TWI868402B - Working vehicle - Google Patents

Abstract

Disclosed is a working vehicle that can perform planting at an optimal planting depth. The working vehicle of one of the embodiments has: a traveling vehicle body (2); a seedling planting part (50) which can be mounted on the traveling vehicle body (2) so as to be raised and lowered; and a depth adjustment part which is configured to adjust the planting depth of the seedlings by changing the position of the seedling planting part (50); the soft and hard sensor which is configured to detect the hardness of the field; and the control device (150) which is configured to control the depth adjustment part based on the planting depth determined based on the hardness of the field detected by the soft and hard sensor.

Description

Working vehicles

The present invention relates to a working vehicle.

In the past, there were working vehicles such as rice seedling transplanters used for field work that had an adjustment mechanism for manually adjusting the planting depth of the rice seedlings (for example, refer to Patent Document 1).

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2017-55704.

However, when adjusting the planting depth, it is difficult to adjust the planting depth during the operation, so the operator needs to confirm the hardness of the field and decide the planting depth before the operation. However, if the planting depth is determined incorrectly, the planting depth may be too shallow and cause the seedlings to fall over, or the seedlings may be planted too deeply.

The present invention is completed in view of the above situation, and its purpose is to provide a working vehicle that can plant at the optimal planting depth.

In order to solve the above-mentioned problems and achieve the purpose, a working vehicle in one embodiment comprises: a driving body (2); a seedling planting part (50) which is installed on the driving body (2) in a manner that it can be raised and lowered; a depth adjustment part which adjusts the planting depth of the seedlings by changing the position of the seedling planting part (50); a hardness sensor which detects the hardness of the field; and a control device (150) which controls the depth adjustment part according to the planting depth determined based on the hardness of the field detected by the hardness sensor.

According to one of the implementation forms, planting can be performed at an optimal planting depth.

1: Seedling transplanter

2: Driving body

4:Front wheel

5: Rear wheel

7: Main frame

10: Engine

11: Engine hood

13: Front wheel end housing

15: Power transmission device

16: Hydraulic continuously variable transmission device

17: Power transmission unit

18: Transmission

22: Rear wheel end housing

26:Front pedal

27: Rear pedal

28: Operating seat

30: Manipulation Department

31: Front cover

32: Steering wheel

33: Dashboard

40: Lifting mechanism for seedling planting section

41: Lifting connecting rod device

41a: Upper connecting rod

41b: Lower connecting rod

43: Linkage base frame

44: Hydraulic lifting cylinder

47: Floating body

48: Central Float

49: Side float

50: Seedling planting department

51: Seedling loading platform

52: Seedling loading surface

55: Planting support frame

60: Seedling planting device

61: Planting body

62: Planting pole

63: Rotating box

64: Planting transmission box

67: Rotor for land preparation

68: Line marker

70: Fertilizer device

71: Storage hopper

72: Delivery device

73: Blower

74: Fertilizer hose

75: Fertilizer guide

76: Channel opener

81: Main gear lever

82: Sub-shift lever

83: Straight-line support start switch

100: Throttle motor

110: Steering gear

112: Transmission mechanism

120: Location information acquisition device

121: GNSS unit

122: Receiving antenna

124: Antenna frame

124a: Lower frame

124b: Upper frame

124c: Second reinforcement frame

124d: Rotating shaft

124e: First reinforcement frame

124f: Connector

124g: Aluminum block

125: Rotate the connecting plate

130: Camera

131: Axle

140: Information processing terminal device

143: Memory Department

150: Controller

150a: Regional identification unit

150b: Reciprocating driving frequency calculation unit

150c: Operation start position setting unit

150d: Aircraft sedimentation determination unit

153: Switch

154a: Floating Potentiometer

160: Rudder angle sensor

165: Rotor motor

170: Position sensor

175: Posture sensor

180: Tilt sensor

190: Seating sensor

199: Various sensors

200: Notification device

220: Axle

310: Straight support organization

315: Steering column

331: Display device

353: Center leader

400: Prepared seedling loading section

500: Planting Clutch

510: Planting Clutch Motor

700: Bumper

Q: Operation channel

[Figure 1] is a side view of a rice seedling transplanter as a working vehicle.

[Figure 2] is a top view with part of the rice seedling transplanter omitted.

[Figure 3] is a functional block diagram of the rice seedling transplanter in its implementation form.

[Figure 4] is a flow chart showing the process of the automatic adjustment of the amount of rice seedlings removed by the controller.

[Figure 5] is a flow chart showing the process of obtaining the planting path information performed by the controller.

[Figure 6] is a flow chart showing the process of obtaining plant spacing information performed by the controller.

[Figure 7] is a flow chart showing the process of obtaining the lateral feed speed information performed by the controller.

[Figure 8] is a flow chart showing the process of determining the number of rice seedlings performed by the controller.

[Figure 9] is a flow chart showing the process of determining the amount of rice seedlings to be taken out by the controller.

[Figure 10] is a flow chart showing the process of adjusting the amount of rice seedlings removed by the controller.

[Figure 11] is a flow chart showing the process of adjusting the amount of rice seedlings removed by the controller.

[Figure 12] is a flow chart showing the processing procedure of the intermediate correction process performed by the display controller.

[Figure 13] is a flow chart showing the processing procedure of the controller for adjusting the planting depth.

[Figure 14] is a flow chart showing the processing procedure of the controller for adjusting the planting depth.

[Figure 15] is a flow chart showing the processing procedure of the adjustment process of the planting depth performed by the controller.

Hereinafter, the control system of the working vehicle of the embodiment of the present invention will be specifically described with reference to the drawings. In addition, the structural elements in the following embodiment include structural elements that can be replaced by a person of ordinary knowledge in the relevant technical field, or structural elements that are substantially the same, so-called structural elements within the scope of equality. Moreover, the present invention is not limited to the above-mentioned embodiment, and can be implemented in various modifications within the scope of the subject matter of the present invention.

First, the overall structure of the working vehicle is described with reference to Figures 1 and 2. Figure 1 is a side view of a rice seedling transplanter as a working vehicle. Figure 2 is a top view with a portion of the rice seedling transplanter omitted.

The rice seedling transplanter 1 of this embodiment has a controller 150 (see FIG. 3 ) as a control device, and can be controlled by the controller 150 to perform the rice seedling planting operation while driving automatically.

As shown in Figures 1 and 2, the rice seedling transplanter 1 has a driving body 2, which has a pair of front wheels 4 and rear wheels 5 on the left and right, and can travel in the field. The driving body 2 is provided with an operating seat 28 for the operator to sit on, and the rice seedling planting part 50 as the working machine is connected at the rear so that it can be raised and lowered freely. In addition, the rice seedling planting part 50 is configured to be freely loaded and unloaded relative to the driving body 2.

The front wheel 4 is a steering wheel, and is turned left and right by a steering device 110 (see FIG. 3 ) including a steering wheel 32 as a steering wheel. In addition, in the following description, the front and rear, left and right directions of the rice seedling transplanter 1 are based on the directions observed by the operator sitting in the operating seat 28 in the correct posture.

In addition, the controller 150 has the following functions: according to the steering angle (steering angle) of the front wheel 4 as a steering wheel and the position information of the rice seedling transplanter 1, the action of the steering device 110 is controlled to support the automatic driving of the rice seedling transplanter 1 in the field. In addition, the steering angle is set as the steering angle of the front wheel 4, but for example, the steering angle of the steering wheel 32 can also be detected as the steering angle. In addition, the position information of the rice seedling transplanter 1 is obtained by the position information acquisition device 120 provided on the driving vehicle body 2.

As shown in FIG1 , a rice seedling planting section 50 is installed on a traveling vehicle body 2 of a rice seedling transplanter 1 in a manner that allows it to be raised and lowered via a rice seedling planting section lifting mechanism 40 as a lifting device. The traveling vehicle body 2 is a four-wheel drive vehicle that is driven by a pair of left and right rear wheels 5 together with the front wheels 4. The front wheels 4 that serve as steering wheels are steered by turning the steering wheel 32 to travel on fields, paths, etc.

The vehicle body 2 has: a main frame 7, which is arranged at the approximate center of the vehicle body; an engine 10 as a prime mover, which is mounted on the main frame 7; and a power transmission device 15, which transmits the power of the engine 10 to the front wheels 4 and the rear wheels 5 and the rice seedling planting part 50. In the rice seedling transplanter 1, the engine 10 as a power source uses an internal combustion engine such as a diesel engine or a gasoline engine, and the power generated is not only used to make the vehicle body 2 move forward or backward, but also used to drive the rice seedling planting part 50.

In addition, the power transmission device 15 has: a hydraulic continuously variable transmission device 16, which is called a so-called HST (Hydro Static transmission; hydraulic transmission device), which is used to change the speed of the driving force transmitted from the engine 10 and output it; and a power transmission unit 17, which transmits the power from the engine 10 to the hydraulic continuously variable transmission device 16.

In addition, the power transmission device 15 has a transmission 18 composed of a plurality of gears. The driving force from the engine 10 is transmitted to the hydraulic continuously variable transmission device 16 via the power transmission unit 17, and the power after the hydraulic continuously variable transmission device 16 is transmitted to the transmission 18. The transmission 18 is installed at the front of the main frame 7. In addition, a safety rod 700 is provided at the front end of the main frame 7.

Part of the power transmitted from the transmission 18 to the front wheel 4 and the rear wheel 5 can be transmitted to the front wheel 4 via the left and right front wheel end housings 13, and the remaining part can be transmitted to the rear wheel 5 via the left and right rear wheel end housings 22. The left and right front wheel end housings 13 are arranged on the left and right sides of the transmission 18. The left and right front wheels 4 are connected to the left and right front wheel end housings 13 via the axle 131. Such a front wheel end housing 13 is driven in accordance with the steering operation of the steering wheel 32, and the front wheel 4 can be turned.

Similarly, the rear wheel 5 is connected to the left and right rear wheel end shells 22 via the axle 220. On the other hand, the power is transmitted from the transmission 18 to the seedling planting section 50 via the planting clutch 500, which is set from the working machine drive shaft (not shown) to the rear of the driving body 2. In addition, the planting clutch 500 is operated by the planting clutch motor 510 connected to the controller 150 (Figure 3).

However, the engine 10 is arranged approximately in the center of the vehicle body 2 in the left-right direction and in a state protruding upward from the front pedal 26 on which the worker places his feet when riding. The front pedal 26 is arranged to span between the front of the vehicle body 2 and the rear of the engine 10 and is mounted on the main frame 7. A portion of the front pedal 26 is lattice-shaped, so that mud attached to the shoes can fall into the field. In addition, a rear pedal 27 that also serves as a fender for the rear wheel 5 is arranged behind the front pedal 26. The rear pedal 27 has an inclined surface that inclines toward the upward direction as it moves toward the rear, and is arranged on the left and right sides of the engine 10.

In addition, the engine 10 protrudes upward from the front pedal 26 and the rear pedal 27, and an engine hood 11 covering the engine 10 is provided at the protruding portion from the front pedal 26 and the rear pedal 27.

Furthermore, an operating seat 28 for the operator to sit is provided on the upper part of the engine hood 11, and an operating unit 30 is provided in front of the operating seat 28 and in the front center of the vehicle body 2. The operating unit 30 is arranged in a state protruding upward from the floor surface of the front pedal 26, dividing the front side of the front pedal 26 into left and right.

A steering post 315 is provided on the operating unit 30, a steering wheel 32 for the operator to steer is provided on the upper part of the steering post 315, and a dashboard 33 serving as a display device is provided. The dashboard 33 is provided with a touch panel display screen (see FIG. 2 ). In addition, image display can be realized, and various switches 153 including a straight support start switch 83 are provided as shown in FIG. 3 .

In addition, the operating unit 30 has a tablet terminal device 140 to be detachably mounted on the lower side of the steering column 315. In addition, a notification device 200 such as a light or a buzzer is provided at a predetermined position of the operating unit 30 (FIG. 3). Using such a notification device 200, it is possible to notify, for example, the support status of automatic driving, abnormal occurrence of various device types, etc.

Furthermore, in the operating unit 30, a main shift lever 81 and a sub shift lever 82 are provided near the steering column 315. The main shift lever 81 is provided on the right side of the operating unit 30, and the sub shift lever 82 is provided below the steering wheel 32.

The main gear lever 81 is a lever for switching the forward and reverse movement and driving output of the driving body 2. The operator can operate it to adjust the rotation angle of the trunnion (not shown) of the hydraulic continuously variable transmission 16 to adjust the speed of the driving body 2.

On the other hand, the auxiliary transmission lever 82 is a lever that switches the driving mode of the predetermined driving speed of the driving body 2 to a low speed mode and a high speed mode according to the place to be driven. Here, the low speed mode refers to a driving mode predetermined within a speed range corresponding to the planting operation of the rice seedling transplanter 1 in the field.

In addition, the high-speed mode refers to a driving mode when the rice seedling transplanter 1 is moved on a path, etc., and can be driven at a higher speed than the low-speed mode. These modes are switched by the auxiliary transmission mechanism provided in the transmission 18 in accordance with the position of the auxiliary transmission lever 82.

In addition, a front cover 31 that can be opened and closed is provided in front of the operating part 30. In addition, a center mascot 353 serving as an indicator member for driving is installed in the center of the front end of the front cover 31. In addition, although the illustration is omitted in FIG. 1 for convenience, as shown in FIG. 2, a pre-prepared seedling loading part 400 is provided on the left and right sides of the front side of the driving body 2, and a working passage Q is separated between the pre-prepared seedling loading part 400 and the operating part 30.

In addition, the rice seedling transplanter 1 of this embodiment is equipped with a GNSS (global navigation satellite system) unit 121 connected to a receiving antenna 122 as a position information acquisition device 120 on the driving body 2. The GNSS unit 121 uses the receiving antenna 122 to obtain GNSS coordinates at a certain time, thereby being able to obtain position information on the earth at predetermined intervals. In addition, although not shown in the figure, the GNSS unit 121 of this embodiment has an inertial navigation device using a gyro sensor and an acceleration sensor, and a control substrate for controlling them.

As shown in Figures 1 and 2, the GNSS unit 121 is mounted on the top of the antenna frame 124 so as to be located directly above the axle 131 of the front wheel 4, and the base end of the antenna frame 124 is connected to the front end side of the vehicle body 2. The height of the antenna frame 124 in a normal state is set to a height that does not interfere with the head even if a standard ordinary male stands on the front step 26.

As shown in Figures 1 and 2, the antenna frame 124 is composed of left and right lower frames 124a, 124a and left and right upper frames 124b, 124b (refer to the two-point chain in Figure 1). The left and right upper frames 124b, 124b are connected to the upper ends of the lower frames 124a, 124a via connecting members 124f, 124f and can be rotated backward by a predetermined angle via rotating connecting plates 125 respectively arranged in the middle. A rotating support shaft 124d is arranged between the rotating connecting plates 125, 125, and the upper frame 124b rotates around the rotating support shaft 124d.

Furthermore, a GNSS unit 121 is disposed between the upper parts of the left and right upper frames 124b and 124b. In addition, the GNSS unit 121 is disposed on the aluminum block 124g. That is, the non-magnetic aluminum block 124g is sandwiched between the GNSS unit 121 and the antenna frame 124 made of a steel pipe, thereby improving the reception sensitivity. In addition, the antenna frame 124 itself may be formed of a non-magnetic material instead of the aluminum block 124g.

In this way, the antenna frame 124 is configured so that a portion of the upper portion of the antenna frame 124 can be rotated backward at a predetermined angle. Specifically, the upper side of the upper frame 124b is folded by rotating the rotating connecting plate 125 provided in the middle of the upper frame 124b. Therefore, even in the folded state, the operator can sit on the operating seat 28 to perform normal operations.

In addition, due to the adoption of the above structure, the GNSS unit 121 is located relatively far from the engine 10 and will not be adversely affected by the vibration of the engine 10. In addition, the antenna frame 124 can also function as a protective frame for the operating unit 30. In addition, the left and right lower frames 124a, 124a and the left and right upper frames 124b, 124b can also be used as handrails for operators, thereby improving convenience.

In addition, a first reinforcing frame 124e is provided between the connecting pieces 124f, 124f provided at the upper ends of the lower frames 124a, 124a and the front cover 31. Furthermore, the base end of the first reinforcing frame 124e and the rotating connecting plate 125 provided at the upper frame 124b are connected via the second reinforcing frame 124c.

Next, the rice seedling planting section 50 and other structures are explained. As shown in FIG1 , the rice seedling planting section 50 is installed at the rear of the traveling body 2 via the rice seedling planting section lifting mechanism 40 in a manner that allows it to be raised and lowered. The rice seedling planting section lifting mechanism 40 has a lifting connecting rod device 41, and the lifting connecting rod device 41 has a parallel connecting rod mechanism, and the parallel connecting rod mechanism connects the rear of the traveling body 2 with the rice seedling planting section 50. Such a parallel connecting rod mechanism has an upper connecting rod 41a and a lower connecting rod 41b, and these upper connecting rods 41a and lower connecting rods 41b are rotatably connected to a rear view door type connecting rod base frame 43 vertically arranged at the rear end of the main frame 7. Furthermore, the other ends of the upper link 41a and the lower link 41b are rotatably connected to the rice seedling planting section 50. In this way, the rice seedling planting section 50 is connected to the traveling vehicle body 2 in a manner that allows it to be raised and lowered.

In addition, the seedling planting section lifting mechanism 40 has a hydraulic lifting cylinder 44 that is extended and retracted by hydraulic pressure, and the seedling planting section 50 can be raised and lowered by the extension and retraction action of the hydraulic lifting cylinder 44. The hydraulic lifting cylinder 44 is driven by the above-mentioned hydraulic continuously variable transmission 16, and the seedling planting section 50 can be raised to a non-working position or lowered to a ground working position (planting position) by the lifting action of the seedling planting section lifting mechanism 40. In addition, the seedling planting section lifting mechanism 40 can adjust the planting depth of the seedlings by the lifting action of the seedling planting section 50. That is, the seedling planting section lifting mechanism 40 functions as a depth adjustment section, and the depth adjustment section adjusts the planting depth of the seedlings by changing the position of the seedling planting section 50.

The seedling planting section 50 is capable of planting seedlings in a plurality of areas or a plurality of rows within the range of planting seedlings. For example, the seedling planting section 50 can be set to be a so-called six-row planting section capable of planting seedlings in six areas.

In addition, the rice seedling planting section 50 includes: a rice seedling planting device 60, a rice seedling loading platform 51, and a floating body 47 (48, 49). The rice seedling loading platform 51 is provided at the rear of the vehicle body 2 as a rice seedling loading component for loading a plurality of rice seedlings, and has a rice seedling loading surface 52 divided into a number of planting rows in the left-right direction of the vehicle body 2, and a pad-shaped rice seedling with soil can be loaded on each rice seedling loading surface 52. In addition, the rice seedling loading platform 51 is connected to an actuator (e.g., a motor) not shown in the figure, and can be moved in the up-down direction by such an actuator. By moving the seedling loading platform 51 in the up-down direction, the distance between the seedling loading platform 51 and the seedling planting device 60 can be changed, and as a result, the amount of seedlings placed on the seedling loading platform 51 by the seedling planting device 60 (hereinafter referred to as the seedling removal amount) can be adjusted. That is, the actuator functions as a seedling removal amount adjustment unit, and the seedling removal amount adjustment unit adjusts the seedling removal amount of the seedling planting device 60 by changing the position of the seedling loading platform 51.

The seedling planting device 60 is a device that is arranged at the bottom of the seedling loading platform 51 on which the seedlings are loaded, and takes out the seedlings from the seedling loading platform 51 and plants them in the field. The seedling planting device 60 is supported by a planting support frame 55 arranged on the front surface side of the seedling loading platform 51. The seedling planting device 60 has a planting transmission box 64 and a planting body 61. The planting body 61 has a pair of planting rods 62 so that the seedlings can be taken out from the seedling loading platform 51 and planted in the field, and can be rotatably connected to the planting transmission box 64.

The planting transmission box 64 is configured to supply the power transmitted from the engine 10 to the seedling planting part 50 to the planting body 61. In addition, the planting body 61 has: a planting rod 62, which takes out the seedlings from the seedling loading platform 51 and plants them in the field; and a rotary case 63, which supports the planting rod 62 so that it can rotate and is rotatably connected to the planting transmission box 64. The rotary case 63 has a built-in unequal speed transmission mechanism (not shown), and the unequal speed transmission mechanism can rotate the planting rod 62 while changing the rotation speed when the planting rod 62 is rotated by the driving force transmitted from the planting transmission box 64. Thus, when the planting body 61 rotates, the planting rod 62 rotates while changing the rotation speed by the rotation angle relative to the rotating box 63.

A rice seedling planting device 60 of this structure is provided for every two rows. That is, if there are six rows of planting, three rice seedling planting devices 60 are provided. In addition, each planting transmission box 64 has two planting bodies 61 that can rotate. That is, in one planting transmission box 64, two rotating boxes 63 are connected to both sides of the machine body in the left and right directions.

In addition, the float 47 slides on the field surface as the traveling vehicle body 2 moves to level the land, and has: a central float 48 located in the center of the rice seedling planting section 50 in the left-right direction of the traveling vehicle body 2; and side floats 49 located on both sides of the rice seedling planting section 50 in the left-right direction.

The center float 48 in this embodiment is provided with a float potentiometer 154a (see FIG. 3 ), which functions as a hydraulic sensitivity mechanism for raising and lowering the seedling planting section 50 in accordance with the conditions of the field. Such a float potentiometer 154a is capable of changing the amplitude of the sensitivity for detecting the up and down movement of the center float 48. For example, if the sensitivity is made sensitive, the smaller up and down movement of the center float 48 is also detected, and the detection signal is sent to the controller 150. On the other hand, if the sensitivity is made dull, the smaller up and down movement of the center float 48 is not detected, and only the up and down movement above a certain amplitude is detected, and the detection signal is sent to the controller 150.

In addition, a plurality of land leveling rotors (here, three rotors on the left, right and center) 67 for land leveling are provided at the front side of the lower side of the seedling planting section 50. The land leveling rotor 67 is configured to be able to rotate by the output from the engine 10 transmitted through the rear wheel end housing 22, and is configured to be able to be raised and lowered by the rotor motor 165 (see FIG. 3 ) which is an electric motor.

In this way, if the rotor motor 165 can be used to independently drive the plurality of land leveling rotors 67, 67, for example, when the orientation of the machine body is swung to either the left or right side, the rotation of the land leveling rotor 67 on the swinging side can be accelerated to correct the orientation of the machine body in a straight manner. In addition, the driving force for the plurality of land leveling rotors 67, 67 can also be received from the engine 10 instead of the rotor motor 165.

In addition, there are line markers 68 on the left and right sides of the seedling planting section 50, and the line markers 68 form a line on the next planting strip as a reference for the direction of travel. When the seedling transplanter 1 moves straight in the field, the line markers 68 draw a mark on the field when it turns at the edge of the field and moves straight. The seedling transplanter 1 of this embodiment can use GNSS to perform straight-moving support, so the line markers 68 can also be discarded.

A fertilizer device 70 is mounted behind the operating seat 28 of the driving body 2. The fertilizer device 70 includes left and right storage hoppers 71 for storing fertilizers, a delivery device 72 for delivering a set amount of fertilizers supplied from the storage hoppers 71 each time, a fertilizer hose 74 belonging to a fertilizer passage for supplying the fertilizers delivered by the delivery device 72 to the field, and a blower 73 for supplying transport air to the fertilizer hose 74. The blower 73 is used to transfer the fertilizers in the fertilizer hose 74 to the rice seedling planting section 50 side. Furthermore, the fertilizer device 70 also has: a fertilizer guide 75 for transferring fertilizer via the fertilizer hose 74; and a trencher 76 for allowing the fertilizer transferred via the fertilizer hose 74 to fall into a fertilizer groove formed near the side of the seedling planting strip.

Next, the mechanism structure of the rice seedling transplanter 1 of the embodiment is described using FIG3. FIG3 is a functional block diagram of the rice seedling transplanter 1 of the embodiment. As shown in FIG3, the rice seedling transplanter 1 has a controller 150 (an example of a control device), and the controller 150 supports automatic driving and controls each part by electronic control. The controller 150 is provided with a processing unit having a CPU (Central Processing Unit), a memory unit such as a ROM (Read Only Memory), a RAM (Random Access Memory), and an input-output unit, which are connected to each other and can transmit signals to each other.

A computer program for controlling the rice seedling transplanter 1 is stored in the memory. In addition, various information related to the field is also stored in the memory. The information related to the field may include, for example, the name of the work area and representative coordinates or coordinate center values, coordinate information of the vertices in the case where the field is a polygon, arbitrary position coordinates between the vertices, and position coordinate information set at the entrance and exit of the field. In addition, the information stored in the memory may also be stored in the memory 143 of the tablet terminal device 140.

For example, the CPU functions as the area identification unit 150a, the reciprocating driving number calculation unit 150b, the operation start position setting unit 150c, and the body settlement determination unit 150d shown in FIG3 by reading and executing the program stored in the ROM. In addition, at least one or all of the area identification unit 150a, the reciprocating driving number calculation unit 150b, the operation start position setting unit 150c, and the body settlement determination unit 150d can also be constituted by hardware such as ASIC (Application Specific Integrated Circuit); specific application integrated circuit, FPGA (Field Programmable Gate Array); field programmable gate array.

As shown in FIG3 , the controller 150 is connected to various actuators, sensors for obtaining information of various parts, etc., starting with the tablet terminal device 140, in a communicative manner. In addition, in this embodiment, the controller 150 and the tablet terminal device 140 are wirelessly connected based on a predetermined wireless communication standard.

As actuators, for example, the controller 150 is connected with: a throttle motor 100 for adjusting the intake volume of the engine 10; a rotor motor 165 for raising and lowering the rotor 67 for leveling the land; and a planting clutch motor 510 for actuating the planting clutch 500. In addition, although not shown in the figure, the ear shaft drive motor for changing the rotation angle of the ear shaft of the hydraulic continuously variable transmission 16 is also connected to the controller 150.

In addition, the controller 150 is connected to a dashboard 33 provided in the operating unit 30. In the dashboard 33, a display screen 33 (see FIG. 2 ) functioning as a display device 331 is formed by a touch panel. By operating the straight support start switch 83 and other various switches 153 displayed on the display screen, various devices can be driven and stopped.

Furthermore, the controller 150 is connected to various sensors 199 including a steering angle sensor 160, an azimuth sensor 170, a posture sensor 175, a tilt sensor 180, a seat sensor 190, and a lever sensor for detecting the operation amount of the main shift lever 81 and the auxiliary shift lever 82 at a tilt angle. The controller 150 stores the values detected by the steering angle sensor 160, the azimuth sensor 170, the posture sensor 175, the tilt sensor 180, the seat sensor 190, and the various sensors 199 in the RAM of the memory unit.

The steering angle sensor 160 is, for example, a sensor that detects the rotation angle of the steering wheel 32 as a steering wheel, or a sensor that detects the steering angle when the front wheel 4 as a steering wheel is steered by operating the steering wheel 32.

The direction sensor 170 is a sensor for detecting the orientation of the body, and is generally used in the car navigation system of a car. The controller 150 is able to derive the actual direction of travel of the body based on the value obtained from such a direction sensor 170.

The posture sensor 175 detects the degree to which the posture of the driving vehicle body 2 is tilted relative to the automatic straight line, and is composed of a gyro sensor, etc.

The tilt sensor 180 detects the vertical tilt of the vehicle body 2, that is, detects the degree of the forward tilt or backward tilt of the vehicle body 2, and functions as a vehicle body tilt detection device, for example, composed of an acceleration sensor, etc.

As described above, the rice seedling transplanter 1 comprises: a rice seedling planting section 50 having a rice seedling planting device 60; and a transmission 18 having a transmission gear, wherein the transmission gear comprises a relatively low-speed gear and a relatively high-speed gear. The body settlement determination section 150d of the controller 150 determines the settlement state of the traveling body 2 relative to the field during the operation of the rice seedling planting device 60 according to the detection result of the tilt sensor 180, and when it is determined that the traveling body 2 is in a settlement state for a predetermined period of time, the selection gear of the transmission 18 is switched to a low-speed gear, thereby increasing the planting distance of the rice seedlings planted by the rice seedling planting device 60. That is, although the seedling planting device 60 operates at a planting spacing corresponding to the vehicle speed, the actual vehicle speed decreases due to the body settling when the planting spacing remains unchanged, so the selection gear of the transmission 18 is switched to a low-speed gear in order to change the planting spacing. In this way, the seedlings can be planted neatly even if the body settles.

That is, in the operation based on automatic driving, although it is difficult to avoid the sinking of the machine body depending on the state of the field, the seedlings can be planted even if they sink. Therefore, after the planting operation of the seedlings based on automatic driving, there is no need to carry out replanting. In addition, the disorder of the planting posture of the seedlings in the field can be suppressed as much as possible. In addition, as a tilt sensor 180, if it can detect not only the tilt in the up and down direction of the driving body 2 but also the tilt in the left and right direction, it can also be determined that it is in a sinking trend according to the left and right tilt state of the machine body.

In addition, the seat sensor 190 is a sensor composed of a load sensor, a pressure-sensitive film sensor, etc., and can detect the pressure when the worker sits on the operating seat 28.

With such a structure, when the seat sensor 190 detects pressure, the controller 150 can determine that the worker has taken a seat. Conversely, when no pressure is applied to the seat sensor 190, the controller 150 determines that the worker has not taken a seat.

In addition, the rice seedling transplanter 1 has a steering device 110, a GNSS unit 121 and a receiving antenna 122 for constituting a position information acquisition device 120, and a tablet terminal device 140 as an information processing terminal device, which are connected to a controller 150.

The steering device 110 has a steering wheel 32 and a transmission mechanism 112 linked to the shaft of the steering wheel 32, and has a straight support mechanism 310 for applying an arbitrary rotational force to the shaft of the steering wheel 32, and can realize automatic steering based on the controller 150. The transmission mechanism 112 includes a steering motor for rotating the steering wheel 32. For example, when the straight support start switch 83 is operated, the controller 150 automatically steers the steering wheel (front wheel 4) through the straight support mechanism 310 based on the position information obtained by the GNSS unit 121, thereby maintaining the driving body 2 in the straight direction.

The GNSS unit 121 has a receiving antenna 122 (see FIG. 4 ) for receiving signals from an artificial satellite used by the GNSS, obtains the position information (coordinate information) of the rice seedling transplanter 1 on the earth, and transmits the obtained position information to the controller 150.

Based on the position data of the machine body obtained by the GNSS unit 121 and the working area W based on the map data of the field stored in the memory of the controller 150, the rice seedling transplanter 1 plants the rice seedlings while traveling without protruding out of the working area W. In addition, if a non-working area X is set in the working area W, the controller 150 controls so that the rice seedlings are not planted in such a non-working area X.

In addition, the GNSS unit 121 can also derive the actual speed of the rice seedling transplanter 1. That is, the actual driving speed can be calculated sequentially according to the movement amount of the machine body within a certain period of time, so even if the driving wheels (front wheels 4, rear wheels 5) slip, the controller 150 can obtain the actual vehicle speed of the rice seedling transplanter 1 regardless of the rotation amount of the rear wheels 5.

Here, the control contents of the controller 150 as a control device are explained using Figures 4 to 15.

FIG. 4 is a flow chart showing the process of automatically adjusting the amount of rice seedlings removed by the controller 150.

As shown in FIG4 , the controller 150 first obtains the planting path information (step S101). The planting path information refers to information related to the operation path of the planting operation in the field.

Next, the controller 150 obtains the plant spacing information (step S102). The plant spacing information refers to the information of the plant spacing (planting spacing) of the planted seedlings.

Next, the controller 150 obtains the lateral feed speed information (step S103). The lateral feed speed information refers to the information related to the lateral feed speed when the seedlings taken out by the planting rod 62 are fed horizontally to the left and right directions of the machine body.

Next, the controller 150 obtains the rice seedling number information input by the operator or other user, for example, through the information processing terminal device 140 (step S104). The rice seedling number information is information related to the total amount of rice seedlings planted in the field, for example, input as the number of rice seedling pads. In addition, the rice seedling number information can also be input as the total number of pads planted in the field, for example, it can also be input as the number of pads per turn.

Next, the controller 150 calculates the amount of rice seedlings removed based on the information obtained in steps S101 to S104 (step S105). In addition, the detailed calculation method of the amount of rice seedlings removed will be described later.

Next, the controller 150 controls the rice seedling removal amount adjustment unit according to the calculated rice seedling removal amount (step S106), and the process ends. That is, the controller 150 drives the actuator (not shown) to change the position of the rice seedling loading platform 51 so as to achieve the calculated rice seedling removal amount.

Next, the acquisition process of the planting path information is described using FIG5. FIG5 is a flow chart showing the process of the acquisition process of the planting path information performed by the controller 150.

As shown in FIG5 , the controller 150 first obtains the working area information based on teaching (step S201). Specifically, the controller 150 causes the rice seedling transplanter 1 to automatically move around the periphery of the field, thereby obtaining working area information related to the size and shape of the area within the periphery, i.e., the working area.

Next, the controller 150 generates a driving path for the rice seedling transplanter 1 (a working path for planting) based on the working area information (step S202). Next, the controller 150 generates a driving path for the rice seedling transplanter 1 (step S203).

Next, the controller 150 determines whether the rice seedling transplanter 1 is in operation based on the position information (step S204). If the rice seedling transplanter 1 is in operation (step S204: yes), the controller 150 subtracts the operation completion path amount from the total length of the planting path (step S205), generates planting path information (step S206), and ends the processing.

That is, the controller 150 obtains the planting path information by automatically driving the rice seedling transplanter 1 on the periphery of the field and on at least one of the multiple reciprocating paths as the working path set within the periphery.

On the other hand, when the rice seedling transplanter 1 is not operating (step S204: No), the controller 150 executes step S206.

In addition, the planting path information can also be generated based on the planting area, for example. Specifically, the value obtained by dividing the planting area by the number of trees and rounding up the decimal is generated as the planting path information.

Next, the process of obtaining the plant spacing information is described using FIG6. FIG6 is a flow chart showing the process of obtaining the plant spacing information performed by the controller 150.

As shown in FIG6 , the controller 150 uses a potentiometer not shown in the figure to obtain the potential value of the plant spacing speed changer not shown in the figure (step S301). The plant spacing speed changer is a machine that changes the planting interval (plant spacing) of the seedlings of the seedling planting device 60 of a preset predetermined area in accordance with the operating position of the plant number changing lever. The seedling planting device 60 has a cam mechanism and a gear mechanism, and uses the cam mechanism and the gear mechanism to change the conveying speed of the seedling feeding conveyor belt and the number of rotations (rotation speed) of the planting claw in accordance with the operating position of the plant number changing lever, thereby changing the planting interval of the seedlings. The controller 150 uses a potentiometer to read the positions of the gear shifting stages of the main gear shifting rod and the auxiliary gear shifting rod as potential values for the gear shifting rod composed of a plurality of main gear shifting rods and a plurality of auxiliary gear shifting rods.

Next, the controller 150 determines the plant spacing based on the obtained potential value (step S302), generates plant spacing information (step S303), and ends the process.

In addition, as a method for obtaining plant spacing information, there is also a method based on the rotation speed of the shaft connected to the transmission 18. Specifically, the controller 150 obtains the rotation speed of the travel shaft connected to the front wheel 4 and the rear wheel 5 and the rotation speed of the above-mentioned working machine drive shaft from the transmission 18. And the controller 150 determines the plant spacing based on the relative relationship between these two rotation speeds.

Next, the process of obtaining the lateral feed speed information is described using FIG. 7 . FIG. 7 is a flow chart showing the process of obtaining the lateral feed speed information performed by the controller 150.

As shown in FIG7 , the controller 150 uses a potentiometer (not shown) to obtain the potential value of the lateral feed rod (not shown) (step S401). Then, the controller 150 determines the lateral feed speed according to the potential value (step S402), generates lateral feed speed information (step S403), and ends the processing.

In addition, as a method for obtaining the lateral feed speed information, there is also a method based on the rotation speed of the planting body 61 in the planting transmission box 64. Specifically, the controller 150 detects the rotation speed of the planting body 61 before and after the lateral feed change, and determines the lateral feed speed based on the relative relationship between the two rotation speeds.

Next, the process of determining the number of seedlings will be described using FIG8 . FIG8 is a flow chart showing the process of determining the number of seedlings performed by the controller 150.

As shown in FIG8 , the controller 150 obtains the planting path information, the plant spacing information, and the lateral feed speed information (step S501). Then, the controller 150 receives the range designation of the rice seedling removal amount (step S502).

The range of the rice seedling removal amount can be received from the user via the information processing terminal device 140, or it can be set to a pre-set range.

Next, the controller 150 determines the selection range of the number of seedlings based on the information obtained (accepted) in steps S501 and S502 (step S503).

Next, the controller 150 receives the input of the number of seedlings through the information processing terminal device 140 (step S504). Next, the controller 150 determines whether the input number of seedlings is within the determined selection range (step S505).

When the input number of seedlings is within the selection range (step S505: yes), the controller 150 determines the input number of seedlings as a determined value (step S506) and ends the processing.

On the other hand, the controller 150 executes step S504 when the input number of seedlings is outside the selection range (step S505: No).

In addition, although FIG. 8 shows a case where the input number of seedlings is not within the selection range, the number of seedlings is accepted for re-entry, but for example, changes in the spacing between plants and the horizontal feed speed can also be accepted.

Next, the process of determining the amount of rice seedlings to be taken out is described using FIG. 9 . FIG. 9 is a flow chart showing the process of determining the amount of rice seedlings to be taken out performed by the controller 150 .

As shown in FIG. 9 , the controller 150 obtains the planting path A (step S601). Then, the controller 150 obtains the number of seedlings B (step S602). Then, the controller 150 obtains the plant spacing C (step S603). Then, the controller 150 obtains the lateral feed speed D (step S604).

Furthermore, the controller 150 determines the rice seedling removal amount E according to each of the obtained setting values A to D (step S605). Specifically, the rice seedling removal amount E is calculated by E=A÷B÷C÷D.

Next, the adjustment process of the rice seedling removal amount is described using FIG10. FIG10 is a flow chart showing the process of the adjustment process of the rice seedling removal amount performed by the controller 150.

As shown in FIG10 , the controller 150 determines the potential value of the seedling loading platform 51 based on the obtained seedling removal amount information (step S701). Then, the controller 150 drives the actuator used to move the seedling loading platform 51 up and down until the determined potential value is reached (step S702), and the processing ends. In this way, the seedling removal amount is adjusted to correspond to the potential value.

Next, the adjustment process of the rice seedling removal amount taking into account the gap shift process is described using FIG. 11 . FIG. 11 is a flow chart showing the process of the adjustment process of the rice seedling removal amount performed by the controller 150.

As shown in FIG11 , the controller 150 determines the first potential value of the seedling loading platform 51 according to the obtained seedling removal amount information (step S801). Then, the controller 150 drives the actuator used to move the seedling loading platform 51 up and down until it reaches a second potential value greater than the determined first potential value (step S802). Then, after reaching the second potential value, the controller 150 drives the actuator used to move the seedling loading platform 51 up and down until it reaches the first potential value (step S803), and ends the processing. In this way, the seedling removal amount corresponding to the first potential value is adjusted. That is, the second potential value is set as the gap shift position.

In addition, although the second potential value as the gap shift position can also be set to a value slightly larger than the first potential value, for example, the second potential value can also be set to the maximum value.

Next, the intermediate correction process is explained using Figure 12. The intermediate correction process refers to the process of correcting (adjusting) the planting parameters (seedling removal amount, plant spacing and lateral feed speed) based on the actual remaining amount of the aforementioned seedlings in the middle of the planting operation and the assumed remaining amount based on the completion path of the operation.

FIG. 12 is a flow chart showing the processing procedure of the intermediate correction processing performed by the controller 150.

As shown in FIG. 12 , the controller 150 detects the actual remaining amount of the seedlings based on the rotation speed of the seedling feeding conveyor belt (not shown) provided on the seedling loading platform 51 (step S901). Specifically, the actual remaining amount is detected by subtracting the consumption of the seedlings calculated based on the rotation speed of the seedling feeding conveyor belt from the total amount of the seedlings.

Next, the controller 150 detects the assumed remaining amount based on the operation completion path (step S902). Specifically, the assumed remaining amount is detected by subtracting the assumed consumption calculated according to the operation completion path from the total amount of seedlings.

Next, the controller 150 determines whether the actual remaining amount deviates from the assumed remaining amount (step S903). If the actual remaining amount deviates from the assumed remaining amount by more than the predetermined amount (step S903: yes), the controller 150 performs a planting parameter adjustment process according to the remaining working path distance (step S904) and ends the process. In addition, in the planting parameter adjustment process, at least one of the rice seedling removal amount, plant spacing, and lateral feed speed is adjusted.

On the other hand, the controller 150 terminates the processing when the actual remaining amount and the assumed remaining amount do not deviate from the predetermined amount (step S903: No).

In addition, in the case of detecting the actual remaining amount of the seedlings, for example, a camera 130 may be installed on the seedling mounting platform 51, and the actual remaining amount may be detected by analyzing the image captured by the camera 130. In such a case, it is preferable that the camera 130 is installed on a gimbal that can rotate around three axes, and the shooting range of the camera 130 can be changed in accordance with the position of the seedling pad.

Next, the automatic adjustment process of the planting depth is described using FIG13. FIG13 is a flow chart showing the process of the adjustment process of the planting depth performed by the controller 150.

As shown in FIG. 13 , the controller 150 first detects the hardness of the field using a hardness sensor (not shown) (step S1001). Then, the controller 150 determines the planting depth based on the detection result (step S1002). Then, the controller 150 drives the actuator corresponding to the determined planting depth (step S1003) and ends the processing. That is, the controller 150 causes the actuator of the seedling planting part lifting mechanism 40, which functions as a depth adjustment part, i.e., the hydraulic lifting cylinder 44, to extend and retract to raise and lower the seedling planting part 50, thereby adjusting the planting depth. For example, the harder the field, the deeper the planting depth, and the softer the field, the shallower the planting depth.

In addition, the soft and hard sensor is a sensor used to read the position (depth) of multiple grounding bodies with different grounding voltages using a potentiometer, for example. In addition, the soft and hard sensor can also be configured as a camera 130. In the case where the soft and hard sensor is a camera 130, the camera 130 is used to take pictures of the seedlings planted in the field, and the soft and hardness is detected according to the planting state of the seedlings. Specifically, in the case of a poor planting state (a state of falling, etc.), the planting depth is deepened.

In addition, the controller 150 can also drive the planting frame (not shown) to which the central float 48 and the side float 49 are fixed as a motor of an actuator to adjust the planting depth. This is explained using FIG. 14.

FIG. 14 is a flow chart showing the processing procedure of adjusting the planting depth performed by the controller 150.

As shown in FIG14 , the controller 150 uses a hardness sensor (not shown) to detect the hardness of the field (step S1101). Then, the controller 150 determines the potential value of the planting frame corresponding to the planting depth according to the hardness of the field as the detection result (step S1102). Then, the controller 150 drives the motor as an actuator to move the planting frame until the determined potential value is reached (step S1103), and the processing ends.

In addition, the controller 150 can also detect the moisture content of the field and determine the planting depth based on the moisture content. Specifically, the controller 150 uses the rotating electrode (an example of a moisture content detection sensor) used by the fertilization device 70, calculates the moisture content of the field based on the battery resistance value of such a rotating electrode, and estimates the hardness of the field. For example, the more moisture content, the deeper the planting depth, and the less moisture content, the shallower the planting depth.

In addition, as a method for detecting hardness or softness, there is a method of using the cumulative value of the angle based on the potential value of the floating body potentiometer 154a. Specifically, the controller 150 detects hardness or softness by counting the cumulative angle changes within a certain interval. For example, when the cumulative angle changes greatly, the planting depth is deepened because the field is hard, and when the cumulative angle changes are small, the planting depth is shallow because the field is soft.

Next, the application example in the automatic adjustment process of the planting depth is explained using FIG15. FIG15 is a flow chart showing the processing procedure of the adjustment process of the planting depth performed by the controller 150.

As shown in FIG15 , the controller 150 first detects the hardness of the field using a hardness sensor (not shown) (step S1201). Then, the controller 150 adjusts the angle of attack of the float (central float 48 and side float 49) according to the hardness of the field (step S1202). Then, the controller 150 detects the hardness of the field again after adjusting the angle of attack of the float (step S1203).

Next, the controller 150 drives the actuator to adjust the planting depth according to the hardness of the field (step S1204). Next, the controller 150 adjusts the height of the land leveling rotor 67 according to the determined planting depth (step S1205), and the process ends.

The following describes other processing in the controller 150.

First, the automatic differential lock is explained. For example, the controller 150 measures the torque, and if the torque is less than a certain value, it is considered to be idling and the differential lock is activated. In addition, the controller 150 detects the position information and the axle rotation, and if it does not move by the amount of the axle speed, it is considered to be idling and the differential lock is activated. In addition, if the speed difference between the left and right wheels of the front wheel 4 is greater than a predetermined value during the turning process of the body, the controller 150 activates the differential lock.

Next, the automatic pumping brake is explained. For example, the controller 150 activates the pumping brake when the front wheel 4 or the rear wheel 5 is detected to be slipping. In addition, when the vehicle body is turning, when the speed difference between the left and right wheels of the front wheel 4 is greater than a predetermined value, the controller 150 activates the pumping brake. In addition, when the left and right wheels of the front wheel 4 rotate at a high speed during straight driving, the controller 150 activates the pumping brake in the rear wheel 5. In addition, in this case, the pumping brake is performed with a finer rest interval than when turning.

In addition, automatic differential lock and automatic pump-up brake can also be coordinated.

As mentioned above, the working vehicle of one embodiment has: a driving body 2; a seedling planting part 50, which has a seedling loading platform 51 and a seedling planting device 60 for taking out the seedlings loaded on the seedling loading platform 51 and planting them in the field, and can be installed on the driving body 2 in a lifting manner; a seedling taking amount adjustment part, which adjusts the seedling taking amount of the seedling planting device 60 by changing the position of the seedling loading platform 51; and a control device 150, which controls the seedling taking amount adjustment part in accordance with the seedling taking amount calculated according to the total amount of seedlings planted in the field. In this way, the seedling taking amount can be adjusted with high precision, so that the target amount of seedlings can be planted in the field with high precision.

In addition, as described above, the working vehicle of one embodiment has: a driving body 2; a seedling planting part 50, which is installed on the driving body 2 so as to be able to be raised and lowered; a depth adjustment part, which adjusts the planting depth of the seedlings by changing the position of the seedling planting part 50; a hardness sensor, which detects the hardness of the field; and a control device 150, which controls the depth adjustment part in accordance with the planting depth determined according to the hardness of the field detected by the hardness sensor. In this way, planting can be performed at the optimal planting depth.

A person with ordinary knowledge in the relevant technical field can easily derive further effects and variations. Therefore, the broader aspects of the present invention are not limited to the specific details and representative implementation forms shown and described above. Therefore, various changes can be made without departing from the spirit or scope of the general concept of the invention defined by the attached patent application scope and its equivalents.

33: Dashboard

83: Straight-line support start switch

100: Throttle motor

110: Steering gear

112: Transmission mechanism

120: Location information acquisition device

121: GNSS unit

122: Receiving antenna

130: Camera

140: Information processing terminal device

143: Memory Department

150: Controller

150a: Regional identification unit

150b: Reciprocating driving frequency calculation unit

150c: Operation start position setting unit

150d: Aircraft sedimentation determination unit

153: Switch

154a: Floating Potentiometer

160: Rudder angle sensor

165: Rotor motor

170: Position sensor

175: Posture sensor

180: Tilt sensor

190: Seating sensor

199: Various sensors

200: Notification device

310: Straight support organization

331: Display device

510: Planting Clutch Motor

Claims (6)

A working vehicle comprises: a driving body; a seedling planting part which is installed on the driving body in a manner that it can be raised and lowered; a depth adjustment part which adjusts the planting depth of the seedlings by changing the position of the seedling planting part; a hardness sensor which detects the hardness of the field; a control device which controls the depth adjustment part according to the planting depth determined based on the hardness of the field detected by the hardness sensor; and a floating body which is used to adjust the planting depth of the seedlings. The land leveling device is used to level the field; and the land leveling rotor is used to level the field; the control device adjusts the angle of attack of the float in accordance with the hardness of the field detected by the hardness sensor, adjusts the planting depth in accordance with the hardness of the field detected by the hardness sensor after the angle of attack is adjusted, and adjusts the height of the land leveling rotor in accordance with the planting depth. The working vehicle as described in claim 1 further comprises: a moisture detection sensor for detecting the moisture content of the aforementioned field; and the aforementioned control device for determining the aforementioned planting depth based on the aforementioned moisture content detected by the aforementioned moisture detection sensor. The working vehicle as described in claim 1 or 2, wherein the depth adjustment unit comprises: a planting frame for adjusting the planting depth; and a frame position sensor for detecting the position of the planting frame; and the control device for controlling the movement of the planting frame to a position corresponding to the calculated planting depth. The working vehicle as described in claim 1 or 2 further comprises: a ground leveling float; and a float sensor for detecting the up and down movement of the ground leveling float; The control device determines the planting depth based on the detection result of the float sensor and the detection result of the soft and hard sensor. The working vehicle as described in claim 3 further comprises: a ground leveling float; and a float sensor for detecting the up and down movement of the ground leveling float; and the control device determines the planting depth based on the detection result of the float sensor and the detection result of the soft and hard sensor. As described in claim 4, the control device adjusts the height of the floating ground leveling body according to the determined planting depth.