Work vehicle

Abstract

To provide a work vehicle capable of inhibiting a seedling planting start position from being deviated.SOLUTION: A work vehicle includes a traveling vehicle body, a seedling planting unit attached to the traveling vehicle body, a rotation speed sensor that detects a rotation speed of a wheel of the traveling vehicle body, a steering amount sensor that detects a steering angle of a steering device of the traveling vehicle body, and a control device that controls raising and lowering of the seedling planting unit and an operation state of the seedling planting unit. When the traveling vehicle body turns, the control device calculates the orientation of the traveling vehicle body and the position of the seedling planting unit based on the rotation speed and the steering angle. When the traveling vehicle body turns, the control device calculates the angular velocity of the traveling vehicle body using a preset prediction formula based on the vehicle speed calculated based on the rotation speed and the steering angle, and calculates the orientation of the traveling vehicle body based on the calculated angular velocity.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a work vehicle. [Background technology]

[0002] BACKGROUND ART Conventionally, there is known a work vehicle that raises and lowers a seedling planting unit in response to steering operation when turning, thereby controlling the operating state of the seedling planting unit (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-296314 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the work vehicle described above turns, the seedling planting unit lowers and begins planting when the rotation speed of the rear wheel on the inside of the turn reaches a predetermined number of rotations. Therefore, depending on the turning conditions, the starting position of the seedling planting unit may deviate from the desired position.

[0005] The present invention has been made in consideration of the above, and aims to provide a work vehicle that prevents the start position of seedling planting from shifting. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a work vehicle (1) according to one aspect of the embodiment includes a traveling body (2), a seedling planting unit (4) attached to the traveling body (2), a rotation speed sensor (90) that detects the rotation speed of the wheels (11) of the traveling body (2), a steering amount sensor (91) that detects the steering angle of the steering device (35) of the traveling body (2), and a control device (100) that controls the elevation and lowering of the seedling planting unit (4) and the operating state of the seedling planting unit (4). When the traveling body (2) turns, the control device (100) calculates the orientation of the traveling body (2) and the position of the seedling planting unit (4) based on the rotation speed and steering angle. When the traveling vehicle body (2) turns, the control device (100) calculates the angular velocity of the traveling vehicle body (2) using a preset prediction formula based on the vehicle speed calculated based on the number of rotations and the steering angle, and calculates the orientation of the traveling vehicle body (2) based on the calculated angular velocity. [Effects of the Invention]

[0007] According to one aspect of the embodiment, deviation of the starting position for planting seedlings can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing a work vehicle. [Figure 2] FIG. 2 is a plan view showing the work vehicle. [Figure 3] FIG. 3 is a block diagram showing a control system centered on the control device of the seedling transplanter. [Figure 4] FIG. 4 is a diagram showing a method for setting a work area by teaching travel according to the embodiment. [Figure 5] FIG. 5 is a flowchart illustrating the turning control according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] First, an overview of a work vehicle 1 according to an embodiment will be described with reference to Figures 1 and 2. Figure 1 is a side view showing the work vehicle 1. Figure 2 is a plan view showing the work vehicle 1.

[0010] In the following description, the forward / rearward direction refers to the direction of travel of the work vehicle 1 when traveling straight, with the front side of the traveling direction being defined as "front" and the rear side being defined as "rear." The traveling direction of the work vehicle 1 is the direction from the driver's seat 41 toward the handlebars 35 (steering device) when traveling straight (see Figures 1 and 2).

[0011] The left-right direction is a direction that is horizontally perpendicular to the front-rear direction and defines left and right facing the "front." In other words, when the operator (also referred to as an operator) 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."

[0012] The up-down direction is the vertical direction. The front-rear direction, left-right direction, and up-down direction are perpendicular to each other. Each direction is defined for the convenience of explanation, and the present invention is not limited to these directions.

[0013] In this embodiment, the work vehicle 1 will be described as a riding seedling transplanter 1 that is equipped with a seedling planting unit 4 as a work machine and that receives seedlings in a field. As shown in Figures 1 and 2, the seedling transplanter 1 is equipped with the seedling planting unit 4, which can be raised and lowered via a lifting link mechanism 3 on the rear side of the traveling body 2, to plant seedlings in the field.

[0014] The main body of the fertilizer applicator 5 is disposed on the upper rear side of the traveling body 2. If the work vehicle 1 is not a seedling transplanter 1, it may be provided with a sowing device that supplies seeds as a work device.

[0015] The traveling body 2 is a four-wheel drive vehicle equipped with left and right front wheels 10 and rear wheels 11, which are also driving wheels. On the front side of the main frame 15 that forms the body skeleton of the traveling body 2, there are provided a transmission case 13 that transmits driving force to the seedling planting section 4 and the like, and a hydraulic continuously variable transmission 14 that outputs driving force supplied from the engine 30, i.e., the rotation generated by the engine 30, to the transmission case 13.

[0016] The continuously variable transmission 14 is a hydrostatic continuously variable transmission known as an HST (Hydro Static Transmission). In the following, a case where the continuously variable transmission is the HST 14 will be described.

[0017] An auxiliary transmission mechanism 16 is provided within the transmission case 13 to switch the driving mode of the traveling vehicle body 2 between high-speed mode for road driving and low-speed mode for planting seedlings, etc. Front wheel final cases 10a are provided on the left and right sides of the transmission case 13, and front wheels 10 are attached to left and right front axles 10b that protrude outward from front wheel support parts that can change the steering direction of the left and right front wheel final cases 10a.

[0018] In addition, rear wheel gear cases 11a are attached to both the left and right sides of a rear frame 22 (see Figure 2) that is arranged laterally on the rear side of the main frame 15, and rear wheels 11 are attached to left and right rear axles 11b that protrude outward from the rear wheel gear cases 11a, respectively.

[0019] Left and right link support frames 23 that support the lifting link mechanism 3 protrude upward from the upper part of the rear frame 22. A pair of left and right lower link arms 24 are provided below and between the left and right link support frames 23. A hydraulically operated lifting cylinder 25 is provided between the left and right lower link arms 24.

[0020] An upper link arm 26 is provided above the lifting cylinder 25, forming a parallel link mechanism, the lifting link mechanism 3. The left and right lower link arms 24, the lifting cylinder 25, and the other end of the upper link arm 26, each of which has one end connected to the traveling vehicle body 2, are attached to the front of the seedling planting section 4.

[0021] An engine 30 is mounted on the main frame 15. Rotational power of the engine 30 is transmitted to the transmission case 13 via the belt transmission device 21 and the HST 14. The rotational power transmitted to the transmission case 13 is changed in speed by the sub-transmission mechanism 16 inside the transmission case 13, and then separated into traveling power and externally extracted power.

[0022] 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, a power steering mechanism 88 (see FIG. 3) of the handle 35, the lift cylinder 25, etc.

[0023] The externally extracted power extracted from the rotational power transmitted to the transmission case 13 is transmitted to the planting clutch case 27 provided at the rear of the running body 2, and is transmitted from the planting clutch case 27 to the seedling planting section 4 via the planting transmission shaft 67.

[0024] Meanwhile, left and right drive shafts 42 are provided at the rear of the transmission case 13. Rotational power from the engine 30 is transmitted via the transmission case 13 and the drive shafts 42 to the left and right rear wheel gear cases 11a.

[0025] A side clutch 44 (see FIG. 3) that turns on and off the power transmission to the left and right drive shafts 42 is disposed upstream of the left and right drive shafts 42 in the power transmission direction. As shown in FIG. 1, a side clutch pedal 43a that turns on and off the left and right side clutches 44 is provided at the front lower part of the cockpit 41 and on one of the left and right sides.

[0026] 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 then the steering wheel 35 is operated to make a turn, the drive rotation of the rear wheel 11 on the inside of the turn can be completely cut off.

[0027] A bonnet 39 with an operation panel 38 arranged on top for operating each section is provided on the upper front side of the traveling vehicle body 2. The operation panel 38 is provided with a monitor 86 (see FIG. 3) and the like.

[0028] The hood 39 is also provided with a handlebar 35 for steering the traveling body 2, a speed change operation lever 36 for operating the HST 14 and the seedling planting unit 4, and an auxiliary transmission operation lever 37 for operating the auxiliary transmission mechanism 16. By operating the speed change operation lever 36, the traveling body 2 can be switched between forward and reverse.

[0029] An openable front cover 40 is provided in front of the hood 39. Inside the front cover 40, a fuel tank, a battery, and an interlocking mechanism that rotates the left and right front wheels 10 and the lower sides of the left and right front wheel final cases 10a in response to steering of the handlebars 35 are provided. The front wheels 10 are, for example, steerable wheels that turn in response to steering of the handlebars 35.

[0030] An engine cover 30a that covers the top and sides of the engine 30 is provided behind the hood 39 and above the engine 30, and a pilot's seat 41 where the pilot sits is provided above the engine cover 30a.

[0031] The fertilizer applicator 5 is provided behind the driver's seat 41, at the rear end of the main frame 15. The driving force of the fertilizer applicator 5 is transmitted by a fertilizer transmission mechanism provided so as to face the fertilizer applicator 5 from one of the left and right rear wheel gear cases 11a.

[0032] Approximately horizontal floor steps 33 are formed on both the left and right sides of the lower part of the engine cover 30a and the hood 39. As shown in Fig. 2, the floor steps 33 are partially lattice-shaped, so that even if mud on the shoes of an operator walking on the floor steps 33 falls off, the fallen mud will fall into the field.

[0033] 2, a rear step 330 is connected to the rear of the floor step 33. The surface of the rear step 330 is preferably provided with an anti-slip finish, for example, with a pattern of multiple protrusions, to prevent feet from slipping during work.

[0034] In addition, on the front side of the traveling body 2 and on both the left and right sides, spare seedling frames 50 are provided, each with a seedling frame support 51 on which multiple spare seedling loading tables 52 are arranged at intervals in the vertical direction, so that work materials such as seedlings and fertilizer bags to be replenished in the seedling planting section 4 can be placed.

[0035] A seedling tank 53 for carrying seedlings to be planted in the field is attached to the rear end of the lifting link mechanism 3, along with a sliding mechanism for sliding it left and right. Seedling partition fences 54, which are long in the vertical direction, are placed on the seedling tank 53 at predetermined intervals in the horizontal direction. Below the seedling tank 53 is a seedling planting device 55 that picks up the loaded seedlings and plants them in the field.

[0036] The seedling planting device 55 plants eight rows at the same time, the same number as the number of rows to be planted separated by the seedling partition fence 54. Four planting transmission cases 56 are arranged at intervals below the seedling tank 53, and planting rotaries 57 are attached to both the left and right sides of the planting transmission cases 56, which rotate to pick up seedlings using planting rods 58 and plant them in the field.

[0037] In the fertilizer applicator 5, the fertilizer hopper 70 that stores the fertilizer is divided into the same number of sections as the number of working rows in the seedling planting section 4 (eight rows in the example shown in FIG. 2). Note that the eight-row fertilizer hopper 70 is long in the left-right direction, which reduces the convenience of adding fertilizer and attaching and detaching it, so it may have a so-called side fertilizer application structure, in which sections divided into four rows are lined up on each side.

[0038] Below the fertilizer hopper 70, a dispensing device 71 that supplies a set amount of fertilizer is provided for each row. Below the dispensing device 71, a ventilation duct 72 is provided in the left-right direction, through which conveying air passes to move the fertilizer. Below the dispensing device 71, a fertilizer hose 73 is provided to guide the fertilizer near the seedling planting position in the seedling planting section 4. Also, at one end of the ventilation duct 72, a blower 74 that is operated by an electric blower motor 76 to generate conveying air is provided.

[0039] 1 and 2, a center float 62C that slides on the field surface and two side floats 62L and 62R are provided rotatably about axes below the seedling planting section 4. The center float 62C and the left and right side floats 62L and 62R are sometimes collectively referred to as floats 62.

[0040] In addition, below the seedling planting section 4, and forward of the float 62, a ground leveling rotor 63 for leveling unevenness in the field is provided. Driving force is transmitted to the ground leveling rotor 63 from the rear wheel gear case 11a on the other left or right side via a rotor transmission shaft 63a.

[0041] 1, line-drawing markers 65 are provided on both the left and right sides of the seedling planting section 4. One of the markers 65 touches the ground on the field surface to form a groove that serves as a guide for traveling in the next work row (next process). When one of the markers 65 touches the ground, the other moves upward, and when the seedling planting section 4 is raised during rotation, both the left and right sides move upward, and when the seedling planting section 4 is lowered after rotation, one of the markers 65 moves upward and the other moves downward.

[0042] 1 and 2, a center mascot 66 that is long in the vertical direction is provided in the center of the left and right of the traveling vehicle body 2, and in front of the hood 39. By aligning the center mascot 66 with the grooves formed in the field by the left and right line markers 65, it becomes possible to travel in accordance with the work position of the previous work row, improving work accuracy and preventing non-working.

[0043] Depending on the soil quality of the field, the guide lines formed by the left and right line-drawing markers 65 may quickly become buried, causing the guide for going straight to disappear. In such cases, it is advisable to use the left and right side markers 19, which are located forward of the left and right line-drawing markers 65. In other words, by moving the left and right side markers 19 outward and positioning them above the planted seedlings, planting work can be performed in accordance with the planting of the seedlings in the previous work row.

[0044] As shown in FIG. 1, the seedling transplanter 1 further includes a position detection device 150 and an antenna 151.

[0045] The antenna 151 receives satellite signals, for example, from GPS (Global Positioning System) satellites. The antenna 151 is attached to the mounting stay 59, for example, and disposed above the traveling vehicle body 2. The antenna 151 is provided with an inertial positioning unit 152 (IMU: Internal Measurement Unit). The inertial positioning unit 152 can detect the acceleration of the traveling vehicle body 2, the inclination of the traveling vehicle body 2, and the like.

[0046] The position detection device 150 detects the current position of the seedling transplanter 1. The position detection device 150 detects the position of the traveling vehicle body 2 based on a satellite signal received by an antenna 151.

[0047] Next, the control system of the seedling transplanter 1 will be described with reference to Fig. 3. Fig. 3 is a block diagram showing the control system centered on the control device 100 of the seedling transplanter 1. The seedling transplanter 1 is capable of controlling each part by electronic control, and is equipped with a control device (hereinafter referred to as a controller) 100 that controls each part.

[0048] The controller 100 is provided with a processing unit having a CPU (Central Processing Unit), a storage unit such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and an input / output unit, which are interconnected to allow signals to be exchanged between them.

[0049] The storage unit stores a computer program for controlling the seedling transplanter 1. The controller 100 performs each function by reading out the computer program stored in the storage unit.

[0050] The controller 100 is connected to 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 HST motor 85, a line drawing marker lifting motor 87, a steering motor 95, and a differential lock switching motor 96.

[0051] The throttle motor 80 increases or decreases the rotation speed of the output shaft of the engine 30 by operating a throttle that adjusts the amount of air intake into the engine 30. The hydraulic control valve 81 controls the extension and retraction of the lifting cylinder 25. The hydraulic control valve 82 controls the power steering mechanism 88. The power steering mechanism 88 changes the direction of the front wheels 10, which are the steering wheels of the traveling body 2. The planting clutch operating solenoid 83 operates the planting clutch 27a.

[0052] The side clutch actuation solenoid 84 actuates the side clutch 44, which switches the state of power transmission to the rear wheels 11 (see FIG. 1). The side clutch 44 is provided on each of the left and right rear wheels 11, and two side clutch actuation solenoids 84 are provided corresponding to each side clutch 44.

[0053] The HST motor 85 changes the rotation angle of the trunnion of the HST 14, thereby changing the tilt angle of the swash plate of the HST 14. The steering motor 95 is a motor that drives the handle 35, which is a steering device that adjusts the steering amount (steering angle) of the front wheels 10 (see Figure 1) when automatic turning control is performed. The steering motor 95 rotates the handle 35. The line drawing marker lifting motor 87 lifts and lowers the line drawing marker 65.

[0054] The differential lock switching motor 96 is a motor that switches between operating and deactivating a differential lock mechanism 97 (hereinafter referred to as the differential lock mechanism) that rotates the left and right running wheels, for example, the left and right front wheels 10, at the same rotational speed. When the differential lock mechanism 97 is engaged, the left and right running wheels rotate at the same rotational speed.

[0055] The controller 100 is connected to detection devices such as a rotation speed sensor 90, a steering amount sensor 91, a position detection device 150, and an inertial positioning unit 152. 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 sensors 90 may also detect the rotation speeds of the left and right front wheels 10.

[0056] The steering amount sensor 91 detects the steering angle of the steering wheel 35, which is a steering device. In other words, the steering amount sensor 91 detects the operating position of the steering wheel 35, i.e., the steering amount (steering angle) of the front wheels 10. The steering amount sensor 91 is provided, for example, on a shaft connected to a pitman arm. The steering angle is detected in both the left and right directions, with the value when the steering wheel 35 is in a preset straight-ahead position being set as a reference value (0 degrees). For example, the steering angle is detected in conjunction with the turning direction of the steering wheel 35.

[0057] Furthermore, signals are input to the controller 100 as operation signals from the speed change operation lever 36, the auxiliary speed change operation lever 37, the autonomous travel selector switch 46, the planting section lift switch 47, the automatic planting selector switch 49, the automatic straight travel selector switch 45, and the automatic turning selector switch 48. At least one of the switches may be a button.

[0058] The autonomous driving changeover switch 46 is a switch that switches whether or not autonomous driving is performed. Specifically, the autonomous driving changeover switch 46 is a switch that switches the driving mode between manual driving mode and autonomous driving mode (automatic driving mode). The manual driving mode is a mode in which the vehicle drives by manual operation by the operator. The autonomous driving mode is a mode in which the vehicle drives automatically without manual operation by the operator.

[0059] For example, when the autonomous driving selector switch 46 is "ON," the driving mode is set to autonomous driving mode. When the autonomous driving selector switch 46 is "OFF," the driving mode is set to manual driving mode. When the autonomous driving selector switch 46 is turned "ON," the automatic straight driving selector switch 45 and the automatic turning selector switch 48 are turned "ON." Note that even if the automatic straight driving selector switch 45 and the automatic turning selector switch 48 are once turned "ON," they can be changed to "OFF" by the operator.

[0060] The planting section lifting / lowering switch 47 is a switch that switches whether to lift or lower the seedling planting section 4. The planting section lifting / lowering switch 47 can be changed to the "up" and "down" positions.

[0061] When the planting unit lift switch 47 is in the "up" position, the seedling planting unit 4 enters a non-working state in which the seedling planting device 55 stops and the seedling planting unit 4 rises to a predetermined non-working position. When the planting unit lift switch 47 is in the "down" position, the seedling planting unit 4 descends to a predetermined working position (predetermined planting work position) and enters a working state in which the seedling planting device 55 operates.

[0062] The automatic planting selector switch 49 is a switch that automatically switches the seedling planting unit 4 between a non-working state and a working state when the traveling body 2 turns. When the automatic planting selector switch 49 is "ON," the seedling planting unit 4 enters a non-working state when the traveling body 2 starts turning. That is, when the automatic planting selector switch 49 is "ON," the seedling planting device 55 stops and the seedling planting unit 4 rises to a predetermined non-working position when the traveling body 2 starts turning. Also, when the automatic planting selector switch 49 is "ON," the seedling planting unit 4 enters a working state when the traveling body 2 finishes turning. That is, when the automatic planting selector switch 49 is "ON," the seedling planting unit 4 descends to a predetermined working position and the seedling planting device 55 enters a working state when the traveling body 2 finishes turning. Details of the control when the automatic planting selector switch 49 is "ON" will be described later.

[0063] The automatic straight-line driving selector switch 45 is a switch that switches whether or not automatic straight-line driving is enabled. When the automatic straight-line driving selector switch 45 is set to "ON," a driving assist function, which will be described later, is enabled, and automatic straight-line driving can be performed. When the automatic straight-line driving selector switch 45 is set to "OFF," the driving assist function is disabled, and automatic straight-line driving cannot be performed.

[0064] The automatic turning selector switch 48 is a switch that switches whether or not automatic turning is enabled. When the automatic turning selector switch 48 is set to "ON," the turning assist function described below is enabled, and automatic turning can be performed. When the automatic turning selector switch 48 is set to "OFF," the turning assist function is disabled, and automatic turning cannot be performed. When the automatic turning selector switch 48 is set to "OFF," automatic turning is not performed even if the conditions for performing automatic turning are met. Note that when the automatic turning selector switch 48 is set to "ON," the automatic planting selector switch 49 is set to "ON."

[0065] The controller 100 switches the driving mode between a manual driving mode and an autonomous driving mode in response to the operation of the autonomous driving changeover switch 46, the automatic straight driving changeover switch 45, and the automatic turning changeover switch 48.

[0066] Furthermore, information relating to the current position of the traveling vehicle body 2 is input to the controller 100 from the position detection device 150. The controller 100 executes an autonomous traveling mode in which the traveling vehicle body 2 performs work while traveling automatically.

[0067] Moreover, various types of information are input to the controller 100 from a remote control device 170 (hereinafter referred to as "remote control"). For example, various types of information are input to the controller 100 from the remote control 170 via a receiver 180 (see FIG. 1). The receiver 180 is attached to, for example, a mounting stay 59 (see FIG. 1) and is arranged above the front side of the traveling vehicle body 2. Note that multiple receivers 180 may be provided. The mounting stay 59 is attached to the traveling vehicle body 2.

[0068] The remote control 170 can remotely control the seedling transplanter 1. The remote control 170 may be a terminal device such as a smartphone. The remote control 170 transmits a control signal in response to an operation by an operator. The remote control 170 is communicably connected to the controller 100 via short-range wireless communication such as Wi-fi (registered trademark) or BLE (Bluetooth (registered trademark) Low Energy), but is not limited thereto, and may be communicably connected via a communication network or the like in addition to or instead of short-range wireless communication.

[0069] There may be provided a plurality of remote controls 170. That is, the controller 100 may be able to acquire the position information of each remote control 170 from a plurality of remote controls 170.

[0070] Here, we will explain the autonomous driving (automatic driving) in the field by the seedling transplanter 1. The controller 100 has an autonomous driving mode (automatic driving mode) in which the steering motor 95 (see FIG. 3) is controlled to operate the handlebars 35 (see FIG. 3) while feeding back the steering amount of the front wheels 10 (see FIG. 1). The autonomous driving mode includes an automatic straight-line mode and an automatic turning mode.

[0071] In the automatic straight-line mode, the steering motor 95 is controlled so that the traveling vehicle body 2 moves straight along a preset straight-line path. In the automatic straight-line mode, the traveling vehicle body 2 moves straight without the driver's operation while the seedling planting unit 4 plants seedlings in the field. In other words, the traveling assist function for transplanting seedlings into the field is enabled and executed while the traveling vehicle body 2 moves automatically straight.

[0072] In the automatic turning mode, when the traveling vehicle body 2 reaches a predetermined planting end position, the seedling planting unit 4 stops planting seedlings, and the steering motor 95 is controlled to turn the traveling vehicle body 2 along a predetermined turning path. The predetermined planting end position is set, for example, based on the travel distance of the process where the work was performed and position information related to the process where the work was performed.

[0073] In the automatic turning mode, for example, the seedling planting unit 4 is raised and put into a non-working state, and the traveling body 2 turns automatically without the operator's operation. In other words, the turning assist function that turns the traveling body 2 without the seedling planting unit 4 planting seedlings is enabled, and the turning assist function is executed.

[0074] As shown in Fig. 4, a working area in which the autonomous traveling mode is executed is set by performing teaching traveling along three sides La to Lc of the field under the operator's operation. Fig. 4 is a diagram showing a method for setting a working area by teaching traveling according to an embodiment.

[0075] For example, when a work area setting button (not shown) is operated to start traveling, the position information of the traveling vehicle body 2 is recorded as the start point of side La, and the position information of the traveling vehicle body 2 while traveling is recorded. Then, when the handlebars 35 are turned by the operator by a predetermined turning angle or more, the end point of side La is recorded and side La is set. In addition, the position information of the traveling vehicle body 2 at the start point of side Lb is recorded. The predetermined turning angle is a preset value, and is an angle at which it can be determined that the traveling vehicle body 2 has turned along the edge of a riverbank.

[0076] Furthermore, after the traveling vehicle body 2 has traveled straight, when the driver turns the handlebars 35 by a predetermined angle or more, the end point of side Lb is recorded and side Lb is set. In addition, the position information of the traveling vehicle body 2 at the start point of side Lc is recorded.

[0077] When the working area setting button is operated after the traveling vehicle body 2 has traveled straight, the position information of the traveling vehicle body 2 is recorded as the end point of side Lc, and side Lc is set. The working area is set by setting the three sides La to Lc. In teaching traveling, seedlings are planted in the field by the seedling planting unit 4 while the traveling vehicle body 2 is traveling straight. Teaching traveling is a perimeter process in which planting work is carried out along the perimeter of the field. The working area is the area in the field where seedlings are planted by the reciprocating process in which the traveling vehicle body 2 travels back and forth.

[0078] In a field where a work area is set, the autonomous driving mode can be executed. For example, in the field, automatic straight driving along a straight driving path parallel to side La or side Lc is possible. Automatic turning is also possible when turning near the ridge on the side of side Lb. When turning near a side of the field that was not traveled during teaching travel, i.e., near the ridge opposite side Lb, turning can be performed by remote control. Note that automatic turning may also be performed when turning near the ridge on the side of the field that was not traveled during teaching travel.

[0079] Furthermore, even when the teaching driving is completed and the working area is set, if the driving mode is manual driving mode, the seedling transplanter 1 can be driven by the operator and seedlings can be transplanted into the field.

[0080] When the driving mode is the manual driving mode and the seedling transplanter 1 is being driven by the operator, if the automatic straight driving selector switch 45 is turned "ON", the seedling transplanter 1 will automatically drive in a straight line. In other words, the seedling transplanter 1 can execute the driving assist function even when the driving mode is the manual driving mode.

[0081] Furthermore, when the driving mode is the manual driving mode and the seedling transplanter 1 is being driven by the operator, if the automatic turning selector switch 48 is turned "ON", the seedling transplanter 1 can perform automatic turning. In other words, the seedling transplanter 1 can perform the turning assist function even when the driving mode is the manual driving mode.

[0082] Next, the turning control according to the embodiment will be described with reference to Fig. 5. Fig. 5 is a flowchart illustrating the turning control according to the embodiment. The turning control is executed when the automatic planting changeover switch 49 is "ON".

[0083] The controller 100 determines whether the traveling vehicle body 2 has started turning (S100). Specifically, the controller 100 determines whether the steering angle detected by the steering amount sensor 91 is equal to or greater than a predetermined angle. The predetermined angle is a preset angle at which it can be determined that the traveling vehicle body 2 has started turning from a state in which it is traveling straight. The predetermined angle is set relative to a reference value. If the steering angle detected by the steering amount sensor 91 is equal to or greater than the predetermined angle, the controller 100 determines that the traveling vehicle body 2 has started turning. If the steering angle detected by the steering amount sensor 91 is less than the predetermined angle, the controller 100 determines that the traveling vehicle body 2 has not started turning.

[0084] When the controller 100 determines that the traveling vehicle body 2 has not started turning (S100: No), the controller 100 ends the current processing.

[0085] When the controller 100 determines that the traveling body 2 has started turning (S100: Yes), it puts the seedling planting unit 4 into a non-working state (S101). The controller 100 stops the seedling planting device 55 and raises the seedling planting unit 4 to a predetermined non-working position. In other words, the controller 100 ends the planting of seedlings in the planting process.

[0086] Next, the controller 100 calculates the orientation of the traveling vehicle body 2 (S102). The controller 100 calculates the vehicle speed of the traveling vehicle body 2 from the rotation speed detected by the rotation speed sensor 90. The controller 100 calculates the vehicle speed of the traveling vehicle body 2 from the larger rotation speed of the left and right rear wheels 11. Specifically, the controller 100 calculates the vehicle speed of the traveling vehicle body 2 from the rotation speed of the rear wheel 11 on the outside of the turn. The controller 100 calculates the angular velocity (deg / s) of the traveling vehicle body 2 using the prediction formula shown in Equation (1) based on the calculated vehicle speed (m / s) and the steering angle (deg) detected by the steering amount sensor 91. Angular velocity = 0.078 × steering angle × vehicle speed × slip ratio (1)

[0087] The value "0.078" in the formula (1) is set depending on the type (size, etc.) of the seedling transplanter 1.

[0088] Controller 100 calculates the slip ratio from the difference between a predicted rotation speed of rear wheel 11 on the inside of a turn, which is predicted based on the steering angle, and the actual rotation speed of rear wheel 11 on the inside of a turn. The predicted rotation speed is calculated from the steering angle and the rotation speed of rear wheel 11 on the outside of a turn in a state where there is no slip. In other words, the predicted rotation speed is the rotation speed predicted for rear wheel 11 on the inside of a turn in a state where there is no slip. For example, the predicted rotation speed is calculated using a preset prediction formula based on the steering angle and the rotation speed of rear wheel 11 on the outside of a turn in a state where there is no slip. Note that the predicted rotation speed may also be the rotation speed of rear wheel 11 on the inside of a turn, which is detected in a state where there is no slip. The actual rotation speed is calculated based on the rotation speed detected by rotation speed sensor 90.

[0089] The controller 100 calculates the orientation of the traveling vehicle body 2 from the calculated angular velocity of the traveling vehicle body 2. The controller 100 calculates the orientation of the traveling vehicle body 2 by setting the orientation of the traveling vehicle body 2 when the traveling vehicle body 2 starts turning as a reference (0 degrees) and accumulating angles based on the calculated angular velocity. For example, the controller 100 calculates the amount of change in angle per unit time (1 second) from the calculated angular velocity and accumulating the calculated amount of change in angle to calculate the orientation of the traveling vehicle body 2. The orientation of the traveling vehicle body 2 is the angle of the traveling vehicle body 2 with respect to the reference.

[0090] Next, the controller 100 calculates the position of the seedling planting unit 4 (S103). The controller 100 calculates the position of the seedling planting unit 4 based on the calculated direction of the traveling vehicle body 2 and the vehicle speed of the traveling vehicle body 2. For example, the controller 100 estimates the position of the seedling planting unit 4 by integrating the direction of the traveling vehicle body 2 and the vehicle speed of the traveling vehicle body 2, and sets the estimated position as the position of the seedling planting unit 4.

[0091] The controller 100 may also calculate the position of the seedling planting unit 4 using the following method. The controller 100 calculates the cumulative value of the rotation speed of the left and right rear wheels 11 after the planting clutch 27a is released (disengaged state), and estimates the position of the seedling planting unit 4 based on the cumulative value of the rotation speed. In other words, the controller 100 calculates the position of the seedling planting unit 4 using the cumulative value of the rotation speed of the left and right rear wheels 11.

[0092] Next, the controller 100 determines whether the orientation of the traveling body 2 has become a predetermined orientation (S104). The predetermined orientation is a preset orientation, for example, 180 degrees. The predetermined orientation is the opposite orientation to the orientation at the position where the traveling body 2 started turning, i.e., the position where planting of seedlings was completed. If the controller 100 determines that the orientation of the traveling body 2 has not become a predetermined orientation (S104: No), the controller 100 returns to step S102 and repeats the above process. If the controller 100 determines that the orientation of the traveling body 2 has become a predetermined orientation (S104: Yes), the controller 100 lowers the seedling planting unit 4 to a predetermined work position (S105).

[0093] Next, the controller 100 determines whether the position of the seedling planting unit 4 is the seedling planting start position (S106). The controller 100 determines that the position of the seedling planting unit 4 is the seedling planting start position when the heading of the traveling vehicle body 2 is in a predetermined heading and the value obtained by accumulating the vehicle speed of the traveling vehicle body 2 is equal to or greater than a predetermined accumulated value. The predetermined accumulated value is a value set in advance.

[0094] When estimating the position of the seedling planting unit 4 based on the cumulative value of the rotation speed of the rear wheels 11, the controller 100 determines that the position of the seedling planting unit 4 is the seedling planting start position when the traveling body 2 is heading in a predetermined direction and the cumulative value of the rotation speed is a value obtained by adding a correction value to a predetermined turning constant. The correction value is the number of rotations corresponding to the distance traveled by the traveling body 2 from when the planting clutch 27a is released until the steering angle reaches a preset turning angle. The controller 100 determines whether the position of the seedling planting unit 4 has reached the seedling planting start position set by the end of planting work by the seedling planting unit 4 before turning.

[0095] When the controller 100 determines that the seedling planting unit 4 is not at the seedling planting start position (S106: No), the controller 100 returns to step S103 and repeats the above process. When returning to step S103 and repeating the process, the processes of steps S104 and S105 may be skipped. In addition, in step S105, the seedling planting unit 4 may be held at a predetermined work position.

[0096] When the controller 100 determines that the seedling planting unit 4 is at the seedling planting start position (S106: Yes), it activates the seedling planting device 55 and puts it into a working state (S107). As a result, the seedling transplanter 1 starts planting seedlings in the field.

[0097] The seedling transplanter 1 includes a traveling body 2, a seedling planting unit 4 attached to the traveling body 2, a rotation speed sensor 90 that detects the rotation speed of the rear wheels 11 of the traveling body 2, a steering amount sensor 91 that detects the steering angle of the steering wheel 35 of the traveling body 2, and a controller 100 that controls the elevation and operation of the seedling planting unit 4. When the traveling body 2 turns, the controller 100 calculates the orientation of the traveling body 2 and the position of the seedling planting unit 4 based on the rotation speed and steering angle. When the traveling body 2 turns, the controller 100 calculates the angular velocity of the traveling body 2 using a preset prediction formula based on the vehicle speed calculated based on the rotation speed and the steering angle, and then calculates the orientation of the traveling body 2 based on the calculated angular velocity.

[0098] This allows the seedling transplanter 1 to control the start of seedling planting by the seedling planting unit 4 based on the calculated orientation of the traveling body 2. Therefore, the seedling transplanter 1 can prevent deviations in the seedling planting start position. For example, even if the traveling of the traveling body 2 varies when turning, the seedling transplanter 1 can prevent deviations in the seedling planting start position.

[0099] Furthermore, the rotation speed sensor 90 detects the rotation speeds of the left and right wheels of the traveling vehicle body 2. The controller 100 calculates the angular velocity of the traveling vehicle body 2 based on the vehicle speed calculated from the larger of the left and right rotation speeds and the steering angle. For example, the controller 100 calculates the angular velocity of the traveling vehicle body 2 based on the vehicle speed calculated from the rotation speed of the rear wheel 11 on the outside of the turn and the steering angle.

[0100] This allows the seedling transplanter 1 to accurately calculate the angular velocity of the traveling body 2 when turning. Therefore, the seedling transplanter 1 can accurately calculate the orientation of the traveling body 2 when turning, and can prevent deviations in the starting position for planting the seedlings.

[0101] In addition, the controller 100 lowers the seedling planting unit 4 to a predetermined work position when the calculated orientation of the traveling body 2 becomes a predetermined orientation, based on the orientation of the traveling body 2 when the planting work by the seedling planting unit 4 is completed.

[0102] As a result, even if the traveling body 2 of the seedling transplanter 1 is uneven when turning, the seedling transplanter 1 can prevent deviation in the timing for lowering the seedling planting unit 4 to the predetermined working position.

[0103] Furthermore, the controller 100 calculates the orientation of the traveling vehicle body 2 by integrating the calculated angular velocities of the traveling vehicle body 2.

[0104] This allows the seedling transplanter 1 to accurately calculate the orientation of the traveling body 2 when turning, and prevents deviation of the seedling planting start position.

[0105] In addition, the controller 100 calculates the position of the seedling planting section 4 based on the direction and vehicle speed of the traveling vehicle body 2.

[0106] This allows the seedling transplanter 1 to accurately calculate the position of the seedling planting section 4 during turning. Therefore, the seedling transplanter 1 can prevent deviation of the seedling planting start position after turning.

[0107] In addition, the controller 100 starts planting by the seedling planting unit 4 when the calculated orientation of the traveling vehicle body 2 becomes a predetermined orientation based on the orientation of the traveling vehicle body 2 when the planting work by the seedling planting unit 4 is completed, and the position of the seedling planting unit 4 becomes the starting position set by the completion of the planting work by the seedling planting unit 4 before turning.

[0108] This allows the seedling transplanter 1 to align the seedling planting start position by the seedling planting unit 4 with the planting end position before turning.

[0109] Furthermore, when the traveling vehicle body 2 turns, the controller 100 calculates the slip ratio from the difference between the predicted rotation speed of the rear wheel 11 on the inside of the turn, which is predicted based on the steering angle, and the actual rotation speed of the rear wheel 11 on the inside of the turn. The predicted rotation speed is calculated from the steering angle and the rotation speed of the rear wheel 11 on the outside of the turn in a state where there is no slip.

[0110] This allows the seedling transplanter 1 to accurately calculate the slip rate that occurs during turning. Therefore, the seedling transplanter 1 can, for example, take the slip rate into account when turning and start lowering the seedling planting unit 4 and planting by the seedling planting unit 4. Therefore, the seedling transplanter 1 can prevent deviations in the starting position for planting the seedlings.

[0111] The seedling transplanter 1 may reduce the predetermined direction as the angular velocity of the traveling body 2 calculated using the prediction equation increases. In other words, the seedling transplanter 1 advances the timing at which the seedling planting unit 4 descends to the predetermined working position as the angular velocity of the traveling body 2 calculated using the prediction equation increases.

[0112] This allows the seedling transplanter 1 to adjust the timing of lowering the seedling planting unit 4 in accordance with the angular velocity of the traveling body 2. Therefore, the seedling transplanter 1 can optimize the timing of lowering the seedling planting unit 4.

[0113] The seedling transplanter 1 may detect the angular velocity and orientation of the traveling body 2 based on information obtained from the antenna 151. For example, the seedling transplanter 1 calculates the angular velocity of the traveling body 2 from the time change in orientation based on the orientation information obtained from the antenna 151.

[0114] The seedling transplanter 1 prohibits the seedling planting unit 4 from descending if the position of the seedling planting unit 4 is equal to or greater than a predetermined threshold. For example, the seedling transplanter 1 prohibits the seedling planting unit 4 from descending if the position of the seedling planting unit 4 reaches the seedling planting start position (predetermined threshold) before the traveling body 2 is oriented in a predetermined direction. For example, when turning in a field with a sloping ridge, the seedling transplanter 1 first leaves the field before turning. In this case, there is a risk that the seedling planting unit 4 will descend immediately after turning and before entering the field. Therefore, the seedling transplanter 1 prohibits the seedling planting unit 4 from descending if the position of the seedling planting unit 4 is equal to or greater than a predetermined threshold. This allows the seedling transplanter 1 to prevent the seedling planting unit 4 from descending in a location that is not suitable for planting seedlings.

[0115] The seedling transplanter 1 may retain the calculated slip ratio until the slip ratio is updated during the next turn. This allows the seedling transplanter 1 to use the slip ratio calculated during the turn while traveling straight after the turn. Therefore, the seedling transplanter 1 can, for example, adjust the amount of fertilizer applied by correcting the amount of fertilizer based on the slip ratio. The seedling transplanter 1 can also adjust the amount of seedlings removed by correcting the amount of seedlings removed based on the slip ratio. The seedling transplanter 1 can also adjust the spacing between plants during the straight traveling process by correcting the number of plants to be planted based on the slip ratio.

[0116] The seedling transplanter 1 may adjust the amount of fertilizer applied in conjunction with a map of the field. When the turning assist function is enabled, the seedling transplanter 1 may correct turning and the seedling planting start position according to the angle between the working direction of the traveling body 2 and the ridge on the map. The seedling transplanter 1, for example, calculates the angle at which the current path of the seedling transplanter 1 intersects with the line of the field shape on the map, among the straight traveling paths parallel to the straight line set by teaching traveling (for example, side La (see Figure 4)). The seedling transplanter 1 corrects turning and the seedling planting start position according to the calculated angle. This allows the seedling transplanter 1 to automatically turn even on angled ridges, i.e., ridges that are not approximately perpendicular to the straight line set by teaching traveling.

[0117] The seedling transplanter 1 identifies the ridge that exists in the current direction of travel of the traveling body 2 based on the traveling direction of the traveling body 2 and the traveling direction of the traveling body 2 on the straight line set by teaching travel. The identified ridge is the closest ridge in the direction of travel from the current position of the traveling body 2.

[0118] The seedling transplanter 1 adjusts the amount of backing up during an assisted back turn when automatically turning and the planting start position according to the angle between the working direction of the traveling vehicle body 2 and the ridge on the map, the working width of the seedling transplanter 1, and the turning direction. For example, if the ridge narrows in the turning direction, the seedling transplanter 1 increases the amount of backing up and sets the seedling planting start position to the back side (ridge side). Also, if the ridge widens in the turning direction, the seedling transplanter 1 decreases the amount of backing up and sets the seedling planting start position to the front side (opposite the ridge).

[0119] The increase in the amount of backing up coincides with the increase in the amount of backing up towards the planting start position. Furthermore, if the angle between the working direction of the traveling vehicle body 2 and the ridge on the map exceeds a predetermined threshold, the amount of backing up and the planting start position are determined with the threshold as the upper limit. Furthermore, if the angle between the working direction of the traveling vehicle body 2 and the ridge on the map is within a predetermined range of 90 degrees or more, the amount of backing up and the planting start position are not changed. This predetermined range is the range within which it can be determined that the angle between the working direction of the traveling vehicle body 2 and the ridge on the map is close to 90 degrees.

[0120] The angle between the working direction of the traveling body 2 and the ridge on the map is calculated, for example, by a terminal device and transmitted to the seedling transplanter 1 via wireless communication. When the seedlings are being planted and a certain period of time has passed, the seedling transplanter 1 updates the angle between the working direction of the traveling body 2 and the ridge on the map that it has stored. When the seedling transplanter 1 is performing automatic straight-line driving and a certain period of time has passed, the seedling transplanter 1 may also update the angle between the working direction of the traveling body 2 and the ridge on the map that it has stored.

[0121] If the steering angle remains within a certain range from a straight-ahead state for a certain period of time, the seedling transplanter 1 may update the angle between the working direction of the traveling body 2 and the ridge on the map.

[0122] Furthermore, after updating the angle between the working direction of the traveling body 2 and the ridge on the map, the seedling transplanter 1 does not update the angle between the working direction of the traveling body 2 and the ridge on the map until it starts automatic turning.

[0123] The seedling transplanter 1 may be provided with a constant slow speed mode switch that switches the speed of the traveling body 2 to a constant slow speed mode. When the constant slow speed mode switch is "ON," the controller 100 sets the maximum position of the speed change lever 36 as the target constant slow speed. The slow speed adjustment until it reaches the maximum can be changed according to the operator's operation of the speed change lever 36.

[0124] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0125] 1. Seedling transplanter (work vehicle) 2 Running vehicle 4 Seedling planting department 10 Front wheels 11 Rear wheel 27a Planting clutch 35 Handle (steering device) 49 Automatic planting switch 55 Seedling planting device 90 RPM sensor 91 Steering amount sensor 100 Controller (control device)

Claims

1. A running vehicle body, A seedling planting unit attached to the traveling vehicle body; a rotation speed sensor for detecting the rotation speed of a wheel of the traveling vehicle body; a steering amount sensor for detecting a steering angle of a steering device of the traveling vehicle body; a control device that controls the elevation and lowering of the seedling planting unit and the operating state of the seedling planting unit; Equipped with The control device When the traveling vehicle body turns, the orientation of the traveling vehicle body and the position of the seedling planting unit are calculated based on the number of rotations and the steering angle; When the traveling vehicle body turns, a work vehicle calculates the angular velocity of the traveling vehicle body using a preset prediction formula based on the vehicle speed calculated based on the number of rotations and the steering angle, and calculates the orientation of the traveling vehicle body based on the calculated angular velocity.

2. the rotation speed sensors detect the rotation speeds of the left and right wheels of the vehicle body, The work vehicle according to claim 1 , wherein the control device calculates the angular velocity based on the steering angle and a vehicle speed calculated from a larger one of the left and right rotation speeds.

3. The control device The work vehicle described in claim 1, wherein the seedling planting unit is lowered to a predetermined planting work position when the calculated orientation of the traveling body becomes a predetermined orientation based on the orientation of the traveling body when planting work by the seedling planting unit is completed.

4. The work vehicle according to claim 3 , wherein the control device reduces the predetermined direction as the rotation speed increases.

5. The control device The work vehicle according to claim 1 , wherein the orientation of the traveling vehicle body is calculated by integrating the calculated angular velocity of the traveling vehicle body.

6. The control device The work vehicle according to claim 1 , wherein the position of the seedling planting section is calculated based on the orientation of the traveling vehicle body and the vehicle speed.

7. The control device The work vehicle described in claim 1, wherein the seedling planting unit starts planting when the calculated orientation of the traveling vehicle body becomes a predetermined orientation based on the orientation of the traveling vehicle body when the planting work by the seedling planting unit is completed, and when the position of the seedling planting unit becomes a start position set by the completion of the planting work by the seedling planting unit before turning.

8. The control device The work vehicle according to claim 6, wherein lowering of the seedling planting section is prohibited when the position of the seedling planting section is equal to or greater than a predetermined threshold value.

9. The control device When the traveling vehicle body is turning, a slip ratio is calculated from the difference between a predicted rotation speed of the wheel on the inside of the turning that is predicted in accordance with the steering angle and an actual rotation speed of the wheel on the inside of the turning; The work vehicle according to claim 1 , wherein the predicted rotational speed is calculated from the steering angle and the rotational speed of the wheel on the outside of a turn in a state where there is no slip.

Images