third notification signal is output, the speaker 42 completes the output of the voice guidance based on the first notification signal, and then, after the buzzer 41 finishes outputting the buzzing sound based on the third notification signal, the speaker 42 is configured to output the voice guidance based on the third notification signal.

[0098] In the example shown in FIG. 10, immediately before the third notification signal is output, the notification control device 2 executes control to cause the display device 43 to display notification information based on the first notification information, and the display device 43 is displaying the notification information based on the first notification information. At the timing when the third notification signal is output, the notification control device 2 continues to control the display device 43 based on the first notification signal as it is, and after the voice guidance of the speaker 42 based on the first notification signal is completed, the notification control device 2 executes control of the display device 43 based on the third notification signal. That is, the display of the display device 43 switches from the display based on the first notification signal to the display based on the third notification signal at the timing when the voice guidance of the speaker 42 based on the first notification signal is completed. In addition, the display device 43 ends the display of the notification information based on the third notification signal simultaneously with the end of the output of the voice guidance based on the third notification signal from the speaker 42.

[0099] 〔Alternative Embodiment〕 The present invention is not limited to the configurations exemplified in the above-described embodiments, and representative alternative embodiments of the present invention will be exemplified below.

[0100] (1) In the above embodiment, the current value suppression processing module 16 sets the magnification factor K shown in FIGS. 5 and 7 within the range from the first parameter to the second parameter, and multiplies the commanded current value calculated by the current PI control module 15 by the magnification factor K. However, the present invention is not limited to this embodiment. For example, the current value suppression processing module 16 may be configured to suppress the commanded current value calculated by the current PI control module 15 to be equal to or less than a preset threshold value.

[0101] (2) As described above with reference to FIG. 5, the current value suppression processing module 16 of the steering control device 1 is configured to hold the magnification factor K at 0.5 (the first parameter) for a period of time from the start timing to the set time T1. Also, as described above with reference to FIG. 7, the current value suppression processing module 16 of the steering control device 1 is configured to change the setting of the magnification factor K so that it approaches 1.0 (the second parameter) as time elapses for a period of time from the start timing of the automatic steering control to the set time T1. However, the present invention is not limited to these embodiments. For example, as shown in FIG. 11, the current value suppression processing module 16 of the steering control device 1 may be configured to hold the magnification factor K at 0.5 (the first parameter) for a period of time from the start timing of the automatic steering control to the set time T1 (not the end timing). Then, the current value suppression processing module 16 of the steering control device 1 may be configured to change the setting of the magnification factor K so that it approaches 1.0 (the second parameter) as time elapses for a period of time from the set time T1 (not the start timing) to the set time T2 (the end timing). That is, the current value suppression processing module 16 of the steering control device 1 may be configured to hold the magnification factor K (the target steering parameter) at the first parameter for at least a preset time (the time up to the set time T1) from the start timing to the end timing. Also, the current value suppression processing module 16 of the steering control device 1 may be configured to change the setting of the magnification factor K (the target steering parameter) so that it approaches the second parameter as time elapses for at least a preset time (the time from the set time T1 to the set time T2) until the end timing is reached from the start timing to the end timing.

[0102] (3) In the above-described embodiment based on FIG. 4, the azimuth angular velocity PI control module 13 calculates the deviation of the azimuth angular velocity between the target azimuth angular velocity calculated by the azimuth angle PI control module 12 and the actual azimuth angular velocity measured by the inertial measurement device 36. Then, based on the deviation of the azimuth angular velocity, the azimuth angular velocity PI control module 13 calculates the target steering angular velocity of the steering wheel for turning the field working vehicle along the target azimuth angular velocity. The target steering angular velocity of the steering wheel is the target change amount per unit time of the steering angle of the steering wheel. The target change amount per unit time of the steering angle of the steering wheel corresponds to the "first angular velocity" of the present invention. As shown in FIG. 12, when executing the suppression process, the steering control device 1 may be configured to suppress the first angular velocity. In the form shown in FIG. 12, instead of the current value suppression processing module 16, a target steering angular velocity regulation processing module 17 is provided. The target steering angular velocity regulation processing module 17 executes a process for suppressing a sharp operation of the steering wheel 3A at the start timing of the automatic steering control. For example, the target steering angular velocity regulation processing module 17 may be configured to set the magnification K shown in FIGS. 5 and 7 within the range from the first parameter to the second parameter and multiply the target steering angular velocity calculated by the azimuth angular velocity PI control module 13 by the magnification K. Further, for example, the target steering angular velocity regulation processing module 17 may be configured to suppress the target steering angular velocity calculated by the azimuth angular velocity PI control module 13 to be equal to or lower than a preset threshold value. Thereby, when the steering control device 1 changes its state from the non-control state to the automatic control state, the steering control device 1 outputs the first angular velocity as the target steering parameter so that the change amount of the steering amount of the steering device (for example, the steering wheel 3A) per unit time is less than a preset threshold value. In this case, the target steering parameter of the present invention may be the first angular velocity. The configuration shown in FIG. 12 may be provided with both the current value suppression processing module 16 and the target steering angular velocity regulation processing module 17. In this case, the target steering parameter of the present invention may include the commanded current value to the electric motor 31 and the first angular velocity.

[0103] (4) In the above-described embodiment based on FIG. 4, the azimuth angle PI control module 12 calculates the amount of azimuth deviation between the target azimuth calculated by the vehicle body position PI control module 11 and the actual azimuth of the field working vehicle measured by the inertial measurement device 36. Then, based on the amount of azimuth deviation, the azimuth angle PI control module 12 calculates a target azimuth angular velocity for aligning the azimuth of the field working vehicle with the target azimuth. The target azimuth angular velocity for aligning the azimuth of the field working vehicle with the target azimuth corresponds to the "second angular velocity" of the present invention. As shown in FIG. 13, when executing the suppression process, the steering control device 1 may be configured to suppress the second angular velocity. In the form shown in FIG. 13, instead of the current value suppression processing module 16, a target azimuth angular velocity regulation processing module 18 is provided. The target azimuth angular velocity regulation processing module 18 executes a process for suppressing a sharp operation of the steering wheel 3A at the start timing of the automatic steering control. For example, the target azimuth angular velocity regulation processing module 18 may be configured to set the magnification K shown in FIGS. 5 and 7 within the range from the first parameter to the second parameter and multiply the target azimuth angular velocity calculated by the azimuth angle PI control module 12 by the magnification K. Further, for example, the target azimuth angular velocity regulation processing module 18 may be configured to suppress the target azimuth angular velocity calculated by the azimuth angle PI control module 12 to be equal to or less than a preset threshold value. In this case, the target steering parameter of the present invention may be the second angular velocity. Also, in the form shown in FIG. 13, a configuration may be provided that includes both the current value suppression processing module 16 and the target azimuth angular velocity regulation processing module 18. In this case, the target steering parameter of the present invention may include the instructed current value to the electric motor 31 and the second angular velocity.

[0104] (5) As the "first detection unit" of the present invention, the motor encoder 33 is shown. The first detection unit may be, for example, an encoder that detects the steering amount of the steering wheel 3A. In short, the first detection unit is configured to be able to detect at least one of the driving amount of the steering drive device (for example, the electric motor 31) and the steering amount of the steering tool (for example, the steering wheel 3A). And the steering angle calculation unit 34 may be configured to calculate the angular velocity of the steered wheels based on the detection value of the first detection unit.

[0105] (6) The first detection unit of the present invention may be configured to detect, for example, the steering amount of the steering wheel 3A. Also, as the "steering tool" of the present invention, the steering wheel 3A is shown. The steering tool may be, for example, a steering lever. When the steering tool is a steering lever, the first detection unit of the present invention may be configured to detect the steering amount of the steering lever.

[0106] (7) As the "steering drive device" of the present invention, the electric motor 31 is shown. The steering drive device may be, for example, a hydraulic motor. When the steering drive device is a hydraulic motor, for example, the opening degree of the hydraulic valve for the hydraulic motor may be included in the target steering parameter of the present invention.

[0107] (8) In the above-described embodiment based on FIGS. 2 and 3, the steering control device 1 determines whether or not the condition #01 for shifting to the automatic steering mode is satisfied in the preparation mode. At this time, the operator manually steers so that the attitude azimuth of the field work vehicle coincides with a preset reference azimuth. The preset reference azimuth is, for example, a reference azimuth set based on two points, a starting point and an ending point, in teaching driving. The present invention is not limited to this embodiment, and the target azimuth of automatic steering may not be a preset reference azimuth. For example, when the operator travels in the same direction for a preset predetermined distance D1 or a preset time (for example, 3 to 5 seconds), the target azimuth may be set in that direction. And when the target azimuth along the said direction is set, the control mode of the steering control apparatus 1 may be comprised so that it may switch from a manual steering mode to an automatic steering mode.

[0108] (9) The inertial measurement device 36 described above based on FIG. 1 may not be provided. In this case, the second detection unit of the present invention may be, for example, the navigation positioning device 35. That is, based on the difference per unit time of the positioning data output by the navigation positioning device 35, the target change amount of the direction of the vehicle body may be calculated.

[0109] (10) The magnification K shown in FIGS. 5, 7, and 11 is set to 0.5 as the first parameter and 1.0 as the second parameter. The present invention is not limited to this embodiment, and the values of the first parameter and the second parameter can be appropriately set and changed.

[0110] Note that 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 no contradiction occurs. In addition, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be appropriately modified within the scope not departing from the object of the present invention.

Industrial Applicability

[0111] The present invention is applicable to a notification device for a work vehicle and a field work vehicle equipped with the notification device.

Explanation of reference numerals

[0112] 1: Steering control device (automatic steering control device) 3: Steering mechanism 3A: Steering wheel (steering tool) 31: Electric motor (steering drive device) 33: Motor encoder (first detection unit) 34: Steering angle calculation unit 36: Inertial measurement device (second detection unit) GL: Automatic steering target line (target path)

Claims

1. A field working vehicle capable of automatic steering along a target path, comprising a steering wheel, a steering device for receiving manual operation, and a steering mechanism for steering the steering wheel; configured to be changeable between a non-control state in which the automatic steering is not performed and an automatic control state in which the automatic steering is performed, and an automatic steering control device for outputting target steering parameters for traveling along the target path in the automatic control state; a steering drive device for driving and controlling the steering mechanism based on the target steering parameters when the automatic steering control device is in the automatic control state; the steering device is configured such that the steering amount changes in conjunction with the drive control by the steering drive device; the automatic steering control device is configured to execute a suppression process for suppressing the target steering parameters when changing the state from the non-control state to the automatic control state. A field working vehicle.

2. The steering drive device is an electric motor, the target steering parameters include a current value for the electric motor, The field working vehicle according to claim 1, wherein the automatic steering control device is configured to suppress the current value when executing the suppression process.

3. equipped with a steering angle calculation unit for calculating the steering angle of the steering wheel, the target steering parameters include a first angular velocity which is a target change amount of the steering angle per unit time, The field working vehicle according to claim 1 or 2, wherein the automatic steering control device is configured to suppress the first angular velocity when executing the suppression process.

4. equipped with a first detection unit capable of detecting at least one of the drive amount of the steering drive device and the steering amount of the steering device, The field working vehicle according to claim 3, wherein the steering angle calculation unit is configured to calculate the steering angle based on the detection value of the first detection unit.

5. equipped with a second detection unit for detecting the orientation of the vehicle body, the target steering parameters include a second angular velocity which is a target change amount of the orientation of the vehicle body per unit time, The field working vehicle according to claim 1 or 2, wherein the automatic steering control device is configured to suppress the second angular velocity when executing the suppression process.

6. The field work vehicle according to claim 1 or 2, wherein the automatic steering control device is configured to output the target steering parameter such that a change amount of a steering amount of the steering device per unit time is less than a preset threshold value when changing the state from the non-control state to the automatic control state.

7. The automatic steering control device is configured to execute the suppression process from a start timing at which the execution of the suppression process is started to an end timing at a timing when a preset time has elapsed from the start timing. The field work vehicle according to claim 1 or 2, wherein the automatic steering control device is configured to set the target steering parameter to a first parameter at the start timing and set the target steering parameter to a second parameter larger than the first parameter at the end timing.

8. The field work vehicle according to claim 7, wherein the automatic steering control device is configured to hold the target steering parameter at the first parameter for at least a preset time from the start timing to the end timing.

9. The field work vehicle according to claim 7, wherein the automatic steering control device is configured to change the setting of the target steering parameter so as to approach the second parameter as time elapses for at least a preset time until the end timing is reached from the start timing to the end timing.

10. The field work vehicle according to claim 1 or 2, wherein the automatic steering control device is configured to be able to change the state to the automatic control state when the vehicle travels in the same direction for a preset distance or time based on a manual operation of the steering device in the non-control state.

Images