JP7697496B2 - Work vehicles - Google Patents

Description

The present invention relates to a work vehicle.

Conventionally, a work vehicle that automatically drives and plants in a field is known (see, for example, Patent Document 1).

Patent No. 6643091

However, with the above technology, the height of the seedling planting section is not regulated when automatic travel begins, leaving room for improvement in terms of workability when automatic travel begins.

The present invention has been made in consideration of the above, and aims to provide a work vehicle that improves workability when starting autonomous driving.

In order to solve the above problems and achieve the object, a work vehicle (1) according to one aspect of the embodiment includes a traveling body (2), a working machine (50) attached to the traveling body (2) and capable of being raised and lowered to a predetermined working position and a predetermined non-working position, a positioning device (150) that detects the position of the traveling body (2), and a control device (150) that automatically drives the traveling body (2) along a straight line based on the detected position of the traveling body (2). When an ON operation is performed to start automatic driving, the control device (150) activates automatic driving regardless of the elevation height of the working machine (50), and deactivates automatic driving when it is detected that the height of the working machine (50) is equal to or higher than a predetermined height that is higher than the predetermined working position after the automatic driving is activated.

According to one aspect of the embodiment, the work vehicle improves workability when starting autonomous driving.

FIG. 1 is an explanatory diagram showing an overview of a straight-line support of a seedling transplanter according to an embodiment of the present invention. FIG. 2 is a side view of the seedling transplanter according to the embodiment. FIG. 3 is a schematic diagram of the steering post as viewed from the front. FIG. 4 is a schematic diagram of a monitor. FIG. 5 is a schematic diagram showing the monitor and the frame as viewed from the front. FIG. 6 is a view of the mounting member as viewed from the front side. FIG. 7 is a front perspective view of the monitor mounted on the frame. FIG. 8 is a functional block diagram focusing on the controller of the seedling transplanter. FIG. 9 is a flowchart illustrating the start process of the automatic straight driving according to the embodiment. FIG. 10 is a side view showing an outline of the seedling planting section. FIG. 11 is a side view showing an outline of the seedling planting section.

Below, a work vehicle according to an embodiment of the present invention will be described in detail with reference to the drawings as a riding seedling transplanter 1. Note that the components in the following embodiment include those that are easily replaceable by a person skilled in the art, or those that are substantially the same, or so-called equivalents. Furthermore, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention. In addition, hereinafter, the entire seedling transplanter 1 may be referred to as the machine body.

Figure 1 is an explanatory diagram showing an overview of the straight-line support (automatic straight-line movement) of the seedling transplanter 1 according to the embodiment. The seedling transplanter 1 according to this embodiment has a traveling body 2 with a seedling planting unit 50 connected to the rear and a pair of front wheels 4 and rear wheels 5 on the left and right.

In this embodiment, the straight-line support refers to a function that supports the automatic straight-line driving (automatic driving) of the seedling transplanter 1 in the field F by controlling the operation of the steering wheels based on the steering angle (turning angle) of the steering wheels of the seedling transplanter 1 and the position information of the seedling transplanter 1. Here, the steering angle is the turning angle of the front wheels 4, but for example, the steering angle of the handle 32 (steering, see FIG. 2) may be detected as the steering angle. In addition, the position information of the seedling transplanter 1 is acquired by the GNSS unit 120 (positioning device, see FIG. 8) provided on the traveling vehicle body 2. In the following description, the forward/backward and left/right directional references of the seedling transplanter 1 are based on the traveling direction of the traveling vehicle body 2 as seen from the driver's seat 28 (see FIG. 2) where the operator can sit.

As shown in the figure, the seedling transplanter 1 plants seedlings at a specified working width D while traveling back and forth within a specified work area G in the field F. At this time, if straight-line support is performed, the operator's manual operation using the handle 32 only requires a turning operation near the headland, and the seedling transplanter 1 automatically travels straight along the automatic straight-line line L1 (straight-line). In FIG. 1, the symbol L3 indicates the turning line by manual operation of the seedling transplanter 1 at the headland. Also, the symbol E indicates the entrance and exit of the seedling transplanter 1 into the field F.

The automatic straight line L1 of the seedling transplanter 1 using straight support is approximately parallel to the reference line L2 that serves as the reference for performing straight support, and this reference line L2 is set in advance in the field F according to the seedling planting direction. That is, the start and end positions of the straight support are acquired as the reference start point (hereinafter referred to as "point A") and reference end point (hereinafter referred to as "point B"), respectively, by the travel reference registration unit 152 (see Figure 8) equipped in the seedling transplanter 1, and the line segment connecting the acquired points A and B is registered as the reference line L2.

The automatic straight line L1 is set as a line shifted from the reference line L2 by the planting width of the seedling transplanter 1.

The specific configuration of the seedling transplanter 1 will be described below with reference to Figure 2. Figure 2 is a side view of the seedling transplanter 1 according to the embodiment.

The seedling planting unit 50, which is a working machine, is attached to the traveling body 2 of the seedling transplanter 1 so that it can be raised and lowered via the seedling planting unit lifting mechanism 40, which is a lifting device. The traveling body 2 is a four-wheel drive vehicle in which a pair of left and right front wheels 4 and a pair of left and right rear wheels 5 are both driven, and the front wheels 4, which become the steered wheels, are steered by turning the steering wheel 32, making it possible to travel on farm fields F and roads between farm fields F.

The seedling transplanter 1 can be fitted with auxiliary wheels 5A on the rear wheels 5. Specifically, the auxiliary wheels 5A are attached to the axles 220 of the rear wheels 5 and rotate together with the rear wheels 5. The seedling transplanter 1 can be fitted with auxiliary wheels 5A on the inside of the rear wheels 5, the outside of the rear wheels 5, or both the inside and outside of the rear wheels 5. In other words, the seedling transplanter 1 can change the mounting position of the auxiliary wheels 5A.

The traveling body 2 also includes a main frame 7 located approximately in the center of the body, an engine 10 as a prime mover mounted on the main frame 7, and a power transmission device 15 that transmits the power of the engine 10 to the front and rear wheels 4, 5 and the seedling planting section 50. In this seedling transplanter 1, an internal combustion engine such as a diesel engine or a gasoline engine is used for the engine 10 as the power source, and the generated power is used not only to move the traveling body 2 forward and backward, but also to drive the seedling planting section 50.

The power transmission device 15 also has a hydraulic continuously variable transmission (hereinafter referred to as "HST") 16 that changes the speed of the driving force transmitted from the engine 10 and outputs it, and a power transmission section 17 that transmits the power from the engine 10 to the HST 16.

The power transmission device 15 also has a power transmission section 17. That is, the driving force from the engine 10 is transmitted to the HST 16 via the transmission case 18, and the power that has been changed in speed by the HST 16 is transmitted to the transmission case 18. The transmission case 18 is equipped with an auxiliary transmission mechanism (not shown) that switches between a high-speed mode and a low-speed mode, which will be described later, and is attached to the front of the main frame 7.

A portion of the power transmitted from the transmission case 18 to the front wheels 4 and rear wheels 5 can be transmitted to the front wheels 4 via the left and right front wheel final cases 13, and the remainder can be transmitted to the rear wheels 5 via the left and right rear wheel gear cases 22. The left and right front wheel final cases 13 are disposed on the left and right sides of the transmission case 18. The left and right front wheels 4 are connected to the left and right front wheel final cases 13 via axles 131, and these front wheel final cases 13 are driven in response to the steering operation of the handlebars 32, allowing the front wheels 4 to be steered.

Similarly, the rear wheels 5 are connected to the left and right rear wheel gear cases 22 via axles 220. Meanwhile, power is transmitted from the transmission case 18 to the seedling planting section 50 via a planting clutch 500 provided at the rear of the traveling body 2 from a working machine drive shaft (not shown). The planting clutch 500 is operated by a planting clutch motor 510 (see FIG. 8) connected to a controller 150 (see FIG. 8), which will be described in detail later.

The engine 10 is positioned approximately in the center of the traveling body 2 in the left-right direction and protrudes above the floor step 26 on which the operator places his/her feet when getting on. The floor step 26 is provided between the front of the traveling body 2 and the rear of the engine 10 and is attached to the main frame 7, and a portion of it is latticed so that mud on shoes can be dropped into the field F. In addition, a rear step 27 that also serves as a fender for the rear wheel 5 is provided behind the floor step 26. The rear step 27 has an inclined surface that slopes upward as it extends to the rear, and is positioned on each of the left and right sides of the engine 10.

The engine 10 also protrudes upward from the floor step 26 and rear step 27, and an engine cover 11 that covers the engine 10 is provided on the portion that protrudes from these steps 26, 27.

A pilot's seat 28 on which an operator sits is installed above the engine cover 11, and a control unit 30 is provided in front of the pilot's seat 28 and in the center of the front side of the traveling vehicle body 2. The control unit 30 is disposed in a state in which it protrudes upward from the floor surface of the floor step 26, and divides the front side of the floor step 26 into left and right parts.

The steering section 30 is provided with a steering post 315, and a handle 32 that can be steered by an operator is provided on the top of the steering post 315. As shown in FIG. 3, the steering post 315 is provided with a finger-up lever 34. FIG. 3 is a schematic diagram of the steering post 315 as viewed from the front. The finger-up lever 34 is operated by the operator, for example, when obtaining points A and B. The finger-up lever 34 can be rotated in the vertical direction.

Furthermore, a monitor 33 is provided in front of the steering post 315, as shown in FIG. 4. FIG. 4 is a schematic diagram of the monitor 33. As shown in FIG. 5, the monitor 33 is attached to an inverted U-shaped frame 320. FIG. 5 is a schematic diagram of the monitor 33 and the frame 320 as viewed from the front. A space is provided below the monitor 33. The monitor 33 is provided so that the upper end of the display surface is inclined backward. For example, the monitor 33 is provided so that the upper end of the display surface is inclined backward by 5 degrees with respect to the vertical direction.

The monitor 33 is attached to the frame 320 by the attachment member 321 shown in Figures 6 and 7. Figure 6 is a view of the attachment member 321 as seen from the front side. Figure 7 is a front perspective view of the monitor 33 attached to the frame 320. Figure 7 is a view showing the state in which the front cover of the monitor 33 has been removed.

The monitor 33 is arranged so that the frame 320 is sandwiched between a rear cover 33a and a front cover.

The mounting member 321 is provided inside the monitor 33. The mounting member 321 is attached to the frame 320 by a fixing portion 322 and a nut 323. A part of the fixing portion 322 is curved in a U-shape, and the frame 320 is inserted into the curved portion. The nut 323 is inserted into the first hole 321a of the mounting member 321. The mounting member 321, together with the fixing portion 322, clamps the frame 302, thereby fixing the monitor 33 to the frame 320.

The mounting member 321 has a second hole 321b for attaching the front cover with a screw and a third hole 321c for attaching the rear cover 33a with a screw 324.

The mounting member 321 also has a notch 321d formed in it. The notch 321d is formed in a position corresponding to the weld bead 320a of the frame 320. Specifically, the notch 321d is formed behind the weld bead 320a. By forming the notch 321d, the mounting member 321 can be attached to the frame 320 in the left-right direction without the weld bead 320a and the mounting member 321 coming into contact with each other. Therefore, the mounting member 321 is attached so as to be parallel to the axis (not shown) of the frame 320 extending in the left-right direction, and the monitor 33 can be prevented from being attached at an angle to the frame 320.

Returning to FIG. 4, the monitor 33 is provided with, for example, a straight-line support lamp 331 that is turned on when the machine performs automatic straight-line driving using straight-line support, an A point lamp 332, a B point lamp 333, and a GNSS lamp 334. Note that the monitor 33 is also provided with indicator lights other than lamps. The seedling transplanter 1 may also have multiple monitors. The monitor may be a detachable tablet terminal device, etc.

On the monitor 33, when point A is acquired by operating the finger-up lever 34, the point A lamp 332 is lit. Also, when point B is acquired by operating the finger-up lever 34, the point B lamp 333 is lit. On the monitor 33, when the vehicle is in a state capable of automatic straight-ahead driving, both the point A lamp 332 and the point B lamp 333 are lit.

The GNSS lamp 334 has three indicator lamps, and the number of indicator lamps that are lit changes according to the GNSS reception level. The monitor 33 informs the operator of the GNSS reception status by this display mode.

In addition, a buzzer 215, which is an example of an alarm device 200, is provided at a predetermined position on the control unit 30 (see Figure 8).

Returning to FIG. 2, the steering unit 30 is provided with a main shift lever 81 (shift lever) and an auxiliary shift lever 82 (travel speed change lever) near the steering post 315. The main shift lever 81 is provided on the right side of the steering unit 30, and the auxiliary shift lever 82 is provided below the handlebars 32.

The main speed change lever 81 is a lever that switches between forward and backward travel and the driving power of the traveling body 2, and by operating it, the operator can adjust the rotation angle of the trunnion (not shown) of the HST 16 to adjust the speed of the traveling body 2. In other words, the main speed change lever 81 sets the target vehicle speed of the traveling body 2.

The sub-speed change lever 82 is a lever that switches the driving mode, which determines the driving speed of the traveling vehicle body 2, between low-speed mode and high-speed mode depending on the place where the vehicle is traveling. The mode switching is performed by the sub-speed change mechanism provided in the transmission case 18 depending on the position of the sub-speed change lever 82.

An openable front cover 31 is provided at the front of the control unit 30. A center mascot 350 is attached to the center of the front end of the front cover 31 as an indicator member that serves as a driving indicator. Although not shown in FIG. 2 for convenience, spare seedling carriers (not shown) are provided on the left and right front sides of the traveling body 2.

The center mascot 350 is attached to the front center of the traveling body 2 and functions as a guide for the direction of travel when the operator sitting in the driver's seat 28 operates the seedling transplanter 1. The center mascot 350 in this embodiment also functions as an alarm device 200 that notifies the operator of the support status, including whether or not the straight-line support described above can be performed.

The seedling transplanter 1 according to this embodiment may use the center mascot 350, which serves as the notification device 200, to notify not only the status of the straight-line support, but also information regarding the remaining amount of work materials such as seedlings and fertilizers provided in the seedling planting section 50.

The center mascot 350 is always in the field of vision of the worker facing forward, allowing the worker to constantly be aware of the status of the seedling transplanter 1 without having to take his or her eyes off the front, greatly contributing to improved safety.

The seedling transplanter 1 according to this embodiment has a GNSS unit 120 with a built-in receiving antenna 121 (see FIG. 8) mounted on the traveling vehicle body 2. This GNSS unit 120 can obtain position information on the earth at predetermined intervals by acquiring GNSS coordinates at predetermined time intervals using the receiving antenna 121.

The GNSS unit 120 is attached to the top of an antenna frame 124 whose base end is connected to the front end of the vehicle body 2 so that it is located directly above the axle 131 of the front wheel 4.

Here, the seedling planting section 50 and other components will be described. The seedling planting section 50 is attached to the rear of the traveling body 2 via the seedling planting section lifting mechanism 40 so that it can be raised and lowered. The seedling planting section lifting mechanism 40 has a lifting link device 41, which has a parallel link mechanism that connects the rear of the traveling body 2 to the seedling planting section 50. The parallel link mechanism has an upper link 41a and a lower link 41b, and these links 41a and 41b are rotatably connected to a link base frame 43 that is a rear-view gate type erected at the rear end of the main frame 7. The other ends of the links 41a and 41b are rotatably connected to the seedling planting section 50. In this way, the seedling planting section 50 is connected to the traveling body 2 so that it can be raised and lowered.

The seedling planting section lifting mechanism 40 also has a hydraulic lifting cylinder 44 that expands and contracts hydraulically, and the seedling planting section 50 can be raised and lowered by the expansion and contraction action of the hydraulic lifting cylinder 44. The hydraulic lifting cylinder 44 is driven by the HST 16 described above, and the seedling planting section 50 can be raised to a non-working position or lowered to a ground work position (planting position) by the lifting action of the seedling planting section lifting mechanism 40.

The seedling planting section 50 can also plant seedlings in multiple sections or multiple rows. For example, the seedling planting section 50 can plant seedlings in six sections, which is known as a six-row planting section.

The seedling planting section 50 also includes a seedling planting device 60, a seedling placement platform 51, and floats 47 (48, 49). Of these, the seedling placement platform 51 is provided at the rear of the traveling body 2 as a seedling placement member for loading multiple rows of seedlings, and has seedling placement surfaces 52 partitioned in the left and right directions of the traveling body 2, the number of which corresponds to the number of rows of seedlings to be planted, and it is possible to place seedlings with soil on each seedling placement surface 52.

The seedling planting device 60 is disposed under the seedling placement table 51 on which the seedlings are placed, and is a device that picks up the seedlings from the seedling placement table 51 and plants them in the field F, and is supported by a planting support frame 55 disposed on the front side of the seedling placement table 51. The seedling planting device 60 has a planting transmission case 64 and a planting body 61, and the planting body 61 is configured so that it can pick up the seedlings from the seedling placement table 51 and plant them in the field F, and the planting transmission case 64 can supply driving force to the planting body 61.

The planting transmission case 64 is configured to be able to supply the power transmitted from the engine 10 to the seedling planting section 50 to the planting body 61, and the planting body 61 is rotatably connected to the planting transmission case 64. The planting body 61 also has a planting rod 62 that picks up the seedlings from the seedling placement table 51 and plants them in the field F, and a rotary case 63 that rotatably supports the planting rod 62 and is rotatably connected to the planting transmission case 64.

The rotary case 63 is fitted with a variable speed transmission mechanism (not shown) that can vary the rotational speed when rotating the planting rod 62 using the driving force transmitted from the planting transmission case 64. As a result, when the planting body 61 rotates, the planting rod 62 can rotate with its rotational speed changing depending on the rotation angle relative to the rotary case 63.

The seedling planting devices 60 configured in this manner are arranged one for every two rows. In other words, each of the multiple seedling planting devices 60 is assigned a planting row. Also, each planting transmission case 64 is equipped with two planting bodies 61 that can rotate. In other words, two rotary cases 63 are connected to one planting transmission case 64 on both sides of the left and right direction of the machine body.

The float 47 glides over the field to level the ground as the traveling body 2 moves, and has a center float 48 located in the center of the seedling planting section 50 in the left-right direction of the traveling body 2, and side floats 49 located on both sides of the seedling planting section 50 in the left-right direction.

In this embodiment, the center float 48 is provided with a float potentiometer 154 (see FIG. 8) that functions as a hydraulic sensitivity mechanism that raises and lowers the seedling planting section 50 according to the conditions of the field F. The float potentiometer 154 can change the sensitivity range for detecting the up and down movement of the center float 48.

For example, if the sensitivity is increased, even small up and down movements of the center float 48 will be detected and a detection signal will be sent to the controller 150. On the other hand, if the sensitivity is decreased, small up and down movements of the center float 48 will not be detected, and only up and down movements of a certain amplitude or more will be detected and a detection signal will be sent to the controller 150.

In addition, a rotor 67 for leveling the field F is provided on the front side at a position below the seedling planting section 50. This rotor 67 is configured to be rotatable by the output from the engine 10 transmitted via the rear wheel gear case 22, and is configured to be raised and lowered by the rotor motor 165 (see Figure 8), which is an electric motor.

In addition, in the seedling transplanter 1 according to this embodiment, the controller 150 performs the straight-line support on the condition that the ground-leveling rotor 67 is in contact with the ground. In other words, the straight-line support is performed only when seedling planting work is being performed.

In addition, on both the left and right sides of the seedling planting section 50, there are line drawing markers 68 that form lines that serve as a guide for the direction of travel for the next planting row. When the seedling transplanter 1 moves forward in a straight line within the field F, the line drawing markers 68 draw lines on the field F as a guide for moving forward in a straight line after turning at the edge of the field F.

Furthermore, a fertilizer applicator 70 is mounted behind the driver's seat 28 on the traveling vehicle body 2. The fertilizer applicator 70 includes left and right storage hoppers 71 for storing fertilizer, a feed device 72 for feeding a set amount of fertilizer supplied from the storage hopper 71, a fertilizer hose 74 that is a fertilizer passage for supplying the fertilizer fed by the feed device 72 to the field F, and a blower 73 for supplying transport air to the fertilizer hose 74.

The blower 73 transfers the fertilizer in the fertilizer hose 74 to the seedling planting section 50. The fertilizer application device 70 also has a fertilizer guide 75 to which the fertilizer is transferred by the fertilizer hose 74, and a furrow former 76 that drops the fertilizer transferred by the fertilizer hose 74 into a fertilizer furrow formed near the side of the seedling planting row.

Figure 8 is a functional block diagram focusing on the controller 150 of the seedling transplanter 1. The seedling transplanter 1 according to this embodiment is capable of controlling each part by electronic control, and the seedling transplanter 1 is equipped with a controller 150 as a control device that controls each part. This controller 150 is provided with a processing section having a CPU (Central Processing Unit) and the like, a storage section such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and an input/output section, which are connected to each other and can exchange signals with each other. The storage section stores a computer program that controls the seedling transplanter 1.

As shown in the figure, various actuators and sensors that acquire information from each part are connected to the controller 150.

Actuators connected to the controller 150 include, for example, a throttle motor 100 that adjusts the amount of intake air for the engine 10, a rotor motor 165 that raises and lowers the rotor 67 for leveling the ground, and a planting clutch motor 510 that operates the planting clutch 500. Although not shown in the figure, a trunnion drive motor that changes the rotation angle of the trunnion of the HST 16 is also connected to the controller 150.

The controller 150 is also connected to various other sensors, including a steering angle sensor 130, a direction sensor 160, an inertial positioning device 170, a vehicle speed sensor 180 (rotation sensor), a seating sensor 190, and a lever sensor (not shown) that detects the amount of operation of the main shift lever 81 and the sub shift lever 82 by the tilt angle. The controller 150 is also connected to an imaging device such as a camera.

The steering angle sensor 130 is a sensor that detects the steering angle when the front wheels 4, which are steered wheels, are steered by operating the steering wheel 32. The steering angle sensor 130 may detect the steering angle based on the angle of the rotating seedling feed belt of the steering wheel 32.

The orientation sensor 160 is a sensor that detects the direction in which the aircraft is facing. The controller 150 can derive the actual traveling direction of the aircraft based on the value acquired from the orientation sensor 160. The orientation sensor 160 may be provided in the GNSS unit 120. The orientation may also be calculated based on the position information of the traveling vehicle body 2 detected by the GNSS unit 120.

The inertial positioning device 170 includes a gyro sensor and an acceleration sensor, and has a built-in control board that controls these. The inertial positioning device 170 may be provided in the GNSS unit 120.

The inertial positioning device 170 detects the degree to which the posture of the traveling vehicle body 2 is inclined with respect to the automatic straight line L1. The inertial positioning device 170 detects the inclination of the traveling vehicle body 2. The inertial positioning device 170 detects the inclination of the traveling vehicle body 2 in the forward/rearward and left/right directions.

The seating sensor 190 is a sensor that is provided in the pilot's seat 28 and is composed of a load cell, a pressure-sensitive film sensor, etc., and can detect whether an operator is seated in the pilot's seat 28.

The vehicle speed sensor 180 acquires information regarding the vehicle speed of the traveling vehicle body 2. The vehicle speed sensor 180 detects the rotation of the front wheels 4 or the rear wheels 5 of the traveling vehicle body 2. For example, the vehicle speed sensor 180 detects the rotation of the rear wheels 5.

The controller 150 can prohibit straight-line support if the steering angle detected by the steering angle sensor 130 is not within the allowable range for moving the traveling vehicle body 2 in a straight line, or if the direction detected by the orientation sensor 160 or the attitude detected by the inertial positioning device 170 is not a value indicating a straight-line direction.

The steering angle is within the allowable range for moving the vehicle body 2 in a straight line when, for example, the absolute value of the steering angle (turning angle) of the front wheels 4 is 15 degrees or less. In addition, if the steering angle detected by the steering angle sensor 130 after the vehicle body 2 turns indicates a value that does not cause the vehicle body 2 to move in a straight line (for example, 5 degrees), straight-line support can be prohibited.

It is also advisable to set an acceptable range for the orientation sensor 160, and if an orientation or attitude outside the acceptable range continues for a period of time set in the controller 150, it is determined that the robot is not facing in a straight line and straight line support is prohibited.

In addition, if some kind of trouble occurs and the straight-line support of the seedling transplanter 1 is stopped, in order to improve safety or prevent operational errors, the straight-line support can be controlled so that it will not resume unless certain conditions are met, such as the seedling planting section 50 being lowered, the spare seedling carrier being stored, and the planting clutch 500 being engaged.

The controller 150 is also connected to an alarm device 200, such as a monitor 33 and a buzzer 215 that issues an alarm or the like.

The controller 150 can use the buzzer 215 and monitor 33 to notify the support status, including whether straight-line support is being performed or stopped. Therefore, the operator can easily recognize whether the current forward-leaning attitude of the aircraft, the rudder angle after turning the aircraft, and the attitude of the aircraft are appropriate for performing straight-line support. This can improve the operability of switching from a turning operation to straight-line support, for example. The notification device 200 may be a tablet terminal device (not shown) that can be brought in from outside.

The seedling transplanter 1 also includes a steering device 110 that can be controlled by the controller 150, and a GNSS unit 120, which are connected to the controller 150.

The steering device 110 is equipped with a transmission mechanism (not shown) that is interlocked with the steering wheel 32, and is equipped with a straight-line support mechanism 310 that applies any rotational force to the steering wheel 32, enabling automatic steering by the controller 150. The transmission mechanism includes a steering motor 112 that rotates the steering wheel 32.

When performing straight-line support, the controller 150 automatically steers the steering wheel 32 via the straight-line support mechanism 310 based on the position information acquired by the GNSS unit 120 to maintain the traveling vehicle body 2 in a straight-line direction.

The GNSS unit 120 has a receiving antenna 121 that receives signals from artificial satellites used in the GNSS, acquires position information (coordinate information) of the seedling transplanter 1 on the Earth, and transmits the acquired position information to the controller 150.

In addition, various switches such as the finger lever 34, float potentiometer 154, automatic driving lever 140, height detection sensor 141, and automatic driving changeover switch 142 (driving mode changeover section) are connected to the controller 150.

The finger-up lever 34 accepts the operator's operation regarding straight-line support. The finger-up lever 34 is operated by the operator when obtaining points A and B. The finger-up lever 34 is also operated when canceling the reference line L2.

The float potentiometer 154 is attached to the center float 48, which moves up and down following the unevenness of the field F, and senses the up and down movement of the center float 48, i.e., the depth of the field F. The controller 150 raises and lowers the seedling planting section 50 according to the sensed unevenness of the field F.

The height detection sensor 141 detects the height of the seedling planting section 50. For example, the height detection sensor 141 is a potentiometer that detects the rotation angle of the links 41a and 41b. The height detection sensor 141 detects the height of the seedling planting section 50 by detecting the rotation angle of the links 41a and 41b.

The automatic driving changeover switch 142 is a switch that switches whether automatic driving is performed. Specifically, the automatic driving changeover switch 142 is a switch that switches the driving mode between manual driving mode and automatic driving mode. The manual driving mode is a mode in which driving is performed by manual operation of the operator. The automatic driving mode is a mode in which automatic straight-ahead driving can be performed without manual operation of the operator.

The automatic travel lever 140 is a lever for starting automatic straight travel along an automatic straight line L1 that is approximately parallel to the reference line L2 after the traveling vehicle body 2 has turned.

When the driving mode is set to automatic driving mode by the automatic driving changeover switch 142 and the automatic driving lever 140 is operated to "ON", automatic straight-line driving can be started. Note that when the driving mode is set to manual driving mode by the automatic driving changeover switch 142, automatic straight-line driving cannot be performed even if the automatic driving lever 140 is operated to "ON". Also, even if the driving mode is set to automatic driving mode by the automatic driving changeover switch 142, if the automatic driving lever 140 is set to "OFF", automatic straight-line driving will not be executed.

The controller 150 has a travel reference registration unit 152 in which the reference line L2 is registered. In order to allow the seedling transplanter 1 to perform straight-line support, a teaching operation is required in advance. The travel reference registration unit 152 registers, for example, the reference line L2 (see FIG. 1) for performing straight-line support and controlling straight-line movement through the teaching operation.

The driving reference registration unit 152 acquires point A, which is the start position of the straight-line support, and point B, which is the end position, and registers the line segment connecting the acquired points A and B as the reference line L2.

By registering the reference line L2, the traveling direction when straight-line support is performed and the distance for which straight-line support is performed are registered. Note that by registering the length of the reference line L2 as the distance for which straight-line support is performed, it is possible to notify the operator that, for example, the operator is approaching a point where a turning operation will be performed, i.e., that the edge of the field (ridge) is approaching, based on the straight-line distance of the traveling vehicle body 2. Note that the traveling distance of the traveling vehicle body 2 can be calculated, for example, based on the rotation speed of the rotor 67.

Next, the start process of automatic straight-ahead driving according to the embodiment will be described with reference to FIG. 9. FIG. 9 is a flowchart illustrating the start process of automatic straight-ahead driving according to the embodiment. Here, it is assumed that the driving mode is set to automatic driving mode by the automatic driving changeover switch 142. It is also assumed that the traveling body 2 is turning. For example, when turning the traveling body 2 near a ridge in a farm field, the automatic driving lever 140 is operated to "OFF", and the turning is performed by manual operation of the operator.

The controller 150 determines whether the automatic driving lever 140 has been operated to "ON" (S100). If the automatic driving lever 140 has not been operated to "ON" (S100: No), i.e., if the automatic driving lever 140 is "OFF", the controller 150 ends the current process.

When the automatic driving lever 140 is operated to "ON" (S100: Yes), the controller 150 starts automatic straight-ahead driving (S101). In other words, the controller 150 activates automatic driving.

Next, the controller 150 determines whether the height of the seedling planting unit 50 is equal to or higher than a predetermined height (S102). The predetermined height is a height that is set in advance and is higher than the ground work position.

If the height of the seedling planting section 50 is equal to or greater than the predetermined height (S102: Yes), the controller 150 stops the automatic straight-line driving (S103). That is, if the height of the seedling planting section 50 is equal to or greater than the predetermined height, the controller 150 deactivates the automatic driving. For example, the controller 150 turns the automatic driving lever 140 to "off."

If the height of the seedling planting section 50 is less than the predetermined height (S102: No), the controller 150 continues automatic straight-ahead driving (S104).

In addition, after starting the automatic straight-line driving in step S101, the controller 150 may proceed to step S102 after a preset time (e.g., several seconds) has elapsed, or after the traveling vehicle body 2 has traveled a preset distance (e.g., several tens of centimeters).

The seedling transplanter 1 includes a traveling body 2, a seedling planting section 50, a GNSS unit 120, and a controller 150. The seedling planting section 50 is attached to the traveling body 2 and can be raised and lowered to a ground work position and a non-work position. The GNSS unit 120 detects the position of the traveling body 2. The controller 150 automatically drives the traveling body 2 along the automatic straight line L1 based on the detected position of the traveling body 2. When an ON operation is performed to start automatic driving, the controller 150 activates automatic driving regardless of the elevation height of the seedling planting section 50, and deactivates automatic driving when it is detected that the height of the seedling planting section 50 is equal to or higher than a predetermined height that is higher than the work position after the automatic driving is activated.

This allows the seedling transplanter 1 to start automatic straight-line travel even when the seedling planting section 50 is higher than the working position. Therefore, the seedling transplanter 1 can improve the workability when starting automatic travel.

The controller 150 may stop the automatic straight-ahead driving depending on the position of the sub-shift lever 82. For example, the controller 150 detects the position of the sub-shift lever 82 after the automatic driving lever 140 is turned to "ON" and automatic straight-ahead driving is started.

When the position of the sub-shift lever 82 is in the high-speed mode, the controller 150 stops the automatic straight-line driving. When the position of the sub-shift lever 82 is in the low-speed mode, the controller 150 continues the automatic straight-line driving.

The seedling transplanter 1 can start automatic straight-line travel even when the sub-speed lever 82 is in the high-speed mode. This allows the seedling transplanter 1 to improve operability when starting automatic travel. Note that the seedling transplanter 1 stops automatic straight-line travel if the sub-speed lever 82 remains in the high-speed mode. This allows the seedling transplanter 1 to ensure safety and properly plant seedlings in the field.

The monitor 33 can display the driving mode and the deviation of the driving direction of the traveling vehicle body 2. The deviation of the driving direction is a deviation from the automatic straight line L1. The controller 150 calculates the deviation of the driving direction regardless of the driving mode. The controller 150 calculates the deviation of the driving direction based on the direction on the automatic straight line L1 and the direction detected by the direction sensor 160.

When the driving mode is the automatic driving mode, the controller 150 does not display the deviation in the driving direction on the monitor 33. This is because when the driving mode is the automatic driving mode, the deviation in the driving direction is corrected by the automatic driving.

When the driving mode is the manual driving mode, the controller 150 displays the deviation in the driving direction on the monitor 33. This allows the operator to know the deviation from the automatic straight line L1 when the traveling vehicle body 2 is being driven manually.

The controller 150 calculates the vehicle speed of the traveling vehicle body 2 (hereinafter, sometimes referred to as the "first vehicle speed") based on the position information detected by the GNSS unit 120. The vehicle speed data based on the position information acquired by the GNSS unit 120 is acquired at a predetermined sampling frequency (e.g., 10 Hz). The controller 150 retains the acquired vehicle speed data for a predetermined time (e.g., 310 ms). The controller 150 calculates the first vehicle speed by applying a predetermined low-pass filter (e.g., cutoff frequency 0.33 Hz) to the retained vehicle speed data. This allows the seedling transplanter 1 to accurately calculate the first vehicle speed of the traveling vehicle body 2.

The controller 150 determines that the calculation condition for the first vehicle speed is not met when the target vehicle speed of the traveling vehicle body 2 set by the main shift lever 81 is equal to or lower than a predetermined vehicle speed (for example, forward second gear). The controller 150 also determines that the calculation condition for the first vehicle speed is not met when the steering wheel 32 is not within a predetermined straight-line range, specifically, when the steering angle detected by the steering angle sensor 130 is not within an allowable range for moving the traveling vehicle body 2 straight. The controller 150 also determines that the calculation condition for the first vehicle speed is not met when the seedling planting section 50 is in a non-working position. The controller 150 also determines that the calculation condition for the first vehicle speed is not met when the reception level of the GNSS unit 120 is a non-reception level. The controller 150 also determines that the calculation condition for the first vehicle speed is not met when the first vehicle speed is zero.

If the conditions for calculating the first vehicle speed are not met, the controller 150 discards the stored vehicle speed data and sets the first vehicle speed to zero.

As described above, the controller 150 also detects the vehicle speed of the traveling vehicle body 2 (hereinafter, sometimes referred to as the "second vehicle speed") using the vehicle speed sensor 180. Specifically, the vehicle speed data based on the rotation speed acquired by the vehicle speed sensor 180 is acquired at a predetermined sampling frequency. The controller 150 retains the acquired vehicle speed data for a predetermined period of time. The controller 150 calculates the second vehicle speed by applying a predetermined low-pass filter (for example, a cutoff frequency of 0.33 Hz) to the retained vehicle speed data. This allows the seedling transplanter 1 to accurately calculate the second vehicle speed of the traveling vehicle body 2.

The controller 150 may also apply the calculation conditions for the first vehicle speed to the second vehicle speed.

The second vehicle speed may be a target vehicle speed calculated from the target opening of the HST 16 and the engine speed.

The controller 150 calculates the slip ratio of the traveling vehicle body 2 using the first vehicle speed and the second vehicle speed. Specifically, the controller 150 calculates the slip ratio by subtracting the first vehicle speed from the second vehicle speed and dividing the result by the second vehicle speed.

When the slip ratio is equal to or greater than a predetermined upper limit slip ratio, the controller 150 sets the slip ratio to the predetermined upper limit slip ratio. When the slip ratio is equal to or less than a predetermined lower limit slip ratio, the controller 150 sets the slip ratio to the predetermined lower limit slip ratio.

The predetermined upper slip ratio is a non-volatile value (e.g., 20%) stored by the controller 150. The predetermined lower slip ratio is a non-volatile value (e.g., 0%) stored by the controller 150. The predetermined upper slip ratio and the predetermined lower slip ratio can be changed using a service tool. The predetermined upper slip ratio may have a regulated value that can be input (e.g., 10 to 50%). The predetermined lower slip ratio may have a regulated value that can be input (e.g., -50 to 10%).

When the slip ratio falls below a predetermined slip ratio range (predetermined range), the controller 150 increases the amount of fertilizer applied by the fertilizer application device 70 based on the slip ratio. When the slip ratio exceeds a predetermined slip ratio range (predetermined range), the controller 150 decreases the amount of fertilizer applied by the fertilizer application device 70 based on the slip ratio. Note that when the slip ratio is within the predetermined slip ratio range, no correction of the amount of fertilizer applied is performed. The predetermined slip ratio range is a non-volatile value (e.g., 3%) stored in the controller 150. The predetermined slip ratio range can be changed using a service tool.

This allows the seedling transplanter 1 to correct the amount of fertilizer applied taking into account the slip rate, enabling uniform fertilization. If an excessive slip rate is calculated, the seedling transplanter 1 determines that the slip rate calculation is inappropriate or that the field conditions are irregular, and regulates the slip rate. The seedling transplanter 1 can regulate the correction of the amount of fertilizer applied by setting an upper limit (a predetermined upper limit slip rate) and a lower limit (a predetermined lower limit slip rate) for the slip rate.

The controller 150 corrects the amount of fertilizer application as described above at predetermined intervals. The predetermined interval is a non-volatile value (e.g., 3 seconds) stored in the controller 150. The predetermined interval can be changed using a service tool.

If the controller 150 cannot properly calculate the slip ratio, it will not correct the amount of fertilizer applied.

If the calculation conditions for the first vehicle speed or the second vehicle speed are not met, the controller 150 sets the slip ratio to a default value (e.g., 10%).

The seedling transplanter 1 may be provided with a brake plate 520 and a seedling number count switch 521 as shown in FIG. 10 in the seedling planting section 50. FIG. 10 is a side view showing an outline of the seedling planting section 50. The brake plate 520 is provided above the seedling number count switch 521. The brake plate 520 is provided to temporarily support the mat seedlings. The brake plate 520 supports the lower end of the mat seedlings. The brake plate 520 has multiple steps, for example, two steps. The brake plate 520 is provided so that the mat seedlings climb over the brake plate 520 after the seedling feed belt 522 has operated multiple times.

When the seedling feed belt 522 is activated and the mat seedlings are fed, the mat seedlings climb over the brake plate 520 and move downward. The seedling number count switch 521 is a switch for counting the number of mat seedlings. The seedling number count switch 521 is, for example, a switch that is common to the seedling reduction switch. The seedling number count switch 521 counts the number of mat seedlings by turning OFF and ON depending on the seams between the mat seedlings. The mat seedlings are temporarily supported by the brake plate 520, creating gaps between the mat seedlings, which reliably turns the seedling number count switch 521 OFF and ON, allowing the seedling transplanter 1 to accurately count the number of mat seedlings.

The seedling count switch 521 does not count when the seedlings are above the seedling count switch 521, but counts when the seedling count switch 521 is not pressed.

The seedling count switch 521 is set up so that if the switch is not pressed even after a certain number of seedling transfers, it is determined that there are no seedlings remaining.

The seedling feed belt 522 is driven by an electric motor. If the mat seedling cannot get over the brake plate 520, the seedling feed belt 522 is rotated upward once and then downward. If the mat seedling cannot get over the brake plate 520, the operating speed of the electric motor may be increased. If the mat seedling cannot get over the brake plate 520, the feed amount of one pass of the seedling feed belt 522 may be divided into small increments.

As shown in FIG. 11, the seedling planting section 50 may be provided with seedling reduction switches 530, each with an independent sensor, at the center bottom of each row of the seedling tank. FIG. 11 is a side view showing an outline of the seedling planting section 50. The seedling planting section 50 is provided with a mechanism above the seedling reduction switch 530 that can deploy or retract a wall 532 that is driven by a motor to hold back the seedlings into the seedling tank.

The walls 532 are independent for each row, and the walls 532 of each row are arranged to move by a pivot 533 on the same axis. The walls 532 are operated by one motor via a spring 534. On the opposite side of the pivot 533, there is a point 535 that protrudes above the seedling loading surface 52 of the seedling tank when the wall 532 is in the stored state. The wall 532 that blocks the seedlings, the pivot 533, the point 535 that protrudes above the seedling loading surface 52 of the seedling tank, and the seedling reduction switch 530 are arranged in order from the top. The pivot 533 is provided on the side closer to the wall 532 that blocks the seedlings. The point 535 that protrudes above the seedling loading surface 52 of the seedling tank and the seedling reduction switch 530 are provided at the same position in the vertical direction, or the seedling reduction switch 530 is provided slightly below. The wall 532 that holds back the seedlings is located above the seedling transport belt 522.

When any one of the seedling reduction switches 530 for each row is turned OFF, the motor operates to store the wall 532, and after a certain period of time, the motor operates to deploy the wall 532.

If any one of the seedling reduction switches 530 for each row is turned OFF and the wall 532 that blocks the seedlings is retracted and then turned ON within a certain period of time, the seedling count is incremented by one. If any one of the seedling reduction switches 530 for each row is turned OFF and the wall 532 that blocks the seedlings is retracted and then turned ON within a certain period of time, an alarm is issued for the reduction in seedlings for that row.

Further advantages and modifications may 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 equivalents thereof.

1. Seedling transplanter (work vehicle)
2 Running body 4 Front wheels 5 Rear wheels 32 Handle (steering)
33 Monitor 50 Seedling planting section (working machine)
70 Fertilizer applicator 81 Main shift lever (shift lever)
82 Sub-speed change lever (travel speed change lever)
120 GNSS unit (positioning device)
140 Automatic travel lever 141 Height detection sensor 142 Automatic travel changeover switch (travel mode changeover section)
150 Controller (control device)
160: Orientation sensor 180: Vehicle speed sensor (rotation sensor)

Claims (9)

A running vehicle body,
A working machine attached to the traveling vehicle body and capable of ascending and descending to a predetermined working position and a predetermined non-working position;
A position measuring device for detecting the position of the traveling vehicle body;
and a control device that automatically drives the traveling vehicle body along a straight line based on the detected position of the traveling vehicle body,
The control device includes:
When an ON operation for starting the automatic travel is performed, the automatic travel is activated regardless of the lift height of the work machine,
A work vehicle in which, when a predetermined time has elapsed since the automatic driving was activated and the automatic driving was started, or after a predetermined distance has been traveled , if it is detected that the height of the work implement is equal to or greater than a predetermined height that is higher than the predetermined work position, the automatic driving is deactivated. a travel speed switching lever for switching the travel speed of the travel vehicle body between low speed and high speed,
The control device includes:
When an ON operation for starting the automatic traveling is performed, the automatic traveling is activated regardless of the operation position of the traveling speed switching lever,
2. The work vehicle according to claim 1, wherein after the automatic driving is activated, if it is detected that the operation position of the travel speed switching lever is a position corresponding to high speed, the automatic driving is deactivated. A driving mode switching unit for switching a driving mode of the traveling vehicle body to an automatic driving mode capable of executing the automatic driving or a manual driving mode in which the traveling vehicle body is driven by an operator;
a display unit that displays the driving mode and is capable of displaying a deviation in the driving direction of the traveling vehicle body;
The control device includes:
When the driving mode is the automatic driving mode, the deviation of the driving direction is not displayed on the display unit,
The work vehicle according to claim 1 , wherein when the driving mode is the manual driving mode, the deviation of the driving direction is displayed on the display unit. The control device includes:
2. The work vehicle according to claim 1, wherein the positioning device holds vehicle speed data acquired at a predetermined sampling frequency for a predetermined period of time, and calculates a first vehicle speed of the traveling body by applying a predetermined low-pass filter to the held vehicle speed data. a gear shift lever for setting a target vehicle speed of the traveling vehicle body;
A steering wheel is provided on the traveling vehicle body and adjusts a steering angle of the traveling vehicle body.
The control device includes:
5. The work vehicle according to claim 4, wherein the calculation condition for the first vehicle speed is determined to be not satisfied when at least one of the following conditions is satisfied: the target vehicle speed of the traveling body is equal to or lower than a predetermined vehicle speed, the steering is not within a predetermined straight-line range, the work machine is in a non-working state, the reception level of the position measuring device is at a non-reception level, and the first vehicle speed is zero. The control device includes:
The work vehicle according to claim 5 , wherein when the vehicle speed data acquired by the position measurement device does not satisfy a calculation condition for the first vehicle speed, the stored vehicle speed data is discarded and the first vehicle speed is set to zero. A rotation sensor for detecting the rotation of the wheels of the vehicle body,
The control device includes:
5. The work vehicle according to claim 4, wherein the vehicle speed data acquired by the rotation sensor at a predetermined sampling frequency is held for a predetermined time, and a second vehicle speed of the traveling body is calculated by applying a predetermined low-pass filter to the held vehicle speed data. The control device includes:
Calculating a slip ratio of the traveling vehicle body using the first vehicle speed and the second vehicle speed;
If the calculated slip ratio is equal to or greater than an upper limit slip ratio, the slip ratio is set as the upper limit slip ratio;
The work vehicle according to claim 7 , wherein, when the calculated slip ratio is equal to or less than a lower limit slip ratio, the slip ratio is set to the lower limit slip ratio. a fertilizer application device provided on the traveling vehicle body and configured to supply fertilizer to the field;
The control device includes:
Calculating a slip ratio of the traveling vehicle body using the first vehicle speed and the second vehicle speed;
The work vehicle according to claim 7 , wherein, when the slip ratio falls below a predetermined range, an amount of fertilizer applied by the fertilizer application device is increased based on the slip ratio.

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