JP7747697B2 - Work vehicle - Google Patents

Description

The present invention relates to a work vehicle configured to automatically travel along a set travel line based on detection values from GPS, gyro sensors, etc.

As disclosed in Patent Document 1, a work vehicle such as a riding rice transplanter travels from one end of the work area to the other, then turns at the other end of the work area, and then travels from the other end of the work area back to the one end, repeatedly traveling from one end (or the other) of the work area to the other (or the first) end and turning at one end (or the other) of the work area.

In Patent Document 1, when a reference driving line is set (obtained from outside), a number of set driving lines are set so as to be parallel to the reference driving line and spaced apart from the reference driving line at intervals corresponding to the width of the aircraft.
As a result, in Patent Document 1, the front wheels are automatically steered so that the vehicle automatically travels along a first set travel line, and the first work run is carried out, and when the first work run is completed and the vehicle reaches one end of the work site, a turn is made at one end of the work site.
Next, the front wheels are automatically steered so that the vehicle automatically travels along a second set travel line adjacent to the first set travel line, and a second work run is carried out, and when the second work run is completed and the vehicle reaches the other end of the work site, a turn is made at the other end of the work site.

JP 2008-92818 A

In automatic driving along a set driving line as in Patent Document 1, if automatic driving along the set driving line is to be started when the turning has not been completely completed, there is a possibility that a large difference will occur between the set driving line and the position of the aircraft.
Therefore, when automatic driving along the set driving line begins when there is a large difference between the set driving line and the aircraft's position, the aircraft will automatically attempt to move to the position of the set driving line while making large changes to its orientation and position, leaving room for improvement in terms of the aircraft's stability.
The present invention aims to ensure that automatic travel along a set travel line is properly initiated after turning at the edge of a work site is completed.

[I] (Configuration)
The work vehicle of the present invention comprises a setting unit that sets a set driving line, an automatic driving control unit that operates the driving device so that the vehicle automatically drives along the set driving line, an operation unit that operates the automatic driving control unit between an operating state and a stopped state, and a turning end detection unit that detects the end of a turn, and if the turning end detection unit does not detect the end of a turn, prevents the operation unit from operating the automatic driving control unit to an operating state, and a restraining unit that prevents the operation unit from operating the automatic driving control unit to an operating state until the vehicle has driven a set distance or a set time after the turning end detection unit detects the end of the turn, and the set driving line is not set when turning between the set driving lines, and the set driving line after the turn is generated based on the position at the time the automatic driving control unit becomes operating after the end of the turn is detected.
A first feature of the present invention resides in the following configuration of a work vehicle.
a setting unit for setting a set driving line;
an automatic travel control unit that operates a travel device so that the vehicle automatically travels along the set travel line;
An operation unit that operates the automatic driving control unit between an operating state and a stopped state, and a turning end detection unit that detects the end of turning,
The device is equipped with a restraining section that prevents the operating section from operating the automatic driving control unit to an operating state when the end of the turn is not detected by the turn end detection section, and allows the operating section to operate the automatic driving control unit to an operating state when the end of the turn is detected by the turn end detection section.
The vehicle may also include a blocking notification unit that notifies the driver that the restraining unit has blocked the operation unit from switching the automatic driving control unit to an operating state.
In addition, a pre-set reference direction may be provided, and the setting unit may set the set driving line parallel to the reference direction based on the position of the aircraft at the time the automatic driving control unit is operated to an operating state by the operating unit.
The work vehicle of the present invention may also include a setting unit that sets a set travel line, an automatic travel control unit that operates the travel device so that it automatically travels along the set travel line, an operation unit that manually operates the automatic travel control unit between an activated state and a stopped state, a steering member that accepts steering operations between the left and right steering limits and a straight-ahead position, a turning end detection unit that detects, as the end of a turn, a state in which the steering member is operated from the steering limit side toward the straight-ahead position beyond a set angle at which the transmission of power to the travel device is turned on and off, and a restraining unit that prevents the operation unit from switching the automatic travel control unit to an activated state if the turning end detection unit does not detect the end of the turn, and immediately allows the automatic travel control unit to switch to an activated state if the end of the turn is detected.

(Action and Effect of the Invention)
According to a first feature of the present invention, the vehicle is provided with an automatic driving control unit that operates the driving device so that the vehicle automatically drives along a set driving line, an operation unit that operates the automatic driving control unit between an operating state and a stopped state, and a turning end detection unit that detects the end of a turn.

According to the first feature of the present invention, when a turn is made at the edge of a work site and then the automatic driving control unit is operated to an active state by the operating unit, if the turn has not ended (if the end of the turn is not detected by the turn end detection unit), the operating unit is prevented from operating the automatic driving control unit to an active state.
This prevents the automatic driving control unit from being operated when there is a large difference between the set driving line and the vehicle's position, thereby ensuring the stability of the vehicle.

[II] (Configuration)
A second feature of the present invention is that the work vehicle according to the first feature of the present invention is configured as follows.
With a preset reference direction,
The setting unit sets the set driving line parallel to the reference direction from the position of the aircraft at the time when the automatic driving control unit is operated to an operating state by the operating unit.

(Action and Effect of the Invention)
According to the second feature of the present invention, the set driving line is set parallel to the reference direction from the position of the aircraft at the time when the automatic driving control unit is operated to the operating state by the operation unit.
This means that, for example, when automatic driving along the first set driving line is completed and a work site is reached, the position of the vehicle at the time the automatic driving control unit is operated to the operating state by the operating unit can be set at the driver's discretion by turning at the edge of the work site with a large turning radius or a small turning radius, and the position of the set driving line can be set at the driver's discretion.

[III] (Configuration)
A third feature of the present invention resides in that the work vehicle according to the first or second feature of the present invention is configured as follows.
The operating unit is manually operated to switch the automatic driving control unit between an operating state and a stopped state.

(Action and Effect of the Invention)
According to a third feature of the present invention, after the end of a turn is detected by the turn end detection unit and operation of the automatic driving control unit into an operating state is permitted, the driver can operate the automatic driving control unit into an operating state.
This allows the driver to decide whether or not to operate the automatic driving control unit to an active state based on his or her intention.

[IV] (Configuration)
A fourth feature of the present invention resides in that the work vehicle according to the third feature of the present invention is configured as follows.
The operating unit is provided in a gear change operating unit that is manually operated to operate a transmission for traveling.

(Action and Effect of the Invention)
As described in the previous paragraph [III], when the driver operates the operation unit, according to the fourth feature of the present invention, the operation unit is provided in the gear change operation unit that operates the traveling transmission.
This allows the driver to operate the operating part while operating the gear shift operating part, improving operability.

[V] (Configuration)
A fifth feature of the present invention resides in that any one of the work vehicles according to the first to fourth features of the present invention is configured as follows.
The restraining unit allows the operating unit to operate the automatic driving control unit to an operating state after the aircraft has traveled a set distance or a set time after the end of the turn has been detected by the turn end detection unit.

(Action and Effect of the Invention)
As described in the previous section [I], when the end of a turn is detected by the turn end detection unit and the operation unit is permitted to operate the automatic driving control unit to an operating state, according to the fifth feature of the present invention, after the end of the turn is detected by the turn end detection unit and the aircraft has traveled a set distance (set time), the operation unit is permitted to operate the automatic driving control unit to an operating state.
This allows the aircraft's attitude to be stabilized by traveling a set distance (set time) from the end of the turn, and then by operating the automatic traveling control unit to an active state, the stability of the aircraft can be ensured.

[VI] (Configuration)
A sixth feature of the present invention resides in that any one of the work vehicles according to the first to fifth features of the present invention is configured as follows.
Equipped with a direction detection unit that detects the direction of the aircraft,
In a state where the operation of the automatic traveling control unit to the operating state by the operation unit is permitted and the automatic traveling control unit is operated to the working state by the operation unit,
The restraining unit prevents the operating unit from operating the automatic driving control unit to an operating state if the angular difference between the set driving line and the aircraft's orientation exceeds a set value, and allows the operating unit to operate the automatic driving control unit to an operating state if the angular difference between the set driving line and the aircraft's orientation does not exceed a set value.

(Action and Effect of the Invention)
As described in the previous paragraphs [I] and [V], even if the operating unit is permitted to operate the automatic driving control unit to an operating state, when the operating unit operates the automatic driving control unit to an operating state, it is expected that there will actually be a large angular difference between the set driving line and the aircraft's orientation.

According to the sixth feature of the present invention, in the above-mentioned state, after the operation of the automatic driving control unit to an operating state by the operating unit is permitted, when the automatic driving control unit is operated to an operating state by the operating unit, if the angle difference between the set driving line and the orientation of the aircraft exceeds a set value, the operation of the automatic driving control unit to an operating state by the operating unit is prevented.
This prevents the automatic driving control unit from being operated when there is a large angular difference between the set driving line and the aircraft's orientation, thereby ensuring the stability of the aircraft.

[VII] (Configuration)
A seventh feature of the present invention resides in that any one of the work vehicles according to the first to fifth features of the present invention is configured as follows.
Equipped with a direction detection unit that detects the direction of the aircraft,
When the operation unit is allowed to operate the automatic driving control unit into an operating state and the automatic driving control unit is operated into an operating state by the operation unit, the automatic driving control unit is provided with an automatic deceleration unit that decelerates the driving speed of the aircraft if the angular difference between the set driving line and the aircraft's orientation exceeds a set value.

(Action and Effect of the Invention)
As described in the previous paragraphs [I] and [V], even if the operating unit is permitted to operate the automatic driving control unit to an operating state, when the operating unit operates the automatic driving control unit to an operating state, it is expected that there will actually be a large angular difference between the set driving line and the aircraft's orientation.

According to the seventh feature of the present invention, in the above-mentioned state, after the operating unit is permitted to operate the automatic driving control unit to the operating state, when the automatic driving control unit is operated to the working state by the operating unit, if the angular difference between the set driving line and the aircraft's orientation exceeds a set value, the aircraft's driving speed is automatically reduced and the automatic driving control unit is operated to the operating state, thereby ensuring the stability of the aircraft.

[VIII] (Configuration)
An eighth feature of the present invention is that the work vehicle according to the seventh feature of the present invention is configured as follows.
The vehicle is provided with a deceleration notification unit that notifies the user that the traveling speed of the vehicle has been decelerated by the automatic deceleration unit.

(Action and Effect of the Invention)
As described in the preceding paragraph [VII], when the vehicle's traveling speed is automatically reduced and the automatic traveling control unit is operated to an operating state, according to the eighth feature of the present invention, the automatic deceleration unit notifies the driver that the vehicle's traveling speed has been reduced, so that the driver can understand that the vehicle's traveling speed has been reduced and there is no misunderstanding on the part of the driver.

[IX] (Configuration)
A ninth feature of the present invention resides in that any one of the work vehicles according to the first to eighth features of the present invention is configured as follows.
The restraining unit prevents the operating unit from operating the automatic driving control unit to an operating state when the vehicle is in a reverse state, and operates the automatic driving control unit to a stopped state when the vehicle is in a reverse state when the automatic driving control unit is in an operating state.

(Action and Effect of the Invention)
According to the ninth feature of the present invention, it is possible to avoid a state in which the vehicle loses stability, such as when the automatic driving control unit is activated while the vehicle is in reverse, thereby ensuring the stability of the vehicle.

[X] (Configuration)
A tenth feature of the present invention is that the work vehicle according to the ninth feature of the present invention is configured as follows.
The vehicle is provided with a reverse stop notification unit that notifies the driver that the automatic driving control unit has been operated to a stopped state by the restraining unit when the vehicle enters a reverse state while the automatic driving control unit is in an operating state.

(Action and Effect of the Invention)
As described in the previous paragraph [IX], when the automatic driving control unit is operated to a stopped state because the vehicle is in reverse while the automatic driving control unit is in an operating state, according to the tenth feature of the present invention, the restraining unit notifies the driver that the automatic driving control unit has been operated to a stopped state, so that the driver can understand that the automatic driving control unit has been operated to a stopped state and the driver will not be misled.

[XI] (Configuration)
An eleventh feature of the present invention is that any one of the work vehicles according to the first to tenth features of the present invention is configured as follows.
The vehicle is provided with a blocking notification unit that notifies the user that the restraining unit has blocked the automatic driving control unit from being operated.

(Action and Effect of the Invention)
According to the eleventh feature of the present invention, when the restraining unit prevents the automatic driving control unit from being operated to an operating state, the restraining unit notifies the driver that the automatic driving control unit has been prevented from being operated to an operating state, so that the driver can understand that the automatic driving control unit has been prevented from being operated to an operating state, and the driver is not misled.

[XII] (Configuration)
A twelfth feature of the present invention resides in that any one of the work vehicles according to the first to eleventh features of the present invention is configured as follows.
The device is provided with an allowance notification unit that notifies that the restraint unit has permitted the operation unit to set the automatic driving control unit to an operating state.

(Action and Effect of the Invention)
According to the twelfth feature of the present invention, when the restraining unit allows the operating unit to operate the automatic driving control unit to an operating state, the restraining unit notifies the driver that the operating unit is allowed to operate the automatic driving control unit to an operating state, so the driver can understand that the restraining unit has allowed the operating unit to operate the automatic driving control unit to an operating state, and the driver will not be misled.

[XIII] (Configuration)
A thirteenth feature of the present invention resides in that any one of the work vehicles according to the first to twelfth features of the present invention is configured as follows.
The vehicle further includes an operation notification unit that notifies the driver that the automatic driving control unit is in an operating state.

(Action and Effect of the Invention)
According to the thirteenth feature of the present invention, the driver is notified that the automatic driving control unit is in an operating state, so that the driver is not misled.

[XIV] (Configuration)
A fourteenth feature of the present invention resides in that any one of the work vehicles according to the first to thirteenth features of the present invention is configured as follows.
The turning end detection unit detects that the working device, which is supported on the machine body so as to be able to rise and fall freely, has descended from a raised position to the ground as the end of turning.

(Action and Effect of the Invention)
In a work vehicle having a working implement supported on the body so that it can be raised and lowered, the working implement may be raised from the ground when a turn begins and lowered to the ground when the turn ends.
According to the fourteenth feature of the present invention, the end of the swing can be clearly detected by detecting that the working implement has descended from the raised position to the ground as the end of the swing.

[XV] (Configuration)
A fifteenth feature of the present invention resides in that any one of the work vehicles according to the first to thirteenth features of the present invention is configured as follows.
The turning end detection unit detects that a working clutch that transmits power to a working device supported on the machine body has been operated into a transmission state as the end of turning.

(Action and Effect of the Invention)
In a work vehicle equipped with a working implement, the working clutch may be operated to a disengaged state when turning begins to stop the working implement, and the working clutch may be operated to a transmission state when turning ends to operate the working implement.
According to the fifteenth feature of the present invention, the end of a turn can be clearly detected by detecting that the working clutch has been operated into a transmission state as the end of the turn.

[XVI] (Configuration)
A sixteenth feature of the present invention resides in that any one of the work vehicles according to the first to thirteenth features of the present invention is configured as follows.
The turning end detection unit detects that the turning has ended when a steering operation unit, which is manually operated to change the direction of the aircraft, has been operated from a turning position to a straight-ahead position.

(Action and Effect of the Invention)
Since work vehicles are equipped with a steering control unit (such as a steering handle or steering lever) that is manually operated to change the orientation of the vehicle, the end of a turn can be clearly detected by detecting that the steering control unit has been operated from a turning position to a straight-ahead position as the end of the turn.

[XVII] (Configuration)
A seventeenth feature of the present invention resides in that any one of the work vehicles according to the first to thirteenth features of the present invention is configured as follows.
right and left side clutches for transmitting power to the right and left traveling devices;
A side clutch operating unit is provided which operates the side clutch on the side of the turning center to a disengaged state when the turning starts, and operates the side clutch on the side of the turning center to a transmitted state when the turning ends,
The turning end detection unit detects that the side clutch on the turning center side has been operated into a transmission state as the end of the turning.

(Action and Effect of the Invention)
Some work vehicles are equipped with right and left side clutches that transmit power to the right and left traveling devices, and are configured so that when a turn begins, the side clutch on the side of the turning center is operated to a disengaged state (free rotation state of the traveling device on the side of the turning center), and when the turn ends, the side clutch on the side of the turning center is operated to a transmission state (drive state of the traveling device on the side of the turning center).
According to the seventeenth feature of the present invention, the end of turning can be clearly detected by detecting that the side clutch on the turning center side has been operated into a transmission state as the end of turning.

[XVIII] (Configuration)
An eighteenth feature of the present invention is that any one of the work vehicles according to the first to thirteenth features of the present invention is configured as follows.
The running device has front and rear wheels,
a front wheel speed increasing device that can be freely operated between a standard state in which the front wheels and the rear wheels are driven at approximately the same speed and an increased speed state in which the front wheels are driven at a higher speed than the rear wheels;
an operating device that operates the front wheel speed increasing device to an accelerating state when a turn starts and operates the front wheel speed increasing device to a standard state when a turn ends,
The turning end detection unit detects that the front wheel speed increasing device has been operated to the standard state as the end of a turn.

(Action and Effect of the Invention)
Some work vehicles are equipped with a front wheel speed increaser that can be freely operated between a standard state in which the front and rear wheels are driven at approximately the same speed, and an accelerated state in which the front wheels are driven at a higher speed than the rear wheels, and are configured so that the front wheel speed increaser is operated to the accelerated state when a turn begins and to the standard state when the turn ends.
According to the eighteenth feature of the present invention, the end of a turn can be clearly detected by detecting that the front wheel speed increasing device has been operated to the standard state as the end of the turn.

[XIX] (Configuration)
A nineteenth feature of the present invention resides in that any one of the work vehicles according to the first to thirteenth features of the present invention is configured as follows.
Equipped with a direction detection unit that detects the direction of the aircraft,
The turning end detection unit detects the end of turning based on the detection value of the direction detection unit.

(Action and Effect of the Invention)
According to the nineteenth feature of the present invention, the orientation detection unit is provided to detect the orientation of the aircraft, thereby making it possible to clearly detect the end of a turn.

FIG. 1 is an overall side view of a riding rice transplanter. FIG. 1 is an overall plan view of a riding rice transplanter. FIG. 2 is a schematic plan view showing a steering system for the front wheels and a transmission system for the front and rear wheels. FIG. 2 is a diagram showing the state of cooperation between the control device and each part. FIG. 1 is a plan view showing an outline of the working form of a riding rice transplanter. This is a plan view showing the state from the start position K1 to the end position K2 in the operating mode of the riding rice transplanter. This is a plan view showing the state from the starting position K1 to the position K3 in the operating mode of the riding rice transplanter. This is a plan view showing the state from the starting position K1 to the position K4 in the operating mode of the riding rice transplanter. This is a plan view showing the state from the starting position K1 to the position K5 in the operating mode of the riding rice transplanter. This is a plan view showing the state from the starting position K1 to the position K6 in the operating mode of the riding rice transplanter. This is a plan view showing the state from the starting position K1 to the position K7 in the operating mode of the riding rice transplanter. FIG. 10 is a diagram showing the control flow in the operation mode of the riding rice transplanter. FIG. 10 is a diagram showing the control flow in the operation mode of the riding rice transplanter. FIG. 10 is a diagram showing the control flow in the operation mode of the riding rice transplanter. FIG. 11 is a schematic plan view showing the state of the aircraft in a third modified embodiment of the invention. FIG. 13 is a diagram showing the state of cooperation between the control device and each part in a fifth modified embodiment of the invention. FIG. 13 is a schematic diagram showing a steering system for the front wheels and a transmission system for the front and rear wheels in an eighth alternative embodiment of the invention.

Unless otherwise specified, the front-to-rear and left-to-right directions in the embodiments of the present invention are described as follows: The forward traveling direction of the machine when it is traveling for work is "forward," and the backward traveling direction is "rear." With the forward-facing posture in the front-to-rear direction as the reference, the direction corresponding to the right side is "right," and the direction corresponding to the left side is "left."

[1]
As shown in Figures 1 and 2, the rear of the machine body is equipped with right and left front wheels 1 (corresponding to the running gear) and right and left rear wheels 2 (corresponding to the running gear), and is equipped with a link mechanism 3 and a hydraulic cylinder 4 that drives the link mechanism 3 up and down.An eight-row seedling planting device 5 (corresponding to the working device) is supported at the rear of the link mechanism 3, thereby forming a riding rice transplanter, which is an example of a work vehicle.

As shown in Figures 1 and 2, the seedling planting device 5 is configured as an eight-row planting type, and includes four planting transmission cases 6 arranged at a predetermined interval in the left-right direction, a rotating case 7 rotatably supported on the right and left rear sides of the planting transmission cases 6, a pair of planting arms 8 provided at both ends of the rotating case 7, a float 9, and a seedling tray 10.

As shown in Figures 1 and 4, right and left markers 19 are provided on the right and left sides of the seedling planting device 5 and are configured to be freely changeable between an operating position (see Figure 1) in which they are in contact with the rice field surface to form indicators for work steps L01 to L05 (see Figure 5), and a stored position (see Figure 4) above the rice field surface. The right and left markers 19 are configured with an arm portion 19a supported on the seedling planting device 5 so that they can swing up and down, and a rotor 19b supported at the tip of the arm portion 19a so that they can rotate freely. An electric motor 21 is provided to operate the right and left markers 19 between the operating position and the stored position, and the electric motor 21 is operated by a control device 23.

[2]
The transmission system to the right and left front wheels 1 and the right and left rear wheels 2 will now be described.
As shown in Figures 1 and 3, the power of an engine 31 provided at the front of the vehicle is transmitted via a transmission belt 32 to a hydrostatic continuously variable transmission 33 (corresponding to a transmission for driving) and a transmission case 34, and then transmitted from an auxiliary transmission (not shown) inside the transmission case 34 to the right and left front wheels 1 via a front wheel differential mechanism (not shown) and a transmission shaft (not shown) inside a front axle case 35.

As shown in Figures 1 and 3, the power of the auxiliary transmission is transmitted to the right and left rear wheels 2 via the transmission shaft 36, the input shaft 38 of the rear axle case 37, the bevel gear 38a fixed to the input shaft 38, the bevel gear 39a meshing with the bevel gear 38a, the transmission shaft 39 to which the bevel gear 39a is fixed, and the right and left side clutches 40.

As shown in Figures 1, 2, and 4, a shift lever 45 (corresponding to the shift operation unit) is provided on the left side of the steering handle 20 (corresponding to the steering operation unit), and the shift lever 45 operates the hydrostatic continuously variable transmission 33. The shift lever 45 allows the hydrostatic continuously variable transmission 33 to be continuously operated from the neutral position N to the forward side F and the reverse side R.

As shown in FIG. 3, a steering member 41 (corresponding to a side clutch operating unit) is supported for free swinging motion around a vertical axis P2 at the bottom of the transmission case 34, and is configured to be swingably operated by the steering handle 20, with tie rods 42 connected between the steering member 41 and the right and left front wheels 1. By operating the steering handle 20, the right and left front wheels 1 can be steered from a straight-ahead position A1 through right and left steering limits A3.

As shown in Figure 3, the right and left side clutches 40 are configured as friction multi-plates and are biased into a transmission state by springs (not shown). Right and left operating shafts 43, which operate the right and left side clutches 40 against the springs to disengage them, are supported downward on the rear axle case 37, and right and left operating rods 44 (corresponding to side clutch operating units) are connected between the steering member 41 and the right and left operating shafts 43. The right and left operating rods 44 have long holes 44a at the connection points with the right and left operating shafts 43 for flexibility.

As shown in Figure 3, when the right and left front wheels 1 are steered within the range of the straight-ahead position A1 and the right and left set angles A2, the right and left side clutches 40 are operated into a transmission state due to the flexibility of the long holes 44a of the right and left operating rods 44. As a result, the vehicle moves forward (reverse) with power transmitted to the right and left front wheels 1 and the right and left rear wheels 2 (transmission state of the right and left side clutches 40).

As shown in Figure 3, when the right and left front wheels 1 are steered beyond the right set angle A2 toward the right steering limit A3, the right (left) operating rod 44 is pulled beyond the range of the long hole 44a of the right operating rod 44, and the right side clutch 40 is disengaged by the right operating shaft 43. As a result, power is transmitted to the right and left front wheels 1 and the left rear wheel 2 (outside of the turn) (transmission state of the left side clutch 40), and the right rear wheel 2 (towards the center of the turn) (disengagement state of the right side clutch 40) rotates freely, causing the aircraft to turn to the right.

As shown in Figure 3, when the right and left front wheels 1 are steered beyond the left set angle A2 toward the left steering limit A3, the left operating rod 44 is pulled beyond the range of its elongated hole 44a, and the left side clutch 40 is disengaged by the left operating shaft 43. As a result, power is transmitted to the right and left front wheels 1 and the right rear wheel 2 (outside of the turn) (right side clutch 40 transmission state), and the left rear wheel 2 (center of the turn) (left side clutch 40 disengaged state) rotates freely, causing the aircraft to turn left.

As shown in Figure 3, when the right and left front wheels 1 are steered from the right (left) steering limit A3 side beyond the right (left) set angle A2 toward the straight-ahead position A1, the right (left) side clutch 40, which had been in the disengaged state, is operated into the engaged state, and the right and left side clutches 40 return to their engaged state.

[3]
The transmission system to the seedling planting device 5 will now be described.
As shown in Figures 1 and 4, in the transmission case 34, the power branched off from just before the sub-transmission device is transmitted to the seedling planting device 5 via the planting clutch 26 (corresponding to the working clutch) and the PTO shaft 25, and an electric motor 28 is provided to operate the planting clutch 26 in the transmission and disconnection states.

As shown in Figures 1 and 2, when the planting clutch 26 is operated into the transmission state, the seedling tray 10 is driven to move back and forth horizontally, while the rotating case 7 is driven to rotate counterclockwise in the plane of the page in Figure 1, and the planting arm 8 alternately picks up seedlings from the bottom of the seedling tray 10 and plants them in the rice field. When the planting clutch 26 is operated into the disengaged state, the reciprocating horizontal movement of the seedling tray 10 and the rotation of the rotating case 7 stop.

[4]
The automatic lifting control unit 59 of the seedling planting device 5 will be described.
As shown in Figure 4, the rear of the central float 9 is supported around the horizontal axis P1 of the seedling planting device 5 so that it can swing up and down, and a potentiometer-type height sensor 22 is provided to detect the height of the central float 9 relative to the seedling planting device 5, and the detection value of the height sensor 22 is input to the control device 23. As the machine moves forward, the central float 9 makes contact with the paddy field surface, and the height from the paddy field surface (central float 9) to the seedling planting device 5 can be detected from the detection value of the height sensor 22.

As shown in Figure 4, the automatic lift control unit 59 is provided as software in the control device 23, and the control valve 24, which supplies and discharges hydraulic oil to the hydraulic cylinder 4, is operated by the automatic lift control unit 59. When hydraulic oil is supplied to the hydraulic cylinder 4 by the control valve 24, the hydraulic cylinder 4 contracts and the seedling planting device 5 rises, and when hydraulic oil is discharged from the hydraulic cylinder 4 by the control valve 24, the hydraulic cylinder 4 extends and the seedling planting device 5 descends.

As shown in Figure 4, the automatic lift control unit 59 operates the control valve 24, causing the hydraulic cylinder 4 to extend and retract, and the seedling planting device 5 to automatically lift and lower so that the seedling planting device 5 is maintained at a set height above the rice field surface based on the height from the rice field surface (central float 9) (so that the detection value of the height sensor 22 (the vertical distance between the height sensor 22 and the central float 9) is maintained at the set value).

[5]
The lift lever 11 will now be described.
1, 2, and 4, a lift lever 11 is provided on the right side of the driver's seat 13, and the lift lever 11 is configured to be freely operable to an automatic position, a raised position, a neutral position, a lowered position, and a planting position, and the operating position of the lift lever 11 is input to a control device 23. A potentiometer 29 is provided to detect the vertical angle of the link mechanism 3 relative to the machine body, and the detection value of the potentiometer 29 is input to the control device 23.

As shown in Figure 4, when the lift lever 11 is operated to the raised position, neutral position, lowered position, or planting position (when the lift lever 11 is not operated to the automatic position), the functions of the first and second raised positions U1, U2 and the first and second lowered positions D1, D2 of the operating lever 12 described in [6] below do not operate, and only the functions of the right and left marker positions R, L of the operating lever 12 operate.

As shown in Figure 4, when the lift lever 11 is operated to the raised position, the automatic lift control unit 59 is stopped, the planting clutch 26 is disengaged by the electric motor 28, the right and left markers 19 are operated to the stored position by the electric motor 21, the control valve 24 is operated to the supply position, the hydraulic cylinder 4 is contracted, and the seedling planting device 5 is raised. When the potentiometer 29 detects that the seedling planting device 5 has reached the upper limit position, the control valve 24 is operated to the neutral position and the hydraulic cylinder 4 is automatically stopped.

As shown in Figure 4, when the lift lever 11 is operated to the lowered position, the automatic lift control unit 59 is stopped, the electric motor 28 operates the planting clutch 26 to the disengaged state, the electric motor 21 operates the right and left markers 19 to the stored position, the control valve 24 is operated to the discharge position, the hydraulic cylinder 4 is extended, and the seedling planting device 5 is lowered.

As shown in Figure 4, when the lift lever 11 is operated to the lowered position and the central float 9 touches the rice field surface, the central float 9 rises slightly. When the height sensor 22 detects that the central float 9 has touched the rice field surface (the central float 9 has risen slightly), the automatic lift control unit 59 becomes operational, and the seedling planting device 5 touches the rice field surface and stops.

As shown in Figure 4, when the lift lever 11 is operated to the neutral position, the automatic lift control unit 59 is stopped, the planting clutch 26 is disengaged by the electric motor 28, the right and left markers 19 are operated to the storage position by the electric motor 21, the control valve 24 is operated to the neutral position, and the hydraulic cylinder 4 is stopped. In this way, by operating the lift lever 11 to the raised, neutral, and lowered positions, the seedling planting device 5 can be raised and lowered to any height and stopped.

As shown in Figure 4, when the lift lever 11 is operated to the planting position, the electric motor 21 operates the right and left markers 19 to the stored position, the automatic lift control unit 59 is activated, and the electric motor 28 operates the planting clutch 26 to the transmission state. As a result, the seedling tray 10 is driven to move back and forth horizontally, which rotates the rotating case 7, and the planting arms 8 alternately pick up seedlings from the bottom of the seedling tray 10 and plant them in the rice field.

[6]
The operating lever 12 will now be described.
1, 2, and 4, an operating lever 12 is provided on the right side below the steering handle 20, and extends outward to the right side. The operating lever 12 is configured to be operable in a cross direction from a neutral position N to a first raised position U1, a second raised position U2 on the upper side, a first lowered position D1, a second lowered position D2 on the lower side, a rear right marker position R, and a front left marker position L. The operating position of the operating lever 12 is input to a control device 23.

As shown in FIG. 4, when the lift lever 11 is set to the automatic position, the operation lever 12 functions as follows.
4, when the operating lever 12 is operated to the second raised position U2, the planting clutch 26 is disengaged by the electric motor 28, the automatic lifting control unit 59 is stopped, the right and left markers 19 are operated by the electric motor 21 to the stored position, the control valve 24 is operated to the supply position, the hydraulic cylinder 4 is contracted, and the seedling planting device 5 is raised. When the potentiometer 29 detects that the seedling planting device 5 has reached the upper limit position, the control valve 24 is operated to the neutral position, and the hydraulic cylinder 4 is automatically stopped.

As shown in Figure 4, when the operating lever 12 is operated to the second lowered position D2, the electric motor 28 operates the planting clutch 26 to the disengaged state, the automatic lifting control unit 59 is stopped, and with the right and left markers 19 operated by the electric motor 21 to the stored position, the control valve 24 is operated to the discharge position, the hydraulic cylinder 4 is extended, and the seedling planting device 5 is lowered. When the center float 9 touches the rice field surface, the automatic lifting control unit 59 is activated, and the seedling planting device 5 touches the rice field surface and comes to a stop (see the state when the lifting lever 11 is operated to the lowered position described in the previous section [5]).
After operating the operating lever 12 to the second lowered position D2 and then to the neutral position N, when the operating lever 12 is again operated to the second lowered position D2, the planting clutch 26 is operated to a transmission state by the electric motor 28 while the automatic lifting control unit 59 is in an operating state.

When the automatic lift control unit 59 is stopped, the planting clutch 26 is disengaged by the electric motor 28, and the right and left markers 19 are moved to the storage position by the electric motor 21, as shown in Figure 4, operating the operating lever 12 to the first raised position U1 operates the control valve 24 to the supply position, contracts the hydraulic cylinder 4, and lifts the seedling planting device 5 only while the operating lever 12 is in the first raised position U1. When the operating lever 12 is operated to the neutral position N, the control valve 24 is operated to the neutral position and lifting of the seedling planting device 5 stops.

When the automatic lift control unit 59 is stopped, the planting clutch 26 is disengaged by the electric motor 28, and the right and left markers 19 are stored by the electric motor 21, operating the operating lever 12 to the first lowered position D1 as shown in Figure 4 operates the control valve 24 to the discharge position, extends the hydraulic cylinder 4, and lowers the seedling planting device 5 only while the operating lever 12 is in the first lowered position D1. When the operating lever 12 is operated to the neutral position N, the control valve 24 is operated to the neutral position and the lowering of the seedling planting device 5 stops.

As described above, the seedling planting device 5 can be raised and lowered only while the operating lever 12 is operated to the first raised and lowered positions U1 and D1, and the seedling planting device 5 can be raised and lowered to any height and then stopped.

As shown in Figure 4, when the operating lever 12 is operated to the right marker position R, the electric motor 21 operates the right marker 19 to the operating position. When the operating lever 12 is operated to the left marker position L, the electric motor 21 operates the left marker 19 to the operating position.

As described above, the lifting lever 11 described in the previous paragraph [5] and the operating lever 12 described in this paragraph [6] are used to lift and lower the seedling planting device 5, operate the planting clutch 26, and operate the right and left markers 19. The lifting and lowering of the seedling planting device 5 (activating and stopping the automatic lifting control unit 59), operating the planting clutch 26, and operating the right and left markers 19 in [9] to [13] described below are performed using the lifting lever 11 or the operating lever 12.

[7]
The configuration for detecting the position and direction of the aircraft will be described.
As shown in Figures 1 and 2, right and left support frames 16 are provided on the right and left front portions of the machine body, and spare seedling trays 15 are supported on the support frames 16. A support frame 17 is connected across the upper parts of the right and left support frames 16.

As shown in Figures 1 and 2, a measurement device 30 is attached to the support frame 17 in a portion located at the center CL of the aircraft in a plan view. The measurement device 30 is equipped with a receiving device (not shown) that acquires position information using a satellite positioning system, and an inertial measurement unit (not shown) that detects the inclination (pitch angle, roll angle) of the aircraft.

As shown in Figures 1 and 2, an inertial measurement unit 48 that measures inertial information is attached to the rear axle case 37 in a section located at the center CL of the vehicle body in a plan view. The inertial measurement unit 48 and the inertial measurement of the measurement unit 30 are configured using an IMU (Inertial Measurement Unit).

A representative example of the aforementioned satellite positioning system (GNSS: Global Navigation Satellite System) is the Global Positioning System (GPS). GPS measures the position of the receiver of the measurement device 30 using multiple GPS satellites orbiting the Earth, a control station that tracks and controls the GPS satellites, and a receiver provided in the target (aircraft) being positioned.

The inertial measurement unit 48 is equipped with a gyro sensor (not shown) that can detect the angular velocity of the aircraft's yaw angle (aircraft turning angle), and an acceleration sensor (not shown) that detects acceleration in three mutually perpendicular axial directions. The inertial information measured by the inertial measurement unit 48 includes orientation change information detected by the gyro sensor and position change information detected by the acceleration sensor.

[8]
The configuration related to automatic driving will be described.
1, 2, and 4, the operating position of the gearshift lever 45 is input to the control device 23. A center mascot 14 is provided at the front of the vehicle body at the center CL of the vehicle body in a plan view. A steering motor 51 is provided to steer the steering member 41.

As shown in Figures 3 and 4, a ring member 49 having many small irregularities formed on its outer periphery is fitted onto the clutch cases of the right and left side clutches 40, and right and left rotation speed sensors 50 of the proximity sensor type are fixed to the upper part of the rear axle case 37 so as to face the ring member 49, and the detection values of the right and left rotation speed sensors 50 are input to the control device 23.
Pulses are emitted from the right and left rotation speed sensors 50 in accordance with the unevenness of the ring member 49, and the rotation speeds of the right and left rear wheels 2 can be detected from the pulses of the right and left rotation speed sensors 50.

As shown in Figure 4, the control device 23 is provided with a reference direction setting unit 60, a setting unit 61, an automatic driving control unit 62, a turning end detection unit 63, a restraining unit 64, a reverse stop notification unit 65, a blocking notification unit 66, a permission notification unit 67, an operation notification unit 68, and a travel distance detection unit 69 as software.

As shown in Figures 2 and 4, an operation button 18 (corresponding to the operation unit) that manually operates the automatic driving control unit 62 to switch between the operating state and the stopped state is provided on the grip portion of the gear shift lever 45, and the operation signal of the operation button 18 is input to the control device 23.

As shown in Figures 2 and 4, a display panel 27 is provided at the front of the steering handle 20, a start point setting switch 46 is provided to the right of the display panel 27, and an end point setting switch 47 is provided to the left of the display panel 27. Operation signals from the start point and end point setting switches 46, 47 are input to the control device 23.

[9]
The operating mode of the riding rice transplanter will be explained.
For example, as shown in FIG. 5, in a paddy field that is square in plan view, a riding rice transplanter may adopt the following working form.

First, position the machine in the position shown in Figure 5 (starting position K1), lower the seedling planting device 5 to the rice field surface, and operate the left marker 19 to the operating position (the right marker 19 to the stored position). In this state, operate the planting clutch 26 to the disengaged state and travel along ridge B (automatic lift control unit 59 is in operating state), and use the left marker 19 to form an indicator on the rice field surface for the next work stroke L01 (standard work stroke LA1).

As mentioned above, during the standard operation stroke LA1, the seedling planting device 5 is lowered to the rice field surface and driven without the planting clutch 26 being operated into the transmission state, in order to erase the trails of the front and rear wheels 1 and 2 using the floats 9 of the seedling planting device 5.

As shown in Figure 5, when the machine reaches the edge of the paddy field from the standard work stroke LA1, the seedling planting device 5 is raised from the paddy field surface (automatic lifting control unit 59 is stopped), a turn LL1 (to the left) is performed, the seedling planting device 5 is lowered to the paddy field surface (automatic lifting control unit 59 is operating), the planting clutch 26 is operated to the transmission state, and work stroke L01 begins.

In work step L01, the left marker 19 is operated to the stored position and the right marker 19 is operated to the operating position, and the machine travels along the marker formed on the rice field surface in the standard work step LA1, planting seedlings while the right marker 19 forms an marker on the rice field surface for the next work step L02.

As shown in Figure 5, when the machine reaches the edge of the paddy field from work stroke L01, the planting clutch 26 is disengaged, the seedling planting device 5 is raised from the paddy field surface (automatic lift control unit 59 is stopped), a turn LL2 (to the right) is performed, the seedling planting device 5 is lowered to the paddy field surface (automatic lift control unit 59 is operating), the planting clutch 26 is operated to the transmission state, and work stroke L02 begins.

In work step L02, the right marker 19 is operated to the stored position and the left marker 19 is operated to the operating position, and the machine is caused to travel along the marker formed on the rice field surface in work step L01, planting seedlings while the left marker 19 forms an marker on the rice field surface for the next work step L03.

As shown in Figure 5, multiple work strokes L01, L02, L03, L04, and L05 and turns LL1 (left), LL2 (right), LL3 (left), LL4 (right), and LL5 (left) create an area along ridge B where no seedlings have been planted. In this state, when the machine reaches the edge of the ridge from work stroke L05, the planting clutch 26 is disengaged, the seedling planting device 5 is raised from the rice field surface (automatic lift control unit 59 is stopped), and a turn LL6 (right) is performed to position the machine at position K10.

As shown in Figure 5, at position K10, the seedling planting device 5 is lowered to the rice field surface (automatic lift control unit 59 is in operation), the planting clutch 26 is operated to the transmission state, and the right and left markers 19 are operated to the retracted position, and the device travels along ridge B (circling work process). As a result, seedlings are planted in the areas where seedlings have not been planted in work processes L01 to L05.

[10]
The state in which the present invention is applied to the working form of the riding rice transplanter described in the previous section [9] and Figure 5 will be described (part 1).
As shown in Figures 6 and 12, when the driver operates the start point setting switch 46 while the vehicle is positioned at the start point position K1 (step S1), the position of the vehicle at the time the start point setting switch 46 is operated is set as the start point position K1 based on the detection value of the measuring device 30 (step S2).

Next, as shown in Figures 6 and 12, the operator lowers the seedling planting device 5 to the rice field surface (automatic lift control unit 59 is in operation), operates the left marker 19 to the operating position (right marker 19 to the stored position), and maintains the planting clutch 26 in the disengaged state. The operator operates the control handle 20 and gear lever 45 to travel the machine along ridge B, and uses the left marker 19 to form an indicator for the next work stroke L01 on the rice field surface (reference work stroke LA1).

As shown in Figures 6 and 12, when the machine reaches the edge of the field from the standard work path LA1 and the driver operates the end point setting switch 47 (step S3), the machine's position at the time the end point setting switch 47 was operated is set as the end point position K2 based on the detection value of the measurement device 30 (step S4). Once the end point position K2 is set, the reference orientation setting unit 60 sets the straight line (orientation) connecting the start point position K1 and the end point position K2 as the reference orientation E (step S5).

Next, as shown in Figures 7 and 12, the driver raises the seedling planting device 5 (the automatic lifting control unit 59 is stopped, the planting clutch 26 is disengaged, and the right and left markers 19 are in the stored position), and operates the steering handle 20 and the speed change lever 45 to perform a turn LL1.
During the standard work process LA1, the left marker 19 forms an indicator for the next work process L01 on the rice field surface, so the driver seated in the driver's seat 13, while visually checking the center mascot 14 and the aforementioned indicator during the turn LL1, operates the control handle 20 to aim for the indicator on the rice field surface, and positions the machine at position K3.

In this case, because the seedling planting device 5 is being raised during rotation LL1, the rotation end detection unit 63 does not detect the end of rotation (step S6), and the restraint unit 64 prevents the automatic driving control unit 62 from being operated.

Therefore, even if the driver operates the operation button 18 in the above-mentioned state (step S7), the restraining unit 64 prevents the automatic driving control unit 62 from being operated (step S8), and the prevention notification unit 66 is activated to notify the driver that operation of the automatic driving control unit 62 has been prevented (by display on the display panel 27 and by audio notification) (step S9).

[11]
The state in which the present invention is applied to the working form of the riding rice transplanter described in the previous section [9] and Figure 5 will be described (part 2).
7 and 12, when the swing LL1 is completed and the machine is positioned at position K3, the operator lowers the seedling planting device 5 to the rice field surface (the automatic lift control unit 59 is in operation) (step S10), operates the planting clutch 26 to the transmission state, and operates the right marker 19 to the operating position (the left marker 19 to the retracted position). Then, the operator operates the control handle 20 and the speed change lever 45 to enter the next operation process L01.

As described above, when the height sensor 22 detects that the central float 9 has touched the paddy field surface (the central float 9 has risen slightly) due to the descent of the seedling planting device 5 (see the previous section [5]) (step S10), the end of rotation is detected by the rotation end detection unit 63 (step S11). In this case, the restraint unit 64 maintains a state in which the automatic driving control unit 62 is prevented from being operated.

As shown in Figures 7 and 13, when the work process L01 begins, the travel distance detection unit 69 begins detecting the travel distance D of the aircraft based on the detection value of the rotation speed sensor 50 (step S12).

As shown in Figures 8 and 13, even if the driver operates the operation button 18 (step S13) before the vehicle's travel distance D reaches the set distance D1, the restraining unit 64 prevents the automatic driving control unit 62 from being activated (step S14), and the prevention notification unit 66 is activated to notify the driver that the automatic driving control unit 62 has been prevented from being activated (by display on the display panel 27 and by audio notification) (step S15).

As shown in Figures 8 and 13, when the travel distance detection unit 69 detects that the vehicle's travel distance D has reached the set distance D1 (position K4) (step S16), the restraint unit 64 allows the automatic travel control unit 62 to be operated (step S17), and the permission notification unit 67 is activated to notify the user that the automatic travel control unit 62 is allowed to be operated (notification by display on the display panel 27 and audio) (step S18).

[12]
We will now explain the state in which the present invention is applied to the working form of the riding rice transplanter described in the previous section [9] and Figure 5 (part 3).
As shown in Figures 8 and 13, when the driver operates the operation button 18 (step S19) while the restraining unit 64 allows the automatic driving control unit 62 to be operated into an operating state (position K4), the automatic driving control unit 62 enters an operating state (step S20), and the operation notification unit 68 is activated to notify the driver that the automatic driving control unit 62 is in an operating state (notification by display on the display panel 27 and by voice) (step S21).

As shown in Figures 8 and 13, at the same time that the automatic driving control unit 62 enters an operating state, the setting unit 61 sets a set driving line LB1 parallel to the reference direction E from the position of the aircraft (position K4) at the time the automatic driving control unit 62 enters an operating state based on the detection value of the measuring device 30 (step S22).
In this case, if the position of the machine (position K4) at the time the automatic driving control unit 62 is activated is outside the indicator of work process L01 formed on the rice field surface by the left marker 19 in the standard work process LA1, the aforementioned indicator and the set driving line LB1 will not coincide.

As a result, as shown in Figures 9 and 13, when the automatic driving control unit 62 is in an operating state, the steering motor 51 is operated by the automatic driving control unit 62 based on the detection values of the measuring device 30 and the inertial measurement device 48 so that the vehicle automatically drives along the set driving line LB1 (the front wheel 1 is automatically steered).
In this case, the driver can operate the hydrostatic continuously variable transmission 33 by operating the speed change lever 45, thereby changing the traveling speed of the vehicle.

[13]
We will now explain the state in which the present invention is applied to the working form of the riding rice transplanter described in the previous section [9] and Figure 5 (part 4).
As shown in Figures 9 and 13, when the work process L01 is completed and the machine reaches the ridge B (position K5), the driver operates the operation button 18 to stop the automatic driving control unit 62 (step S23).

Next, similar to the turning LL1 described in the previous section [10], as shown in Figures 10 and 14, the driver raises the seedling planting device 5 (the automatic lifting control unit 59 is stopped, the planting clutch 26 is disengaged, and the right and left markers 19 are in the stored position), and operates the operating handle 20 and the shift lever 45 to perform turning LL2.
In this case, as with turning LL1, the driver seated in the driver's seat 13 visually checks the center mascot 14 and the indicator for the next work step L02 formed on the rice field surface by the right marker 19 during work step L01, and operates the control handle 20 to aim at the indicator on the rice field surface, positioning the machine at position K6 and entering work step L02.

As shown in Figure 11, at the turn LL2 and from position K6 to position K7, the same operations as steps S6 to S22 in Figures 12 and 13 are performed to set the set driving line LB2, and when the automatic driving control unit 62 is in an operating state (operation process L02), the steering motor 51 is operated by the automatic driving control unit 62 based on the detection values of the measuring device 30 and the inertial measurement device 48 so that the vehicle automatically drives along the set driving line LB2 (the front wheel 1 is automatically steered).
Thereafter, in the work steps L02 to L05 and the turns LL3 to LL5 shown in FIG. 5, the same operations as in steps S6 to S22 in FIGS. 12 and 13 are performed.

When the driver operates the shift lever 45 to the reverse side R while the automatic driving control unit 62 is in operation during the above-described work steps L01 to L05, the automatic driving control unit 62 is operated to a stopped state by the restraint unit 64, and the currently set driving line LB1 (LB2) is erased. At the same time, the reverse stop notification unit 65 is activated, and a notification is issued (by display on the display panel 27 and by voice) that the automatic driving control unit 62 has been operated to a stopped state.
In this case, when the automatic driving control unit 62 is operated to a stopped state based on the shift lever 45 being operated to the reverse side R, even if the driver operates the operation button 18, the restraint unit 64 prevents the automatic driving control unit 62 from being operated to an operating state.

As described above, when the automatic travel control unit 62 is in a stopped state due to the shift lever 45 being operated to the reverse side R, if the driver operates the shift lever 45 to the neutral position N or the forward side F, the automatic travel control unit 62 will be permitted to be operated into an active state by the restraint unit 64 after the vehicle has traveled the set distance D1 since the driver operated the shift lever 45 to the neutral position N or the forward side F, as in steps S12 to S19 of Figure 13.

After this, when the driver operates the operation button 18 while the restraint unit 64 allows the automatic driving control unit 62 to be put into an operating state, the automatic driving control unit 62 enters an operating state, and a new set driving line LB1 (LB2) is set parallel to the reference direction E from the position of the aircraft at the time the automatic driving control unit 62 enters an operating state.

[First Alternative Embodiment of the Invention]
In the above-mentioned [Form for implementing the invention], instead of setting the reference direction E and the set driving lines LB1, LB2 each time the operation button 18 is operated, the position information of the paddy field (farm field) may be prepared in advance as map data, and the set driving lines LB1, LB2 may be set in advance in the map data of the paddy field (farm field).
In this case, instead of setting the multiple set driving lines LB1, LB2 parallel to each other, the multiple set driving lines LB1, LB2 may be set so as to be inclined relative to each other, or the multiple set driving lines LB1, LB2 may be set so as to be perpendicular to each other.

As mentioned above, if map data of the rice paddy (field) is provided, the positional relationship between the position of the machine and the ridge B can be recognized.
In this case, when the automatic driving control unit 62 is in an operating state, it can be configured to issue an alert when the vehicle approaches ridge B, and when the automatic driving control unit 62 is in a stopped state, it can be configured not to issue an alert when the vehicle approaches ridge B.

[Second Alternative Embodiment of the Invention]
In the above-mentioned [Form for implementing the invention] [First alternative form for implementing the invention], instead of the set distance D1 (see steps S12 to S16 in Figures 8, 11, and 13), the automatic driving control unit 62 may be configured to be allowed to be operated into an operating state by the restraint unit 64 when the vehicle has traveled for a set time.

In the above-mentioned [Form for implementing the invention] [First alternative form for implementing the invention], the set distance D1 (see steps S12 to S16 in Figures 8, 11, and 13) may be eliminated, and when the turns LL1 to LL5 are completed (when the end of the turn is detected by the turn end detection unit 63), the restraint unit 64 may immediately allow the automatic driving control unit 62 to be operated to an operating state.
Similarly, in [13] of the aforementioned [Form for implementing the invention], when the shift lever 45 that has been operated to the reverse side R is operated to the neutral position N or the forward side F, the restraining unit 64 may immediately allow the automatic driving control unit 62 to be operated to an operating state.

[Third Alternative Embodiment of the Invention]
In the above-described [Mode for Carrying Out the Invention], [First Alternative Embodiment of the Invention], and [Second Alternative Embodiment of the Invention], the check unit 64 may be provided with the following functions.
As shown in Figure 15, when the driver operates the operation button 18 while the restraint unit 64 allows the automatic driving control unit 62 to be operated into an operating state, the measurement device 30 (corresponding to the direction detection unit) and the inertial measurement unit 48 (corresponding to the direction detection unit) detect the direction E1 of the aircraft at the time the driver operates the operation button 18.

At the same time as detecting the aircraft's heading E1 as described above, the set driving lines LB1, LB2 (reference heading E) are compared with the aircraft's heading E1, and if the angular difference θ1 between the set driving lines LB1, LB2 (reference heading E) and the aircraft's heading E1 does not exceed the set value, the automatic driving control unit 62 is maintained in an operating state (operation to the automatic driving control unit 62 in an operating state is permitted).

At the same time as detecting the aircraft's heading E1 as described above, the set driving lines LB1, LB2 (reference heading E) are compared with the aircraft's heading E1, and if the angular difference θ1 between the set driving lines LB1, LB2 (reference heading E) and the aircraft's heading E1 exceeds a set value, the automatic driving control unit 62 is operated to a stopped state (the automatic driving control unit 62 is prevented from being operated).

In this case, the driver is notified that the angular difference θ1 exceeds the set value (by display on the display panel 27 and by audio notification), so he or she operates the control handle 20 to align the aircraft's heading E1 with the set driving lines LB1, LB2 (reference heading E) (so that the angular difference θ1 becomes smaller than the set value).

After this, when the angle difference θ1 becomes smaller than the set value, the restraint unit 64 allows the automatic driving control unit 62 to be operated into an operating state, and the permission notification unit 67 is activated to notify that the automatic driving control unit 62 is allowed to be operated into an operating state (by display on the display panel 27 and by audio notification).
As a result, when the driver operates the operation button 18, the automatic driving control unit 62 is operated to an active state.

[Fourth Alternative Embodiment of the Invention]
In the aforementioned [third alternative embodiment of the invention], when the vehicle's orientation E1 at the time the driver operates the operation button 18 is detected, instead of comparing the set driving lines LB1, LB2 (reference orientation E) with the vehicle's orientation E1, the vehicle may be configured as described below.

The system detects the direction of a straight line connecting the aircraft's position at the time the driver operates the operation button 18 with the aircraft's position a predetermined distance behind (past) this position, compares this direction with the aircraft's direction E1, and determines the angular difference θ1. Based on the result of this comparison (angular difference θ1), the system performs the operations described in the aforementioned "Third Alternative Embodiment of the Invention."

[Fifth Alternative Embodiment of the Invention]
In the above-mentioned [Form for implementing the invention], [First alternative embodiment of the invention] to [Fourth alternative embodiment of the invention], as shown in FIG. 16, the automatic deceleration unit 70 and the deceleration notification unit 71 may be provided as software in the control device 23.

As shown in Figure 15, when the driver operates the operation button 18 while the restraint unit 64 allows the automatic driving control unit 62 to be put into an operating state, the measurement device 30 (corresponding to the orientation detection unit) and the inertial measurement unit 48 (corresponding to the orientation detection unit) detect the aircraft's orientation E1 at the time the driver operates the operation button 18.

At the same time as detecting the aforementioned aircraft orientation E1, the set driving lines LB1, LB2 (reference orientation E) are compared with the aircraft orientation E1, and if the angular difference θ1 between the set driving lines LB1, LB2 (reference orientation E) and the aircraft orientation E1 exceeds a set value, the automatic deceleration unit 70 activates the actuator 52, and the speed change lever 45 (hydrostatic continuously variable transmission 33) is operated to the low speed side (or the accelerator lever (not shown) of the engine 31 is operated to the low speed side).
At the same time, the deceleration notification unit 71 is activated to notify the user that the vehicle's traveling speed has been decelerated by the automatic deceleration unit 70 (by display on the display panel 27 and by voice notification).

In the above-described [Embodiment for Carrying Out the Invention], [First Alternative Embodiment of the Invention], and [Second Alternative Embodiment of the Invention], when the automatic travel control unit 62 is operated to an active state, the travel speed of the vehicle is decelerated by the automatic deceleration unit 70.

After this, when the angle difference θ1 becomes smaller than the set value by the automatic cruise control unit 62 (or the driver operates the steering wheel 20 against the steering motor 51), the automatic deceleration unit 70 stops and an alert is issued (by display on the display panel 27 and by voice), allowing the driver to operate the gear shift lever 45 (or accelerator lever) to the high-speed side (original operating position).

In the above-mentioned [Third alternative embodiment of the invention] and [Fourth alternative embodiment of the invention], when the automatic driving control unit 62 is operated to a stopped state (a state in which operation of the automatic driving control unit 62 to an operating state is prevented), the automatic deceleration unit 70 decelerates the vehicle's running speed.
After this, when the driver operates the steering wheel 20 and the angle difference θ1 becomes smaller than the set value, the automatic deceleration unit 70 stops and this state is notified (by display on the display panel 27 and by voice), so the driver can operate the gear shift lever 45 (or accelerator lever) to the high-speed side (original operating position) and operate the operation button 18 to operate the automatic driving control unit 62 to the operating state.

In this section [fourth alternative embodiment of the invention], when the angular difference θ1 becomes smaller than a set value, the automatic deceleration unit 70 may be stopped, and the actuator 52 may automatically operate the gearshift lever 45 (or accelerator lever) to its original operating position.

[Sixth Alternative Embodiment of the Invention]
In the above-mentioned [Fifth Alternative Embodiment of the Invention], if the angular difference θ1 exceeds a set value, the speed change lever 45 (hydrostatic continuously variable transmission 33) may be configured to be unable to be operated to a higher speed (the accelerator lever may be configured to be unable to be operated to a higher speed), and an alert may be given that the vehicle's traveling speed cannot be increased ( an alert is given by display on the display panel 27 and by voice).

After this, when the driver operates the steering wheel 20 and the angular difference θ1 becomes smaller than the set value, the automatic deceleration unit 70 stops and this state is notified (by display on the display panel 27 and by voice), so the driver can operate the gear shift lever 45 (or accelerator lever) to the high-speed side and operate the operation button 18 to activate the automatic driving control unit 62.

[Seventh Alternative Embodiment of the Invention]
In the above-mentioned [Form for implementing the invention], [First alternative embodiment of the invention] to [Sixth alternative embodiment of the invention], instead of the configuration in which the end of rotation is detected by the rotation end detection unit 63 when the height sensor 22 detects that the central float 9 has touched the rice field surface (the central float 9 has risen slightly) due to the descent of the seedling planting device 5, the configuration described in (1) to (6) below may be used to detect the end of rotation by the rotation end detection unit 63.

(1)
A state in which the planting clutch 26 (a work clutch that transmits power to the work device) (see Figure 4) is operated to a transmission state.

(2)
The right (left) marker 19 (see FIG. 4) is in the operating position.

(3)
A state in which the steering member 41 (steering handle 20) (right and left front wheels 1) (see Figure 3) is operated from the right (left) steering limit A3 side beyond the right (left) set angle A2 toward the straight-ahead position A1 (equivalent to a state in which it is operated from a turning position to a straight-ahead position).

(4)
The right (left) side clutch 40 (see Figure 3), which was operated to the disengaged state, is operated to the transmission state, and the right and left side clutches 40 are restored to the state in which they are operated to the transmission state.

(5)
The aircraft's orientation E1 is detected by the measuring device 30 (corresponding to the orientation detection unit) and the inertial measurement device 48 (corresponding to the orientation detection unit), and the driver operates the operation button 18 to stop the automatic driving control unit 62, and then the aircraft's orientation E1 changes by a set angle (for example, approximately 180°).

(6)
A state in which a turning end switch (not shown) provided separately from the operation button 18 is manually operated by the driver.

In this case, two or more of the seven states, namely, the state in which the central float 9 touches the paddy field surface due to the descent of the seedling planting device 5 described above, and the seven states described in paragraphs (1) to (6), may be selected, and when the two or more selected states are established, the rotation end detection unit 63 may detect the end of rotation.

[Eighth Alternative Embodiment of the Invention]
The above-described [Mode for Carrying Out the Invention], [First Alternative Embodiment of the Invention] to [Seventh Alternative Embodiment of the Invention] may also be provided with the following configurations.

As shown in FIG. 17, power from the engine 31 is transmitted to the hydrostatic continuously variable transmission 33, and then to the right and left rear wheels 2 via a gear-type auxiliary transmission (not shown) and a rear wheel differential mechanism (not shown) in the transmission case 53. Power branched between the auxiliary transmission and the rear wheel differential mechanism is transmitted to the right and left front wheels 1 via the front wheel speed increasing device 54, transmission shaft 55, and front wheel differential mechanism 56.

As shown in Figure 17, the front wheel speed increaser 54 is configured to be freely operable between a standard state in which the front wheel 1 and rear wheel 2 are driven at approximately the same speed, and an accelerated state in which the front wheel 1 is driven at a higher speed than the rear wheel 2. The steering system for the front wheel 1 and the front wheel speed increaser 54 are linked by an operating device 57 (such as a linking rod or linking link), and the front wheel speed increaser 54 is operated as follows:

As shown in FIG. 17, when the right and left front wheels 1 are steered within a range of a straight ahead position A1 and right and left set angles A2, the front wheel speed increasing device 54 is operated in the standard state.
When the right and left front wheels 1 exceed the right set angle A2 and are steered toward the right (left) steering limit A3, the front wheel speed increase device 54 is operated to the speed increase state. As a result, the vehicle turns to the right (left) with the front wheels 1 driven at a higher speed than the rear wheels 2. When the right and left front wheels 1 exceed the left set angle A2 and are steered toward the straight ahead position A1, the front wheel speed increase device 54 is operated to the standard state.
In the above configuration, when the front wheel speed increasing device 54 is operated to the standard state, the turning end detecting section 63 is configured to detect the end of the turn.

In this case, a right hand brake (not shown) may be provided between the rear wheel differential mechanism and the right rear wheel 2, and a left hand brake (not shown) may be provided between the rear wheel differential mechanism and the left rear wheel 2.
When the right and left front wheels 1 exceed the right set angle A2 and are steered toward the right (left) steering limit A3, the front wheel speed increase device 54 is operated to an accelerating state, and the right (left) side brake is operated to a braking state (the left (right) side brake is released), so that the front wheels 1 are driven at a higher speed than the rear wheels 2 and the rear wheel 2 on the turning center side is braked, and the aircraft turns to the right (left). When the right and left front wheels 1 exceed the left set angle A2 and are steered toward the straight-ahead position A1, the front wheel speed increase device 54 is operated to a standard state, and the right (left) side brake is released.

[Ninth Alternative Embodiment of the Invention]
The above-described [Mode for Carrying Out the Invention], [First Alternative Embodiment of the Invention] to [Seventh Alternative Embodiment of the Invention] may also be provided with the following configurations.

Instead of the right and left front wheels 1 and the right and left rear wheels 2, the vehicle is equipped with right and left crawler traveling devices (equivalent to traveling devices) (not shown). Based on the detection values of the measurement device 30 and the inertial measurement device 48, the automatic traveling control unit 62 generates a difference in the driving speed of the right and left crawler traveling devices, thereby steering the vehicle so that it automatically travels along the set traveling line LB1.

When the right and left crawler travel devices are driven at the same drive speed (when the difference in drive speed between the right and left crawler travel devices is less than a set value), it is determined that the vehicle is not in a turning state. When the difference in drive speed between the right and left crawler travel devices exceeds the set value, it is determined that the vehicle is in a turning state.

In the above configuration, when the difference in drive speed between the right and left crawler traveling devices exceeds a set value and then falls below the set value, the turning end detection unit 63 detects that the turning has ended.

[Tenth Alternative Embodiment of the Invention]
In a tractor, which is an example of a work vehicle, a rotary tiller (corresponding to a working implement) (not shown) is supported at the rear of the vehicle body so that it can be raised and lowered. In a combine, which is also an example of a work vehicle, a harvester (corresponding to a working implement) (not shown) is supported at the front of the vehicle body so that it can be raised and lowered.
When lowering a rotary tillage implement (cutting implement) to the ground, the rotary tillage implement (cutting implement) is often lowered from a raised position to the ground while the rotary tillage implement (cutting implement) is operating (with the work clutch in a transmission state).

As a result, when the rotary tillage device is lowered to the ground, it is detected that the rotary tillage device has been lowered to the ground (that the tillage tines have touched the ground) based on the detection value of a height sensor (not shown) that detects the height of the rotary tillage device relative to the machine body, or based on the movement of the cover sensor (not shown) at the rear of the rotary tillage device to the rear (upward) side.
When the harvesting device is lowered to the ground, it is detected that the harvesting device has lowered to the ground based on the detection value of a height sensor (not shown) that detects the height of the harvesting device relative to the machine body, or based on the detection of grain stalks in the field by a stalk base sensor (not shown) provided on the harvesting device.

[Eleventh Alternative Embodiment of the Invention]
In the above-mentioned [Form for implementing the invention], [First alternative embodiment of the invention] to [Tenth alternative embodiment of the invention], the operation button 18 may be eliminated, and the control device 23 may be provided with an operation unit as software.
As a result, when the end of the turn is detected by the turn end detection unit 63 and the restraint unit 64 allows the automatic driving control unit 62 to be operated into an operating state, the automatic driving control unit 62 is automatically operated into an operating state by the operation unit of the control device 23.

[Twelfth Alternative Embodiment of the Invention]
The above-described [Mode for Carrying Out the Invention], [First Alternative Embodiment of the Invention] to [Eleventh Alternative Embodiment of the Invention] may be configured as shown below.

In step S21 of FIG. 13, when the operation notification unit 68 is activated to notify that the automatic driving control unit 62 is in an operating state (notification by display on the display panel 27 and audio), the lamps (not shown) built into the start point and end point setting switches 46, 47 are configured to flash to notify that the automatic driving control unit 62 is in an operating state.

In steps S9 and S15 of Figures 12 and 13, if the prevention notification unit 66 is activated to notify that the restraint unit 64 has prevented the automatic driving control unit 62 from being operated to an operating state, for example, a display is made on the display panel 27, but no audio notification is made. No display is made on the display panel 27, and no audio notification is made. No display is made on the display panel 27, and no audio notification is made.

The system notifies the driver that the automatic driving control unit 62 is stopped (by displaying a message on the display panel 27 or by audio notification, etc.). Alternatively, if the automatic driving control unit 62 is stopped, no notification is given.

An operating switch (not shown) is provided that can be manually switched between a state in which the various notifications mentioned above (such as display on the display panel 27 or audio notifications) are made and a state in which they are not made.

The present invention can be applied not only to riding rice transplanters, but also to riding direct seeding machines, work vehicles such as combine harvesters and tractors, and work vehicles for civil engineering and construction.

REFERENCE SIGNS LIST 1 Traveling device, front wheel 2 Traveling device, rear wheel 5 Work device 18 Operation unit 20 Steering operation unit 26 Work clutch 30, 48 Direction detection unit 33 Traveling transmission 40 Side clutch 41, 44 Side clutch operation unit 45 Speed change operation unit 54 Front wheel speed increase device 57 Operation device 61 Setting unit 62 Automatic travel control unit 63 Turning end detection unit 64 Restraint unit 65 Reverse stop notification unit 66 Block notification unit 67 Allowance notification unit 68 Operation notification unit 70 Automatic deceleration unit 71 Deceleration notification unit D1 Set distance E Reference direction E1 Airframe direction LB1, LB2 Set travel line LL1, LL2 Turning θ1 Angle difference

Claims (3)

a setting unit for setting a set driving line;
an automatic travel control unit that operates a travel device so that the device automatically travels along the set travel line;
an operation unit that manually operates the automatic travel control unit between an operating state and a stopped state;
a steering member that accepts steering operation between left and right steering limits and a straight-ahead position;
a turning end detection unit that detects a state in which the steering member is operated from the steering limit side to the straight- ahead position side beyond a set angle at which power transmission to the traveling device is turned on and off as the end of turning;
A work vehicle equipped with a restraining unit that prevents the operating unit from operating the automatic driving control unit to an operating state when the end of the turn is not detected by the turn end detection unit, and immediately allows the automatic driving control unit to operate to an operating state when the end of the turn is detected. The work vehicle described in claim 1, wherein the set driving line is not set when turning between the set driving lines, but is generated based on the vehicle's position at the time the automatic driving control unit is activated by the operating unit. Further comprising a notification unit that issues a predetermined notification,
The work vehicle according to claim 1 or 2, wherein the notification unit issues a notification when a state in which operation to the operating state is permitted is reached.