JP7392689B2 - work vehicle - Google Patents

Description

The present invention relates to a work vehicle.

2. Description of the Related Art Conventionally, a work vehicle is known in which an operating device is held in a straight-ahead position and a traveling vehicle body automatically travels straight (see, for example, Patent Document 1).

JP2016-24541A

However, in the above-mentioned work vehicle, the turning operation must be operated by a worker, and there is a possibility that the position after turning does not match the position of the next process.

The present invention has been made in view of the above, and an object of the present invention is to provide a work vehicle that can execute highly accurate turns.

In order to solve the above problems and achieve the purpose, a work vehicle (1) according to an aspect of the embodiment includes a traveling vehicle body (2), a seedling planting section (4), and an orientation detecting section (150). , a floor step (33), a first limit sensor (212), a cockpit (41), a second limit sensor (222), and a control device (100). The seedling planting section (4) is provided on the traveling vehicle body (2). The orientation detection section (150) detects the orientation of the traveling vehicle body (2). The floor step (33) is rotatably provided on the main frame (15) of the traveling vehicle body (2). The first limit sensor (212) is provided between the main frame (15) and the floor step (33), is turned ON when a worker is on the floor step (33), and is turned on when the worker is on the floor step (33). 33) is turned OFF when no worker is on board. The cockpit (41) is rotatably provided on the engine cover (30a). The second limit sensor (222) is provided between the engine cover (30a) and the cockpit (41), is turned ON when a worker is in the cockpit (41), and is turned on when a worker is in the cockpit (41). 41) is turned OFF when no worker is on board. A control device (100) controls the steering angle of the traveling vehicle body (2) when traveling straight and when turning, and causes the traveling vehicle body (2) to automatically travel straight and automatically turn. In automatic straight-ahead mode, the vehicle travels along a preset straight-ahead route. During automatic turning, the vehicle body (2) travels in an ideal direction at the end point of the turn so as to head toward the straight path of the next process. When a deviation occurs between the detected orientation of the traveling vehicle body (2) and the ideal orientation for turning during automatic turning, the control device (100) corrects the misaligned orientation of the traveling vehicle body (2) to the ideal orientation. Therefore, a correction amount for adjusting the steering angle is calculated based on the azimuth of the traveling vehicle body (2) that deviates from the ideal azimuth, and the steering angle is controlled based on the calculated correction amount. The automatic turning is not performed if the second limit sensor (222) is OFF and the first limit sensor (212) is ON .

According to one aspect of the embodiment, the work vehicle can perform highly accurate turning.

FIG. 1 is a side view showing a work vehicle. FIG. 2 is a plan view showing the work vehicle. FIG. 3 is a block diagram showing a control system centered on the control device of the seedling transplanter. FIG. 4 is a diagram illustrating automatic turning. FIG. 5 is a flowchart illustrating automatic turning processing according to the embodiment. FIG. 6 is a diagram showing an adjustment dial of a seedling transplanter according to a modified example. FIG. 7 is a side view schematically showing a part of a seedling transplanter according to a modification. FIG. 8 is a side view schematically showing a part of a seedling transplanter according to a modification.

(Overview of work vehicle)
First, an overview of a work vehicle 1 according to an embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a side view showing a work vehicle 1. FIG. FIG. 2 is a plan view showing the work vehicle 1.

In the following description, the front-rear direction refers to the traveling direction of the work vehicle 1 when traveling straight, and the front side in the traveling direction is defined as "front" and the rear side is defined as "rear". The traveling direction of the work vehicle 1 is the direction from the driver's seat 41 toward the steering wheel 35 (steering device) when traveling straight (see FIGS. 1 and 2).

The left-right direction is a direction horizontally orthogonal to the front-back direction, and defines left and right toward the "front" side. That is, when an operator (also referred to as a worker) is seated in the operator's seat 41 and facing forward, the left hand side is the "left" and the right hand side is the "right".

The vertical direction is the vertical direction. The front-back direction, the left-right direction, and the up-down direction are orthogonal to each other. Each direction is defined for convenience of explanation, and the present invention is not limited to these directions.

In the embodiment, the working vehicle 1 will be described as a riding-type seedling transplanter 1 that includes a seedling planting section 4 as a field working device and receives seedlings in the field. As shown in FIGS. 1 and 2, the seedling transplanter 1 includes a seedling planting section 4 that can be raised and lowered to plant seedlings in a field via a lifting link mechanism 3 on the rear side of a traveling vehicle body 2.

A main body portion of the fertilization device 5 is arranged on the upper rear side of the traveling vehicle body 2. Note that when the working vehicle 1 is not the seedling transplanter 1, the working device may include a sowing device or the like that supplies seeds.

The traveling vehicle body 2 is a four-wheel drive vehicle including left and right front wheels 10 and rear wheels 11, which are wheels and drive wheels. On the front side of the main frame 15 that constitutes the body frame of the traveling vehicle body 2, there is a transmission case 13 that transmits driving force to the seedling planting section 4, etc., and a driving force that is supplied from the engine 30, that is, the driving force generated by the engine 30. A hydraulic continuously variable transmission 14 that outputs rotation to the mission case 13 is provided.

The continuously variable transmission 14 is a hydrostatic continuously variable transmission called HST (Hydro Static Transmission). Below, the case where the continuously variable transmission is HST14 will be explained.

A sub-transmission mechanism 16 is provided in the transmission case 13 for switching the driving mode of the vehicle body 2 when traveling on the road in a high-speed mode or when planting seedlings in a low-speed mode. Front wheel final cases 10a are provided on the left and right sides of the mission case 13, and the front wheels 10 are mounted on left and right front axles 10b that respectively protrude outward from front wheel supports that can change the steering direction of the left and right front wheel final cases 10a. can be installed.

Further, on the rear side of the main frame 15, rear wheel gear cases 11a are attached to both left and right sides of a rear frame 22 (see FIG. 2) provided laterally, and left and right rear wheel gear cases 11a respectively protrude outward from the rear wheel gear case 11a. The rear wheels 11 are respectively attached to the rear axle 11b.

Furthermore, left and right link support frames 23 that support the elevating link mechanism 3 are provided on the upper part of the rear frame 22 to protrude upward. A pair of left and right lower link arms 24 are provided on the lower side of the left and right link support frames 23 and between the left and right links. A lift cylinder 25 operated by hydraulic pressure is provided between the left and right lower link arms 24 .

An upper link arm 26 is provided above the lifting cylinder 25, and the lifting link mechanism 3, which is a parallel link mechanism, is configured. Note that the left and right lower link arms 24, the lifting cylinder 25, and the upper link arm 26, each of which has one end connected to the traveling vehicle body 2 side, and the other end side of the upper link arm 26 are attached to the front part of the seedling planting section 4. .

Further, an engine 30 is mounted on the main frame 15. Rotational power of engine 30 is transmitted to mission case 13 via belt transmission 21 and HST 14. The rotational power transmitted to the mission case 13 is shifted by the auxiliary transmission mechanism 16 inside the mission case 13, and then divided into traveling power and externally extracted power.

Further, the rotational power of the engine 30 is transmitted to a hydraulic pump (not shown). The hydraulic pressure generated by the hydraulic pump is supplied to the HST 14, the power steering mechanism 88 of the handle 35 (see FIG. 3), the lifting cylinder 25, and the like.

The external power taken out from the rotational power transmitted to the transmission case 13 is transmitted to the planting clutch case 27 provided at the rear of the traveling vehicle body 2, and the seedlings are planted from the planting clutch case 27 by the planting transmission shaft 67. The information is transmitted to section 4.

On the other hand, left and right drive shafts 42 are provided at the rear of the mission case 13. Rotational power from the engine 30 is transmitted to the left and right rear wheel gear cases 11a via the mission case 13 and the drive shaft 42.

Note that a side clutch 44 (see FIG. 3) that turns on/off power transmission to the left and right drive shafts 42 is disposed above the left and right drive shafts 42 in the transmission direction. As shown in FIG. 1, a side clutch pedal 43a for operating the left and right side clutches 44 on and off is provided at the front lower part of the cockpit 41 and on one of the left and right sides.

Of the left and right side clutch pedals 43a, when the side clutch pedal 43a on the inside of the turn is depressed to disengage the side clutch 44 and the steering wheel 35 is operated to drive the turn, the drive rotation of the rear wheel 11 on the inside of the turn is completely controlled. Can be blocked.

A bonnet 39 is provided at the upper front side of the traveling vehicle body 2 and has a control panel 38 disposed thereon for operating various parts. The control panel 38 is provided with a monitor 86 (see FIG. 3) and the like.

Further, the bonnet 39 is provided with a handle 35 for steering the traveling vehicle body 2, a shift operation lever 36 for operating the HST 14 and the seedling planting section 4, an auxiliary shift operation lever 37 for operating the auxiliary transmission mechanism 16, and the like.

Furthermore, a front cover 40 that can be opened and closed is provided on the front side of the bonnet 39. Inside the front cover 40, an interlocking mechanism is provided that rotates the lower sides of the left and right front wheels 10 and the left and right front wheel final cases 10a in response to the fuel tank, battery, and steering of the handlebar 35. The front wheel 10 is, for example, a steered wheel that is steered in accordance with the steering of the handlebar 35.

An engine cover 30a is provided behind the bonnet 39 and above the engine 30 to cover the upper and side parts of the engine 30, and a cockpit 41 in which an operator is seated is provided above the engine cover 30a. provided.

A fertilizer application device 5 is provided on the rear side of the cockpit 41 and on the rear end side of the main frame 15. The driving force of the fertilization device 5 is transmitted by a fertilization transmission mechanism provided so as to face the fertilization device 5 from one left and right side of the left and right rear wheel gear cases 11a.

A substantially horizontal floor step 33 is formed on both left and right sides of the lower part of the engine cover 30a and the bonnet 39. As shown in FIG. 2, the floor step 33 has a partially grid-like shape, and even if, for example, mud from the shoes of an operator walking on the floor step 33 falls off, the mud will fall onto the field.

Furthermore, a rear step 330 is connected to the rear of the floor step 33, as shown in FIG. Preferably, the surface of the rear step 330 is treated with a non-slip finish having a plurality of protrusion patterns formed thereon so that the user's feet do not easily slip during operation.

In addition, on the front side of the traveling vehicle body 2 and on both left and right sides, there are provided preliminary seedling frames 50 in which a plurality of preliminary seedling mounting stands 52 are arranged at intervals in the vertical direction on seedling frame supports 51. Work materials such as seedlings and fertilizer bags to be replenished can be placed on the attachment part 4.

Further, a seedling tank 53 for loading seedlings to be planted in a field is attached to the rear end of the lifting link mechanism 3 along with a sliding mechanism for sliding in the left and right direction. In the seedling tank 53, seedling partition fences 54 which are long in the vertical direction are arranged at predetermined intervals in the left-right direction. A seedling planting device 55 is arranged below the seedling tank 53 to scrape off the loaded seedlings and plant them in the field.

The seedling planting device 55 simultaneously plants the same number of rows as the number of planting rows separated by the seedling partition fence 54, that is, 8 rows, and a planting transmission case 56 is arranged below the seedling tank 53 at intervals of four rows. Planting rotaries 57 are mounted on both left and right sides of the planting transmission case 56, respectively, for picking up seedlings and planting them in the field using a planting rod 58 while rotating.

In the fertilization device 5, a fertilization hopper 70 in which fertilizer is stored is partitioned into the same number of working rows as the seedling planting section 4 (8 rows in the example shown in FIG. 2). The fertilization hopper 70 for 8 rows is long in the left and right direction, which reduces the convenience of loading and removing fertilizer. Good too.

At the lower part of the fertilization hopper 70, a feeding device 71 is provided for supplying a set amount of fertilizer for each row. Below the feeding device 71, a ventilation duct 72 is provided in the left-right direction, through which conveying air for moving the fertilizer passes. Below the feeding device 71, a fertilizing hose 73 is provided that guides fertilizer near the seedling planting position of the seedling planting section 4. Further, a blower 74 is provided at one end of the ventilation duct 72 and is operated by a blower electric motor 76 to generate conveying air.

As shown in FIGS. 1 and 2, below the seedling planting section 4, there are a center float 62C that slides while touching the field, and two side floats 62L and 62R on the left and right sides that rotate around an axis. It is movable. Note that the center float 62C and the left and right side floats 62L, 62R may be collectively referred to as the float 62.

Further, below the seedling planting section 4 and in front of the float 62, a leveling rotor 63 is provided to level the unevenness of the field. Driving force is transmitted to the ground leveling rotor 63 from the left and right rear wheel gear cases 11a via the rotor transmission shaft 63a.

In addition, as shown in FIG. 1, grooves are formed on both the left and right sides of the seedling planting section 4 so that one of the left and right sides is in contact with the field and serves as a guide for running in the next working row (next process). A line marker 65 is provided respectively. When the left and right side of the left and right line markers 65 touch the ground, the other side separates upward, and when the seedling planting section 4 is raised during turning, both the left and right sides are separated upward, and when the seedling planting section 4 is lowered after turning, One side of the left and right is separated upward and the other side is grounded.

Further, as shown in FIGS. 1 and 2, a center mascot 66 that is long in the vertical direction is provided at the left and right center portions of the vehicle body 2 and in front of the bonnet 39. As shown in FIGS. By aligning the center mascot 66 with the grooves formed in the field by the left and right line markers 65, it is possible to travel in line with the working position of the immediately preceding work strip, improving work accuracy and preventing the occurrence of non-work. be able to.

Note that depending on the soil quality of the field, the guide line formed by the left and right line markers 65 may be quickly buried, and the guide line for straight movement may disappear. In such a case, it is preferable to use the left and right side markers 19 provided in front of the left and right line markers 65. That is, by moving the left and right side markers 19 outward and positioning the side markers 19 above the planted seedlings, it becomes possible to perform the planting operation in accordance with the planting of the seedlings in the previous working row.

Further, as shown in FIG. 1, the seedling transplanter 1 includes a position acquisition device 150. The position acquisition device 150 acquires the current position and direction of the seedling transplanter 1. The position acquisition device 150 includes, for example, a direction sensor and positioning means such as GPS (Global Positioning System) and GNSS (Global Navigation Satellite System). The position acquisition device 150 may be configured by a plurality of devices. The position acquisition device 150 may include a camera or an ultrasonic sensor, and may acquire the turning position in the field and detect the distance to the turning position.

For example, the position acquisition device 150 receives positioning information from the positioning means, creates current position information and azimuth information of the traveling vehicle body 2 based on the received positioning information, and acquires the current position and azimuth. The position acquisition device 150 is, for example, attached to the attachment stay 59 and disposed above the traveling vehicle body 2.

The straight-travel control program and the turning control program, which are created based on the position information from the position acquisition device 150, are stored in different locations. The straight-line control program is stored, for example, in a straight-line control ECU (Electronic Control Unit) 100a in the position acquisition device 150, and the turning control program is stored, for example, in a turning control ECU 100b housed in the bonnet 39. . Note that the straight-line control ECU 100a and the turning control ECU 100b are included in a control device 100 (see FIG. 3), which will be described later. The straight-line control ECU 100a and the turning control ECU 100b may be stored in the same ECU.

(Control system of seedling transplanter)
Next, the control system of the seedling transplanter 1 will be explained with reference to FIG. FIG. 3 is a block diagram showing a control system centered on the control device 100 of the seedling transplanter 1. The seedling transplanter 1 can control each part by electronic control, and includes a control device (hereinafter referred to as a controller) 100 that controls each part.

The controller 100 is provided with a processing section including a CPU (Central Processing Unit), a storage section such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and an input/output section, which are connected to each other. It is possible to exchange signals with each other. A computer program for controlling the seedling transplanter 1 and the like are stored in the storage unit. The controller 100 performs each function by reading a computer program stored in a storage unit.

The controller 100 includes, for example, actuators such as a throttle motor 80, hydraulic control valves 81 and 82, a planting clutch actuation solenoid 83, a side clutch actuation solenoid 84, an HST14 motor 85, a line drawing marker lift motor 87, a steering motor 95, and a differential lock. A switching motor 96 and the like are connected.

The throttle motor 80 increases or decreases the rotational speed of the output shaft of the engine 30 by operating a throttle that adjusts the intake air amount of the engine 30 . The hydraulic control valve 81 controls the expansion and contraction operation of the lifting cylinder 25. Hydraulic control valve 82 controls power steering mechanism 88 . The planting clutch actuation solenoid 83 operates the planting clutch 27a.

The side clutch operation solenoid 84 operates the side clutch 44 that switches the state of power transmission to the rear wheel 11 (see FIG. 1). Note that the side clutches 44 are provided on the left and right rear wheels 11, respectively, and two side clutch actuation solenoids 84 are provided corresponding to each side clutch 44.

The HST14 motor 85 changes the tilt angle of the swash plate of the HST14 by changing the rotation angle of the trunnion of the HST14. The steering motor 95 is a motor that drives the steering wheel 35, which is a steering device that adjusts the steering angle (steering amount) of the front wheels 10 (see FIG. 1) when automatic turning control is performed. Steering motor 95 rotates handle 35. The line drawing marker elevating motor 87 raises and lowers the line drawing marker 65.

The differential lock switching motor 96 is a motor that switches between activation and deactivation of a differential lock mechanism 97 (hereinafter referred to as a differential lock mechanism) that rotates the left and right running wheels, specifically, the left and right front wheels 10 at the same rotational speed. be. With the differential lock mechanism 97 in the engaged state, the left and right running wheels rotate at the same rotational speed.

The controller 100 is connected to a rotation speed sensor 90, a steering amount sensor 91, an inclination sensor 92, and the like, which are detection devices. Two rotation speed sensors 90 are provided corresponding to the left and right rear wheels 11, and detect the rotation speeds of the left and right rear wheels 11, respectively. Note that the rotation speed sensor 90 may detect the rotation speed of the left and right front wheels 10.

The steering amount sensor 91 detects the amount of operation of the steering wheel 35, which is a steering device, that is, the steering angle of the front wheels 10. The steering amount sensor 91 is provided, for example, on a shaft connected to the pitman arm. Note that the steering amount is detected in each of the left and right directions, with the value when the steering wheel 35 reaches a preset straight-ahead position as a reference value. The inclination sensor 92 detects the inclination angle, which is the inclination of the traveling vehicle body 2 .

The controller 100 also includes, as operation signals, a speed change operation lever 36, an auxiliary speed change operation lever 37, an autonomous travel changeover switch 46, a planting section lift switch 47, an automatic straight ahead changeover switch 45, an automatic turning changeover switch 48, an automatic delineation marker A signal is input from a lift switch 49 or the like.

The autonomous driving changeover switch 46 is a switch that switches whether or not to execute autonomous driving. Specifically, the autonomous driving changeover switch 46 is a switch that switches the driving mode to an autonomous driving mode or a manual driving mode. For example, when the autonomous driving selector switch 46 is “ON”, the driving mode is set to the autonomous driving mode. When the autonomous running selector switch 46 is "OFF", the running mode is set to manual running mode. When the autonomous travel changeover switch 46 is turned "ON," the automatic straight-ahead changeover switch 45 and the automatic turning changeover switch 48 are turned "ON." Note that even if the automatic straight-ahead changeover switch 45 and the automatic turning changeover switch 48 are once turned "ON", they can be changed to "OFF" by the operator's operation.

The planting section lift switch 47 is a switch for switching whether or not to raise/lower the seedling planting section 4 . The planting section lift switch 47 is changed to the "raise" and "lower" positions.

When the planting section lift switch 47 is in the "raise" position, the seedling planting section 4 rises to a predetermined non-working position and enters a non-working state in which the seedling planting device 55 stops. When the planting section lift switch 47 is in the "lower" position, the seedling planting section 4 is lowered to a predetermined working position and enters a working state in which the seedling planting device 55 is activated. That is, the planting section lift switch 47 is a switch that detects the working state of the seedling planting section 4. Note that a switch for detecting the working state of the seedling planting section 4 may be separately provided.

The line drawing marker automatic elevation switch 49 is a switch that switches whether or not to automatically raise and lower the line drawing marker 65 in conjunction with the amount of operation of the handle 35, that is, the amount of steering of the front wheels 10. When the line-drawing marker automatic raising/lowering switch 49 is "ON," control is executed to automatically raise and lower the line-drawing marker 65 in conjunction with the amount of steering. On the other hand, when the line drawing marker automatic raising/lowering switch 49 is "OFF", the control for automatically raising and lowering the line drawing marker 65 in conjunction with the amount of steering is not executed.

The automatic straight-ahead changeover switch 45 is a switch for switching whether or not to enable automatic straight-ahead travel. When the automatic straight-ahead selector switch 45 is set to "ON," a travel assist function, which will be described later, is enabled and automatic straight-ahead travel becomes possible. When the automatic straight-ahead changeover switch 45 is set to "OFF," the driving assist function is disabled and automatic straight-ahead travel becomes impossible.

The automatic turning changeover switch 48 is a switch for switching whether or not to enable automatic turning. When the automatic turning changeover switch 48 is turned on, a turning assist function, which will be described later, is enabled and automatic turning becomes possible. When the automatic turning changeover switch 48 is set to "OFF," the turning assist function is disabled and automatic turning cannot be performed. When the automatic turning changeover switch 48 is set to "OFF," automatic turning is not performed even if the conditions for performing automatic turning are met.

Further, current position information of the traveling vehicle body 2, the direction of the traveling vehicle body 2, etc. are input to the controller 100 from the position acquisition device 150. The controller 100 executes an autonomous driving mode in which the traveling vehicle body 2 performs work while automatically traveling.

Further, various information is input to the controller 100 from a remote control device 170 (hereinafter referred to as a "remote controller"). For example, the controller 100 receives various information from the remote controller 170 via the receiver 180 (see FIG. 1). The receiver 180 is attached to the mounting stay 59 (see FIG. 1), for example, and is disposed above the front side of the traveling vehicle body 2. Note that a plurality of receivers 180 may be provided.

The remote control 170 can remotely control the seedling transplanter 1. Remote control 170 may be a terminal device such as a smartphone. Remote control 170 transmits a control signal according to the operator's operation. The remote control 170 is communicably connected to the controller 100 by short-range wireless communication such as Wi-fi (registered trademark) or BLE (Bluetooth (registered trademark) Low Energy), but is not limited to this. In addition to, or instead of, they may be communicatively connected via a communication network or the like.

(autonomous driving mode)
Here, autonomous travel (automatic travel) in the field by the seedling transplanter 1 will be explained. The controller 100 (see FIG. 3) has an autonomous driving mode in which the steering wheel 35 (see FIG. 3) is operated by controlling the steering motor 95 (see FIG. 3) while feeding back the amount of steering of the front wheels 10 (see FIG. 1). . The autonomous driving mode includes an automatic straight-ahead mode and an automatic turning mode.

The automatic straight-ahead mode is a mode in which the steering motor 95 is controlled so that the vehicle body 2 travels straight along a preset straight-ahead route. In the automatic straight-ahead mode, the traveling vehicle body 2 travels straight without the operator's operation while planting seedlings in the field by the seedling planting section 4. That is, the driving assist function for transplanting seedlings to the field while automatically moving the traveling vehicle body 2 straight ahead is activated, and the driving assist function is executed.

In the automatic turning mode, when the traveling vehicle body 2 reaches a predetermined turning position, the seedling planting section 4 stops planting seedlings, and the steering motor 95 is controlled so that the traveling vehicle body 2 follows a preset ideal direction. It is a rotating mode. The predetermined turning position is set based on, for example, the traveling distance of the process in which the work was performed, position information regarding the process in which the work was performed, and the like.

In the automatic turning mode, for example, the seedling planting section 4 is raised and placed in a non-working state, and the traveling vehicle body 2 turns without the operator's operation. That is, the turning assist function for turning the traveling vehicle body 2 is enabled and executed without planting the seedlings by the seedling planting section 4.

Next, a turning method in automatic turning mode will be explained. In the automatic turning mode, the steering wheel 35 is driven so that the steering angle of the front wheels 10 becomes a value corrected to a predetermined steering angle. The predetermined steering angle is a preset amount. A method of correcting the predetermined steering angle will be described below.

In the automatic turning mode, as shown in FIG. 4, an ideal orientation is set so that the traveling vehicle body 2 travels on an arc (ideal trajectory) having a predetermined radius from a predetermined turning center from a turning start point. Ru. The predetermined radius is set depending on the type of traveling vehicle body 2. The predetermined radius is set, for example, according to the number of planting rows. FIG. 4 is a diagram illustrating automatic turning. Note that the predetermined radius may be set using a dial provided on the control panel 38 or the like.

The predetermined turning center is set based on the turning start point, straight route information of the traveling vehicle body 2, and a predetermined radius. Specifically, a predetermined turning center is set at a point on an imaginary line extending from the turning start point in a direction orthogonal to the straight path and a predetermined radius away from the turning start point.

Further, the turning end point is on an imaginary line extending in a direction perpendicular to the straight path, and is provided at a point a predetermined radius away from a predetermined turning center. Further, the straight path in the next step is set as a path extending from the turning end point and parallel to the straight path in the previous step.

Next, xy coordinates are set, with the predetermined turning center as the origin and the virtual line as the x-axis. Then, the position information of the vehicle body 2 in the y-axis direction is calculated based on the position information of the vehicle body 2 in the x-axis direction and the arc information (predetermined radius) having the predetermined turning center as the origin.

For example, when the position of the traveling vehicle body 2 in the x-axis direction is "c", the position "d" in the y-axis direction is calculated using equation (1). Here, the predetermined radius is "1200 mm".

c ² + d ² =1200 ² ...(1)

The ideal orientation of the traveling vehicle body 2 at the position (c, d) is the tangential direction of the circular arc at the position (c, d). Therefore, the ideal orientation α at position (c, d) is expressed by equation (2).

α=tan ^-1 (d/c)...(2)

The actual orientation β of the traveling vehicle body 2 is detected by the position acquisition device 150. Therefore, the difference a between the orientation β of the traveling vehicle body 2 and the ideal orientation α is calculated as “a=α−β”.

When the angular velocity change of the traveling vehicle body 2 with respect to one degree of steering angle (the amount of steering of the handle 35) is, for example, 0.04 degree/sec according to actual measurement, the correction amount u of the steering angle is "u=a/0 .04''. The change in angular velocity of the traveling vehicle body 2 with respect to one degree of steering angle (steering amount of the steering wheel 35) may be set by, for example, a dial provided on the control panel 38.

The steering angle of the front wheels 10 in the automatic turning mode is calculated by adding the calculated correction amount u to the predetermined steering angle. Such correction is performed, for example, immediately after starting automatic turning. Furthermore, such correction is executed until, for example, the automatic turning is completed. That is, the correction of the steering angle of the front wheels 10 based on the azimuth is executed until the next step of straight-ahead control is started. The above correction is executed by the controller 100.

By setting the ideal orientation in the tangential direction to the circular arc (ideal trajectory), it becomes easy to calculate the ideal orientation. Therefore, for example, even if the controller 100 has a slow calculation speed, it is possible to quickly calculate the ideal orientation. Therefore, the cost of the seedling transplanter 1 can be reduced.

Further, the controller 100 performs the correction within a range in which the steering angle during automatic turning is from the maximum turning angle to the extent that the side clutch 44 on the inner side of the turn does not enter the engaged state.

Note that the correction may be performed after turning by a predetermined angle by automatic turning. The predetermined angle is, for example, 90 degrees. For example, the correction is started after the vehicle has turned 90 degrees from the start of the turn. Thereby, it is possible to suppress the traveling vehicle body 2 from coming into contact with the ridge when the correction is applied excessively.

Moreover, the controller 100 may perform the above correction once or multiple times during automatic turning. The controller 100 may be able to set the number of times the correction is performed. Thereby, for example, since the followability of the handle 35 and the traveling vehicle body 2 can be determined depending on the field conditions, the operator can set the correction interval based on the field conditions. Therefore, the seedling transplanter 1 can rotate with high accuracy during automatic rotation.

Next, automatic turning processing according to the embodiment will be described with reference to FIG. 5. FIG. 5 is a flowchart illustrating automatic turning processing according to the embodiment.

The controller 100 determines whether the traveling vehicle body 2 has reached the turning start point (S100). If the traveling vehicle body 2 has not reached the turning start point (S100: No), the controller 100 ends the current process.

When the traveling vehicle body 2 reaches the turning start point (S100: Yes), the controller 100 sets an ideal orientation (S101).

The controller 100 executes automatic turning (S102). The controller 100 controls the steering angle of the front wheels 10 so that the deviation between the azimuth of the traveling vehicle body 2 detected by the position acquisition device 150 of the traveling vehicle body 2 and the ideal orientation is corrected. Specifically, the controller 100 controls the steering motor 95 so that the steering angle of the front wheels 10 becomes the corrected steering angle.

The controller 100 determines whether the traveling vehicle body 2 has reached the turning end point (S103). If the traveling vehicle body 2 has not reached the turning end point (S103: No), the controller 100 continues the automatic turning (S102).

When the traveling vehicle body 2 reaches the turning end point (S103: Yes), the controller 100 ends the automatic turning (S104).

The seedling transplanter 1 includes a traveling vehicle body 2, a seedling planting section 4, a position acquisition device 150, and a controller 100. The seedling planting section 4 is provided on the traveling vehicle body 2. The position acquisition device 150 detects the direction of the traveling vehicle body 2 . The controller 100 controls the steering angle of the traveling vehicle body 2 when turning, and causes the traveling vehicle body 2 to automatically turn. The controller 100 corrects the deviation between the detected orientation of the traveling vehicle body 2 and the ideal orientation for turning during automatic turning, and controls the steering angle.

Thereby, the seedling transplanter 1 can turn with high accuracy during automatic turning.

The controller 100 sets the ideal heading at the start of turning. Thereby, the controller 100 can execute a turn starting from the turn start point based on the ideal orientation. Therefore, the seedling transplanter 1 can rotate with high accuracy during automatic rotation.

The controller 100 performs the correction as long as the steering angle during automatic turning is within the range from the maximum turning angle to the extent that the side clutch 44 on the inner side of the turning does not enter the engaged state.

Thereby, the seedling transplanter 1 can suppress excessive load on the steering motor 95 and suppress deterioration of the steering motor 95. In addition, the seedling transplanter 1 prevents the side clutch 44 from being engaged by correcting the steering angle during automatic turning, and suppresses the behavior of the traveling vehicle body 2 from becoming unstable during automatic turning. can do.

The controller 100 corrects the steering angle based on the azimuth until proceeding to the next step of straight-ahead control.

Thereby, the seedling transplanter 1 can rotate with high precision by automatic rotation.

(Modified example)
The seedling transplanter 1 according to the modification predicts the predicted orientation of the traveling vehicle body 2 after a predetermined time based on the orientation of the traveling vehicle body 2 detected by the position acquisition device 150, and determines the deviation between the predicted orientation and the ideal orientation. may be corrected to control the steering angle. The predetermined time is a preset time, for example, about 1 second. Specifically, the seedling transplanter 1 according to the modification predicts the predicted orientation based on the detected orientation of the traveling vehicle body 2 and the vehicle speed of the traveling vehicle body 2. Moreover, the ideal orientation is the ideal orientation of the traveling vehicle body 2 after a predetermined period of time. For example, if the current position of the traveling vehicle body 2 is "(c, d)", the ideal orientation is "θ", and the vehicle speed is "v", the position of the traveling vehicle body 2 after a predetermined time is " (c+vcosθ, d+sinθ)”. The predicted orientation is the ideal orientation in "(c+vcosθ, d+sinθ)".

Thereby, the seedling transplanter 1 according to the modification can control the steering angle of the traveling vehicle body 2 based on the traveling vehicle body 2 after a predetermined time and the ideal orientation after a predetermined time. That is, the seedling transplanter 1 according to the modified example can automatically turn the traveling vehicle body 2 based on the previously read steering angle. Therefore, the seedling transplanter 1 according to the modification can improve the accuracy of automatic turning of the traveling vehicle body 2.

As shown in FIG. 6, the seedling transplanter 1 according to the modification may include an adjustment dial 200 (adjustment unit) that can adjust the amount of correction in automatic rotation. The adjustment dial 200 is provided on the control panel 38, for example. FIG. 6 is a diagram showing an adjustment dial 200 of the seedling transplanter 1 according to a modification.

The seedling transplanter 1 according to the modified example automatically performs automatic transmission when the orientation of the traveling vehicle body 2 is facing toward the outside of the turn with respect to the ideal orientation, and the difference between the orientation of the traveling vehicle body 2 and the ideal orientation is a predetermined value or more. The turning may be stopped and the traveling vehicle body 2 may be stopped.

The seedling transplanter 1 according to the modified example automatically performs automatic transmission when the orientation of the traveling vehicle body 2 is facing toward the outside of the turn with respect to the ideal orientation, and the difference between the orientation of the traveling vehicle body 2 and the ideal orientation is a predetermined value or more. The monitor 86 may display that the turning is deviated.

As a result, the seedling transplanter 1 according to the modified example suppresses the traveling vehicle body 2 from making a large turn with respect to the ideal direction during automatic turning, and, for example, prevents the traveling vehicle body 2 from making a large turn with respect to the ideal direction. It is possible to suppress the vehicle body 2 from shifting in the left-right direction.

At the time of automatic turning, the seedling transplanting machine 1 according to the modification may, for example, turn 90 degrees, move straight a predetermined distance, and then turn 90 degrees. The seedling transplanter 1 according to the modification corrects the steering angle based on the above-mentioned direction when turning.

The seedling transplanter 1 according to the modification may calculate the deviation of the traveling vehicle body 2 with respect to the target line of the straight-ahead control in the next step at the end of the automatic turning.

The seedling transplanter 1 according to the modification may predict the deviation of the traveling vehicle body 2 from the target line of the straight-ahead control in the next step during automatic turning. For example, the seedling transplanter 1 according to the modification may predict the deviation of the traveling vehicle body 2 from the target line of the straight-ahead control in the next step in the case where there is no slip. The seedling transplanter 1 according to the modification may compare the ideal orientation and the orientation of the traveling vehicle body 2, and determine a location where there is a difference in orientation as a location where slipping has occurred.

The seedling transplanter 1 according to the modification may calculate the ideal angular velocity based on the steering angle and the vehicle speed acquired from the position acquisition device 150. The seedling transplanter 1 according to the modification may calculate the orientation of the traveling vehicle body 2 that changes from when the handle 35 starts returning during a turn until the end of the turn, based on the angle of the handle 35 and the vehicle speed. The seedling transplanter 1 according to the modification may calculate the machine direction by integrating ideal angular velocities. The seedling transplanter 1 according to the modification may measure the ideal angular velocity and orientation from the time of starting automatic turning.

The seedling transplanter 1 according to the modification may record the difference from the ideal orientation each time the orientation acquired from the position acquisition device 150 exceeds a certain threshold. The seedling transplanter 1 according to the modification may calculate the difference from the ideal orientation at a plurality of predetermined locations during automatic turning. The seedling transplanter 1 according to the modification may predict the positional deviation of the traveling vehicle body 2 in the left-right direction at the turning end point based on the difference from the ideal orientation calculated at a plurality of locations.

The seedling transplanter 1 according to the modified example finishes recording the difference from the ideal orientation after turning 90 degrees after starting automatic turning until the point at which the turning ends, and uses the obtained data. Based on this, the positional deviation of the traveling vehicle body 2 in the left-right direction at the turning end point may be predicted.

The seedling transplanter 1 according to the modified example uses data on the difference between each direction and the difference in the direction immediately before the turning end point when predicting the horizontal displacement of the traveling vehicle body 2 at the turning end point. Differences may also be used.

The seedling transplanter 1 according to the modified example records the difference from the ideal orientation even if the angle between the target line of the straight-ahead process in the previous process and the orientation of the traveling vehicle body 2 is positive in the turning direction. good.

The seedling transplanter 1 according to the modification calculates the horizontal positional deviation of the traveling vehicle body 2 at the turning end point during automatic turning, and calculates the orientation of the traveling vehicle body 2 at the turning end point from the calculated positional deviation. The seedling transplanter 1 according to the modification may determine the vehicle speed and the timing to start returning the handle 35 from the steering angle. Thereby, the seedling transplanter 1 according to the modification can set the orientation of the traveling vehicle body 2 to the ideal orientation at the turning end point.

The seedling transplanter 1 according to the modification may calculate, when the automatic turning ends, the distance and orientation relationship between the turning end point and the straight line on which straight line control in the next step is performed. The seedling transplanter 1 according to the modification may calculate the ideal orientation during the next automatic turning based on the calculated relationship.

As shown in FIG. 7, the seedling transplanter 1 according to the modification may be provided with a stopper 210, a spring 211, and a limit sensor 212 on the main frame 15. Specifically, the stopper 210, the spring 211, and the limit sensor 212 are provided on the upper surface of the main frame 15. A stopper 210, a spring 211, and a limit sensor 212 are provided between the main frame 15 and the floor step 33. FIG. 7 is a side view schematically showing a part of the seedling transplanter 1 according to a modification.

In the seedling transplanter 1 according to the modified example, the floor step 33 is rotatable as the operator moves up and down. For example, the floor step 33 is provided on the main frame 15 so as to be able to rotate slightly around the rear end. The stopper 210 comes into contact with the floor step 33 and supports the floor step 33 when the worker gets on the floor step 33, that is, when the worker gets on the seedling transplanter 1.

The spring 211 lifts the floor step 33 so that the floor step 33 is separated from the limit sensor 212 when no passenger is riding on the floor step 33.

The limit sensor 212 is turned "ON" when a worker stands on the floor step 33, and turns "OFF" when no worker stands on the floor step 33. That is, the limit sensor 212 detects lifting and lowering of the worker.

The seedling transplanter 1 according to the modification limits the control output from the remote controller 170 when the limit sensor 212 is "ON". This restricts the operation of the seedling transplanter 1 using the remote controller 170 when a worker is riding on the seedling transplanter 1 and working. For example, the remote control 170 can only execute the off-side output of the HST 14. Therefore, when a worker rides on the seedling transplanter 1 and performs work, the seedling transplanter 1 can be prevented from making movements that are not intended by the worker, and the safety of the worker can be improved.

The seedling transplanter 1 according to the modification may prohibit control output from the remote controller 170 when the limit sensor 212 is "ON". Moreover, the seedling transplanter 1 according to the modification may limit the control output from the remote controller 170 when the limit sensor 212 is "ON" based on the acceleration information. The acceleration information may be obtained by the position acquisition device 150, or may be obtained from an acceleration sensor or the like.

As shown in FIG. 8, the seedling transplanter 1 according to the modification may be provided with a stopper 220, a spring 221, and a limit sensor 222 on the engine cover 30a. Specifically, the stopper 220, the spring 221, and the limit sensor 222 are provided on the upper surface of the engine cover 30a. Stopper 220, spring 221, and limit sensor 222 are provided between engine cover 30a and cockpit 41. FIG. 8 is a side view schematically showing a part of the seedling transplanter 1 according to a modification.

In the seedling transplanter 1 according to the modification, the cockpit 41 is rotatable depending on whether a worker is seated or not. For example, the cockpit 41 is provided on the engine cover 30a so as to be able to rotate slightly around the front end.

Limit sensor 222 detects seating in cockpit 41. The limit sensor 222 is turned "ON" when a worker is seated in the cockpit seat 41, and turned "OFF" when the worker leaves the cockpit seat 41. Note that the spring 221 also functions as a shock absorber for the cockpit 41.

The seedling transplanter 1 according to the modification may include a limit sensor 212 and a limit sensor 222. That is, the seedling transplanter 1 according to the modified example may detect when the operator gets on the vehicle and when the operator is seated. The seedling transplanter 1 according to the modification performs control during autonomous travel based on the detection results of the limit sensors 212 and 222.

For example, when the limit sensor 222 is "OFF" and the limit sensor 212 is "ON", the seedling transplanter 1 according to the modification determines that the worker is away from his seat and is performing replenishment work. . In this case, the seedling transplanter 1 according to the modified example does not accelerate, suddenly decelerate, or turn during autonomous travel. When the seedling transplanter 1 according to the modified example needs to turn, it slowly decelerates and stops before turning.

Moreover, the seedling transplanter 1 according to the modification may prohibit control output from the remote controller 170 when the limit sensor 212 is "OFF" and the limit sensor 222 is "OFF". In the seedling transplanter 1 according to the modification, when the limit sensor 222 is "ON" and the limit sensor 212 is "ON", the remote controller 170 may be able to execute only the off-side output of the HST 14.

The seedling transplanter 1 according to the modified example may display an error on the monitor 86 when the limit sensor 212 is "OFF" and the limit sensor 222 is "ON".

The seedling transplanter 1 according to the modification can reduce fertilizer by an operator operating a fertilizer reduction button while planting seedlings. The seedling transplanter 1 according to the modification may map the positional information of the location where the fertilizer has been reduced and the amount of fertilizer reduction between the start of the seedling planting work and the end of the work. Note that mapping may be performed by a terminal device. The seedling transplanter 1 according to the modification may map the position information of the location where the fertilizer has been reduced and the fertilizer reduction rate.

These allow the operator to easily confirm, for example, the locations where fertilizer has been reduced and the plan for the fertilizer reduction rate in subsequent operations.

The seedling transplanter 1 according to the modification may map the location information of the location where fertilizer reduction was performed and the amount of fertilizer reduction for each field. Moreover, the seedling transplanter 1 according to the modification may perform the totaling within a specified period.

The seedling transplanter 1 according to the modified example has a map of location information of locations where fertilizer has been reduced and the amount of fertilizer reduction for each field, and displays the outer periphery of the map based on the field shape created by moving the seedling transplanter 1. Only the outermost periphery may be displayed.

The seedling transplanter 1 according to the modification may display a fertilizer reduction instruction on the monitor 86, for example, based on a fertilizer reduction map created by farming support software or the like. For example, a fertilizer reduction map is transmitted from a device having farming support software to a terminal device, and from the terminal device to the seedling transplanter 1. The seedling transplanter 1 outputs a fertilizer reduction instruction to the monitor 86 based on the current position information of the traveling vehicle body 2 and the fertilizer reduction map. The operator executes fertilizer reduction based on the fertilizer reduction instruction displayed on the monitor 86. Note that the seedling transplanter 1 may perform fertilizer reduction based on the current position information of the traveling vehicle body 2 and the fertilizer reduction map.

The seedling transplanter 1 according to the modification may provide a sheet at the left and right ends of the fertilization hopper 70. The sheet is, for example, polyvinyl chloride. The sheet is attached to the main body of the fertilization hopper 70 and the lid of the fertilization hopper 70. The sheet is attached to the inside of the main body of the fertilization hopper 70 and to the inside of the lid of the fertilization hopper 70. The sheet can be folded inside the fertilization hopper 70. The sheet suppresses fertilizer exposure. Specifically, the sheet suppresses exposure of the fertilizer to air. This suppresses moisture absorption of the fertilizer. The sheet also prevents fertilizer from spreading from the fertilization hopper 70.

Note that the sheet may be provided so as to surround the inside of the fertilization hopper 70, and may be provided so as to be folded inward when the lid of the fertilization hopper 70 is closed.

The seedling transplanter 1 according to the modification may send air into the fertilization hopper 70 to dehumidify the fertilizer in the fertilization hopper 70. For example, the intake port of the blower 74 is connected to the fertilization hopper 70. When the blower 74 operates, the air inside the fertilization hopper 70 is sucked, and new air is sent into the fertilization hopper 70. A filter may be provided on the hose connecting the fertilization hopper 70 and the blower 74, and the fertilizer powder and water may be removed by the filter.

Note that air may be sucked into the blower 74 from outside the fertilization hopper 70, and a portion of the conveying air for moving the fertilization may be sent into the fertilization hopper 70 by the blower 74. The path branching from the blower 74 to the fertilization hopper 70 may be formed by a bellows.

The seedling transplanter 1 according to the modification may be provided with a rain shield and a sunshade on the attachment stay 59 to which the position acquisition device 150 is attached. The rain shield and sunshade are, for example, tarpaulin sheets. A rain shield and a sunshade are provided below the position acquisition device 150.

A rain shield and a sunshade may be provided above the position acquisition device 150. For example, a core portion of a rain shield and a sunshade are attached to the attachment stay 59, and the main body portions of the rain shield and sunshade are provided so as to cover the position acquisition device 150. Thereby, the position acquisition device 150 is protected by the rain shield and the sunshade.

Further advantages and modifications can be easily deduced by those skilled in the art. Therefore, the broader aspects of the invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various changes may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

1 Work vehicle (seedling transplanter)
2 Traveling vehicle body 4 Seedling planting section 100 Control device (controller)
150 Position acquisition device (direction detection unit)
200 Adjustment dial (adjustment section)

Claims (8)

A running vehicle body,
a seedling planting section provided on the traveling vehicle body;
a direction detection unit that detects the direction of the traveling vehicle body;
a floor step rotatably provided on the main frame of the traveling vehicle body;
a first limit provided between the main frame and the floor step, which is turned on when a worker is on the floor step and turned off when no worker is on the floor step; sensor and
A rotatable cockpit on the engine cover,
a second limit provided between the engine cover and the cockpit, which is turned on when a worker is in the cockpit and turned off when no worker is in the cockpit; sensor and
a control device that controls a steering angle of the traveling vehicle body when traveling straight and when turning, and causes the traveling vehicle to automatically travel straight and automatically turn;
Equipped with
The automatic straight-ahead travel includes traveling along a preset straight-ahead route;
The automatic turning is performed so that the traveling vehicle body travels in an ideal orientation at the end point of the turn so as to head toward the straight path of the next process;
The control device includes:
When a deviation occurs between the detected orientation of the traveling vehicle body and the ideal orientation for turning during automatic turning,
In order to correct the deviated azimuth of the traveling vehicle body to the ideal azimuth, a correction amount for adjusting the steering angle is calculated based on the deviated azimuth of the traveling vehicle body from the ideal azimuth;
controlling the steering angle based on the calculated correction amount;
The control is executed until the vehicle shifts to automatic straight ahead after turning,
When the second limit sensor is OFF and the first limit sensor is ON, acceleration, sudden deceleration, and turning during autonomous driving are not performed.
A work vehicle characterized by: The control device predicts a predicted orientation of the traveling vehicle body after a predetermined time based on the detected orientation of the traveling vehicle body,
When a deviation occurs between the predicted azimuth and the ideal azimuth, calculating the correction amount based on the deviated predicted azimuth from the ideal azimuth;
The work vehicle according to claim 1, wherein the steering angle is controlled based on the calculated correction amount . The work vehicle according to claim 2, wherein the control device calculates the predicted orientation from the detected orientation of the traveling vehicle body and a vehicle speed of the traveling vehicle body. The work vehicle according to any one of claims 1 to 3, wherein the control device sets the ideal orientation at the time of starting a turn. The work vehicle according to any one of claims 1 to 4, wherein the control device executes steering angle control based on the correction amount a plurality of times during the turning, and is capable of setting the number of corrections. The work vehicle according to any one of claims 1 to 5, wherein the control device executes the control of the steering angle based on the azimuth until proceeding to the next step of straight-ahead control. The work vehicle according to any one of claims 1 to 6 , further comprising an adjustment section that can adjust the correction amount. The control device causes the automatic turning to occur when the orientation of the traveling vehicle body is facing toward the outside of the turning with respect to the ideal orientation, and the difference between the orientation of the traveling vehicle body and the ideal orientation is a predetermined value or more. The work vehicle according to any one of claims 1 to 7 , wherein the work vehicle stops and the traveling vehicle body is stopped.

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