JP2018166485A - Paddy field working vehicle - Google Patents

Abstract

To provide a paddy field working vehicle in which upper and lower displacement of front wheels is detected, and lifting/lowering control and horizontal control of a planting unit are performed according to each change, and thereby the planting accuracy is improved further.SOLUTION: A paddy field working vehicle includes: a traveling unit 2 supported by front wheels 6, 6 and rear wheels 7, 7; a planting unit 20 supported to the traveling unit 2 in a lifting/lowering manner; a lifting/lowering control unit 60a for controlling the lifting/lowering of the planting unit 20; a float sensor 63 provided in a float 27 of the planting unit 20, and detecting the lifting/lowering displacement of the float 27; a suspension sensor 61 for detecting the stretching displacement of a suspension mechanism provided at the front wheels 6, 6; and a front-rear inclination sensor 62 provided at the traveling unit 2, and detecting the longitudinal inclination of a machine body. A memory unit 66 of the lifting/lowering control unit 60a stores a gain map according to a relationship between the detection value from the front-rear inclination sensor 62 and the detection value of the suspension sensor 61. The lifting/lowering control unit 60a acquires a control amount based on the gain g obtained from the gain map, and performs the lifting/lowering control.SELECTED DRAWING: Figure 4

Description

  The present invention relates to raising / lowering control and horizontal control of a planting part in a paddy field work vehicle in which a planting part for transplanting seedlings is attached to a rear part of a traveling part so as to be able to move up and down.

  Conventionally, a suspension mechanism is provided on the front wheel support part of a rice transplanter with a planting part mounted on the rear part of the traveling part, and the displacement of the lower case of the lower case of the suspension mechanism is detected and planted according to the displacement. A technique for raising and lowering the part is disclosed (for example, see Patent Document 1).

JP 2015-123046 A

However, in the above technique, the vertical movement of the front wheel of the traveling unit is detected to detect the depth of the field, and the planting unit is moved up and down according to the depth, but the front wheel of the traveling unit is a suspension mechanism. Therefore, the forward / backward inclination of the traveling part occurs later than the raising / lowering operation of the front wheels, and the inclination angle and the inclination speed of the traveling part vary depending on the elevation height of the front wheels. Therefore, although the height of the planting part also changes due to the tilting of the traveling part in the front-rear direction, the technique of the above-mentioned patent document cannot sufficiently cope with it. In other words, at the position where the front wheel enters the recess (partially deep part) of the cultivator, the traveling part tilts forward and the planting part keeps the planting depth constant against the forward descending of the traveling part. The field scene is not deep (lower) at the position of the planting part. Therefore, the raising / lowering control of the planting part so that the height of the planting part does not change with respect to the inclination of the traveling part due to the front wheel moving up and down by the unevenness of the cultivator, and the planting part is uneven on the field surface However, it is necessary to control the raising / lowering control so that the planting depth does not change according to each change.
In addition, the left and right front wheels are each equipped with a suspension mechanism, and the traveling section tilts to the left and right when passing through the unevenness of the tillage. It wasn't done.

  Therefore, the present invention detects the vertical displacement of the front wheel according to each change, in addition to the elevation control for raising and lowering the planting unit according to the field depth detected by the float sensor provided in the planting unit. Then, the planting part is controlled to move up and down and level, so that the planting accuracy can be further improved.

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
That is, according to the first aspect, the traveling unit supported by the front wheels and the rear wheels, the planting unit supported by the traveling unit so as to be movable up and down, the elevation control unit that controls the elevation of the planting unit, and the front wheel are provided. A suspension sensor that detects expansion / contraction displacement of the suspension mechanism, and a front / rear inclination sensor that is provided in the traveling unit and detects an inclination of the airframe in the front / rear direction, and the elevation control unit detects a value from the front / rear inclination sensor Ascending / descending control is performed based on the detected value from the suspension sensor.
In Claim 2, the float of the said planting part is provided with the float sensor which detects the raising / lowering displacement of a float, and the said raising / lowering control part performs raising / lowering control further from the detected value from the said float sensor. .
According to a third aspect of the present invention, the storage unit of the lift control unit stores a gain map corresponding to the relationship between the detection value from the front / rear tilt sensor and the detection value of the suspension sensor, and the lift control unit stores the gain The control amount is acquired based on the gain obtained from the map, and the elevation control is performed.

In claim 4, the traveling unit supported by the front and rear wheels, the planting unit supported by the traveling unit so as to be movable up and down, the horizontal control unit for horizontally controlling the planting unit, and the left and right front wheels, respectively A suspension sensor that detects expansion / contraction displacement of the suspension mechanism provided, and a left / right tilt sensor that is provided in the traveling unit and detects a tilt of the airframe in the left / right direction, and the horizontal control unit detects from the left / right tilt sensor. The horizontal control is performed based on the value and the detected value from the suspension sensor.
According to a fifth aspect of the present invention, the storage unit of the horizontal control unit stores a gain map corresponding to the relationship between the detection value of the suspension sensor and the detection value from the left / right tilt sensor, and the horizontal control unit stores the gain map from the gain map. A control amount is acquired based on the gain obtained, and horizontal control is performed.

  According to a sixth aspect of the present invention, the detected value of the traveling speed is input to the elevation control unit and / or the horizontal control unit, and the elevation control and / or the horizontal control corresponding to the traveling speed is performed.

  By using the means as described above, even when the traveling unit is tilted back and forth and left and right due to unevenness of the tiller during planting work, the planting unit can be controlled to move up and down and / or be horizontal against changes in the traveling unit. As a result of the control, a stable state was obtained, the planting depth was stabilized, the stock removal could be prevented, and the planting accuracy could be improved.

Whole side view of rice transplanter. The front sectional view of a suspension mechanism. The side view of a planting apparatus and a float. Control block diagram. Block diagram. The figure which shows the gain map of raising / lowering control. The figure which shows the gain map of horizontal control.

  Embodiments of the present invention will be described in detail. FIG. 1 is a side view of a rice transplanter 1 as a work vehicle. In the following description, the F direction in FIG. 1 is defined as the front direction, and the left / right direction is defined with respect to the forward traveling direction.

  1 and 2, a rice transplanter 1 includes a traveling unit 2, a fertilizer device 15 disposed on the rear part of the traveling unit 2, and a planting unit connected to the rear part of the traveling unit 2 via a lifting and lowering coupling device 10. Attached part 20 and the like are provided.

  In the traveling unit 2, an engine 30 as a power source is placed on the front portion of the vehicle body frame 3, and the engine 30 is covered with a bonnet 4. A mission case 5 is provided behind the engine 30. A transmission is provided in the transmission case 5, and front wheels 6 and 6 are supported from the left and right sides of the transmission case 5 via front axle cases 9 and 9. The left and right rear wheels 7 and 7 are supported behind the transmission case 5 via the rear axle case 8, and the power from the engine 30 is transmitted to the front wheels 6 and 6 and the rear wheels 7 and 7, respectively, so that the vehicle can be driven. Yes.

  A dashboard 14 is provided at the rear part of the bonnet 4, and a steering handle 12 projects upward from the top of the dashboard 14. By rotating the steering handle 12, the direction of the front wheels 6 and 6 is changed through the steering device. A control device 60 is accommodated in the dashboard 14. A driver's seat 13 is provided behind the dashboard 14 at a predetermined distance, and a fertilizer device 15 is disposed on the vehicle body frame 3 behind the driver's seat 13, and an appropriate position of the vehicle body frame 3, for example, the front and rear circumferences An inclination sensor 62 is disposed at a substantially central position on the left and right. The tilt sensor 62 detects the tilt in the front-rear direction and the left-right direction. The tilt sensor 62 is connected to the control device 60 (FIG. 4). Note that the inclination speed and acceleration can be obtained by differentiating the detection value of the inclination sensor 62, but an angular velocity sensor and an acceleration sensor can be separately arranged.

Next, the configuration in the front axle case 9 will be described with reference to FIG. Since the front axle case is configured symmetrically, only the left and right sides will be described.
The front axle case 9 includes an output case 40 that protrudes laterally from the left and right sides of the transmission case 5, a vertical case 41 that is fixed to a side end of the output case 40, and a substantially horizontal lower side of the vertical case 41. The lower case 42 etc. attached rotatably are provided. A downward-opening cylindrical case cover 44 is fixed to the upper side of the vertical case 41.

  A front wheel drive shaft 45 is rotatably supported in the output case 40, and a bevel gear 46 is fixed to the outer end portion of the front wheel drive shaft 45. The bevel gear 46 is meshed with a bevel gear 47 fixed to an upper portion of a kingpin drive shaft 43 that is rotatably supported by the vertical case 41 and the lower case 42 in the vertical direction.

  A front axle 48 projecting leftward and rightward is rotatably supported at the lower portion of the lower case 42, and the front wheel 6 is attached to the front axle 48. A bevel gear is fixedly engaged with the machine body side of the front axle 48 and the lower end of the kingpin drive shaft 43, and the power from the engine 30 is transmitted to the front via the transmission case 5, the front wheel drive shaft 45, the kingpin drive shaft 43, and the like. Transmission to the axle 48 is possible.

  A knuckle arm 49 is fastened to the upper outer side of the lower case 42 with bolts or the like. The knuckle arm 49 is connected to a steering device via a tie rod, and the left and right front wheels 6. 6 can be rotated left and right.

  A base portion of the knuckle arm 49 is extended upward, and a cylindrical rotation support portion 49a is formed on the upper end side. The rotation support portion 49a is fitted on the case cover 44 so as to be slidable and rotatable. A suspension spring 50 and a holder 51 made up of a plurality of compression coil springs having different diameters are housed inside the case cover 44, and the lower part of the suspension spring 50 is brought into contact with the upper end of the kingpin drive shaft 43 via the holder 51. The front wheel 6 is always urged downward through the drive shaft 43 and the lower case 42.

  Thus, the suspension mechanism is configured. The suspension mechanism tries to hold the front part of the traveling unit 2 at a constant height. When the front wheel 6 travels in the recess, the suspension spring 50 extends to lower the front wheel 6 and when the front wheel 6 travels the convex part, the suspension mechanism The spring 50 contracts to raise the front wheel 6 and the front wheels 6 and 6 follow the road surface to prevent slipping.

  A suspension sensor 61 is provided as means for detecting the amount of elevation of the front wheel 6. The suspension sensor 61 is connected to the control device 60. The suspension sensor 61 fixes a magnetic body to the kingpin drive shaft 43 and arranges a coil in the vertical case 41 so as to detect a change in magnetic force as a lift amount. However, the configuration of the suspension sensor 61 is not limited, and the potentiometer may be fixed to the vertical case 41 and the detection unit may be engaged with the kingpin drive shaft 43, or the pressure applied to the suspension spring 50 may be detected. The structure which makes a raising / lowering amount may be sufficient.

  The control device 60 includes a CPU, a RAM and ROM as a storage unit 66, an interface and the like. The control device 60 includes an elevation control unit 60a and a horizontal control unit 60b, and a storage unit 66 stores a control program, gain map, various data, and the like for performing elevation control (pitching control) and horizontal control.

  The planting unit 20 is connected to the rear part of the traveling unit 2 via the lifting and lowering connecting device 10, and the lifting and lowering connecting device 10 includes a top link 23, a lower link 24, and the like, and is provided at the rear part of the traveling unit 2. The planting unit 20 can be moved up and down by extending and contracting a hydraulic cylinder that serves as the planting unit lifting and lowering actuator 35. The planting part raising / lowering actuator 35 is connected to and controlled by the control device 60.

  As shown in FIGS. 1 and 3, the planting unit 20 includes a seedling mounting base 21 on which a seedling mat is placed, a plurality of planting devices 22 for planting seedlings in a farm field, and the like. The seedling stage 21 is arranged so as to incline from front to rear and low, and is arranged so as to be slidable left and right on a seedling rail provided on the planting frame 26. In addition, an inclination actuator 29 is provided between the planting frame 26 (the seedling stage 21) and the lifting and lowering coupling device 10, and the seedling stage 21 can be tilted left and right by the operation of the inclination actuator 29. The tilt actuator 29 is connected to the control device 60, and the control device 60 controls the planting portion 20 to be horizontal by operating the tilt actuator 29 during planting work.

The planting unit 20 includes a planting mission case and a plurality of planting transmission cases 28 extending rearward from the planting mission case below the seedling stage 21, and left and right of the rear end of each planting transmission case 28. The planting device 22 is disposed respectively.
The transmission of power to the planting mission case is performed by transmitting power from the engine 30 to the transmission case 5 provided in the traveling unit 2 and the power transmission case for work implements, and shifting from the power transmission case for work implements. Power is transmitted to the fertilizer application device 15 and the planting unit 20.

  The planting device 22 has planting claws 25 and 25 arranged on both sides of a rotary case rotatably provided on the left and right of the rear portion of the planting transmission case 28, and the power from the engine 30 is used for planting a mission case and planting. The rotary case is rotated through the transmission case 28 and the like, the planting claws 25 and 25 are swung, and a predetermined amount of seedlings are scraped off from the seedling mount 21 and conveyed downward to be planted in the field. Yes.

  A float 27 is provided below the planting frame 26. The float 27 is arranged so that its lower surface can contact the ground. Thereby, the ground can be leveled and planting can be performed cleanly. As shown in FIG. 3, the float 27 is configured to be rotatable up and down around a swing support shaft 32. The float 27 is urged downward by the pressing member 33 at a position in front of the swing support shaft 32. That is, a force is applied so that the front end portion of the float 27 is pressed against the ground.

  At least one of the plurality of floats 27 is provided with a float sensor (float position detection unit) 63 that detects a swing angle (float position) of the float 27. The float sensor 63 is configured as a potentiometer, for example. The detection value of the float sensor 63 is output to the control device 60. In the following description, the swing angle of the float 27 detected by the float sensor 63 may be simply referred to as a float angle.

  In the rice transplanter 1 of this embodiment, the elevating control unit 60a feedback-controls the elevating control of the planting unit 20 so that the float angle detected by the float sensor 63 approaches the target value (target angle) of the float angle. To do. PID control is performed as an example of feedback control. That is, as shown in FIGS. 4 and 5, the target height (planting depth) is set by the height setting machine 64 and compared with the measured value detected by the float sensor 63, and the deviation is compared with the PID control unit 65. Is calculated to operate the lifting actuator 35. For example, when the float 27 is lowered forward compared to the target angle, it means that the planting unit 20 is too high with respect to the ground. Is operated to lower the planting part 20. On the other hand, when the float 27 is lifted forward compared to the target angle, the planting unit 20 is too low with respect to the ground. Therefore, the control device 60 operates the lifting actuator 35 to plant the plant. The appendage 20 is raised.

  The elevating control unit 60 a of the control device 60 according to the present embodiment performs elevating control using the detection values from the float sensor 63 and the front / rear inclination sensor 62 and the detection values from the suspension sensor 61. In other words, the lift control unit 60a automatically changes the target angle of the float 27 based on the detection values of the tilt sensor 62, the float sensor 63, and the suspension sensor 61 to change the gain g of the PID control so that the lift actuator 35 Control. The gain g of the PID control is obtained from the gain map shown in FIG. The gain map is stored in the storage unit 66 of the control device 60, and the inclination angle θ obtained from the inclination sensor 62 of the traveling unit 2 and the float 27 obtained from the float sensor 63 rotate around the swing support shaft 32. A gain map having a relationship with the moving angular velocity Δω is created, and a map is created by assigning a gain g as a control amount corresponding to each value of the displacement Δd of the front wheel 6 obtained from the suspension sensor 61. .

  In the pitching control, for example, in the planting work on the tiller having almost no unevenness, the change in the detected value from the suspension sensor 61 and the float sensor 63 is small. At this time, the control gain g in the lifting control of the planting unit 20 By lowering, the raising / lowering control is shifted to the insensitive side, and the ascending speed of the planting part 20 is reduced. Thereby, the unnecessary raising / lowering motion of the planting part 20 can be suppressed. Further, in the planting work on the uneven cultivator, the change in the detection value from the suspension sensor 61 is large, and the inclination angle θ is also large. At this time, by increasing the control gain g, the elevation control is shifted to the sensitive side, and the elevation speed of the planting unit 20 is increased. Thereby, it can respond to an unevenness | corrugation quickly and the planting part 20 can perform a highly accurate planting operation | work.

Next, horizontal control of the planting unit 20 will be described.
In the present embodiment, the inclination angle of the traveling unit 2 is detected by the inclination sensor 62 provided on the vehicle body frame 3. However, the rolling (left-right inclination) of the vehicle body frame 3 may be detected from the difference between the detection values of suspension sensors 61L and 61R (not shown) provided on the left and right front axle cases 9.

  The horizontal control unit 60 b performs horizontal control based on the detection value from the left / right tilt sensor 62 and the detection value from the suspension sensor 61. In other words, a gain map of the relationship between the left / right inclination angle α obtained from the inclination sensor 62 of the traveling unit 2 and the angular velocity Δβ is created, and further, according to each value of the displacement Δd of the front wheel 6 obtained from the suspension sensor 61. A gain map to which a gain G as a control amount is assigned is created as shown in FIG. 7 and stored in the storage unit 66 in the same manner as described above, and is applied to the horizontal control of the planting unit 20. For example, the tilt actuator 29 is actuated in the upward right direction when the slope is lowered to the right, and the tilt actuator 29 is actuated in the upward direction when the slope is lowered to the left. At this time, when the deviation of the detection value of the suspension sensor 61 is large, the body frame 3 is greatly inclined to the right or left. Therefore, the control device 60 increases the control gain G corresponding to the deviation to shift the sensitivity of the tilt control to the sensitive side. Thereby, since the inclination speed of the planting part 20 increases, the planting part 20 respond | corresponds to tilting quickly, and keeps level. Further, when the deviation of the detected value of the suspension sensor 61 is small, the control gain G corresponding to the deviation is decreased, and the sensitivity of the inclination control is shifted to the insensitive side. Thereby, since the inclination speed of the planting part 20 falls, the planting part 20 does not incline frequently, and a planting precision can be improved. For the displacement Δd of the suspension sensor 61, the larger one of the detected values of the left and right suspension sensors 61L and 61R may be adopted in the map, and the difference between the detected values of the left and right suspension sensors 61L and 61R is calculated. You may adopt it on the map.

  Further, a vehicle speed sensor 67 is provided in the traveling unit 2 and connected to the control device 60, and the gain g · G can be adjusted according to the traveling speed of the rice transplanter 1. For example, the vehicle speed sensor 67 detects the rotation speed of the output shaft of the mission case 5 or the rear axle of the rear axle case 8 to obtain the vehicle speed. Also in this case, a gain map corresponding to the traveling speed is created. The gain K decreases the gain K as the speed increases, and shifts the sensitivity of the elevation control and / or the horizontal control to the insensitive side. Thereby, since the raising / lowering speed and / or inclination speed of the planting part 20 fall, the planting part 20 does not frequently raise / lower and / or tilt, and the stable planting work can be performed. Further, the gain K is increased as the vehicle speed is slower, and the sensitivity of the lift control and / or the tilt control is shifted to the sensitive side. Thereby, since the raising / lowering speed and / or inclination speed of the planting part 20 increase, the raising / lowering and / or tilting of the planting part 20 respond | corresponds quickly, maintaining a setting height and keeping horizontal. Become.

  As described above, the traveling unit 2 supported by the front wheels 6 and 6 and the rear wheels 7 and 7, the planting unit 20 that is supported by the traveling unit 2 so as to be movable up and down, and the elevation that controls the elevation of the planting unit 20 A control unit 60a, a suspension sensor 61 that detects expansion and contraction displacement of a suspension mechanism provided on the front wheels 6 and 6, and a front / rear inclination sensor 62 that is provided on the traveling unit 2 and detects inclination in the front-rear direction of the airframe. The elevating control unit 60a performs elevating control based on the detected value from the front / rear tilt sensor 62 and the detected value of the suspension sensor 61. Therefore, during planting work, the front wheels 6 and 6 reach the unevenness of the tillage, etc. When 2 is tilted back and forth, the change in the suspension mechanism is faster than the actual change in the inclination of the traveling unit 2, which is detected by the suspension sensor 61 and can be used for correction control. As a result, the planting unit 20 can obtain a stable state with respect to the change of the traveling unit 2, the planting depth is stable, and the stocking can be prevented. The planting accuracy can be improved.

In addition, a float sensor 63 provided on the float 27 of the planting unit 20 for detecting the vertical displacement of the float 27 is provided, and the vertical control unit 60a further performs the vertical control from the detection value from the float sensor 27. Therefore, since the attitude of the float 27 itself is also detected and the attitude is corrected, more accurate elevation control can be performed.
The storage unit 66 of the elevation control unit 60a stores a gain map corresponding to the relationship between the detection value from the front / rear inclination sensor 62 and the detection value of the suspension sensor 61, and the elevation control unit 60a Since the control amount is acquired based on the gain obtained from the gain map and the elevation control is performed, the optimum gain g can be obtained and used for the control, and the elevation control can be performed more quickly and accurately than before. .

  Further, the traveling unit 2 supported by the front wheels 6 and 6 and the rear wheels 7 and 7, the planting unit 20 supported by the traveling unit 2 so as to be movable up and down, and a horizontal control unit 60b for controlling the planting unit 20 horizontally. A suspension sensor 61 for detecting expansion / contraction displacement of a suspension mechanism provided on each of the left and right front wheels 6 and 6, and a left / right inclination sensor 62 provided on the traveling unit 20 for detecting the inclination in the left / right direction of the airframe, Since the horizontal control unit 60b performs horizontal control based on the detection value from the left / right inclination sensor 62 and the detection value from the suspension sensor 61, the front wheels 6 and 6 travel to reach the unevenness of the tiller during planting work. When the part 2 tilts to the left and right, the change in the suspension mechanism is faster than the actual change in the inclination of the traveling part 2, which is detected by the suspension sensor 61 and is faster and more accurate than in the past. It becomes possible to perform horizontal control, and the planting unit 20 can obtain a stable state with respect to the change of the traveling unit 2, the planting depth is stabilized, the stocking is prevented, and the planting accuracy is improved. I was able to do that.

  The storage unit 66 of the horizontal control unit 60b stores a gain map corresponding to the relationship between the detection value of the suspension sensor 61 and the detection value from the left / right tilt sensor 62, and the horizontal control unit 60b stores the gain map. Since the control amount is acquired based on the gain obtained from the control and the horizontal control is performed, the gain G is acquired and utilized for the control, and the horizontal control can be performed more quickly and accurately than before.

  In addition, since the detected value of the traveling speed is input to the elevation control unit 60a and / or the horizontal control unit 60b, the elevation control and / or the horizontal control according to the traveling speed is performed. The higher the speed, the greater the front / rear / left / right inclination of the float 27 with respect to the front / rear / right / left inclination of the traveling unit 2, but as the lift mechanism and / or horizontal control is performed according to the change of the suspension mechanism, In addition, a stable state can be obtained, the planting depth is stabilized, the lack of stock can be prevented, and the planting accuracy can be improved.

2 traveling unit 6 front wheel 7 rear wheel 20 planting unit 27 float 60 control device 60a lifting control unit 60b tilt control unit 61 suspension sensor 62 tilt sensor 63 float sensor 66 storage unit 67 vehicle speed sensor

Claims (6)

A traveling unit supported by the front and rear wheels;
A planting part supported by the traveling part so as to be movable up and down;
A lifting control unit for controlling the lifting of the planting unit;
A suspension sensor for detecting expansion and contraction displacement of a suspension mechanism provided on the front wheel;
A front and rear inclination sensor that is provided in the traveling unit and detects the inclination of the aircraft in the front-rear direction;
The up-and-down control unit performs up-and-down control based on a detection value from the front / rear inclination sensor and a detection value from the suspension sensor.   The float of the said planting part is provided with the float sensor which detects the raising / lowering displacement of a float, The said raising / lowering control part further performs raising / lowering control from the detected value from the said float sensor. Paddy field work vehicle as described A gain map corresponding to a relationship between a detection value from the front / rear inclination sensor and a detection value of the suspension sensor is stored in the storage unit of the elevation control unit,
3. The paddy field work vehicle according to claim 2, wherein the lift control unit acquires a control amount based on a gain obtained from the gain map and performs lift control. A traveling unit supported by the front and rear wheels;
A planting part supported by the traveling part so as to be movable up and down;
A horizontal control unit for controlling the planting unit horizontally;
A suspension sensor for detecting expansion and contraction displacement of a suspension mechanism provided on each of the left and right front wheels;
A left and right tilt sensor that is provided in the traveling unit and detects the tilt of the airframe in the left and right direction;
The said horizontal control part performs a horizontal control by the detection value from the said left-right inclination sensor and the detection value from the said suspension sensor, The paddy field work vehicle characterized by the above-mentioned. The storage unit of the horizontal control unit stores a gain map corresponding to the relationship between the detection value of the suspension sensor and the detection value from the left / right tilt sensor,
The paddy field work vehicle according to claim 4, wherein the horizontal control unit acquires a control amount based on a gain obtained from the gain map and performs horizontal control.   6. The lift control unit and / or the horizontal control unit receives a detection value of travel speed, and performs lift control and / or horizontal control according to the travel speed. A paddy field work vehicle given in any 1 paragraph.

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