Work vehicles

Abstract

To improve workability.SOLUTION: A work vehicle comprises a steering member for steering a travel vehicle body, a position information acquisition device for acquiring position coordinates of the travel vehicle body, an automatic traveling device for automatically traveling the travel vehicle body by operating the steering member, and a control device for controlling each part. A first reference position registered at one point of a field and a second reference position registered at another point of the field can be registered. A line connecting the first reference position and the second reference position serves as traveling reference data that is a reference for traveling. An operation unit for turning automatic traveling on and off is provided, and the operation unit is a lever member. When the traveling reference data is registered and automatic traveling is ON, if the lever member is operated in a first direction, automatic traveling is turned OFF. When registering the second reference position, if a distance from the position where the first reference position was acquired is less than a predetermined distance, the second reference position cannot be registered.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, for example, in a work vehicle that travels in a field with a traveling body and performs ground work with a work device mounted on the traveling body, when the work device turns on and off, the work device acquires position information at the start and end of work, creates a reference line from the acquired work start position and work end position, and has a function of automatically steering the steering wheel along the created reference line (see, for example, Patent Document 1).

[0003] In such a work vehicle, in order to acquire the position where the work device turns on and off as the work start position and work end position, the operation of acquiring the work start position and work end position becomes unnecessary.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the conventional work vehicle as described above does not consider the possibility of incorrect operation in the process of creating a reference line.

[0006] For example, there is a problem that the operator accidentally touches an automatic straight-ahead setting member and the reference line becomes short.

[0007] The present invention has been made in view of the above, and an object thereof is to provide a work vehicle capable of improving workability.

Means for Solving the Problems

[0008] To solve the above-mentioned problems and achieve the objective, the work vehicle described in claim 1 is a work vehicle comprising a steering member for steering the vehicle body, a position information acquisition device for acquiring the position coordinates of the vehicle body, an automatic driving device for operating the steering member to automatically drive the vehicle body, and a control device for controlling each part, wherein a first reference position registered at one point in the field and a second reference position registered at another point in the field can be registered, the line connecting the first reference position and the second reference position is the driving reference data that serves as the basis for driving, an operation unit for turning the automatic driving on and off is provided, the operation unit is a lever member, when the driving reference data is registered and the automatic driving is "on", the automatic driving is "off" when the lever member is operated in the first direction, and when registering the second reference position, if the distance from the position where the first reference position was acquired is less than a predetermined distance, the second reference position cannot be registered.

[0009] The work vehicle according to claim 2 is characterized in that, in the work vehicle according to claim 1, the first reference position is registered when the lever member is operated in the second direction.

[0010] The work vehicle according to claim 3 is the work vehicle according to claim 1 or 2, further comprising a work device mounted on the vehicle body for performing work in a field, The location information acquisition device is characterized by deleting the registered first and second reference positions when it recognizes that the final stage of work in the field is headland work. [Effects of the Invention]

[0011] The work vehicle according to the present invention can improve the work efficiency in registering and deleting automatic straight-line driving standards. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a left side view of the work vehicle. [Figure 2] Figure 2 is a plan view of the work vehicle. [Figure 3]FIG. 3 is a main part plan view showing the configuration of a traveling vehicle body. [Figure 4] FIG. 4 is a main part rear view showing the configuration of a steering unit including a steering member. [Figure 5A] FIG. 5A is a main part rear view showing the configuration of an automatic steering device of a steering member. [Figure 5B] FIG. 5B is a main part left side view showing the configuration of an automatic steering device of a steering member. [Figure 6] FIG. 6 is a functional block diagram showing members related to various controls. [Figure 7] FIG. 7 is a flowchart showing control for correcting acquired position coordinates. [Figure 8] FIG. 8 is a flowchart showing automatic straight-ahead control by an automatic steering device. [Figure 9] FIG. 9 is a flowchart showing acquisition of a first reference position and a second reference position by operation of an automatic straight-ahead setting member and turning on and off of automatic straight-ahead control. [Figure 10] FIG. 10 is a flowchart showing an erasing operation of a first reference position and a second reference position. [Figure 11] FIG. 11 is a flowchart showing control for erasing a first reference position by a steering wheel operation after acquisition of the first reference position. [Figure 12] FIG. 12 is a schematic working explanatory view showing a first reference position, a second reference position, a reference line, and a target position. [Figure 13] FIG. 13 is a flowchart showing control for erasing a first reference position, a second reference position, and a reference line by traveling on a headland in a field. [Figure 14] FIG. 14 is a flowchart (part 1) showing control for automatically erasing a reference line. [Figure 15] FIG. 15 is a flowchart (part 2) showing control for automatically erasing a reference line. [Figure 16] FIG. 16 is a flowchart (part 3) showing control for automatically erasing a reference line. [Figure 17] FIG. 17 is a flowchart (part 4) showing control for automatically erasing a reference line. [Figure 18] FIG. 18 is a left side view showing another example of the work vehicle. [Figure 19A] FIG. 19A is an explanatory view (part 1) of the antenna frame. [Figure 19B] FIG. 19B is an explanatory view (part 2) of the antenna frame. [Figure 20A] FIG. 20A is a front view of the antenna frame. [Figure 20B] FIG. 20B is a perspective view of the antenna frame. [Figure 20C] FIG. 20C is a perspective view of the antenna frame from below. [Figure 21] FIG. 21 is an explanatory view of the monitor.

MODE FOR CARRYING OUT THE INVENTION

[0013] Hereinafter, embodiments of the work vehicle disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments shown below.

[0014] The overall configuration of a work vehicle (seedling transplanter) 1 according to an embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a left side view of the work vehicle (seedling transplanter) 1. FIG. 2 is a plan view of the work vehicle (seedling transplanter) 1. In FIG. 2, for convenience of explanation, wheels (front wheels, rear wheels) and the like are omitted. Further, hereinafter, as the work vehicle 1, a seedling transplanter that plants seedlings in a field while traveling in the field will be described as an example.

[0015] In the following description, the front-rear direction is the traveling direction when the work vehicle (hereinafter referred to as the seedling transplanter) 1 travels straight, and the front side in the traveling direction is defined as "front" and the rear side as "rear". The traveling direction of the seedling transplanter 1 is the direction from the driver's seat 41 toward the steering member (hereinafter referred to as the steering wheel) 35 when traveling straight (see FIG. 1).

[0016] Furthermore, the left-right direction is the direction perpendicular to the front-back direction. In the following, left and right are defined with respect to the "front" side. That is, with the operator (also called the pilot) seated in the cockpit 41 and facing forward, the left side is "left" and the right side is "right". Also, the up-down direction and The vertical direction is the direction of movement. The front-back, left-right, and up-down directions are perpendicular to each other.

[0017] These directions are defined for convenience to make the explanation easier to understand, and the present invention is not limited by these directions. Also, in the following, the seedling transplanter 1 may be referred to as the machine body.

[0018] As an embodiment of this work vehicle, the ride-on seedling transplanter 1 shown in Figure 2 has an 8-row planting configuration, but this configuration may be used for rice transplanters with a different number of planting rows. As shown in Figures 1 and 2, the seedling transplanter 1 has a lifting link mechanism 3 on the rear side of the traveling body 2 that allows a seedling planting section, which takes seedlings from a seedling tank 53 and plants them in the field with multiple seedling planting devices 55, a seeding device that supplies seeds, and a working device 4 such as a rotary tiller for cultivating the field to be raised and lowered, and the main body of the fertilizer applicator 5 is positioned on the upper rear side of the traveling body 2.

[0019] First, let's describe the main frame 15 that constitutes the vehicle body 2. As shown in Figure 3, the main frame 15 consists of a front beam frame 16 at the front of the vehicle body, a rear beam frame 17 at the rear of the vehicle body, and a central beam frame 18 between the front and rear of the front beam frame 16 and the rear beam frame 17. The front beam frame 16 and the central beam frame 18 are connected by a pair of left and right front connecting frames 19, 19, and the central beam frame 18 and the rear beam frame 17 are connected by a pair of left and right rear connecting frames 20, 20.

[0020] The front beam frame 16, the central beam frame 18, and the rear beam frame 17 are oriented longitudinally in the left-right direction, while the front connecting frame 19 and the rear connecting frame 20 are oriented longitudinally in the front-back direction. The left-right spacing between the left and right front connecting frames 19,19 and the rear connecting frames 20,20 is approximately the same. Furthermore, the left-right length of the central beam frame 18 and the rear beam frame 17 is longer than the left-right length of the front beam frame 16. Since the left and right front connecting frames 19,19 and the rear connecting frames 20,20 are welded to the lower part of the central beam frame 18, the left and right front connecting frames 19,19 and the rear connecting frames 20,20 may be constructed from a single metal square bar.

[0021] In the space formed by the front beam frame 16, the central beam frame 18, and the left and right front connecting frames 19, 19, a transmission case 13 is provided to transmit driving force to the left and right front wheels 10, 10 and rear wheels 11, 11, work equipment 4, etc., and a hydraulic continuously variable transmission (HST) 14 is provided to output driving force supplied from the engine 30 to the transmission case 13. Then, at the rear of the rear beam frame 17, left and right lifting frames 21, 21 are provided at a narrower distance than the left and right distance between the left and right rear connecting frames 20, 20 and protruding to the rear, and a rear support frame 22 is attached to the lower part of the left and right lifting frames 21, 21.

[0022] Rear wheel transmission cases 11a, 11a are provided on both the left and right sides of the rear support frame 22 to drive the left and right rear wheels 11, 11 of the vehicle body 2, respectively, and left and right link frames 23, 23 that support the lifting link mechanism 3 are provided on the upper part of the rear support frame 22, facing upward.

[0023] The lifting link mechanism 3 is configured by providing a pair of left and right lower link arms 24, 24 on the lower side of the left and right link frames 23, 23 and between them, providing a lifting cylinder 25 between the left and right lower link arms 24, 24, and providing an upper link arm 26 above the lifting cylinder 25. The ends of the left and right lower link arms 24, 24, the lifting cylinder 25, and the upper link arm 26 opposite to the vehicle body 2 are attached to the front side of the work device 4.

[0024] Furthermore, front wheel transmission cases 1 are located on the front of both the left and right ends of the central beam frame 18 and on the left and right outer sides of the left and right front connecting frames 19, 19, respectively, to transmit power to the left and right front wheels 10, 10 of the vehicle body 2. 0a and 10a are provided respectively, and the left and right ends of the central beam frame 18 and the rear beam frame 17 are connected by left and right extension frames 27, 27, respectively. The left and right extension frames 27, 27 are oriented longitudinally in the front-to-back direction.

[0025] Furthermore, a central connecting frame 28 is provided in the front-to-rear direction at the lower part of the central beam frame 18, the rear beam frame 17, and the rear support frame 22, and front and rear support plates 29, 29 that support the engine 30 are provided between the front and rear of the central beam frame 18 and the rear beam frame 17, and between the left and right rear connecting frames 20, 20.

[0026] Each of the front and rear support plates 29, 29 is provided with a receiving plate 29a that receives the engine 30 on both the left and right sides of the central connecting frame 28. On both the left and right sides of the front and rear support plates 29, 29, left and right auxiliary frames 31, 31 are provided that pass below the rear beam frame 17 and protrude to the rear, and the rear ends of the left and right auxiliary frames 31, 31 are connected by a rear auxiliary frame 32 in the left and right direction. The rear ends of the left and right auxiliary frames 31, 31 are connected to the left and right rear wheel transmission cases 11a, 11a.

[0027] The main frame 15 is constructed as described above. The front-to-back width of the main frame 15, from the front beam frame 16 to the rear beam frame 17, and the left-to-right width of the left and right front connecting frames 19, 19 and rear connecting frames 20, 20 are covered by floor steps 33 on which workers stand. The floor steps 33 may be integrally formed to improve strength or reduce the number of parts, or they may be configured to be separable into front and rear, left and right sections, to facilitate attachment and detachment.

[0028] As shown in Figure 3, the areas around the left and right ends of the central beam frame 18 and the rear beam frame 17, and the left and right extension frames 27, 27 are not covered by the floor step 33 and are exposed. In this case, the floor step 33 could be enlarged to cover the entire main frame 15, but in order to share the floor step 33 between machines of different sizes and planting rows, the left and right extension steps 34, 34 are arranged on both the left and right sides of the floor step 33.

[0029] With the above configuration, the main frame 15 is constructed by connecting multiple frame components, thus improving its strength compared to conventional designs. Furthermore, by positioning the central connecting frame 28 below the front and rear support plates 29, 29 on which the engine 30 is mounted, and by connecting the front and rear support plates 29, 29 to the left and right rear auxiliary frames 32, 32, the heavy engine 30 can be firmly held in place.

[0030] As shown in Figures 1 and 2, the front of the vehicle body 2 is provided with a bonnet 39 on top, which has a steering handle 35 for steering the machine, a gear shift lever 36 for operating the continuously variable transmission 14 and the work device 4, a sub-gear shift lever 37 for operating a sub-gear shifting device (not shown) for switching the drive transmission of the vehicle body 2, and a control panel 38 for operating various parts of the machine. The front of the bonnet 39 is provided with an openable and closable front cover 40, and inside the front cover 40 are a fuel tank, a battery, and an interlocking mechanism (not shown) that rotates the left and right front wheels 10, 10 and the lower parts of the left and right front wheel transmission cases 10a, 10a for steering the steering handle 35.

[0031] Furthermore, a center mascot 70 is provided in front of the front cover 40, which displays various information such as the working status of the work device 4, the decrease in work materials consumed during work, and the operation or non-operation of the automatic steering device 205 (described later) by lighting up LEDs or the like. The center mascot 70 is composed of, for example, a work display unit 71 located on the lower and rear side of the machine in a side view, and an automatic straight-ahead display unit 72 located on the upper and front side of the machine.

[0032] Furthermore, an engine cover 30a is provided behind the bonnet 39 and above the engine 30, covering the top and sides of the engine 30, and a cockpit 41 where an operator sits is provided on top of the engine cover 30a.

[0033] Furthermore, the fertilizer application device 5 is mounted behind the cockpit 41, specifically at the rear end of the main frame 15. The driving force for the fertilizer application device 5 is transmitted by a fertilizer transmission mechanism 5a, which is positioned from one side of the left and right rear wheel transmission cases 11a toward the fertilizer application device 5.

[0034] At the front of the transmission case 13 is a front transmission shaft (not shown) that transmits power to the left and right front wheel transmission cases 10a, 10a, and at the rear of the transmission case 13 are left and right drive shafts 42, 42 that transmit power to the left and right rear wheel transmission cases 11a, 11a. Upstream of the left and right drive shafts 42, 42 in the transmission direction are side clutch mechanisms 43, 43 that engage and disengage power to the left and right drive shafts 42, 42. When the steering wheel 35 is turned to rotate the vehicle body 2, the side clutch mechanism 43 located on the inside of the turn is disengaged, stopping power transmission to the rear wheel 11 on the inside of the turn.

[0035] As shown in Figure 3, left and right clutch engagement / disengagement shafts 44, 44 are provided vertically near the left and right center of the rear side of the transmission case 13, and clutch engagement / disengagement arms 45, 45 facing outwards from the aircraft are provided above the left and right clutch engagement / disengagement shafts 44, 44, respectively. Side clutch pedals 43a, 43a for engaging and disengaging the left and right side clutch mechanisms 43, 43 are provided on one side of the front lower part of the cockpit 41.

[0036] Furthermore, as shown in Figures 1 and 2, below the working device 4, there is a center float 62C and left and right side floats 62L and 62R that make contact with and slide on the field surface. In addition, a leveling rotor 63 for leveling uneven surfaces in the field is provided in front of the machine body, beyond the center float 62C and the left and right side floats 62L and 62R. The driving force to the leveling rotor 63 is transmitted by a leveling transmission shaft 65 provided in one of the left or right rear wheel transmission cases 11a. A leveling clutch is also provided in one of the left or right rear wheel transmission cases 11a to switch the power transmission to the leveling rotor 63 on and off.

[0037] The center float 62C is equipped with a rotating potentiometer 64 (see Figure 6) that detects the rotation angle of the center float 62C. When the rotation angle of the rotating potentiometer 64 changes by more than a predetermined angle, the control device 100 determines that the field depth has changed, and extends or retracts the lifting cylinder 25 to rotate the lifting link mechanism 3 up and down, thereby adjusting the vertical height of the work device 4, i.e., the working position, to correspond to the field depth.

[0038] When using the aforementioned work device 4 in a field to plant seedlings, sow seeds, or perform tasks such as fertilizing or weeding after seedling growth, it is common practice to drive the vehicle body 2 in a straight line from one side of the field to the other. However, if the wheels of the vehicle body 2 deviate from the straight-line direction due to the unevenness of the field's plow pan or the viscosity of the topsoil, the vehicle body 2 may gradually move in the direction of deviation. Furthermore, depending on the operator's driving skill, it may not be possible to keep the vehicle body 2 aligned with the straight-line direction, causing it to move in a direction deviating from the straight line.

[0039] As a result, the work trajectory for planting seedlings, sowing seeds, weeding, and fertilizing becomes diagonal, leaving empty spaces where planting or sowing would normally be possible. This necessitates manual planting or sowing by the worker afterward, creating extra labor for the worker. Furthermore, the spacing between planting rows and sowing rows becomes narrower than the spacing between rows of the work device 4, leading to poor ventilation and potential pest and disease outbreaks. Alternatively, during post-planting or sowing operations such as weeding or fertilizing, seedlings may be crushed, leading to reduced yields. Conversely, maneuvering the device to avoid crushing seedlings can reduce work efficiency.

[0040] To solve these problems, one possible solution is to install an automatic straight-line driving system that automatically steers the vehicle body 2 and maintains a straight-line driving posture without human intervention.

[0041] First, as shown in Figures 1 and 2, an antenna frame 201 is provided on the vehicle body 2 to which a GPS (GNSS) antenna 200, which serves as a position information acquisition device, is mounted. The antenna frame 201 consists of a front frame 201a, which is gantry-shaped in a front view, with its left and right bases attached to left and right antenna stays 202, 202 provided on the front side of the main frame 15, and a rear frame 201b that extends from the left and right center of the front frame 201a toward the rear of the vehicle body 2 toward the left and right center of the rear. The bonnet 39 and cockpit 41 are located behind the space of the gantry-shaped front frame 201a.

[0042] Furthermore, the vertical height of the antenna frame 201 is made the highest in the entire machine. In order to prevent workers from hitting their heads while standing on the floor steps 33 and to improve reception accuracy, the upper end of the antenna frame 201 is positioned approximately 2.5 to 3.5 m above the ground. This makes it easier for workers to move on the floor steps 33, improving work efficiency, and also allows the GPS antenna 200 to be positioned higher above the ground, thereby improving reception accuracy.

[0043] The GPS antenna 200 is mounted near the connection point between the front frame 201a and the rear frame 201b. The connection point between the front frame 201a and the rear frame 201b is located near the front-to-rear distance between the bonnet 39 and the driver's seat 41, and is near the center of the vehicle body 2 in the front-to-rear direction.

[0044] As a result of the above, the mounting position of the GPS antenna 200 is near the center of the aircraft in both the front-to-back and left-to-right directions, so the acquired coordinates of the aircraft are less likely to deviate from the actual position of the aircraft. This allows for more accurate setting of the straight-line driving position by the automatic straight-line driving system, improving work accuracy.

[0045] Furthermore, because the cockpit 41 is located behind the space in the front frame 201a, the antenna frame 201 does not obstruct the operator's view, improving visibility and allowing for more accurate positioning before straight-line driving. It also allows for earlier detection of field conditions and obstacles in front of the machine, enabling safer operation by switching to manual control and minimizing deviations in the working position. The GPS antenna 200 should be one of several types, such as standalone positioning, DGPS (Digital GPS) (Digital GPS), or RTK (Real-Time Keying), that is suitable for the area where the work is being performed.

[0046] However, if the ground clearance of the GPS antenna 200 fluctuates due to the aircraft's tilt or vibration, a coordinate position different from the actual aircraft position will be measured, resulting in a decrease in reception accuracy and causing the aircraft to travel in a direction deviating from a straight line.

[0047] To prevent this, as shown in Figure 6, an IMU (Inertial Measurement Unit) 203 is provided in addition to the GPS antenna 200. The IMU 203 corrects the position coordinates acquired by the GPS antenna 200 to the control device 100 based on the difference between the height from the ground to the GPS antenna 200 when the vehicle body 2 is in an inclined position and the height from the ground to the GPS antenna 200 when it is not inclined.

[0048] The height from the ground surface to the GPS antenna 200 is determined by measuring the tilt and other behaviors of the vehicle body 2 using the three-axis acceleration sensor and angular velocity sensor built into the IMU 203.

[0049] In addition, a compass sensor 204 is provided to allow the control device 100 to more reliably determine whether the aircraft's direction of travel by the automatic straight-line system is correct. The correction of the position coordinates at this time is as shown in S101 to S105 of Figure 7. As a result, the aircraft's path can be determined by the measured direction, further improving the accuracy of straight-line travel.

[0050] The position information acquired by the GPS antenna 200 is corrected by the control device 100 based on the information detected by the IMU 203 and the direction sensor 204. The control device 100 then compares the current position information with previously acquired position information, and if the difference in position information exceeds an acceptable range, it steers the left and right front wheels 10, 10 in the left and right directions to return the aircraft to a straight-ahead driving position.

[0051] To automate the steering of the left and right front wheels 10, 10, or pivot turning of crawlers, etc., an automatic steering device 205 is provided that rotates the handle 35 with a steering actuator 206. As shown in S201 to S204 of Figure 8, the automatic steering device 205 adjusts the amount of operation of the steering actuator 206 based on the difference between the X coordinate of the current position information calculated by the control device 100 and the X coordinate of the previously acquired reference position information. This causes the handle 35 to be turned left and right to move the machine toward the straight-ahead driving position, and when the machine reaches the straight-ahead driving position, the steering actuator 206 is stopped, and the automatic steering of the handle 35 is stopped.

[0052] The steering actuator 206 consists of an electric or hydraulic motor, or a cylinder.

[0053] With the above configuration, the steering wheel 35 is automatically steered according to the difference in the X coordinate of the calculated position information, and the machine can be automatically adjusted to a straight-line driving position. This prevents the working position of the work device 4 from shifting left or right, making it less likely that there will be areas in the field where work has not been performed. As a result, there is no need to perform work manually in areas where work was not performed, and the workload of the operator is reduced.

[0054] Furthermore, since the working positions of the previous work row and the current work row do not overlap, the consumption of excess materials such as seedlings, seeds, and fertilizers is prevented, thereby reducing working costs and preventing poor growth caused by an oversupply of materials.

[0055] Furthermore, tractors equipped with tillers, seedling transplanters, and seeders travel to the edge of the field for each work row, turn approximately 180 degrees, and move to the next work row. If the automatic straight-line system is activated during a turn, it may determine that the machine is deviating from its intended straight-line position and activate the steering actuator 206, potentially disrupting the turning trajectory. Therefore, the automatic straight-line system must be configured to be turned off when the machine is turning. It is also conceivable to configure the system so that it turns off when the steering wheel 35 is turned. However, if the machine's direction of travel deviates significantly due to field conditions, or if the operator turns the steering wheel 35 to avoid an obstacle, the automatic straight-line system will turn off. This would require the operator to turn the automatic steering system back on mid-way, increasing the operator's workload. Moreover, the operator might not notice that the automatic straight-line system has turned off, causing the machine to travel in a misaligned position and reducing work accuracy.

[0056] Furthermore, it is conceivable that the automatic straight-line system can be turned on by returning the steering wheel 35 from a turn to a straight-line position. However, when returning from a turn to a straight-line position, fine steering adjustments of the steering wheel 35 are necessary to align the machine with the straight-line position for the next work run. If the automatic steering system is turned on during this operation, the control device 100 will steer if it determines that the machine has deviated from the straight-line driving position. There is a problem where actuator 206 activates, preventing the aircraft from being positioned in the correct straight-line position.

[0057] To prevent such problems from occurring, and to ensure the vehicle travels in a straight line in the appropriate direction and operates within the appropriate section, an automatic straight-line driving system will be explained using Figures 6 and 8 to 11. The Y-coordinate represents the position coordinate of the vehicle body 2 in the forward and backward direction, while the X-coordinate represents the position coordinate in the direction perpendicular to the forward and backward direction, i.e., the left and right direction.

[0058] First, the vehicle body 2 is equipped with an automatic straight-line setting member 207 that acquires the coordinates of one side of the field, which is the starting point of automatic straight-line movement, and the other side of the field, which is the ending point of automatic straight-line movement, and also turns the automatic straight-line system on and off. The automatic straight-line setting member 207 shall be equipped with at least one member that can be operated in at least two directions, such as vertically, horizontally, or in a pushed-in state and a returned state, or it shall be equipped with two or more operating members.

[0059] In this embodiment, the automatic straight-line setting member 207 is equipped with a finger-up lever that can be operated in the vertical direction, as shown in Figure 4, but a toggle switch, push switch, joystick, etc. may also be used. This reduces the number of parts and improves operability, as the operation to acquire the reference position (first reference position A, second reference position B) and the operation to turn the automatic steering device 205 on and off can be performed by operating the automatic straight-line setting member 207 with one hand on the same side.

[0060] As shown in Figure 4, when the automatic straight-line setting member 207 is operated in the first direction W1, which in this embodiment is upward towards the aircraft, the GPS antenna 200 acquires data at the operated position, and the control device 100 records the position coordinates calculated using the detection results of the IMU 203 and the direction sensor 204. Note that operating the automatic straight-line setting member 207 in the first direction W1 corresponds to operating the reference position acquisition member.

[0061] When the automatic straight-line setting member 207 is operated, as shown in S301 to S302 of Figure 9, if no other position coordinates are recorded, the calculated position coordinates are recorded as the first reference point A, and if the first reference point A is recorded, the calculated position coordinates are recorded as the second reference point B. When the automatic straight-line setting member 207 is operated while both the first reference point A and the second reference point B are recorded, no position coordinates are recorded.

[0062] Furthermore, if automatic straight-line movement becomes inaccurate during work in the field, it is necessary to reacquire the first reference point A and the second reference point B. In such cases, as shown in Figure 10 (S401-S406), it is advisable to set the automatic straight-line setting member 207 to erase the recorded first reference point A and second reference point B when operated in the first direction W1 for a predetermined time (for example, 2-3 seconds). Alternatively, a button for erasing the records (not shown) may be provided, which, when operated, deletes the first reference point A and the second reference point B.

[0063] The first reference point A and the second reference point B, which serve as the reference positions for straight-line driving of the automatic straight-line driving system, exhibit smaller X-coordinate deviations the closer they are to each other. However, if the distance between the two points is short, straight-line driving is possible even without using the automatic straight-line driving function. Furthermore, when the distance between the two points is short, it is conceivable that an operator might unintentionally touch the automatic straight-line driving setting member 207, thereby acquiring the second reference point B.

[0064] To prevent such problems from occurring, when the automatic straight-line setting member 207 is operated to acquire the second reference point B, if the distance from the position where the first reference point A was acquired is less than a predetermined distance, for example, less than 8 to 12 m, the control device 100 will delete the second reference point B and will not record it. Subsequently, when the automatic straight-line setting member 207 is operated again and the distance from the position where the first reference point A was acquired is greater than or equal to the predetermined distance, the control device 100 will record the second reference point B. Let's assume that.

[0065] As shown in Figure 11 (S501-S505), if the steering wheel 35 is operated by a predetermined amount or more within a predetermined time while the first reference point A has been acquired, without acquiring the second reference point B, and the vehicle body 2 is turned, the control device 100 deletes the recorded first reference point A. Subsequently, when the automatic straight-ahead setting member 207 is operated in the first direction W1, the control device 100 may record the position coordinates of that location acquired by the GPS antenna 200 as the first reference point A, thereby preventing the line connecting the Y coordinate of the first reference point A and the Y coordinate of the second reference point B from becoming a straight line.

[0066] This allows for the setting of a first reference point A and a second reference point B at predetermined positions at one end and the other end of the field, for example, the position where the vehicle body 2 begins to turn after completing a straight-line run, and the position where the work device 4 is lowered and the vehicle begins to run straight after the turn. By activating the automatic straight-line system at the position where the work device 4 is lowered and the vehicle is running straight, high-precision work becomes possible without the work position shifting laterally relative to the direction of travel.

[0067] Furthermore, since it prevents the second reference point B from being set in a different position than it should be due to operator error, there is no need to reacquire the first reference point A and the second reference point B in the next work run. This allows for an increase in the number of work runs using automatic straight-line movement, further improving the accuracy of work within the field.

[0068] Furthermore, in the first work row performed after entering the field, it is essential to operate the automatic straight-line setting member 207 to the first direction W1 at a predetermined position to acquire the first reference point A and the second reference point B mentioned above. Therefore, the automatic straight-line function is not used, and the operator operates the handle 35 to make the machine move in a straight line.

[0069] As described above, once the first reference point A and the second reference point B are acquired by operating the automatic straight-line setting member 207, the reference line R connecting the Y coordinates of the first reference point A and the second reference point B becomes a guideline for automatic straight-line driving. The system then determines whether the X coordinate of the vehicle's position during driving matches the X coordinate of the guideline for automatic straight-line driving. If they do not match, the automatic steering device 205 automatically steers the steering wheel 35 in the direction that matches, thereby achieving automatic straight-line driving.

[0070] The automatic straight-line driving described above is initiated by operating the automatic straight-line setting member 207 in the second direction W2, which in this embodiment is directed downwards, with the first reference point A and the second reference point B recorded. When the automatic straight-line setting member 207 is operated in the second direction W2, the control device 100 compares the Y coordinate of the position coordinate acquired by the GPS antenna 200 with the Y coordinate of the reference line R, activates the steering actuator 206 to rotate the steering wheel 35 left and right, and starts control to move the vehicle body 2 to the position where it should drive in a straight line. Note that operating the automatic straight-line setting member 207 in the second direction W2 corresponds to operating the on / off member.

[0071] This automatic steering control terminates when the steering wheel 35 is operated to an angle that turns the vehicle body 2 within a predetermined time, or when the automatic straight-ahead setting member 207 is operated in the second direction W2. The steering angle of the steering wheel 35 is detected by the steering wheel potentiometer 35a. Alternatively, the automatic straight-ahead control may be terminated when the vehicle body 2 reaches a location that coincides with the Y coordinate of the first reference point A or the second reference point B.

[0072] As described above, automatic straight-line control is terminated when the steering wheel 35 is turned or when the vehicle reaches the vicinity of the starting point for turning at the edge of the field. Since the position where the vehicle 2 turns is close to the edge of the field, if the operator is performing tasks other than steering while the vehicle is left to automatic straight-line control, a delay in turning will result in seedlings being planted in an unintended location, and the vehicle 2 will move to the edge of the field, requiring it to reverse to the turning position, leading to a decrease in work efficiency. Figure 12 is a schematic diagram showing the first reference position A, the second reference position B, the reference line R, and the target position and the current position of the vehicle.

[0073] To prevent such problems, as shown in Figure 6, a work detection sensor 209 is provided to detect the on / off switching of the leveling rotor 63 due to the on / off switching (operation) and off / stopping of the leveling clutch. When the work detection sensor 209 detects the on / off switching (operation) of the leveling rotor 63, the control device 100 acquires the target position coordinates (end reference position), which are the position coordinates (X and Y coordinates) of the traveling vehicle body 2. The control device 100, or a memory area associated with the control device 100, can simultaneously store at least two sets of these target position coordinates.

[0074] Furthermore, the acquisition of target position coordinates (end reference position) by the work detection sensor 209 may be configured to be performed based on conditions such as the raising or lowering of the work device 4, the turning on or off of the power transmission to the work device 4, or the steering start or end of the turn of the handle 35, instead of the turning on or off of the leveling rotor 63.

[0075] Then, in the work run following the work run in which the position coordinates were acquired, when the automatic steering device 205 is activated to automatically drive the vehicle body 2 in a straight line, the control device 100 sequentially calculates the distance from the Y coordinate of the current position coordinates acquired by the GPS antenna 200 to the Y coordinate of the target position coordinates acquired in the previous work run (the most recent work run). At this time, the control device 100 may be configured to correct the X coordinate of the target position coordinates to the X coordinate of the current position coordinates.

[0076] When the vehicle body 2 reaches a notification position where the distance from the current position coordinates to the target position coordinates is a predetermined distance, for example, 8 to 12 m, a notification device 208 is activated to inform the operator that the vehicle body 2 is approaching the edge of the field and that it is necessary to operate the automatic straight-line setting member 207 in the second direction W2 to terminate the automatic straight-line control. This notification device may activate a buzzer, a lamp, or display numerical values ​​or characters on the screen.

[0077] Furthermore, to display numerical values ​​or characters on the notification device 208, possible configurations include providing a display panel (not shown) on the vehicle body 2, or transmitting and displaying information on an information terminal (smartphone, tablet, etc.) brought in by the worker.

[0078] Furthermore, in work runs where target position coordinates have not been acquired, the distance between the vehicle 2 and the target position cannot be calculated. Therefore, the operator must visually check the edge of the field and operate the automatic straight-line setting member 207 at a position where automatic straight-line control is deemed unnecessary.

[0079] The distance from the current position coordinate to the target position coordinate may be determined by providing rear wheel rotation sensors 210, 210 that detect the rotation of the left and right drive shafts 42, 42 to the left and right rear wheels 11, 11. The control device 100 calculates the travel distance based on the rotation speed detected by the rear wheel rotation sensors 210, 210 from the position where the leveling rotor 63 is turned on, calculates the distance from this travel distance to the Y coordinate position of the position where the leveling rotor 63 is turned on, and activates the notification device 208 if it is within a predetermined distance.

[0080] However, even if the notification device 208 is activated, the vehicle body 2 cannot be turned to the appropriate position unless the operator notices and terminates the automatic straight-line control. To address this, when the vehicle body 2 travels forward for a predetermined distance (for example, 2 to 5 m) after the notification device 208 is activated without the automatic straight-line setting member 207 being operated in the second direction W2, the control device 100 rotates the trunnion shaft 14a of the continuously variable transmission 14 to decelerate the vehicle body 2.

[0081] Alternatively, if, instead of distance, the vehicle body 2 travels forward for a predetermined time (for example, 2 to 5 seconds) after the notification device 208 is activated without the automatic straight-ahead setting member 207 being operated in the second direction W2, the control device 100 reduces the output of the continuously variable transmission 14 and decelerates the vehicle body 2.

[0082] The deceleration of the vehicle body 2 described above is performed by operating an HST servo motor 211 that rotates the trunnion shaft 14a of the continuously variable transmission 14 via a trunnion arm (not shown), thereby rotating the trunnion shaft 14a toward the deceleration side.

[0083] As a result, the vehicle's speed decreases as it approaches the edge of the field, allowing the operator to recognize that the turning point at the edge of the field is approaching, and enabling the vehicle to turn along an appropriate trajectory. Therefore, the work device 4 is prevented from performing repeated ground work on all four sides of the outer perimeter of the field, the so-called headland, and thus avoids the consumption of excess work materials (seedlings, fertilizers, pesticides, etc.).

[0084] Furthermore, since the position where the leveling rotor 63 is turned on after turning and the leveling work begins can be aligned with the position where the leveling work was completed before turning, it is possible to prevent areas where leveling work is not performed by the leveling rotor 63 and areas where ground work is not performed by the work device 4. As a result, problems such as uneven planting depth of seedlings, differences in fertilizer penetration, and irregular movement in areas where leveling work was not performed are prevented, and the operator does not need to perform manual work in areas where ground work was not performed, thus reducing the operator's workload.

[0085] The automatic deceleration described above is configured to gradually reduce the travel speed over time. A control configuration that slows down gradually prevents a decrease in the accuracy of the ground work performed by the work device 4 and the leveling accuracy of the leveling rotor 63, as well as preventing the operator from being shaken. Alternatively, if the control configuration is configured to perform abrupt deceleration once or multiple times at predetermined intervals after the start of automatic deceleration, the shaking of the vehicle body 2 makes it easier for the operator to notice approaching the edge of the field.

[0086] Furthermore, if the automatic straight-line control is canceled by operating the automatic straight-line setting member 207 within a predetermined time (second predetermined time) during which automatic deceleration control is performed, the control device 100 may be configured to maintain the travel speed at that time. As a result, since the work travel does not stop, it is possible to quickly transition to turning travel at the edge of the field, and a decrease in work efficiency is prevented.

[0087] Alternatively, the control device 100 may be configured to rotate the trunnion shaft 14a in the speed-increasing direction by operating the HST servo motor 211 of the continuously variable transmission 14 to change the speed to a preset travel speed or the travel speed at the time automatic deceleration begins. Since the travel speed is increased automatically, the operator does not need to operate the speed change lever 36 to increase the travel speed, thus improving operability.

[0088] In addition to the operation of the notification device 208, it is expected that the automatic deceleration control of the vehicle body 2 will allow the vehicle body 2 to recognize the turning position near the edge of the field, specifically the edge of the field. However, it is conceivable that the worker may not notice the automatic deceleration of the vehicle speed if they are engrossed in another task or if they faint.

[0089] Therefore, the automatic deceleration control of the vehicle body 2 is performed until the continuously variable transmission 14 reaches a neutral state where neither the forward nor reverse travel speed increases or decreases. At this time, the engine 30 is not stopped. This allows the vehicle body 2 to stop in place, preventing it from moving forward until it contacts the edge of the field, the so-called ridge, thus reducing the risk of damage to the machine and minimizing the distance the machine needs to move in reverse to resume work.

[0090] When the vehicle body 2 automatically stops moving due to approaching the edge of the field, returning the gear shift lever 36, which controls the vehicle body 2's speed and forward / reverse movement, to the neutral position causes the control device 100 to accept speed adjustments from the continuously variable transmission 14. Then, when the gear shift lever 36 is moved forward, the vehicle body 2 resumes moving. Naturally, when the auxiliary gear shift lever 37 is moved to the neutral position and no driving force is transmitted to the drive system, the vehicle will not start moving until the auxiliary gear shift lever 37 is moved to a position where the drive force is transmitted.

[0091] The first reference point A and the second reference point B, and the reference line R connecting the first reference point A and the second reference point B, which serve as the basis for the automatic straight-line control described above, are necessary when performing straight-line work from one end of the field to the other, and when performing straight-line work from the other end of the field to one end.

[0092] However, while the work travel along the four sides of the field, the so-called headlands, is in a straight line, there is one side where the direction of travel differs from the straight-line work travel described above, and automatic straight-line control cannot be performed on that side even if the aforementioned reference line R is used.

[0093] Furthermore, when moving the machine to the back of a transport truck or storing it in a barn outside the field, if the automatic straight-line setting member 207 is mistakenly operated to the second direction W2, thereby activating the automatic steering device 205, the X-coordinate of the reference line R and the X-coordinate of the machine will not match when the machine is moved. This may cause the machine to deviate from its straight-line driving position, and the automatic steering device 205 may automatically steer the steering wheel 35. As a result, the machine's path will deviate from its intended path, leading to extra work during loading and storage.

[0094] One way to prevent this is to erase the first reference point A, the second reference point B, and the reference line R before the machine leaves the field. As shown in Figures 6 and 13 (S601-S606), when the vehicle 2 has traveled along three sides of the field, including at least one side perpendicular to the direction of travel for straight-line work, the control device 100 determines that headland work has been performed and deletes the first reference point A, the second reference point B, and the reference line R.

[0095] The direction of travel of the vehicle 2 on the headland is determined by the continuous change in the X-axis or Y-axis coordinates of the vehicle 2's position coordinates acquired by the GPS antenna 200. This allows the first reference point A, the second reference point B, and the reference line R to be deleted while the machine is traveling within the field. As a result, even if the automatic straight-line setting member 207 is operated after leaving the field, automatic straight-line travel will not occur, preventing the machine from traveling in a direction deviating from the intended direction of travel, thus preventing a decrease in work efficiency and improving work safety.

[0096] Furthermore, when the machine is moved to a different field, the absence of records for the first reference point A, the second reference point B, and the reference line R prevents automatic straight-line control from being performed based on a reference line R that is unsuitable for the field being worked on, thus improving the accuracy of automatic straight-line control.

[0097] Furthermore, when moving outside the field, the auxiliary transmission lever 37 is operated to the driving position in order to move it to a transport truck or barn in a short time. An auxiliary transmission position detection switch 37a is provided to detect when the auxiliary transmission lever 37 is operated to the driving position, and when the auxiliary transmission position detection switch 37a detects that the auxiliary transmission lever 37 has been operated to the driving position, the first reference point A, the second reference point B, and the reference line R may be deleted.

[0098] The first reference point A, the second reference point B, and the reference line R will be removed from the driving area that will not be used within the field. By performing the operation based on the operation of the auxiliary transmission lever 37 to the gear, the first reference point A, the second reference point B, and the reference line R can be reliably deleted when the vehicle is traveling on a headland, thus preventing automatic straight-line control from being performed when the vehicle body 2 is moving or when working in another field, and thus preventing a decrease in work accuracy.

[0099] Furthermore, since it is possible to prevent the accidental deletion of the first reference point A, the second reference point B, and the reference line R in the field due to incorrect operation of the sub-transmission lever 37, it is possible to prevent the automatic straight-line function from becoming unusable in work runs where the first reference point A and the second reference point B are reacquired, thereby improving work accuracy. Alternatively, the control device 100 may be configured to delete the first reference point A, the second reference point B, and the reference line R when the vehicle body 2 is tilted forward or backward and left or right by using the IMU 203 and the tilt sensor 212 which detects the tilt of the vehicle body 2 in the front-rear and left-right directions, and when the vehicle body 2 is tilted forward by a predetermined angle or more (for example, 10 to 15 degrees).

[0100] When exiting a field, the vehicle 2 passing through the field entrance / exit assumes a forward-leaning tilt at an angle that is almost impossible during operation. Therefore, when this tilt angle is detected, it can be determined that the vehicle is exiting the field. As a result, if the first reference point A, the second reference point B, and the reference line R have not been deleted while traveling along the headland, they can be reliably deleted. This prevents automatic straight-line control from being performed when the vehicle 2 moves or when working in another field, thus preventing a decrease in work accuracy.

[0101] Furthermore, depending on the field and the nature of the work, it may be necessary to reverse the vehicle body 2 to exit the entrance. Therefore, the control configuration may be such that the first reference point A, the second reference point B, and the reference line R are deleted not only based on the forward upward tilt angle but also on the rear upward tilt angle.

[0102] Furthermore, when moving to another field after completing work in one field, if the reference line R (i.e., driving reference data) used in the previous field remains when starting work in the new field, for example, if the automatic steering function is accidentally turned on, the machine will travel in a direction unsuitable for the field being worked in, resulting in reduced work efficiency. Also, since the direction the machine travels may be unintended by the operator, the operator will be forced to perform extra operations.

[0103] To prevent this, the control device 100 performs control to automatically erase the reference line R when predetermined conditions are met. The automatic erasure control of the reference line R, which will be described below, can detect the headland more accurately than the automatic erasure control described above. Next, the automatic erasure of the reference line R will be explained with reference to Figures 14 to 17. Figures 14 to 17 are flowcharts of the control for automatically erasing the reference line (driving reference data). Note that the following control by the control device 100 is the control when the machine is performing ground work in the field.

[0104] As shown in Figure 14, the control device 100 detects that the machine (vehicle body 2) is moving in an automatic straight line (step S701). If the machine is moving in an automatic straight line (step S701: Yes), the control device 100 detects any other driving state of the machine using the detection means (step S702). If the control device 100 detects any other driving state of the machine using the detection means (step S702: Yes), it performs control to erase the acquired reference line R (step S703).

[0105] In step S701, if the control device 100 does not detect the aircraft moving in an automatic straight line (step S701: No), this process is repeated until automatic straight line movement is detected. Also, in step S702, if the control device 100 does not detect any movement state other than straight line movement (step S702: No), this process is repeated until a movement state other than straight line movement is detected.

[0106] According to this configuration, the detection means detects the aircraft's driving state, which is set to anything other than straight-line driving. When detected, the reference line R is erased, preventing the use of the previous field's reference line R in operations in other fields. This prevents automatic steering from operating in directions unsuitable for the field being worked on or in directions unintended by the operator. This improves work efficiency and reduces labor by preventing unnecessary operations.

[0107] Furthermore, the control device 100 detects any driving state other than straight-line driving of the aircraft by, for example, detecting the deviation angle of the aircraft from the reference line R. In this case, the control device 100 determines that the aircraft is in the aforementioned driving state when the detection means detects a deviation angle of 45 degrees or more from the reference line R.

[0108] In this case, as shown in Figure 15, if the machine is automatically moving in a straight line (step S801: Yes), the control device 100 detects a deviation angle greater than or equal to a predetermined value with respect to the reference line R using the detection means (step S802). When the control device 100 detects a deviation angle greater than or equal to a predetermined value with respect to the reference line R using the detection means (step S802: Yes), it performs control to erase the acquired reference line R (step S803).

[0109] In step S801, if the control device 100 does not detect automatic straight-line movement of the machine (step S801: No), this process is repeated until automatic straight-line movement is detected. Also, in step S802, if the control device 100 does not detect a deviation angle greater than a predetermined value (step S802: No), this process is repeated until a driving state other than straight-line movement is detected.

[0110] Furthermore, the control device 100 may also erase the first reference position A and the second reference position B, in addition to the reference line R acquired in the field.

[0111] Furthermore, as a detection means for detecting deviation angles of the aircraft from the reference line R that exceed a predetermined value, in addition to a means for determining the travel path from position information acquired by the GPS antenna 200, a compass sensor 204, a tilt sensor 212 (see Figure 6), etc., can be used.

[0112] With this configuration, by detecting a deviation angle of the machine from the reference line R that exceeds a predetermined value, it is possible to recognize, for example, the final stage of planting work in a field, which is planting along the outer edge of the field, also known as headland planting. By recognizing headland planting, it is clear that straight-line movement of the machine in the field during work is no longer necessary, and by erasing the reference line R, it is possible to prevent automatic steering from being directed in a direction unsuitable for the field being worked on or in a direction unintended by the operator while moving to another field or working in another field, thereby improving work efficiency. In addition, since there is no need to manually erase the reference line R, the effort involved in erasing the reference line R is saved. This improves operability.

[0113] In addition, when the machine is automatically moving in a straight line, the working state of the work device 4 may be detected (recognized) and the reference line R may be erased, in addition to the machine's own driving state. As shown in Figure 16, the control device 100 detects when the machine is automatically moving in a straight line (step S901). When the machine is automatically moving in a straight line (step S901: Yes), the control device 100 detects a deviation angle greater than a predetermined value relative to the reference line R using the detection means (step S902: Yes), detects the working state of the work device set as working using the detection means (step S903), and when the working state of the work device 4 set as working using the detection means (step S903: Yes), performs control to erase the acquired reference line R (step S904).

[0114] In step S901, if the control device 100 does not detect automatic straight-line movement of the aircraft (step S901: No), this process is repeated until automatic straight-line movement is detected. Also, in step S902, the control device 100 detects a deviation angle greater than a predetermined value. If no detection occurs (Step S902: No), this process is repeated until a deviation angle greater than or equal to a predetermined value is detected. Also, in the process of Step S903, if the control device 100 does not detect the working state of the work device 4 (Step S903: No), this process is repeated until the working state is detected.

[0115] With this configuration, by detecting the working state of the work device 4 (headland planting), it is possible to recognize headland planting, which is the final stage of planting work in the field, where the outer edges of the field are planted. By recognizing headland planting, it is understood that straight-line travel of the vehicle 2 in the field during work is no longer necessary, and by erasing the reference line R, it is possible to prevent automatic steering from being activated in a direction unsuitable for the field being worked on or in a direction unintended by the operator while moving to another field or working in another field, thereby improving work efficiency. In addition, since it is not necessary to manually erase the reference line R, the effort required to erase the reference line R is saved. This improves operability.

[0116] Furthermore, the control device 100 may detect (recognize) the working state of the work device 4, and then erase the reference line R if it detects that the machine has traveled for a predetermined value or more. As shown in Figure 17, the control device 100 detects whether or not the machine is automatically traveling in a straight line (step S1001). If the machine is automatically traveling in a straight line (step S1001: Yes), the control device 100 detects a deviation angle of a predetermined value or more relative to the reference line R using the detection means (step S1002: Yes), and then detects the working state of the work device set as working using the detection means (step S1003). If the control device 100 detects the working state of the work device 4 set as working using the detection means (step S1003: Yes), it detects that the machine has traveled for a predetermined value (for example, 5 m) or more continuously (step S1004). When the control device 100 detects that the aircraft is continuously traveling at a predetermined value or more (step S1004: Yes), it performs control to erase the acquired reference line R (step S1005).

[0117] Furthermore, in step S1001, if the control device 100 does not detect automatic straight-line movement of the machine (step S1001: No), this process is repeated until automatic straight-line movement is detected. Also, in step S1002, if the control device 100 does not detect a deviation angle greater than a predetermined value (step S1002: No), this process is repeated until a deviation angle greater than a predetermined value is detected. Also, in step S1003, if the control device 100 does not detect the working state of the work device 4 (step S1003: No), this process is repeated until the working state is detected. Also, in step S1004, if the control device 100 does not detect movement of the machine greater than a predetermined value (step S1004: No), this process is repeated until movement greater than a predetermined value is detected.

[0118] Furthermore, a rear wheel rotation sensor 210 (see Figure 6) or the like can be used as a detection means to detect when the aircraft is traveling at a predetermined value or higher.

[0119] Furthermore, the detection means detects the working state of the work device 4 by switching the work detection sensor 209 (see Figure 6) on and off. In this case, the detection means for detecting the working state of the work device 4 is preferably, for example, a planting clutch on / off sensor that detects the on / off state of the planting clutch. When the planting clutch on / off sensor is turned on, it can be recognized that the headland planting work has started as described above.

[0120] Furthermore, if the machine is in automatic straight-line movement mode, the control device 100 may, after detecting any movement state other than straight-line movement of the machine using the detection means, erase the acquired reference line R when it detects a work state set as "work in progress" for the work device 4 using the detection means.

[0121] With this configuration, the working state of the work device 4 is detected, and the machine travels at a predetermined value or more. By detecting this, the final stage of planting in the field, headland planting (planting along the outer edge of the field), can be recognized more reliably. Recognizing headland planting indicates that straight-line movement of the machine in the field during operation is no longer necessary. Therefore, by erasing the reference line R, it is possible to prevent automatic steering from diverting in directions unsuitable for the field or unintended by the operator while moving to or working in other fields, thereby improving work efficiency. Furthermore, since there is no need to manually erase the reference line R, the effort required to erase the reference line R is saved. This improves operability.

[0122] Furthermore, the control device 100 erases the travel distance set to detect travel exceeding a predetermined value when it detects the deviation angle of the machine from the reference line R, when it detects the working state of the work device 4, or when it detects both of the above. This prevents malfunctions during work after the reference line R has been erased.

[0123] Furthermore, when the reference line R is erased, the control device 100 may control the notification device 208 (see Figure 6) to emit a notification sound for a predetermined time (approximately 2 seconds). This allows the operator to recognize that the reference line R has been erased. Alternatively, when the reference line R is erased, the control device 100 may control the device to display characters or other information on the monitor. This also allows the operator to recognize that the reference line R has been erased.

[0124] Furthermore, although the work device 4 is configured to allow planting seedlings or sowing seeds in multiple rows simultaneously, it may be configured to have multiple partial row clutches (also called ridge clutches) that turn the device on and off for each work row, and when the drive of some of the work rows of the work device 4 is stopped and work is performed only on the remaining partial row, the detection means may be configured to detect that the operation has been turned off by some of the partial row clutches, and based on this, the reference line R may be erased. In such a configuration, the detection means may be configured to detect the turned-off state of the partial row clutches in addition to the detection function of the detection means described above.

[0125] Furthermore, with reference to Figure 18, another example of a work vehicle (seedling transplanter) will be described. Figure 18 is a left side view showing another example of a work vehicle (seedling transplanter). As shown in Figure 18, the seedling transplanter according to the other example is equipped with a rear camera 400 and a monitor (tablet monitor) 401 in place of, or in addition to, a rearview mirror. The rear camera 400 is mounted on the rear frame 201b of the antenna frame 201 to which the GPS antenna 200 is attached. The monitor 401 is mounted on the front frame 201a of the antenna frame 201.

[0126] With this configuration, in addition to checking the area behind the machine, it is possible to check the planting marks behind the machine in the field and the straight-line movement status of the machine. Furthermore, by processing the images captured by the rear camera 400, it is possible to recognize continuous missing plants behind the machine. For example, when continuous missing plants occur, the notification device 208 (see Figure 6) may emit a notification sound. This allows the operator to recognize that continuous missing plants have occurred.

[0127] Furthermore, in another example of a seedling transplanter, the working device (planting device) 4 is equipped with a seedling reduction switch 403 that detects a decrease in the loaded seedlings. When the machine is automatically moving in a straight line, if the seedling reduction switch 403 detects a decrease in seedlings during seedling planting, for example, the control device 100 (see Figure 6) controls the machine to automatically decelerate using the HST (electric HST) 14. With this configuration, the machine can safely replenish seedlings at a safe speed (for example, a speed of 0.3 m / s or less).

[0128] Furthermore, in other examples of seedling transplanters, the GPS antenna 200 detects the rolling of the machine, for example, using a gyro sensor. When the machine is automatically moving in a straight line, the field during seedling planting work... If the aircraft's rolling exceeds a predetermined value due to uneven surfaces, for example, the control device 100 controls the aircraft to automatically decelerate to a predetermined speed (for example, 0.5 m / s) using the HST (electric HST) 14. With this configuration, the straight-line stability of the aircraft can be improved.

[0129] Furthermore, as shown in Figures 3, 4, 5A, and 5B, even when the vehicle body 2 is automatically driven in a straight line by the automatic steering device 205, the operator needs to stop the vehicle when replenishing the work materials consumed by the work equipment 4, etc., or when any problems occur with the machine or the field. Possible methods for stopping the vehicle include operating the gear shift lever 36 to the neutral position to put the continuously variable transmission 14 into neutral, pressing the brake pedal to apply the brakes, and pressing the side clutch pedal 43a to disengage the side clutch mechanism 43.

[0130] Even when the vehicle body 2 is stopped by any of the methods described above, the control device 100 is configured not to stop the automatic steering system 205. This allows the vehicle to immediately resume automatic straight-line driving when the vehicle is released from its stop by moving the gear shift lever 36 forward or releasing the brake pedal or side clutch pedal 43a, thereby preventing a decrease in work efficiency.

[0131] However, if the steering wheel 35 is manually steered while stopped, or if the automatic steering device 205 is activated and the steering wheel 35 is automatically steered, the direction of travel when automatic straight-line driving resumes may deviate from the direction of travel when stopped, and the direction of travel of the vehicle body 2 may no longer be in a straight line. In particular, when the vehicle body 2 is stopped, the position coordinates acquired by the GPS antenna 200 are easily affected by the Earth's rotation and the revolution of GPS satellites, and may acquire position coordinates that differ from the actual location of the vehicle body 2, making it easy to mistakenly believe that it is located far from the reference line R.

[0132] To prevent this, a lever potentiometer 36a is provided to detect the operating position of the gear shift lever 36, and a pedal depression detection switch 213 is provided to detect the depression operation of the brake pedal or clutch pedal. If an operation to stop driving is detected during automatic straight-line driving, the control device 100 is configured not to reflect the steering operation of the steering wheel 35, or to disable the steering wheel 35.

[0133] The configuration that does not reflect the steering operation of the steering wheel 35 means that even if the X coordinate of the position coordinate of the stationary vehicle body 2 deviates from the X coordinate of the reference line R by a predetermined value or more, the steering actuator 206 will not be activated. Furthermore, the configuration that prevents the steering wheel 35 from moving means that the operating torque of the steering actuator 206 is increased, resulting in a steering wheel lock state.

[0134] With the above configuration, deviations in the direction of travel after resuming movement can be prevented, allowing work to be performed in a straight line and improving work accuracy.

[0135] The steering wheel 35 is automatically steered by the steering actuator 206 during automatic straight-line driving. However, if the field conditions along the path are unsuitable for automatic straight-line driving (rough, deep field, etc.) or if there are obstacles, manual evasive action is required. The steering operation of the steering wheel 35 by the steering actuator 206 is performed by the following configuration: An input gear 352 is provided at the lower part of the steering shaft 351, which rotates in conjunction with the steering operation of the steering wheel 35, and an output gear 353 is provided on the steering actuator 206.

[0136] The input gear 352 and output gear 353 are housed in a steering gear case 354 located below the steering wheel 35 and steering actuator 206. A relay gear 355 is provided between the input gear 352 and output gear 353 to transmit the driving force by changing the transmission ratio.

[0137] The gear ratios of the input gear 352, output gear 353, and intermediate gear 355 are as follows: To prevent interference with manual operation, the gear ratio is set such that the torque from manual operation is strong even when the steering actuator 206 is operating. This prevents an increase in the force required to manually operate the steering wheel 35 even during automatic straight-line driving, improving operability and ensuring safety during work by reliably avoiding fields and obstacles that may affect driving conditions.

[0138] Furthermore, the seedling transplanter 1 has a GNSS unit with a built-in GPS antenna 200 (see Figure 1) mounted on the vehicle body 2. The GNSS unit can acquire positional information on Earth at predetermined intervals by acquiring GNSS coordinates at predetermined time intervals using the GPS antenna 200. In addition to the GPS antenna 200, the GNSS unit also incorporates an inertial navigation system using, for example, a gyro sensor and an acceleration sensor, and a control board to control these.

[0139] Figures 19A and 19B are explanatory diagrams of the antenna frame 201. Figure 19A shows the front view of the seedling transplanter 1, and Figure 19B shows the left side view of the seedling transplanter 1. Figure 20A is a front view of the antenna frame 201. Figure 20B is a perspective view of the antenna frame 201. Figure 20C is a perspective view of the antenna frame 201 from below.

[0140] As shown in Figures 19A and 19B, the GNSS unit, which incorporates the GPS antenna 200, is mounted on top of an antenna frame 201, whose base end is connected to the front end of the vehicle body 2, so that it is positioned directly above the axle 10b of the front wheel 10. In normal conditions, the height of the antenna frame 201 is set to a height that does not interfere with the head of an average man standing on the floor step 33.

[0141] As shown in Figures 20A to 20C, the antenna frame 201 consists of the lower parts of the left and right front frames 201a (front lower frames 201aa), the upper parts of the front frames 201a (front upper frames 201ab), the upper L-shaped frame 201c, and the rear frame 201b.

[0142] A pair of brackets 201e, 201e are provided at the base ends of the left and right front lower frames 201aa, 201aa, and the front lower frames 201aa are attached to the bumper 500 of the vehicle body 2 via these brackets 201e, 201e.

[0143] The front upper frame 201ab is a frame that is roughly U-shaped in plan view, having left and right vertical frames 2011 and 2012 whose base ends are rotatably connected to the left and right front lower frames 201aa and 201aa via rotating connectors 201f and 201f, respectively.

[0144] The left and right rotating connectors 201f, 201f are connected and fixed to each other with knob bolts 201g, as shown in Figures 20A to 20C, and a reinforcing frame 201h (see Figure 19B) is placed between the rotating connectors 201f, 201f and the front cover 40 (see Figure 19B). In this way, a simple configuration prevents rattling of the front lower frames 201aa, 201aa and the left and right vertical frames 2011, 2012.

[0145] As shown in Figure 19A, the left and right front lower frames 201aa, 201aa are erected at an angle so that their upper ends do not come into contact with the front cover 40. As a result, a space is formed between the control unit 41 and the spare seedling trays 501, 501 located on the left and right sides of the machine, allowing, for example, an operator M to move between the front of the machine and the floor step 33.

[0146] The GNSS unit (GPS antenna 200) is mounted on an aluminum block 201i that spans the top of the left and right vertical frames 2011 and 2012. By interposing the aluminum block 201i between the GNSS unit and the steel pipe antenna frame 201 in this way, the reception sensitivity is improved compared to directly attaching it to the GPS antenna 200.

[0147] The upper L-shaped frame 201c has its tip connected to the rear end of the front upper frame 201ab, and wiring such as harnesses extending from the GNSS unit is routed along the upper L-shaped frame 201c.

[0148] The rear frame 201b is connected to the rear step at its lower end behind the cockpit 41. Behind the cockpit 41, the storage hoppers 5b of the fertilizer applicator 5 are located on the left and right sides, but the rear frame 201c is positioned between these left and right storage hoppers 5b, so that it does not interfere when opening or closing the storage hoppers 5b.

[0149] Thus, the antenna frame 201 for mounting the GNSS unit is connected at the front to the bumper 500 and front cover 40, and at the rear to the rear step, providing a structurally stable three-point support, allowing it to be attached to the vehicle body 2 in an extremely stable state.

[0150] The upper end of the rear frame 201b is provided with a connecting portion 201j that detachably connects to the other end of the upper L-shaped frame 201c, thereby detachably connecting the upper L-shaped frame 201c. The connecting portion 201j may be composed of, for example, pin insertion holes (not shown) formed at the connecting ends of the upper L-shaped frame 201c and the rear frame 201b, and fastening pins (not shown) that can be inserted into and removed from these pin insertion holes. In this way, the upper L-shaped frame 201c and the rear frame 201b can be detachably connected with a simple configuration.

[0151] In this way, the upper L-shaped frame 201c is detached from the rear frame 201b, and as shown in Figure 20B, the height of the antenna frame 201 can be reduced by a simple operation in which the front upper frame 201ab and the upper L-shaped frame 201c are rotated downward and rearward relative to the front lower frames 201aa, 201aa using the rotating connectors 201f, 201f, as shown in Figure 19B.

[0152] Therefore, for example, when transporting the seedling transplanter 1 or storing it in a barn, if the thickness of the GNSS unit becomes a height-related obstacle, the overall vehicle height can be reduced without removing the GNSS unit.

[0153] Furthermore, the antenna frame 201 (front upper frame 201ab and upper L-shaped frame 201c) is configured to rotate using a simple rotating connector 201f, which helps to suppress cost increases and minimize rattle of the entire antenna frame 201. Moreover, it offers the convenience of being able to perform the rotation operation in a single action.

[0154] Furthermore, as shown in Figure 19B, a frame support 201k, formed in a roughly Y shape, is provided near the upper end of the rear frame 201b. Therefore, when folding the antenna frame 201 to reduce its height, the upper L-shaped frame 201c can be stably held in place by locking it to the frame support 201k.

[0155] Furthermore, as shown in Figures 20A and 20B, the upper parts of the front frames 201a, 201a of the antenna frame 201, i.e., the front upper frames 201aa, 201aa, The upper L-shaped frame 201c, which is at the end, is formed so that the spacing narrows when viewed from the front. This increases the strength of the antenna frame 201.

[0156] Furthermore, the seedling transplanter 1 is equipped with a monitor 300 in the control unit to inform the operator of the automatic straight-line movement state described above. Figure 21 is an explanatory diagram of the monitor 300. The monitor 300 is equipped with a straight-line assist lamp 301 that lights up when the machine is moving in an automatic straight line, as well as an A-point lamp 302 and a B-point lamp 303. The monitor 300 informs the operator of various information regarding the automatic straight-line movement state through the display patterns of these three lamps 301, 302, and 303. For this reason, the monitor 300 can be configured simply and inexpensively.

[0157] On the monitor 300, for example, if the machine's orientation is shifted to the right, the A-point lamp 302 flashes. Flashing the A-point lamp 302 prompts the operator to turn the steering wheel 35 (see Figure 1) to the left. Also, on the monitor 300, for example, if the machine's orientation is shifted to the left, the B-point lamp 303 flashes. Flashing the B-point lamp 303 prompts the operator to turn the steering wheel 35 to the right. In this way, by displaying the A-point lamp 302 and the B-point lamp 303 in the same manner as turn indicators, the direction in which to turn the steering wheel 35 can be clearly communicated to the operator.

[0158] Furthermore, on the monitor 300, both the A-point lamp 302 and the B-point lamp 303 illuminate when the machine is in a state where automatic straight-line travel is possible. Also, when turning on automatic straight-line travel, for example, if the leveling rotor 63 is turned off, automatic straight-line travel cannot be turned on. In this case, for example, the notification device 208 (see Figure 6) emits a notification sound (warning sound), and the central straight-line assist lamp 301 flashes, for example, twice. This display method informs the operator that automatic straight-line travel is not possible. For this reason, the monitor 300 can be configured simply and inexpensively.

[0159] Furthermore, on the monitor 300, when the machine is in a state where it can automatically travel in a straight line, both the A-point lamp 302 and the B-point lamp 303 light up. In addition, when attempting to activate automatic straight-line travel, for example, if there is a GPS reception failure by the GPS antenna 200, automatic straight-line travel cannot be activated. In this case, for example, the notification device 208 (see Figure 6) emits a notification sound (warning sound), and the central straight-line assist lamp 301 flashes, for example, three times. This display method informs the operator that automatic straight-line travel is not possible. This allows the monitor 300 to be configured simply and inexpensively. Also, by changing the number of flashes of the straight-line assist lamp 301 from that of other warnings, the content of the warning can be communicated to the operator through the display method.

[0160] Furthermore, the monitor 300 is equipped with a GPS lamp 304. The GPS lamp 304 has three indicator lamps, and the number of indicator lamps changes according to the GPS reception status. The monitor 300 informs the operator of the GPS reception status through this display. This prevents automatic straight-line driving in the event of poor GPS reception. The lamps 301, 302, 303, 304 and the notification device 208 described above are controlled by the control device 100 (see Figure 6).

[0161] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of symbols]

[0162] 1. Work vehicle (seedling transplanter) 2. Running vehicle 35. Steering wheel (steering component) 100 Control device 200 GPS antenna (location information acquisition device) 205 Automatic steering system (automatic straight-line driving system) A 1st reference position B 2nd reference position

Claims

1. A steering member for steering the moving vehicle body, A position information acquisition device that acquires the position coordinates of the vehicle body, In a work vehicle equipped with an automatic driving device that operates the steering member to automatically drive the vehicle body, and a control device that controls each part, A first reference point registered at one point in the field and a second reference point registered at another point in the field can be registered. The line connecting the first reference position and the second reference position is the driving reference data that serves as the basis for driving. An operating unit is provided for turning the automatic driving on and off. The aforementioned operating part is a lever member, When the aforementioned driving reference data is registered and the automatic driving is set to "on", operating the lever member in the first direction will turn the automatic driving off. A work vehicle characterized in that, when registering the second reference position, if the distance from the position where the first reference position was obtained is less than a predetermined distance, the second reference position cannot be registered.

2. The work vehicle according to claim 1, characterized in that the first reference position is registered when the lever member is operated in the second direction.

3. The vehicle is equipped with a work device that is mounted on the vehicle body and used for performing work in the field. The work vehicle according to claim 1 or 2, characterized in that when the location information acquisition device recognizes that it is headland work, which is the final stage of work in the field, it deletes the registered first reference position and second reference position.

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