Work vehicles

Abstract

To improve work efficiency while ensuring safety in response to abnormalities in work vehicles. [Solution] The invention is characterized by comprising: a vehicle body having a running device that moves when power is transmitted from an engine; a work machine supported by the vehicle body that performs work on a field; a position acquisition means for acquiring the current position of the vehicle body; a switching means for switching between an automatic driving mode in which the vehicle body is automatically driven in the field based on the current position information acquired by the position acquisition means, and a manual driving mode in which the vehicle body is driven according to the operator's driving operations; an abnormality detection means for detecting abnormalities related to the work vehicle; and a driving control means for stopping the vehicle body when an abnormality is detected by the abnormality detection means, wherein if an abnormality is detected by the abnormality detection means and the vehicle body is stopped, the control unit switches to the manual driving mode if the abnormality detected by the abnormality detection means is a predetermined severe abnormality.

Description

Technical Field

[0001] The present invention relates to a work vehicle, and more particularly to a work vehicle having an automatic driving mode for performing automatic driving based on the current position of the work vehicle.

Background Art

[0002] In work vehicles such as rice transplanters and seedling transplanters, based on the position information obtained by the Global Navigation Satellite System (GNSS), the position (target phase) where the seedlings are to be planted is calculated, and the planting unit (200) is controlled from the actual phase and the target phase of the planting unit (200). Such a technique is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional technology, communication with GNSS artificial satellites may be affected by various factors such as the positional relationship between the artificial satellite and surrounding buildings or bridges, and signal reflection from surrounding buildings, resulting in inaccurate acquisition of position information (so-called "lost"). In addition, errors in GNSS signal processing may also occur. In the technology described in Patent Document 1, if a loss or error occurs during the planting operation, the vehicle may deviate from the automatic driving route, the seedling planting position may not be accurately calculated, the planting positions (planting intervals) may become uneven, or the planting operation itself may become impossible.

[0005] Therefore, when the GNSS signal is lost, in the conventional technology, for safety reasons, the vehicle is stopped, the automatic driving mode is released, and a process of forcibly switching to the manual driving mode is performed.

[0006] Furthermore, if any malfunction occurred in the drive system, transmission, or work equipment while the vehicle was operating automatically, the vehicle would stop for safety reasons, the automatic driving mode would be deactivated, and the system would be forcibly switched to manual driving mode.

[0007] However, when the vehicle made an emergency stop and switched to manual driving mode, it would no longer accept instructions from external terminals or remote controllers for safety checks, requiring the operator to go directly to the vehicle's location and perform the operation to restart it. Therefore, for example, if the vehicle made an emergency stop in the middle of a field, the operator had to go to the site (where the vehicle was located).

[0008] In the case of severe malfunctions, such as a problem with the running gear, which affect not only automatic but also manual driving, it is important for safety reasons that an operator go to the vehicle to check it. On the other hand, even in the case of temporary, minor malfunctions such as the loss of GNSS signals, conventional technology had the problem of poor workability and efficiency because an operator had to go to the vehicle's location to restart it in order to resume automatic driving.

[0009] The technical objective of this invention is to improve work efficiency while ensuring safety in response to abnormalities in work vehicles. [Means for solving the problem]

[0010] The above-mentioned problems of the present invention are solved by the following means.

[0011] The invention described in claim 1 comprises an engine (12) and a vehicle body (1) having a running gear (6,7) which is driven by power transmitted from the engine (12), A work implement (3) is supported by the aforementioned traveling vehicle body (1) and performs work on the field, The system includes: a position acquisition means (301) for acquiring the current position of the vehicle body (1); a switching means (305) for switching between an automatic driving mode, which automatically drives the vehicle body (1) in the field based on the current position information acquired by the position acquisition means (301), and a manual driving mode, which drives the vehicle body (1) according to the operator's driving operations; an abnormality detection means (303) for detecting abnormalities related to the work vehicle; and a driving control means (304) for stopping the vehicle body (1) when an abnormality is detected by the abnormality detection means (303). The work vehicle is characterized by comprising: a control unit (300) that switches to the manual driving mode when an abnormality is detected by the abnormality detection means (303) and the driving vehicle body (1) is stopped, and the abnormality detected by the abnormality detection means (303) is a predetermined severe abnormality.

[0012] The invention described in claim 2 is a work vehicle according to claim 1, characterized in that if the abnormality detected by the abnormality detection means (303) is a predetermined minor abnormality, the automatic driving mode is maintained.

[0013] The invention described in claim 3 is a work vehicle according to claim 1 or 2, characterized in that when an abnormality is detected in the steering control member (16) that controls the direction of travel of the vehicle body (1) in the automatic driving mode, or in the driving device (6, 7), the abnormality detection means (303) determines that the abnormality is a severe abnormality.

[0014] The invention described in claim 4 is a work vehicle according to claim 3, characterized in that an abnormality in the steering control member (16) is determined based on the relationship between the detection result based on the amount of operation of the steering control member (16) and the detection result based on the direction of travel of the vehicle body (1).

[0015] The invention described in claim 5 is a work vehicle according to any one of claims 1 to 4, characterized in that if the abnormality detection means (303) determines that a severe abnormality has occurred, the vehicle cannot return to the automatic driving mode without a predetermined operation by the operator.

Advantages of the Invention

[0016] According to the invention described in claim 1, by stopping the traveling vehicle body when an abnormality is detected and switching to the manual driving mode in the case of a severe abnormality, it is possible to prevent the continuation of inappropriate automatic driving while ensuring safety. [[ID=,8]]

[0017] According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, by maintaining the automatic driving mode in the case of a slight abnormality, it is possible to suppress a decrease in work efficiency without requiring a manual return uniformly as in the prior art.

[0018] According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, by determining an abnormality of the steering control member or the traveling device as a severe abnormality, it is possible to reliably detect an abnormality important for safety and perform an appropriate mode switch.

[0019] According to the invention described in claim 4, in addition to the effect of the invention described in claim 3, by discriminating an abnormality based on the relationship between the operation amount of the steering control member and the detection result based on the traveling direction of the traveling vehicle body, it is possible to detect an abnormality in the steering system with high accuracy.

[0020] According to the invention described in claim 5, in addition to the effect of the invention described in any one of claims 1 to 4, when a severe abnormality occurs, by making it impossible to return to the automatic driving mode unless a predetermined operation is performed by an operator, it is possible to surely perform a safety check and improve safety.

Brief Description of the Drawings

[0021] [Figure 1] The left side view of the seedling transplanter according to an embodiment of the present invention is shown. [Figure 2] It is a plan view of the seedling transplanter according to the embodiment. [Figure 3] It is an explanatory view of a trunnion arm and a trunnion motor portion connected to the hydrostatic continuously variable transmission according to the embodiment. [Figure 4] It is a plan view of the clutch portion of the embodiment. FIG. 4(A) is an explanatory view of the state where the clutch is engaged, and FIG. 4(B) is an explanatory view of the state where the clutch is disengaged. [Figure 5] It is a functional block diagram of the control unit of the embodiment.

Mode for Carrying Out the Invention

[0022] The embodiments of this invention will be described below.

[0023] An example of the working vehicle of this invention, a four-row riding type rice transplanter which is an embodiment of a seedling transplanter, will be described in detail based on the drawings.

[0024] As shown in the side view of FIG. 1 and the plan view of FIG. 2, a riding type rice transplanter (working vehicle) has a seedling planting device 3, which is a kind of working machine, attached to a traveling vehicle body 1 by a lifting link device 2. A fertilizer applicator 4 is provided at the rear part of the traveling vehicle body 1. The traveling vehicle body 1 is a four-wheel drive vehicle having a pair of left and right front wheels 6, 6 and rear wheels 7, 7 which are an example of a traveling device.

[0025] In this specification, the left and right sides are respectively referred to as the left side and the right side toward the forward direction of the rice transplanter, the forward direction is referred to as the front side, and the backward direction is referred to as the rear side.

[0026] As shown in FIG. 1, a transmission case 11 and an engine 12 are arranged on main frames 10a, 10b. A hydraulic pump 13 is assembled integrally with the transmission case 11 on the rear side surface of the transmission case 11, and a steering post 14 projects upward in front of the transmission case 11.

[0027] And a steering handle (steering control member) 16 is provided at the upper end of the steering post​

[0028] In front of the cockpit 20, a control panel (not shown) is provided on the steering post 14.

[0029] A clutch lever 18 is provided on the right side of the cockpit 20. The front wheels 6,6 are pivotally supported by front wheel support cases 22,22 which are rotatably mounted on the sides of the transmission case 11. The rear wheels 7,7 are pivotally supported via rear wheel support bodies 30 by rear wheel transmission cases 24,24 attached to the left and right ends of the left and right frames 37. The left and right frames 37 are supported at the rear ends of the main frames 10a,10b.

[0030] As shown in Figures 1 and 2, which illustrate a portion of the power transmission mechanism to the rear wheels 7, the rotational power of the engine 12 is transmitted to a transmission (not shown) in the transmission case 11. Any conventionally known transmission can be used, but for agricultural work vehicles, a hydrostatic continuously variable transmission (HST) is preferred.

[0031] The rear ends of the rear output shafts 11a and 11b protrude behind the transmission case 11, and the left and right rear wheel transmission shafts 35 and 35, which transmit power to the rear wheel transmission cases 24 and 24, are connected to these protruding ends. The left and right rear wheel transmission shafts 35 and 35 drive and rotate the left and right rear wheels 7 and 7, respectively.

[0032] The seedling planting device 3 is mounted on the vehicle body 1 so as to be able to move up and down using a lifting link device 2.

[0033] A general-purpose lift cylinder 36 (Figure 1), whose base is rotatably mounted on the vehicle body 1, has its piston upper end connected to a lifting link device 2. A hydraulic pump 13 provided on the vehicle body 1 supplies and discharges pressurized oil to the lift cylinder 36 via a lifting valve (not shown), causing the piston of the lift cylinder 36 to extend and retract, thereby moving the seedling planting device 3 connected to the lifting link device 2 up and down.

[0034] The seedling planting device 3 consists of a planting transmission case 38, which also serves as a frame and is mounted to the rear of the lifting link device 2 via left and right frames 37 so as to be able to roll; a seedling tray (seedling tank) 39 that is supported by a support member provided on the planting transmission case 38 and reciprocates in the left-right direction of the machine; a seedling planting tool 41 mounted on the rear end of the planting transmission case 38 and plants seedlings one by one into the field from the lower end of the seedling tray 39; and a center float (sensor float) 42 and side floats 43, etc., which are ground leveling bodies mounted on the lower part of the planting transmission case 38, with their rear end pivotally supported and their front end able to swing up and down. The center float 42 and side floats 43 are provided to level the field and to level the area in front of the field where seedlings will be planted by the seedling planting tool 41.

[0035] The PTO transmission shaft 45 (Figure 1) has universal joints at both ends and is installed to transmit power from the engine 12 to the planting transmission case 38 of the seedling planting device 3.

[0036] The seedling planting device 3 has a four-row configuration and includes a planting transmission case 38 that also serves as a frame, a seedling platform 39 that holds seedlings and moves back and forth to supply seedlings one by one to the seedling outlets 39a (Figure 2) of each row, and a seedling planting tool 41 that plants the seedlings supplied to the seedling outlets 39a into the field.

[0037] Figure 3 is an explanatory diagram of the trunnion arm and trunnion motor section connected to the hydrostatic continuously variable transmission of the embodiment.

[0038] HST (Hydrostatic Continuously Variable Transmission) is a conventionally known transmission that changes speed by tilting a swash plate, and the tilt angle of the swash plate can be changed by rotating the trunnion shaft 101 connected to the swash plate.

[0039] A trunnion arm 102 is connected to the trunnion shaft 101. The trunnion arm 102 is rotatably supported around the rotation axis 102a. One end of a link rod 103 is connected to the trunnion arm 102 at a position offset from the rotation axis 102a. A link plate 104 is connected to the other end of the link rod 103. A link spring 106 is connected to the tip of the link plate 104, biasing the tip of the link plate 104 toward the trunnion shaft 101. Therefore, the elastic force of the link spring 106 constantly pushes the link plate 104, link rod 103, and trunnion arm 102 toward a specific initial position, pushing the trunnion shaft 101 toward the neutral position (= the position where the inclination angle of the swash plate is neutral, the position where no power is output from the HST).

[0040] Figure 4 is a plan view of the clutch portion of the embodiment, with Figure 4(A) being an explanatory diagram of the clutch in the engaged state and Figure 4(B) being an explanatory diagram of the clutch in the disengaged state.

[0041] A clutch 107 is positioned at the base end of the link plate 104. The clutch 107 includes a transmission plate 107b as an example of a first transmission part, which is supported so as not to move in the axial direction relative to the clutch shaft 107a, and a transmitted plate 107c as an example of a second transmission part, which is supported so as to be axially movable relative to the clutch shaft 107a. Multiple engagement recesses 107d are formed on the transmission plate 107b as an example of a first engagement part. Engagement protrusions 107e are formed on the transmitted plate 107c as an example of a second engagement part, corresponding to the engagement recesses 107d.

[0042] Therefore, when the transmission plate 107b and the plate to be transmitted 107c are close together and the meshing projection 107e fits into the meshing recess 107d and meshes, rotation can be transmitted from the transmission plate 107b to the plate to be transmitted 107c (transmission engaged state). On the other hand, when the plate to be transmitted 107c moves axially and separates from the transmission plate 107b, and the meshing projection 107e separates from the meshing recess 107d, rotation cannot be transmitted from the transmission plate 107b to the plate to be transmitted 107c (transmission disengaged state).

[0043] A clutch spring 107f is attached to the clutch shaft 107a, which pushes the transmission plate 107c toward the transmission plate 107b (pushing it in the direction that engages the transmission).

[0044] The link plate 104 is connected to the transmission plate 107c. Therefore, the transmission plate 107c is indirectly connected to the link rod 103, the trunnion arm 102, and the trunnion shaft 101 via the link plate 104.

[0045] Furthermore, a gear section 108 is formed on the outer circumference of the transmission plate 107b. The output gear (not shown) of a gearbox 109, which is an example of a speed change section, meshes with the gear section 108. The output gear 111a of the trunnion motor 111 meshes with the input gear (not shown) of the gearbox 109. The gearbox 109 houses a gear train inside and outputs the drive of the trunnion motor 111 after speed change (reduction). Therefore, the transmission plate 107b is rotated via the gear section 108 by the drive of the trunnion motor 111.

[0046] A first potentiometer SN1, which is an example of a first sensor, is positioned near the gearbox 109. The first potentiometer SN1 can indirectly detect and estimate the rotation amount of the trunnion motor 111 by detecting the rotation amount of the output gear of the gearbox 109.

[0047] Furthermore, a second potentiometer SN2, which is an example of a second sensor, is positioned on the trunnion shaft 101. The second potentiometer SN2 can detect the amount of rotation of the trunnion shaft 101. Therefore, the second potentiometer SN2 can indirectly detect and estimate the amount of movement of the trunnion arm 102 and the link rod 103, which move in conjunction with the trunnion shaft 101.

[0048] The transmission plate 107c supports the detection plate 116. A clutch disengagement sensor SN3, as an example of a separation detection member, is positioned at a distance from the detection plate 116 in the axial direction of the clutch shaft 107a. The clutch disengagement sensor SN3 is supported at the tip of the stay 117 that supports the first potentiometer SN1.

[0049] The clutch 107 of this embodiment also has the function of protecting the components 102 to 109 from damage by disengaging the transmission (so-called "clutch disengagement") when the rotational or movement load torque becomes excessive due to factors such as wear or looseness of the components 102 to 109, or when pebbles or mud get stuck, and reaches the spring force of the clutch spring 107f, the transmitted plate 107c moves away from the transmission plate 107b along the axial direction of the clutch shaft 107a while compressing the clutch spring 107f. The clutch disengagement sensor SN3 can detect clutch disengagement when the transmitted plate 107c moves away from the transmission plate 107b, and the detected plate 116 comes into contact with a switch (not shown) of the clutch disengagement sensor SN3, pressing the switch. Note that the clutch disengagement sensor SN3 is not limited to a switch type (contact type), and non-contact sensors such as optical sensors, infrared sensors, and distance sensors can also be used.

[0050] (Description of the control unit) Figure 5 is a functional block diagram of the control unit according to the embodiment.

[0051] In the block diagram of Figure 5, elements unrelated to the description of the embodiments of the present invention are omitted from the illustration and description.

[0052] The seedling transplanter of this embodiment is configured to send and receive information via a communication line to and from a tablet terminal, which is an example of a terminal, and a distribution server, which is an example of an information processing device.

[0053] (Explanation of the control unit of the seedling transplanter) The seedling transplanter of this embodiment has a control unit 300 that controls each function. The control unit 300 has an input / output interface (I / O) for inputting and outputting signals to and from the outside. The control unit 300 also has a ROM (read-only memory) in which programs and information for performing necessary processing are stored. The control unit 300 also has a RAM (random access memory) for temporarily storing necessary data. The control unit 300 also has a CPU (central processing unit) that performs processing according to the programs stored in the ROM, etc. Therefore, the control unit 300 of this embodiment is composed of a small information processing device, a so-called microcomputer. Thus, the control unit 300 can realize various functions by executing programs stored in the ROM, etc.

[0054] The control unit 300 receives signals from signal input elements such as a touch panel 201, which is an example of an input unit and an example of a display unit, a GNSS positioning device SN0, a first potentiometer SN1, a second potentiometer SN2, a clutch disengagement sensor SN3, a rotation speed sensor SN4, a steering sensor SN5, a lifting sensor SN6, and various other sensors (not shown).

[0055] As an example of a position acquisition device, the GNSS positioning device SN0 detects the current position of the vehicle 1 based on signals from artificial satellites.

[0056] The first potentiometer SN1 detects the amount of rotation of the trunnion motor 111 from the amount of rotation of the output gear of the gearbox 109.

[0057] The second potentiometer SN2 detects the movement of the trunnion arm 102 from the amount of rotation of the trunnion shaft 101.

[0058] The clutch disengagement sensor SN3 detects clutch disengagement at clutch 107.

[0059] As an example of a rotation speed detection member, the rotation speed sensor SN4 measures the rotation speed of the rear wheel 7, which is a drive wheel. In this embodiment, the example shows how to measure the rotation speed of the rear wheel 7, but it is also possible to configure it to measure the rotation speed of the front wheel 6.

[0060] The steering sensor SN5 detects the amount of steering wheel 16 is moved, also known as the steering angle.

[0061] The lifting sensor SN6 detects the amount of movement of the lift cylinder 36, that is, the amount of lifting (height) of the seedling planting device 3.

[0062] Furthermore, the control unit 300 can transmit control signals to controllable elements such as the fertilizer applicator 4, engine 12, steering motor M0, lift cylinder 36, and trunnion motor 111, thereby controlling the movement, acceleration / deceleration, stopping, and steering of the vehicle body 1, as well as the operation and stopping of the fertilizer applicator 4 and the raising and lowering of the seedling planting device 3. The control unit 300 can also output control signals to the touch panel 201 to display work information and work status.

[0063] In Figure 5, the control unit 300 of the embodiment has the following functional means (program module).

[0064] The position acquisition means 301 detects the current position of the vehicle 1 based on the detection results of the GNSS positioning device SN0.

[0065] The work information storage means 302 stores information related to the operation of the riding-type rice transplanter that has been distributed from the distribution server. Examples of work-related information include the travel route within the field, location information such as the start position, end position, and turning position of the operation, the travel speed during operation, the planting depth, and the amount of planting per plant.

[0066] The abnormality detection means 303 includes a steering abnormality discrimination means 303A, a driving abnormality discrimination means 303B, a gear shift abnormality discrimination means 303C, a work equipment abnormality discrimination means 303D, and an abnormality degree discrimination means 303E, and detects abnormalities in the riding-type rice transplanter.

[0067] The steering abnormality detection means 303A determines the occurrence of an abnormality in the steering system based on the detection result of the steering sensor SN5. For example, if the steering motor M0 operates and rotates the steering wheel 16, but the steering sensor SN5 does not detect the rotation of the steering wheel 16, or if the steering sensor SN5 detects the rotation of the steering wheel 16 but the direction of travel does not change to the steered direction, the steering abnormality detection means 303A determines that an abnormality has occurred in the steering system. In other words, it determines that an abnormality such as a malfunction or operational failure of the steering motor M0 or steering sensor SN5 has occurred.

[0068] The driving abnormality detection means 303B determines the occurrence of an abnormality in the driving system (front wheels 6, rear wheels 7 and their transmission systems) based on the detection results of the rotation speed sensor SN4. For example, if the rotation speed sensor SN4 detects the rotation of the rear wheels 7, but the detection results of the GNSS positioning device SN0 show no change in the current position, or if the rotation speed sensor SN4 does not detect the rotation of the rear wheels 7 or the rotation speed is insufficient, even though the engine 12 or the like has been set to a predetermined driving speed, the driving abnormality detection means 303B determines that an abnormality has occurred in the driving system due to an abnormality in the driving system or slippage of the wheels 6 and 7 in the field. It is preferable to reduce false detections by comparing the period for detecting the rotation of the rear wheels 7 by the rotation speed sensor SN4 (sampling interval, the time it takes for the rear wheels 7 to rotate by a predetermined angle α) with the vehicle speed to determine whether the abnormality is due to vibration of the vehicle body 1 (abnormal) or due to forward and reverse movement (normal). Therefore, if the detection period of the rotation actually detected exceeds the range of the target detection period corresponding to the driving speed controlled by automatic driving, it is possible to determine that an abnormality has occurred. Furthermore, by positioning two rotation speed sensors on the rear wheel 7 axle with a phase difference, it becomes possible to distinguish between forward and reverse movement. For example, if vibration causes the vehicle to be moving forward at a low speed but is detected as moving in reverse, it can be identified as an abnormality.

[0069] The gear shift abnormality detection means 303C includes an asynchronous detection means 303C1 and a clutch disengagement detection means 303C2, and detects the occurrence of an abnormality in the HST, which is the gear shift device, and its surrounding components 101 to 117.

[0070] The asynchronous determination means 303C1 determines whether the operation of the trunnion arm 102 and the trunnion motor 111 is synchronized (asynchronous) based on the detection results of the first potentiometer SN1 and the second potentiometer SN2. For example, even if the rotation of the trunnion motor 111 is detected by the first potentiometer SN1, if the movement of the trunnion shaft 101 or trunnion arm 102 is not detected by the second potentiometer SN2, or if the amount of movement of the trunnion arm 102 detected by the second potentiometer SN2 is mismatched with the amount of rotation of the trunnion motor 111 detected by the first potentiometer SN1, asynchronous operation is determined. In this embodiment, even if a clutch disengagement occurs, the rotation of the trunnion motor 111 detected by the first potentiometer SN1 and the movement of the trunnion arm 102 detected by the second potentiometer SN2 will be asynchronous as a result.

[0071] The clutch disengagement detection means 303C2 determines the occurrence of clutch disengagement based on the detection result of the clutch disengagement sensor SN3. Therefore, if asynchronous operation occurs between the trunnion arm 102 and the trunnion motor 111 due to clutch disengagement, the clutch disengagement detection means 303C2 can identify that clutch disengagement has occurred. In this embodiment, a clutch disengagement sensor SN3 was installed to detect clutch disengagement, but this is not the only way to do so.

[0072] For example, it is also possible to omit the clutch disengagement sensor SN3 and instead determine that a clutch disengagement has occurred based on the detection results of two potentiometers SN1 and SN2, if the discrepancy is large.

[0073] The work equipment abnormality detection means 303D determines the occurrence of an abnormality in the work equipment, the seedling planting device 3, based on the detection results of the lifting sensor SN6. For example, if the height of the seedling planting device 3 does not descend to a predetermined height during operation, or does not rise to a predetermined height during rotation, it is determined that an abnormality has occurred. Alternatively, sensors can be installed on various parts of the seedling planting device 3, and abnormalities in the seedling planting device 3 can be determined from the detection results of each sensor.

[0074] The abnormality severity determination means 303E determines whether the detected abnormality is minor or severe. In this embodiment, the abnormality severity determination means 303E determines whether the abnormality is minor, allowing for the possibility of resuming automatic driving, or severe, making it difficult to resume automatic driving. For example, if an abnormality is detected by the steering abnormality determination means 303A, the driving abnormality determination means 303B, or the work equipment abnormality determination means 303D, it is determined to be a severe abnormality. Also, if the gear shift abnormality determination means 303C determines that the system is asynchronous, the abnormality is determined to be severe if the discrepancy between the rotation amount of the trunnion motor 111 and the movement amount of the trunnion arm 102 is excessively large or small compared to a predetermined allowable range of discrepancy, and minor if it is within the allowable range. Furthermore, in this embodiment, the abnormality severity determination means 303E determines that the abnormality is minor if the current position cannot be obtained by the position acquisition means 301, for example, if communication with an artificial satellite is temporarily interrupted, or if communication with a distribution server or tablet terminal is interrupted.

[0075] In this embodiment, if the clutch disengagement detection means 303C2 determines that a minor clutch disengagement has occurred (the misalignment is within the acceptable range and the clutch has disengaged), the abnormality detection means 303 controls the trunnion motor 111 so that the detected value of the first potentiometer SN1 returns to the neutral state. That is, the rotational position of the trunnion motor 111 is returned so that the HST returns to the neutral state (so that the trunnion shaft 101 returns to the neutral position). Then, if the first potentiometer SN1 detects that the trunnion motor 111 has returned to the neutral position within a predetermined time since it started operating, and the second potentiometer SN2 also detects that the trunnion arm 102 and the trunnion shaft 101 have returned to the neutral state, the determination result that the abnormality was minor is maintained. In other words, it is determined that the clutch disengagement has been resolved (automatic recovery from clutch disengagement) by performing the operation to return to the neutral position.

[0076] On the other hand, if the detection value of the first potentiometer SN1 does not return to the neutral state even after a predetermined time has elapsed since the trunnion motor 111 started operating to bring the first potentiometer SN1 to the neutral position, or if the trunnion arm 102 or trunnion shaft 101 has not returned to the neutral state according to the detection value of the second potentiometer SN2, or if the speed at which the trunnion shaft 101 moves is too slow, then it is determined that the abnormality is severe. In other words, even if the clutch disengagement is not resolved, it is determined that there are safety and workability issues if the vehicle continues to be driven.

[0077] Even if it is determined that the clutch disengagement has been resolved, it is desirable to perform a check after the automatic recovery from clutch disengagement by, for example, moving the HST to the maximum forward speed position and checking whether the detected values ​​of each potentiometer SN1 and SN2 are the values ​​for the maximum forward speed; moving the HST to the maximum reverse speed position and checking whether the detected values ​​of each potentiometer SN1 and SN2 are the values ​​for the maximum reverse speed; and moving the HST to the neutral position and checking whether the detected values ​​of each potentiometer SN1 and SN2 are the values ​​for the neutral position. Furthermore, in the check operation, if clutch disengagement occurs on the forward side, it is preferable to check at the maximum reverse speed first, and if clutch disengagement occurs on the reverse side, it is preferable to check at the maximum forward speed first, as this can also be expected to resolve the clutch disengagement.

[0078] If the clutch disengagement is not resolved during the check operation, it is preferable to perform the clutch disengagement resolution operation again. Furthermore, if the clutch disengagement is not resolved even after performing the clutch disengagement resolution operation a predetermined number of times (for example, 3 times), it is preferable to determine that the abnormality is severe.

[0079] Furthermore, during the check operation, it is also possible to consider the possibility of detection discrepancies in potentiometers SN1 and SN2, and update the detection values ​​of potentiometers SN1 and SN2 when the HST is set to the maximum forward speed position or maximum reverse speed position as the detection values ​​for the new maximum forward speed position or maximum reverse speed position, and then terminate the check operation.

[0080] Furthermore, if the clutch disengagement persists even after performing the clutch disengagement correction operation a predetermined number of times, it is also possible to try to resolve the clutch disengagement by intermittently moving the trunnion motor 111 in a predetermined pattern to perform sudden acceleration and deceleration, or gradual acceleration and deceleration, causing the vehicle body 1 to shake.

[0081] The travel control means 304 includes an automatic travel control means 304A and a manual travel control means 304B, and controls the movement of the riding-type rice transplanter. In this embodiment, if an abnormality is detected by the abnormality detection means 303, the travel control means 304 stops the vehicle body 1 for safety. In this embodiment, when the vehicle body 1 is stopped, the HST is returned to the neutral position, and the vehicle body 1 is stopped. Therefore, in this embodiment, even if a clutch disengagement occurs, the vehicle body 1 is braked and stopped by returning the HST to the neutral position.

[0082] Furthermore, when stopping the vehicle body 1, it is possible not only to return the HST to the neutral position, but also to move the brake pedal and activate the brakes (braking device) to stop the vehicle body 1. In particular, even when control is performed to stop the vehicle body 1, if the rotation speed sensor SN4 detects rotation or the position acquisition means 301 detects movement of the current position even after a sufficient amount of time has elapsed, that is, if the vehicle body 1 is moving, it is preferable to activate the brakes to ensure safety. Furthermore, when rotation is detected by the front wheels 6, in a configuration where the clutch of the front wheels 6 can be switched on / off, there is a possibility that only one of the inner or outer wheels will rotate. Therefore, when stopping the vehicle body 1, regardless of the steering angle of the steering wheel 16, the clutch connecting the left and right front wheels is forcibly engaged, so that the rotation of both sides becomes the same, and the movement of the vehicle body 1 can be detected by the rotation speed sensor of the front wheels 6.

[0083] Furthermore, when restarting or switching back to automatic driving mode after an automatic stop, it is possible to ensure that operators perform the necessary operations to ensure proper confirmation. For example, by preventing restarts, etc., until the brake pedal is moved to the locked position (fully depressed), it is possible to suppress sudden movement immediately after a restart, thereby improving safety.

[0084] Furthermore, safety can be ensured compared to cases where the system can be easily restarted by preventing restarts until an abnormal shutdown release operation is performed, such as performing two or more specific screen operations on the touch panel 201, removing a check fuse, requiring operations not only on the touch panel 201 but also on the terminal side, turning a key off once, or pressing a safety switch. It is also possible to set different abnormal shutdown release operations depending on the type of abnormality that occurred.

[0085] Furthermore, by restricting the abnormal stop recovery operation to only authorized personnel through password management, it is possible to prevent use in unsafe conditions. In addition, if an abnormality continues to be detected even after the abnormal stop recovery operation has been performed, it is preferable for safety reasons to prevent switching to automatic driving mode.

[0086] When the user selects an automatic driving mode via the touch panel 201 or tablet terminal, the automatic driving control means 304A controls the engine 12, steering motor M0, lift cylinder 36, brakes (braking device), etc., based on the work information stored in the work information storage means 302, to perform automatic control (automatic driving and automatic work) of the vehicle body 1, steering, operation / stop and lifting / lowering of the seedling planting device 3, etc. Therefore, the vehicle is driven at a driving speed along the driving path, and if the current position deviates from the driving path, the vehicle body 1 is steered to follow the driving path. Since speed control and gear shift control are performed by the automatic control of the trunnion motor 111, it is desirable that the automatic driving mode cannot be started unless the gear shift lever 17 is in the neutral position. This is because if the system switches to manual driving mode while the automatic driving mode is running with the gear shift lever 17 in a position other than neutral, there is a risk of sudden acceleration or deceleration occurring depending on the setting of the gear shift lever 17, which reduces safety.

[0087] When a user selects a manual driving mode from the user's touch panel 201 or tablet terminal, the manual driving control means 304B controls the engine 12 and other components in response to the operator's driving operations, such as the steering wheel 16, gear shift lever 17, accelerator pedal, and brake pedal, to control the driving speed and steering of the vehicle body 1, as well as the raising and lowering of the seedling planting device 3.

[0088] The driving mode switching means (switching means) 305 switches between automatic driving mode and manual driving mode. In this embodiment, the driving mode switching means 305 switches the driving mode between automatic driving mode and manual driving mode in response to input from the touch panel 201 or a tablet terminal. As a general rule, the driving mode does not switch automatically until input is received from the operator via the touch panel 201 or the like.

[0089] In this embodiment, the driving mode switching means 305 maintains the automatic driving mode when an abnormality is detected by the abnormality detection means 303 while driving in automatic driving mode, and the vehicle body 1 stops if the abnormality is minor. In other words, it does not switch to manual driving mode.

[0090] On the other hand, in the case of a severe abnormality, if the vehicle body 1 stops, the engine 12 will also stop, and the driving mode will be forcibly switched to manual driving mode. Therefore, the automatic driving mode cannot be restarted by operating the tablet terminal alone; an operator must go to the vehicle body 1, perform safety checks, and then restart the automatic driving mode.

[0091] Furthermore, it is possible to perform the aforementioned clutch disengagement correction and check operations after the engine has been stopped. In this case, for safety reasons, it is preferable to perform the clutch disengagement correction operation when certain conditions are met, such as the brake pedal being pressed or the gear shift lever 17 being in the neutral position. It is also possible to configure the system so that, if the clutch disengagement is corrected after the clutch disengagement correction operation is performed with the engine stopped, the engine 12 can be released and the system can return to automatic driving mode solely by remote control from a tablet terminal.

[0092] In manual driving mode, since an operator is on board, if the engine 12 suddenly stops and the vehicle decelerates rapidly, there is a risk of injury to the operator, so it is preferable not to stop the engine 12. Also, in manual driving mode, different detection results may be obtained during activities such as climbing up ridges or loading onto trucks, which may lead to false detection of abnormalities. Since stopping the engine 12 while climbing up a ridge would impair work efficiency, it is preferable not to stop the engine 12.

[0093] Similarly, even in automatic driving mode, it is preferable not to immediately stop the engine 12 when an abnormality is detected, for example, if the gear shift lever 17 is operated manually or if an operator is on board, in order to prevent sudden deceleration. Therefore, when there is an operator, it is preferable to stop the engine after decelerating to below a certain speed or traveling a certain distance while an abnormality is detected. At this time, it is preferable to leave the occupant with a voice announcement, buzzer, screen display, etc., informing them that the engine 12 will soon stop. When there is no operator, immediately stopping the engine 12 can shorten the distance traveled in the abnormal state, thereby ensuring safety and reducing the need to redo work.

[0094] In the seedling transplanter of the embodiment having the above configuration, if an abnormality occurs while driving in automatic driving mode, the vehicle body 1 will stop if it is a minor abnormality such as loss of GNSS signal or minor clutch disengagement, but the automatic driving mode will be maintained. Therefore, once the GNSS signal loss is recovered or the clutch disengagement is resolved, the automatic driving mode can be restarted by a command signal from the tablet terminal. On the other hand, in the case of a serious abnormality such as an abnormality in the steering system or driving device, it is important for the operator to go to the vehicle body 1 to perform a safety check, so the system is forcibly switched to manual driving mode. Therefore, compared to the conventional technology, where the system is forcibly switched to manual driving mode regardless of the severity of the abnormality when an abnormality occurs, and it is necessary to go to the site of the vehicle body 1 for a safety check, safety is ensured while work efficiency is improved.

[0095] (Example of change) The work vehicle of the present invention is not limited to rice transplanters, but can also be applied to seedling transplanters for transplanting vegetable seedlings. Furthermore, although a rice transplanter using so-called mat-shaped seedlings has been given as an example, the invention is not limited to this, and can also be applied to rice transplanters using pot-shaped seedlings.

[0096] Furthermore, while a ride-on seedling transplanter was used as an example, the method is not limited to this and can also be applied to autonomous work vehicles.

[0097] Furthermore, while an example configuration has been given in which all processing of each means 301 to 305 is centrally processed by a seedling transplanter, the system is not limited to this. It is also possible to configure a distributed processing system in which one or more of each means 301 to 305 are provided on a server or computer device connected by a communication line. [Explanation of Symbols]

[0098] 1... Vehicle body, 3...Work equipment, 6,7...Traction mechanism, 12... Engine, 16... Steering control member, 101... Trunnion shaft, 102... Trunnion arm, 107...Clutch, 107b...First transmission section, 107c...Second transmission section, 111... Trunnion motor, 300... Control unit, 301...position acquisition means, 303... Anomaly detection means, 304... means for controlling travel, 305... Switching means, HST…Hydrogenic continuously variable transmission, SN1...First sensor, SN2... Second sensor, SN3... Separation detection member.

Claims

1. An engine (12) and a vehicle body (1) having a running gear (6, 7) that moves when power is transmitted from the engine (12), A work machine (3) is supported by the aforementioned traveling vehicle body (1) and performs work on the field, The system includes: a position acquisition means (301) for acquiring the current position of the vehicle body (1); a switching means (305) for switching between an automatic driving mode, which automatically drives the vehicle body (1) in the field based on the current position information acquired by the position acquisition means (301), and a manual driving mode, which drives the vehicle body (1) according to the operator's driving operations; an abnormality detection means (303) for detecting abnormalities related to the work vehicle; and a driving control means (304) for stopping the vehicle body (1) when an abnormality is detected by the abnormality detection means (303). A work vehicle characterized by comprising: when an abnormality is detected by the abnormality detection means (303) and the traveling vehicle body (1) is stopped, the control unit (300) switches to the manual driving mode if the abnormality detected by the abnormality detection means (303) is a predetermined severe abnormality.

2. The work vehicle according to claim 1, characterized in that if the abnormality detected by the abnormality detection means (303) is a predetermined minor abnormality, the automatic driving mode is maintained.

3. The work vehicle according to claim 1 or 2, characterized in that, if an abnormality is detected in the steering control member (16) that controls the direction of travel of the vehicle body (1) in the automatic driving mode, or in the driving device (6, 7), the abnormality detection means (303) determines that the abnormality is a severe abnormality.

4. The work vehicle according to claim 3, characterized in that the abnormality of the steering control member (16) is determined based on the relationship between the detection result based on the amount of operation of the steering control member (16) and the detection result based on the direction of travel of the vehicle body (1).

5. The work vehicle according to any one of claims 1 to 4, characterized in that if the abnormality detection means (303) determines that a severe abnormality has occurred, the vehicle cannot return to the automatic driving mode without a predetermined operation by the operator.

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