Work vehicle

Abstract

To provide a work vehicle capable of executing automatic traveling at low cost.SOLUTION: A work vehicle according to one aspect of an embodiment comprises a traveling vehicle body having a driver's seat on which a driver can be seated, a first operation unit for switching the traveling vehicle body between forward and backward movement, a second operation unit that, when the traveling vehicle body is automatically traveling, allows setting of a vehicle speed of the traveling vehicle body during the automatic traveling, and a control device that causes the traveling vehicle body to perform the automatic traveling. The control device, when the second operation unit is operated by the driver during the automatic traveling, changes the vehicle speed of the traveling vehicle body while maintaining the automatic traveling.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Conventionally, there are known work vehicles that can travel unmanned without a driver (see, for example, Patent Document 1). Such work vehicles perform autonomous travel to work in fields without being operated by a driver. Such work vehicles are equipped with obstacle sensors to detect obstacles, drive controls to prevent the work vehicle from getting stuck in the field, and the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-91595 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned work vehicles require obstacle sensors, etc., making them expensive. Furthermore, although the above-mentioned work vehicles can be used without a driver in the work vehicle, a worker must monitor the work vehicle near the field in order to proceed with the work.

[0005] The present invention has been made in view of the above, and has an object to provide a work vehicle that can perform autonomous driving at low cost. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the object, a work vehicle according to one aspect of the embodiment includes a traveling vehicle body having a driver's seat in which a driver can sit, a first operation unit that switches between forward and reverse travel of the traveling vehicle body, a second operation unit that can set the vehicle speed of the traveling vehicle body while the traveling vehicle body is traveling automatically when the traveling vehicle body is traveling automatically, and a control device that causes the traveling vehicle body to travel automatically. When the second operation unit is operated by the driver during automatic traveling, the control device changes the vehicle speed of the traveling vehicle body while maintaining automatic traveling. [Effects of the Invention]

[0007] According to one aspect of the embodiment, a work vehicle capable of performing autonomous driving can be provided at low cost. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing a work vehicle according to a first embodiment. [Figure 2] FIG. 2 is a plan view showing the work vehicle according to the first embodiment. [Figure 3] FIG. 3 is a block diagram showing a control system centered on the control device of the seedling transplanter according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing a method for setting a work area by teaching travel according to the first embodiment. [Figure 5] FIG. 5 is a flowchart illustrating the autonomous driving control according to the first embodiment. [Figure 6] FIG. 6 is a side view showing the seedling transplanter according to the second embodiment. [Figure 7] FIG. 7 is a block diagram showing a control system centered around a controller of the seedling transplanter according to the second embodiment. [Figure 8] FIG. 8 is a flowchart illustrating the autonomous driving control according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

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

[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 operator's seat 41, which is the driver's seat where the driver can be seated, toward the steering wheel 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 a driver (also referred to as an operator) is seated in the cockpit 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] Here, 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 a seedling planting unit 4 that can be raised and lowered via a lifting link mechanism 3 on the rear side of a traveling body 2 to plant seedlings in a 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 (first operation part) for operating the HST 14 and the seedling planting unit 4, and an auxiliary speed change operation lever 37 for operating the auxiliary speed change 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] As shown in FIG. 2, a seesaw switch 48 (second operating unit) that can set the vehicle speed of the traveling vehicle body 2 during automatic traveling, which will be described later, is provided to the side of the driver's seat 41, for example, on the left side. The seesaw switch 48 is provided so that it can be easily operated by a driver seated in the driver's seat 41. The seesaw switch 48 is provided so that it can be operated along the traveling direction of the traveling vehicle body 2. The seesaw switch 48 is provided so that it can be operated in the front-to-rear direction. For example, the seesaw switch 48 is provided so that it can be tilted in the traveling direction of the traveling vehicle body 2. The seesaw switch 48 may also be provided on the hood 39, etc. The seesaw switch 48 may also be provided so that it can be operated in the up-and-down direction.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] As shown in FIG. 1, the seedling transplanter 1 further includes a position detection device 150 and an antenna 151.

[0046] The antenna 151 receives satellite signals, for example, from GPS (Global Positioning System) satellites, etc. The antenna 151 is attached to the mounting stay 59, for example, and is disposed above the traveling vehicle body 2.

[0047] 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 satellite signals received by the antenna 151, etc. The position detection device 150 can detect the position of the traveling vehicle body 2 by first positioning and second positioning. The second positioning has higher detection accuracy than the first positioning. For example, the first positioning is DGPS (differential GPS) positioning. The second positioning is RTK-GPS (real-time kinematic GPS) positioning.

[0048] 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 according to the first embodiment. 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.

[0049] The controller 100 is provided with a processing unit having a CPU (Central Processing Unit) and the like, storage units such as ROM (Read Only Memory) and RAM (Random Access Memory), and input / output units, which are interconnected and capable of transmitting and receiving signals between them. The controller 100 may be capable of communicating with external devices. The external devices include server devices, terminal devices, and the like.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] The controller 100 is connected to a rotation speed sensor 90, a steering amount sensor 91, a position detection device 150, and the like. 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.

[0057] 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.

[0058] In addition, 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 changeover switch 46, the planting unit lifting / lowering switch 47, and the seesaw switch 48. At least one of the switches may be a button.

[0059] The autonomous driving selector switch 46 is a switch that switches whether autonomous driving is performed. Specifically, the autonomous driving selector switch 46 is a switch that switches the driving mode between manual driving mode and autonomous driving mode. The manual driving mode is a mode in which driving is performed by manual operation of the operator. The autonomous driving mode is a mode in which driving is performed automatically without manual operation of the operator. The autonomous driving mode includes a mode in which driving is performed partially by manual operation of the operator.

[0060] Specifically, autonomous driving includes automatic driving, straight-line assisted driving, and turning assisted driving. Automatic driving is driving in which the traveling vehicle body 2 travels along an automatic driving route set in the work area (described later) without operator operation, and plants in a field. Automatic driving is performed based on the position information of the traveling vehicle body 2 detected by the second positioning. For example, in automatic driving, the steering motor 95 and the like are controlled so that the traveling vehicle body 2 travels along the automatic driving route based on the position information included in the automatic driving route and the position information of the traveling vehicle body 2 detected by the second positioning. The automatic driving route is set based on the size of the work area, the size of the seedling transplanter 1, and the like. The automatic driving route may be set by the control device 100 or an external device.

[0061] In the automatic driving mode, for example, when the traveling vehicle body 2 reaches the planting end position on the automatic driving route, the seedling planting unit 4 stops planting the seedlings, the seedling planting unit 4 rises and goes into a non-working state, and the traveling vehicle body 2 turns automatically without the operation of the operator. Also, in the automatic driving mode, for example, when the traveling vehicle body 2 reaches the planting start position on the automatic driving route, the seedling planting unit 4 descends and goes into a working state, and the seedling planting unit 4 starts planting the seedlings.

[0062] Straight-line assisted driving is driving in which the traveling vehicle body 2 travels based on the orientation of the reference line without operator operation and plants in a field. Straight-line assisted driving is performed based on the orientation of the traveling vehicle body 2, which is based on the position information of the traveling vehicle body 2 detected by the first positioning, and the orientation of the reference line. For example, if the traveling vehicle body 2 travels in the same direction as the traveling direction when the reference line was acquired, in straight-line assisted driving, the steering motor 95 and the like are controlled so that the orientation of the reference line and the orientation of the traveling vehicle body 2 match. The reference line is set, for example, during teaching driving, which will be described later.

[0063] Turning-assisted driving is driving in which the steering motor 95 is controlled so that the orientation of the traveling vehicle body 2 is reversed. Turning-assisted driving is performed based on the orientation of the traveling vehicle body 2 based on the position information of the traveling vehicle body 2 detected by the first positioning and the orientation of the reference line. Turning-assisted driving may also be performed based on the steering angle and the traveling distance of the traveling vehicle body 2.

[0064] In turning-assisted traveling, for example, when the traveling vehicle body 2 reaches a predetermined planting end position, the seedling planting unit 4 stops planting seedlings, the seedling planting unit 4 rises and goes into a non-working state, and the traveling vehicle body 2 turns automatically without operator operation. The predetermined planting end position is set, for example, based on the travel distance of the work process and the position information of the traveling vehicle body 2 obtained by first positioning related to the work process. In turning-assisted traveling, the seedling planting unit 4 may be put into a non-working state and the traveling vehicle body 2 may start turning in response to operation of the planting unit lift switch 47. Turning-assisted traveling ends when the traveling vehicle body 2 reaches the predetermined turning end position.

[0065] When the autonomous driving selector switch 46 is "ON", the driving mode is set to the autonomous driving mode. When the autonomous driving selector switch 46 is "OFF", the driving mode is set to the manual driving mode. Note that a switch for executing straight-line assisted driving may be provided. A switch for executing turning assisted driving may be provided.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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. In the autonomous traveling mode, the controller 100 controls the steering motor 95 (see FIG. 3) to operate the handlebars 35 (see FIG. 3) while feeding back the steering amount of the front wheels 10 (see FIG. 1).

[0070] As shown in Fig. 4, the controller 100 sets a working area in which the autonomous traveling mode is executed 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 the first embodiment.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] In a field where a work area is set, the autonomous driving mode can be executed. For example, an automatic driving route is set in the work area. Furthermore, in the field, a reference line is acquired when traveling along side Lc. For example, the planting start position on side Lc is set as point A. Furthermore, the planting end position on side Lc is set as point B. Then, the line connecting points A and B is set as the reference line. Furthermore, the orientation of the reference line is detected from the position information at points A and B.

[0075] Point A may be set to the position where the traveling vehicle body 2 has traveled a predetermined distance (for example, 2 m) after planting has started on side Lc. Point A may also be set to the position where planting work has been carried out for a predetermined time (for example, 2 seconds) after planting has started on side Lc. This makes it possible to set Point A while avoiding, for example, water inlets or entrances to the field at the edge of the field. Point B may also be set to the position where autonomous traveling started after planting has finished on side Lc.

[0076] Furthermore, during planting on side Lc, points may be acquired every predetermined distance (for example, 2 m) of planting travel, and an approximation line of the multiple points may be used as the reference line. Furthermore, during planting on side Lc, points may be acquired every predetermined time (for example, 2 m) of planting travel, and an approximation line of the multiple points may be used as the reference line.

[0077] 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.

[0078] Next, the autonomous driving control according to the first embodiment will be described with reference to Fig. 5. Fig. 5 is a flowchart illustrating the autonomous driving control according to the first embodiment. Here, it is assumed that a work area has been set and the autonomous driving changeover switch 46 is "ON", i.e., the driving mode is the autonomous driving mode.

[0079] The controller 100 determines whether or not the position of the traveling vehicle body 2 can be detected by the second positioning (S100). For example, if the received signal by the second positioning is equal to or higher than a predetermined level set in advance, the controller 100 determines that the position of the traveling vehicle body 2 can be detected by the second positioning. If the received signal by the second positioning is lower than a predetermined level set in advance, the controller 100 determines that the position of the traveling vehicle body 2 cannot be detected by the second positioning.

[0080] When the position of the traveling vehicle body 2 can be detected by the second positioning (S100: Yes), the controller 100 executes automatic traveling (S101).

[0081] Next, the controller 100 determines whether the seesaw switch 48 has been operated (S102). If the seesaw switch 48 has been operated (S102: Yes), the controller 100 changes the vehicle speed of the traveling vehicle body 2 in accordance with the operation of the seesaw switch 48 (S103). The controller 100 changes the vehicle speed of the traveling vehicle body 2 while maintaining automatic traveling. For example, if the seesaw switch 48 is operated forward (tilted forward), the controller 100 increases the vehicle speed of the traveling vehicle body 2, accelerating the traveling vehicle body 2. If the seesaw switch 48 is operated backward (tilted backward), the controller 100 decreases the vehicle speed of the traveling vehicle body 2, decelerating the traveling vehicle body 2.

[0082] The minimum vehicle speed at which the vehicle speed of the traveling vehicle body 2 is changed by the seesaw switch 48 is the vehicle speed that can be detected by the second positioning, for example, 0.2 m / s. Furthermore, when the seesaw switch 48 is operated continuously, that is, when the operation of the seesaw switch 48 is continued, the vehicle speed changes by one step every second. Furthermore, the distance at which a change in vehicle speed is initiated by operation of the seesaw switch 48 may be set by the operator.

[0083] If the seesaw switch 48 has not been operated (S102: No), the controller 100 ends this processing.

[0084] If the controller 100 cannot detect the position of the traveling vehicle body 2 by the second positioning (S100: No), it executes straight-line assisted traveling and turning-assisted traveling by the first positioning (S104). Note that the controller 100 may execute at least one of straight-line assisted traveling and turning-assisted traveling.

[0085] The controller 100 prioritizes detecting the position of the traveling vehicle body 2 by the second positioning, and when the position of the traveling vehicle body 2 cannot be detected by the second positioning, uses detecting the position of the traveling vehicle body 2 by the first positioning.

[0086] If the gear shift lever 36 is operated during autonomous driving, the controller 100 changes the driving mode from the autonomous driving mode to the manual driving mode.

[0087] The seedling transplanter 1 comprises a traveling body 2, a speed change lever 36, a seesaw switch 48, and a controller 100. The traveling body 2 has a driver's seat 41 where an operator can sit. The speed change lever 36 switches the traveling body 2 between forward and reverse. When the traveling body 2 is traveling automatically, the seesaw switch 48 can set the speed of the traveling body 2 during automatic traveling. The controller 100 causes the traveling body 2 to perform automatic traveling. When the operator operates the seesaw switch 48 during automatic traveling, the controller 100 changes the speed of the traveling body 2 while maintaining automatic traveling.

[0088] This allows the seedling transplanter 1 to perform automatic travel with the operator seated in the operator's seat 41. The operator can also change the vehicle speed during automatic travel while seated in the operator's seat 41. The seedling transplanter 1 can perform automatic travel without, for example, providing an obstacle sensor for detecting obstacles. Therefore, the seedling transplanter 1 can reduce costs and perform automatic travel at low cost.

[0089] The seedling transplanter 1 is equipped with a position detection device 150. The position detection device 150 can detect the position of the traveling vehicle body 2 by first positioning and second positioning. The second positioning has higher detection accuracy than the first positioning. The controller 100 performs automatic traveling based on the position of the traveling vehicle body 2 detected by the second positioning, and if the position of the traveling vehicle body 2 cannot be detected by the second positioning during automatic traveling, the controller 100 performs straight-line assist traveling and turning assist traveling using the first positioning.

[0090] As a result, even when the seedling transplanter 1 cannot perform automatic traveling based on the second positioning, it can perform straight-line assisted traveling and turning assisted traveling, thereby reducing the operator's operations and planting seedlings. In other words, even when the seedling transplanter 1 cannot perform automatic traveling based on the second positioning, it can plant seedlings while reducing the operator's workload.

[0091] The controller 100 acquires a reference line for straight-ahead assist traveling when traveling on side Lc, which is the third side of the teaching traveling that travels along the three sides of the ridge in the field.

[0092] This allows the seedling transplanter 1 to reliably obtain the reference line. Also, the seedling transplanter 1 can accurately obtain the reference line along the ridge. Therefore, when the seedling transplanter 1 performs straight-line assisted traveling, it can accurately transplant seedlings into the field.

[0093] The seesaw switch 48 is arranged so as to be operated along the traveling direction of the traveling body 2. This allows the operator to accurately accelerate and decelerate as intended when operating the seesaw switch 48 to change the speed of the traveling body 2. In other words, the seedling transplanter 1 can accurately accelerate and decelerate during automatic traveling in accordance with the operator's intention.

[0094] When work materials, such as seedlings or fertilizer, are replenished during automatic travel, the seedling transplanter 1 may travel to the ridge in response to operation of the seesaw switch 48. For example, if the traveling body 2 is near the point where it is about to start turning during automatic travel and the seesaw switch 48 is operated to accelerate the traveling body 2, the traveling body 2 will continue straight ahead without turning and travel to the ridge. In other words, when work materials are replenished during automatic travel, the traveling body 2 will travel to the ridge in response to operation of the seesaw switch 48 and perform ridge alignment. The seedling transplanter 1 stops the traveling body 2, for example, when the seesaw switch 48 is no longer operated outside the work area. Note that the seedling transplanter 1 may set the traveling body 2 to a predetermined low speed when the seesaw switch 48 is operated outside the work area. Furthermore, for example, when the seesaw switch 48 is operated to decelerate the traveling body 2 from a stopped state, the seedling transplanter 1 will reverse. Then, when the seedling transplanter 1 returns to the work area, it starts turning by automatic travel.

[0095] This allows the seedling transplanter 1, while automatically traveling, to travel to the ridge where work materials are to be replenished based on the operation of the seesaw switch 48. The seedling transplanter 1 can replenish work materials while maintaining the traveling body 2 in an automatically traveling state.

[0096] The controller 100 may acquire a reference line based on the position of the traveling vehicle body 2 detected during automatic traveling. That is, the controller 100 may acquire a reference line using the azimuth angle of a work process (round trip process) of a route based on the position of the traveling vehicle body 2 detected by the second positioning. If the position of the traveling vehicle body 2 cannot be detected by the second positioning during automatic traveling, the controller 100 controls the steering motor 95 to perform straight-line assisted traveling so that the azimuth of the reference line obtained during automatic traveling matches the azimuth of the traveling vehicle body 2.

[0097] This allows the seedling transplanter 1 to reliably acquire the reference line. Also, the seedling transplanter 1 can accurately acquire the reference line along the route during automatic travel. Therefore, the seedling transplanter 1 can accurately transplant seedlings into the field when performing straight-line assisted travel.

[0098] For example, if a reference line is acquired when traveling along side Lc during teaching travel, and the vehicle moves to a ridge during automatic travel to replenish materials, the reference line acquired when traveling along side Lc may be erased and a new reference line may be acquired based on the position of the traveling vehicle body 2 detected during automatic travel.

[0099] When stopping the traveling body 2, the seedling transplanter 1 may be controlled so that it stops at the target position after a predetermined stopping time, for example, 5 seconds, has elapsed since the start of deceleration. The time at which deceleration begins may be configurable.

[0100] When starting to move forward, the seedling transplanter 1 may be controlled so that it takes a predetermined time, for example, 3 seconds, to reach the set vehicle speed. This prevents sudden acceleration of the seedling transplanter 1 and improves the safety of the operator. The predetermined time may be configurable.

[0101] The seedling transplanter 1 calculates the slip ratio from the vehicle speed calculated from the change in position of the traveling vehicle body 2 detected by the position detection device 150 and the vehicle speed calculated from the rotation speed sensor 90, and if the slip ratio is a predetermined slip ratio, for example, 0.8 or less, the degree of acceleration / deceleration, etc., may be increased by operating the seesaw switch 48, for example.

[0102] The seedling transplanter 1 detects the auto-accelerator dial value, and when the dial value exceeds a set threshold, it may reduce the degree of acceleration or deceleration, for example, by operating the seesaw switch 48. This allows the seedling transplanter 1 to make vehicle speed changes more gradual when the engine speed is increasing, improving the riding comfort of the operator.

[0103] (Second embodiment) Next, a seedling transplanter 1 according to a second embodiment will be described. Here, differences from the first embodiment will be described. Explanations of the same configuration as the first embodiment will be omitted. The seedling transplanter 1 according to the second embodiment is equipped with an accelerator pedal 49 (second operating unit) instead of the seesaw switch 48, as shown in FIG. 6. FIG. 6 is a side view showing the seedling transplanter 1 according to the second embodiment.

[0104] The accelerator pedal 49 is provided on the lower front side of the operator's seat 41. The accelerator pedal 49 is provided so that the operator can operate it with his / her foot. When the traveling body 2 is traveling automatically, the accelerator pedal 49 can set the vehicle speed of the traveling body 2 during automatic traveling. As shown in Figure 7, the accelerator pedal 49 is provided with a limit switch 60. The limit switch 60 detects whether or not the accelerator pedal 49 is being depressed. The limit switch 60 is turned ON when the accelerator pedal 49 is depressed, and is turned OFF when the accelerator pedal 49 is not depressed. Figure 7 is a block diagram showing a control system centered on the controller 100 of the seedling transplanter 1 according to the second embodiment.

[0105] Next, autonomous driving control according to the second embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart illustrating autonomous driving control according to the second embodiment. Here, it is assumed that a work area has been set and the autonomous driving changeover switch 46 is "ON", i.e., the driving mode is the autonomous driving mode.

[0106] The controller 100 determines whether or not the position of the traveling vehicle body 2 can be detected by the second positioning (S100).

[0107] When the position of the traveling vehicle body 2 can be detected by the second positioning (S100: Yes), the controller 100 executes automatic traveling (S101).

[0108] Next, the controller 100 determines whether the limit switch 60 is ON or not (S200). That is, the controller 100 determines whether the accelerator pedal 49 is being depressed or not. If the limit switch 60 is ON (S200: Yes), that is, if the accelerator pedal 49 is being depressed, the controller 100 determines whether the vehicle speed of the traveling vehicle body 2 is at the maximum speed or not (S201). The maximum speed is the maximum speed in automatic traveling, and is a preset speed.

[0109] If the speed of the traveling vehicle body 2 is not the maximum speed (S201: No), the controller 100 increases the speed of the traveling vehicle body 2 to accelerate the traveling vehicle body 2 (S202).

[0110] If the vehicle speed of the traveling vehicle body 2 is at the maximum speed (S201: Yes), the controller 100 maintains the vehicle speed of the traveling vehicle body 2 at the maximum speed (S203).

[0111] If the limit switch 60 is OFF (S200: No), that is, if the accelerator pedal 49 is not depressed, the controller 100 sets the vehicle speed of the traveling vehicle body 2 to a predetermined vehicle speed that has been set in advance. The predetermined vehicle speed is a speed that has been set as a normal speed for automatic traveling. For example, the predetermined vehicle speed is a vehicle speed corresponding to two forward gears. For example, if the accelerator pedal 49 is no longer depressed after being depressed, the controller 100 reduces the vehicle speed of the traveling vehicle body 2, thereby decelerating the traveling vehicle body 2.

[0112] In step S202, when the traveling vehicle body 2 is accelerated, the vehicle speed of the traveling vehicle body 2 becomes greater than the predetermined vehicle speed.

[0113] If the controller 100 cannot detect the position of the traveling vehicle body 2 by the second positioning (S100: No), it executes straight-line assisted traveling and turning-assisted traveling by the first positioning (S104). Note that the controller 100 may execute at least one of straight-line assisted traveling and turning-assisted traveling.

[0114] The seedling transplanter 1 is provided with an accelerator pedal 49 that can be operated by the operator's foot and that can set the speed of the traveling body 2 during automatic traveling when the traveling body 2 is automatically traveling.

[0115] As a result, during automatic driving, the driver can change the vehicle speed of the traveling vehicle body 2 while maintaining automatic driving by operating the accelerator pedal 49 with his / her foot. Therefore, the driver can easily adjust the vehicle speed of the traveling vehicle body 2 during automatic driving.

[0116] The seedling transplanter 1 is equipped with a limit switch 60 that detects whether or not the accelerator pedal 49 is being depressed. When the accelerator pedal 49 is depressed during automatic traveling, the controller 100 accelerates the traveling body 2. When the vehicle speed of the traveling body 2 reaches its maximum speed during automatic traveling, the controller 100 maintains the vehicle speed of the traveling body 2 at the maximum speed.

[0117] This allows the seedling transplanter 1 to change the vehicle speed during automatic driving in accordance with the detection result of the limit switch 60. Therefore, the operator can easily adjust the vehicle speed of the traveling body 2 during automatic driving. Furthermore, the seedling transplanter 1 prevents the vehicle speed of the traveling body 2 from becoming too high during automatic driving, thereby improving the safety of the operator.

[0118] When the accelerator pedal 49 changes from being depressed to not being depressed during automatic traveling, the controller 100 decelerates the traveling vehicle body 2 and then maintains the vehicle speed of the traveling vehicle body 2 at a predetermined vehicle speed.

[0119] As a result, when the accelerator pedal 49 is no longer depressed during automatic driving, the seedling transplanter 1 can continue automatic driving while decelerating the traveling body 2 in response to the driver's operation. In other words, the seedling transplanter 1 can perform automatic driving at the vehicle speed intended by the driver.

[0120] When the accelerator pedal 49 changes from being depressed to not being depressed during automatic driving, the controller 100 may decelerate the traveling vehicle body 2 and then stop the traveling vehicle body 2.

[0121] As a result, when the operator stops depressing the accelerator pedal 49 during automatic travel, the seedling transplanter 1 can stop the traveling body 2 according to the operator's intention.

[0122] The seedling transplanter 1 may be provided with a potentiometer on the accelerator pedal 49. The potentiometer detects the amount of depression of the accelerator pedal 49 by the operator. The controller 100 accelerates or decelerates the traveling vehicle body 2 or maintains the vehicle speed during automatic traveling, depending on the amount of depression of the accelerator pedal 49 detected by the potentiometer.

[0123] The seedling transplanter 1 may be provided with a brake pedal, and a potentiometer may be provided on the brake pedal. The potentiometer detects the amount of depression of the brake pedal. During automatic traveling, the controller 100 accelerates or decelerates the traveling vehicle body 2 or maintains the vehicle speed according to the amount of depression of the brake pedal detected by the potentiometer.

[0124] The seedling transplanter 1 may move the traveling body 2 closer to the ridge for material replenishment by operating the accelerator pedal 49. In this case, the controller 100 controls the speed of the traveling body 2 according to the amount of depression of the accelerator pedal 49.

[0125] The seedling transplanter 1 may be provided with a seesaw switch 48 and an accelerator pedal 49.

[0126] The seedling transplanter 1 may be equipped with a center mascot lamp. The seedling transplanter 1 flashes the green center mascot lamp several times before starting to notify the operator that it is starting. The seedling transplanter 1 flashes the green center mascot lamp several times before accelerating to notify the operator that it is accelerating. The seedling transplanter 1 flashes the red center mascot lamp several times before decelerating to notify the operator that it is decelerating. The seedling transplanter 1 flashes the red center mascot lamp several times before the traveling body 2 stops to notify the operator that the traveling body 2 will stop. In addition to flashing the mascot lamp, the seedling transplanter 1 may also notify the operator by sounding a buzzer. The buzzers may be provided in front of and behind the operator's seat 41. For example, when the traveling body 2 starts or accelerates, a buzzer at the front sounds. When the traveling body 2 decelerates or stops, a buzzer at the rear sounds.

[0127] The seedling transplanter 1 may detect soil fertility. If the soil fertility is lower than a preset reference value, the seedling transplanter 1 increases the amount of seedlings to be harvested. If the soil fertility is higher than the reference value, the seedling transplanter 1 decreases the amount of seedlings to be harvested.

[0128] The seedling transplanter 1 may be configured so that the operator can set the planting depth based on the fertility state using the monitor 86. The seedling transplanter 1 may be configured so that the monitor 86 does not adjust the planting depth based on the fertility state. The seedling transplanter 1 may be configured so that the monitor 86 does not adjust the seedling removal amount based on the fertility state.

[0129] The seedling transplanter 1 may be configured to take the seedling amount set by the operator when the control of planting depth based on fertility is released by the monitor 86. The seedling transplanter 1 may be configured to take the seedling amount set by the operator when the control of planting depth based on fertility is released by the monitor 86.

[0130] The seedling transplanter 1 may adjust the amount of seedlings to be taken by changing the amount of seedlings based on the average fertility of the section over which the traveling body 2 has traveled a certain distance.The seedling transplanter 1 may adjust the planting depth by changing the average fertility of the section over which the traveling body 2 has traveled a certain distance.

[0131] The seedling transplanter 1 may control the seedling removal amount while performing variable fertilization control. The seedling transplanter 1 may control the planting depth while performing variable fertilization control.

[0132] When the seedling transplanter 1 does not control the seedling amount based on fertility, it may control the seedling amount to a set seedling amount position.When the seedling transplanter 1 does not control the planting depth based on fertility, it may control the planting depth to a set planting depth position.

[0133] 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]

[0134] 1. Seedling transplanter (work vehicle) 2 Running vehicle 4 Seedling planting department 35 Handle 36 Gear shift operation lever (first operation part) 41 cockpit (driver's seat) 48 Seesaw switch (second operating part) 49 Accelerator pedal (second operating part) 60 Limit Switch 100 Controller (control device) 150 Position detection device

Claims

1. a traveling vehicle body having a driver's seat in which a driver can be seated; a first operating unit for switching between forward and backward movement of the traveling vehicle body; a second operation unit that can set a vehicle speed of the traveling vehicle body during automatic traveling when the traveling vehicle body is automatically traveling; a control device that causes the traveling vehicle body to automatically travel; Equipped with When the second operating unit is operated by the driver during automatic driving, the control device changes the vehicle speed of the traveling vehicle body while maintaining the automatic driving.

2. The work vehicle according to claim 1 , wherein the traveling body travels to a ridge in response to operation of the second operating unit when work materials are replenished to the traveling body during automatic traveling.

3. a position detection device capable of detecting the position of the traveling vehicle body by first positioning and second positioning; the second positioning has higher detection accuracy than the first positioning, The control device performing automatic traveling based on the position of the traveling vehicle body detected by the second positioning; The work vehicle according to claim 1, wherein, when the position of the traveling vehicle body cannot be detected by the second positioning during automatic traveling, at least one of straight-line assisted traveling and turning assisted traveling is performed by the first positioning.

4. The work vehicle according to claim 3 , wherein the control device acquires a reference line for the straight-line assisted traveling using an azimuth angle of a round trip process of a route based on the position of the traveling vehicle body detected by the second positioning.

5. The work vehicle according to claim 3 , wherein the control device acquires the reference line for the straight-line assisted travel when traveling on a third side of a teaching travel that travels along three sides of a ridge in a farm field.

6. The work vehicle according to claim 1 , wherein the second operating unit is a switch arranged to be operated along a traveling direction of the traveling vehicle body.

7. The work vehicle according to claim 1 , wherein the second operating unit is an accelerator pedal that can be operated by the driver's foot.

8. a limit switch for detecting whether or not the accelerator pedal is depressed; The work vehicle according to claim 7, wherein the control device accelerates the traveling vehicle body when the accelerator pedal is depressed during automatic traveling, and maintains the traveling vehicle body at the maximum speed when the vehicle speed of the traveling vehicle body reaches the maximum speed during automatic traveling.

9. 9. The work vehicle according to claim 8, wherein when the accelerator pedal changes from a depressed state to a not depressed state during automatic traveling, the control device decelerates the traveling vehicle body and then maintains the vehicle speed of the traveling vehicle body at a predetermined vehicle speed.

10. 9. The work vehicle according to claim 8, wherein the control device, when the accelerator pedal changes from a depressed state to a not depressed state, decelerates the traveling vehicle body and then stops the traveling vehicle body.

Images