Work vehicle

Abstract

To enhance workability while securing safety in response to abnormality in a work vehicle.SOLUTION: A control section (300) which switches between an automatic travel mode allowing a travel body (1) to perform automatic travel and a manual travel mode allowing the travel body to travel according to operation of an operator based on information on a present position acquired through positional information acquisition means (301) can improve workability while securing safety in response to abnormality of a work vehicle by maintaining the automatic travel mode when the travel body (1) is stopped with abnormality detection means (303) detecting abnormality.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a work vehicle, and more particularly to a work vehicle having an automatic driving mode in which the work vehicle automatically drives based on its current position. [Background technology]

[0002] In work vehicles such as rice transplanters and seedling transplanters, a technology is known in which the position (target phase) for planting seedlings is calculated based on position information obtained by a Global Navigation Satellite System (GNSS), and the planting unit (200) is controlled based on the actual phase and target phase of the planting unit (200) (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6342344 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional technology, communication with GNSS satellites can sometimes result in inaccurate acquisition of location information (so-called "lost") due to various factors, such as the relative positions of the satellites and surrounding buildings and bridges, and signal reflection from surrounding buildings. Also, errors can occur in GNSS signal processing. In the technology described in Patent Document 1, if a loss or error occurs during planting work, the vehicle may deviate from the automated driving route, the planting position of the seedlings may not be calculated accurately, the planting position (planting spacing) may become inconsistent, or the planting work itself may become impossible.

[0005] Therefore, in the case of a loss of GNSS signals, conventional technology requires the vehicle to be stopped for safety reasons, and the automatic driving mode is cancelled and the vehicle is forcibly switched to manual driving mode. Furthermore, if an abnormality occurs in the driving gear, transmission, or work equipment during automatic driving, the vehicle is stopped for safety reasons, the automatic driving mode is cancelled, and the vehicle is forcibly switched to manual driving mode.

[0006] However, when the vehicle makes an emergency stop and switches to manual driving mode, it no longer accepts commands from external terminals or remote controllers to ensure safety, and an operator must go directly to the vehicle's location to operate it and restart it. Therefore, for example, if the vehicle makes an emergency stop in the middle of a field, an operator must go to the site (the vehicle's location). In the case of a serious abnormality, such as a malfunction in the driving mechanism, which would cause problems not only with automatic driving but also with manual driving, it is important for safety that an operator go to the vehicle to check.However, even in the case of a temporary minor abnormality, such as the loss of the GNSS signal, conventional technology requires an operator to go to the vehicle's location to restart the vehicle before automatic driving can be resumed, which has the problem of poor workability and efficiency.

[0007] The present invention has as its technical object to improve workability while ensuring safety in response to an abnormality in a work vehicle. [Means for solving the problem]

[0008] The above-mentioned problems of the present invention are solved by the following means. The invention described in claim 1 is a traveling vehicle body (1) having an engine (12), traveling devices (6, 7) that travel by receiving drive from the engine (12), a work machine (3) supported by the traveling vehicle body (1) and performing work on a field, a position acquisition means (301) that acquires the current position of the traveling vehicle body (1), an automatic traveling mode that automatically travels the traveling vehicle body (1) in the field based on information on the current position acquired by the position acquisition means (301), and a traveling mode that automatically travels the traveling vehicle body (1) in the field based on driving operation by an operator. a switching means (305) for switching between a manual driving mode and a manual driving mode in which the traveling body (1) is driven; an abnormality detection means (303) for detecting an abnormality related to the work vehicle; a driving control means (304) for stopping the traveling body (1) when an abnormality is detected by the abnormality detection means (303); and a control unit (300) for maintaining the automatic driving mode when an abnormality is detected by the abnormality detection means (303) and the traveling body (1) is stopped.

[0009] The invention described in claim 2 is the work vehicle described in claim 1, characterized in that it is provided with a steering control member (16) that steers and controls the direction of travel of the traveling body (1) in the automatic traveling mode, and the control unit (300) that stops the engine (12) and switches to manual traveling mode when an abnormality is detected in the steering control member (16).

[0010] The invention described in claim 3 is the work vehicle described in claim 1, characterized in that it includes the control unit (300) that stops the engine (12) and switches to a manual travel mode when an abnormality is detected in the travel device (6, 7).

[0011] The invention described in claim 4 includes a hydrostatic continuously variable transmission (HST) that changes speed by changing the angle of a swash plate, a trunnion shaft (101) connected to the swash plate and changing the angle of the swash plate when rotating, a trunnion arm (102) connected to the trunnion shaft (101) and rotating the trunnion shaft (101), a trunnion motor (111) that moves the trunnion arm (102), and a first sensor (SN1) that detects the rotational position of the trunnion motor (111). ), a second sensor (SN2) that detects the position of the trunnion arm (102), and the control unit (300) that stops the engine (12) and switches to a manual travel mode when it is determined that the operations of the trunnion arm (102) and the trunnion motor (111) are not synchronized based on the detection results of the first sensor (SN1) and the second sensor (SN2).

[0012] The invention described in claim 5 is the work vehicle described in claim 4, characterized in that it comprises a clutch (107) arranged between the trunnion motor (111) and the trunnion arm (102) for turning the transmission on and off, and the control unit (300) for braking the travel of the traveling body (1) when it is determined that a deviation in the transmission by the clutch (107) has occurred based on the detection results of the first sensor (SN1) and the detection results of the second sensor (SN2).

[0013] The invention described in claim 6 is the work vehicle described in claim 5, characterized in that it is provided with the control unit (300) that brakes the travel of the traveling body (1) by operating the trunnion motor (111) so that the detection value of the first sensor (SN1) is in a neutral state when the transmission deviation by the clutch (107) is within a predetermined range based on the detection result of the first sensor (SN1) and the detection result of the second sensor (SN2).

[0014] The invention described in claim 7 is the work vehicle described in claim 6, characterized in that it is provided with the control unit (300) that stops the engine (12) if the detection value of the first sensor (SN1) does not reach the neutral state even after a predetermined time has elapsed since the trunnion motor (111) started operating so that the detection value of the first sensor (SN1) reaches the neutral state.

[0015] The invention described in claim 8 is a work vehicle described in claim 5, characterized in that it has a first transmission part (107b) to which drive from the trunnion motor (111) is transmitted, and a second transmission part (107c) connected to the trunnion arm (102) and capable of coming into contact with and separating from the first transmission part (107b), and is equipped with the clutch (107) by which power from the trunnion motor (111) is transmitted to the trunnion arm (102) when the first transmission part (107b) and the second transmission part (107c) come into contact, and a separation detection member (SN3) that detects movement of the second transmission part (107c) in a direction away from the first transmission part (107b). [Effects of the Invention]

[0016] According to the invention described in claim 1, when an abnormality is detected by the abnormality detection means (303) and the traveling vehicle body (1) is stopped, the control unit (300) maintains the automatic traveling mode, thereby ensuring safety in accordance with the abnormality of the work vehicle while improving workability.

[0017] According to the invention of claim 2, in addition to the effect of the invention of claim 1, when an abnormality in the steering control member (16) is detected, the engine (12) is stopped and the driving mode is switched to manual driving mode, thereby ensuring safety.

[0018] According to the invention of claim 3, in addition to the effect of the invention of claim 1, when an abnormality in the traveling device (6, 7) is detected, the engine (12) is stopped and the traveling mode is switched to a manual traveling mode, thereby ensuring safety.

[0019] According to the invention of claim 4, in addition to the effect of the invention of claim 1, if it is determined that the operations of the trunnion arm (102) and the trunnion motor (111) are not synchronized, the engine (12) is stopped and the mode is switched to manual driving mode, thereby ensuring safety.

[0020] According to the invention of claim 5, in addition to the effect of the invention of claim 4, when it is determined that a deviation in transmission due to the clutch (107) has occurred, the traveling vehicle body (1) is braked, thereby ensuring safety.

[0021] According to the invention of claim 6, in addition to the effect of the invention of claim 5, when the deviation in transmission by the clutch (107) is within a predetermined range, the trunnion motor (111) is operated so that the detection value of the first sensor (SN1) is in a neutral state, thereby making it possible to recover from a slight deviation in transmission.

[0022] According to the invention of claim 7, in addition to the effect of the invention of claim 6, if the detection value of the first sensor (SN1) does not reach the neutral state even after a predetermined time has elapsed since the trunnion motor (111) started to operate so that the detection value of the first sensor (SN1) reaches the neutral state, the engine (12) is stopped, thereby stopping travel in a state in which the transmission misalignment has not been resolved and safety is in doubt, and safety can be ensured.

[0023] According to the invention of claim 8, in addition to the effect of the invention of claim 5, the separation detection member (SN3) detects the movement of the second transmission part (107c) in the direction of separation from the first transmission part (107b), thereby making it possible to detect clutch disengagement. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a left side view of a seedling transplanter according to an embodiment of the present invention. FIG. [Figure 2]FIG. 1 is a plan view of a seedling transplanter according to an embodiment. [Figure 3] FIG. 2 is an explanatory diagram of a trunnion arm and a trunnion motor portion connected to the hydrostatic continuously variable transmission according to the embodiment. [Figure 4] 4A and 4B are plan views of a clutch portion of the embodiment, in which FIG. 4A is an explanatory diagram of a clutch engaged state, and FIG. 4B is an explanatory diagram of a clutch disengaged state. [Figure 5] FIG. 2 is a functional block diagram of a control unit according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0025] An embodiment of the present invention will be described below. A four-row planting riding rice transplanter, which is an example of a work vehicle according to the present invention and is one embodiment of a seedling transplanter, will be described in detail with reference to the drawings. As shown in the side view of Fig. 1 and the plan view of Fig. 2, the riding rice transplanter (work vehicle) has a seedling planting device 3, which is a type of work machine, attached to a traveling body 1 by a lifting link device 2. A fertilizer applicator 4 is provided at the rear of the traveling body 1. The traveling body 1 is a four-wheel drive vehicle having a pair of front wheels 6, 6 and a pair of rear wheels 7, 7 on each side, which are an example of traveling devices. In this specification, the left and right sides of the forward movement direction of the rice transplanter are referred to as the left and right sides, respectively, and the forward movement direction is referred to as the front side and the backward movement 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 and 10b, a hydraulic pump 13 is integrally assembled with the transmission case 11 on the rear side of the transmission case 11, and a steering post 14 protrudes from the front upper part of the transmission case 11. A steering handle (steering control member) 16 is provided at the upper end of the steering post 14. A step floor 19, which serves as a floor for operation, is attached to the top of the aircraft, and a pilot's seat 20 is installed above the engine 12. A gear shift operation lever (travel operation member) 17 is provided to the right of the steering handle 16.

[0027] In front of the driver's seat 20, an operation panel (not shown) is provided on the steering post 14. A ridge clutch lever 18 is provided on the right side of the driver's seat 20. The front wheels 6, 6 are journaled on front wheel support cases 22, 22 that are mounted on the sides of the transmission case 11 so that their orientation can be changed. The rear wheels 7, 7 are journaled via rear wheel supports 30 on rear wheel transmission cases 24, 24 attached to both left and right ends of left and right frames 37. The left and right frames 37 are supported on the rear ends of the main frames 10a, 10b.

[0028] As shown in Figures 1 and 2, part of the power transmission mechanism to the rear wheels 7 is shown, and the rotational power of the engine 12 is transmitted to a transmission (not shown) in a transmission case 11. Any conventionally known transmission can be used, but for agricultural work vehicles, a hydrostatic transmission (HST) is preferred. The rear ends of the rear output shafts 11a, 11b protrude rearward from the transmission case 11, and these protruding ends are connected to left and right rear wheel transmission shafts 35, 35 that transmit power to the rear wheel transmission cases 24, 24. The left and right rear wheels 7, 7 are driven and rotated by the left and right rear wheel transmission shafts 35, 35, respectively.

[0029] The seedling planting device 3 is attached to the traveling vehicle body 1 by a lifting link device 2 so that it can be raised and lowered freely. The upper end of the piston of a general lift cylinder 36 (Figure 1), whose base is rotatably mounted on the running body 1, is connected to the lifting link device 2, and pressurized oil is supplied to and discharged from the lift cylinder 36 via a lifting valve (not shown) by a hydraulic pump 13 mounted on the running body 1, thereby extending and retracting the piston of the lift cylinder 36, thereby moving the seedling planting device 3 connected to the lifting link device 2 up and down.

[0030] The seedling planting device 3 is composed 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 in a rolling manner; a seedling carrier (seedling tank) 39 that is supported by supports attached to the planting transmission case 38 and moves back and forth in the left-right direction of the machine body; a seedling planting tool 41 attached to the rear end of the planting transmission case 38 and plants seedlings one by one in the field from the bottom of the seedling carrier 39; and a center float (sensor float) 42 and a side float 43, which are ground leveling bodies whose rear parts are pivotally supported on the bottom of the planting transmission case 38 and whose front parts are attached so that they can swing up and down. The center float 42 and the side floats 43 are provided to level the field and also to level the front of the field where the seedlings will be planted by the seedling planting tool 41.

[0031] The PTO transmission shaft 45 (FIG. 1) has universal joints at both ends and is provided to transmit power from the engine 12 to the planting transmission case 38 of the seedling planting device 3. The seedling planting device 3 has a four-row planting configuration and is equipped with a planting transmission case 38 that also serves as a frame, a seedling loading platform 39 that carries seedlings and moves back and forth from side to side to supply seedlings one by one to the seedling outlet 39a of each row (Figure 2), and a seedling planting tool 41 that plants the seedlings supplied to the seedling outlet 39a in the field.

[0032] FIG. 3 is an explanatory diagram of a trunnion arm and a trunnion motor portion connected to the hydrostatic continuously variable transmission according to the embodiment. An 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 a trunnion shaft 101 connected to the swash plate.

[0033] A trunnion arm 102 is connected to the trunnion shaft 101. The trunnion arm 102 is supported rotatably about a 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, which urges 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 specific initial positions, and pushes the trunnion shaft 101 toward the neutral position (= a position where the inclination angle of the swash plate is neutral, and where no power is output from the HST).

[0034] 4A and 4B are plan views of the clutch portion of the embodiment, with FIG. 4A being an explanatory diagram of the clutch engaged state and FIG. 4B being an explanatory diagram of the clutch disengaged state. A clutch 107 is disposed at the base end of the link plate 104. The clutch 107 has a transmission plate 107b as an example of a first transmission part supported immovably in the axial direction on a clutch shaft 107a, and a transmitted plate 107c as an example of a second transmission part supported movably in the axial direction on the clutch shaft 107a. A plurality of meshing recesses 107d as an example of a first meshing part are formed in the transmission plate 107b. A plurality of meshing protrusions 107e as an example of a second meshing part are formed in the transmitted plate 107c in correspondence with the meshing recesses 107d.

[0035] Therefore, when the transmission plate 107b and the transmitted plate 107c approach each other and the meshing protrusion 107e fits into and meshes with the meshing recess 107d, rotation can be transmitted from the transmission plate 107b to the transmitted plate 107c (transmission on state).On the other hand, when the transmitted plate 107c moves axially and separates from the transmission plate 107b, and the meshing protrusion 107e separates from the meshing recess 107d, rotation cannot be transmitted from the transmission plate 107b to the transmitted plate 107c (transmission off state). A clutch spring 107f is attached to the clutch shaft 107a to push the transmitted plate 107c toward the transmitting plate 107b (toward the direction in which the power is transmitted). The transmitted force plate 107c is connected to the link plate 104. Therefore, the transmitted force plate 107c is indirectly connected to the link rod 103, the trunnion arm 102, and the trunnion shaft 101 via the link plate 104.

[0036] Furthermore, a gear portion 108 is formed on the outer periphery of the transmission plate 107b. An output gear (not shown) of a gear box 109, which is an example of a speed changer, is engaged with the gear portion 108. An input gear (not shown) of the gear box 109 is engaged with an output gear 111a of a trunnion motor 111. A gear train is housed inside the gear box 109, which changes (decelerates) the drive of the trunnion motor 111 and outputs it. Therefore, the drive of the trunnion motor 111 rotates the transmission plate 107b via the gear portion 108.

[0037] A first potentiometer SN1, which is an example of a first sensor, is disposed near the gearbox 109. The first potentiometer SN1 detects the amount of rotation of the output gear of the gearbox 109, and thereby can indirectly detect and estimate the amount of rotation of the trunnion motor 111. Furthermore, a second potentiometer SN2, which is an example of a second sensor, is disposed 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.

[0038] A detection plate 116 is supported on the transmitted plate 107c. A clutch disengagement sensor SN3, which is an example of a separation detection member, is disposed at a position spaced apart in the axial direction of the clutch shaft 107a from the detection plate 116. The clutch disengagement sensor SN3 is supported at the tip of a stay 117 that supports the first potentiometer SN1.

[0039] In the clutch 107 according to the embodiment, when the load torque of rotation or movement becomes excessive due to factors such as wear or rattle of the components 102-109, or the presence of pebbles or mud, and reaches the spring force of the clutch spring 107f, the transmitted plate 107c compresses the clutch spring 107f and moves in a direction away from the transmission plate 107b along the axial direction of the clutch shaft 107a, thereby disengaging power (causing so-called "clutch disengagement") and protecting the components 102-109 from damage. When the transmitted plate 107c moves in a direction away from the transmission plate 107b, the detected plate 116 comes into contact with a switch (not shown) of the clutch disengagement sensor SN3, pressing the switch, thereby enabling clutch disengagement to be detected. Note that the clutch disengagement sensor SN3 is not limited to a switch-type (contact-type) and may be a non-contact type sensor such as an optical sensor, an infrared sensor, or a distance sensor.

[0040] (Explanation of the control unit) FIG. 5 is a functional block diagram of the control unit according to the embodiment. In the block diagram of FIG. 5, elements that are not related to the description of the embodiment of the present invention are not shown or described. The seedling transplanter of the embodiment is configured to be able to send and receive information via a communication line to and from a tablet terminal as an example of a terminal and a distribution server as an example of an information processing device.

[0041] (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 that performs input and output of signals from and to the outside. The control unit 300 also has a read-only memory (ROM) that stores programs and information for performing necessary processing. The control unit 300 also has a random access memory (RAM) for temporarily storing necessary data. The control unit 300 also has a central processing unit (CPU) that performs processing according to the programs stored in the ROM or the like. Therefore, the control unit 300 of this embodiment is configured as a small information processing device, a so-called microcomputer. Therefore, the control unit 300 can realize various functions by executing programs stored in the ROM or the like.

[0042] 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 also an example of a display, 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, an elevation sensor SN6, and various other sensors not shown. The GNSS positioning device SN0, which is an example of a position acquisition device, detects the current position of the traveling vehicle body 1 based on signals from artificial satellites.

[0043] 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. The second potentiometer SN2 detects the movement of the trunnion arm 102 from the amount of rotation of the trunnion shaft 101. The clutch disengagement sensor SN3 detects disengagement of the clutch 107. The rotation speed sensor SN4, which is an example of a rotation speed detection member, measures the rotation speed of the rear wheels 7, which are drive wheels. Although the embodiment has been described as measuring the rotation speed of the rear wheels 7, it is also possible to configure the sensor SN4 to measure the rotation speed of the front wheels 6. The steering sensor SN5 detects the amount of operation of the steering wheel 16, that is, the steering angle. The lifting sensor SN6 detects the amount of operation of the lift cylinder 36, that is, the amount of lifting (height) of the seedling planting device 3.

[0044] The control unit 300 can also send control signals to the fertilizer applicator 4, engine 12, steering motor M0, lift cylinder 36, trunnion motor 111, and the like, which are examples of controlled elements, to control the travel, acceleration / deceleration, stopping, and steering of the traveling body 1, 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.

[0045] In FIG. 5, the control unit 300 according to the embodiment has the following functional means (program modules). The position acquisition means 301 detects the current position of the traveling vehicle body 1 based on the detection result of the GNSS positioning device SN0. The work information storage means 302 stores information about work performed by the riding rice transplanter distributed from the distribution server. Examples of the information about work include the travel route within the field, position information such as the work start position, work end position, and turning position, travel speed during work, planting depth, and planting amount per stalk.

[0046] The abnormality detection means 303 has a steering abnormality determination means 303A, a driving abnormality determination means 303B, a gear change abnormality determination means 303C, a work implement abnormality determination means 303D, and an abnormality degree determination means 303E, and detects abnormalities in the riding rice transplanter. The steering abnormality determination means 303A determines whether an abnormality has occurred in the steering system based on the detection result of the steering sensor SN5. As an example, when the steering motor M0 is operated to rotate the steering wheel 16 but the steering sensor SN5 does not detect the rotation of the steering wheel 16, or when the steering sensor SN5 detects the rotation of the steering wheel 16 but the traveling direction does not change in the steered direction, the steering abnormality determination means 303A determines that an abnormality has occurred in the steering system. In other words, it determines that an abnormality such as a failure or malfunction of the steering motor M0, the steering sensor SN5, etc. has occurred.

[0047] The driving abnormality determination means 303B determines whether an abnormality has occurred in the traveling gear (front wheels 6, rear wheels 7, and their transmission system) based on the detection results of the rotation speed sensor SN4. For example, if the GNSS positioning device SN0 detects no change in the current position despite the rotation speed sensor SN4 detecting the rotation of the rear wheels 7, or if the rotation speed sensor SN4 does not detect the rotation of the rear wheels 7 or the rotation speed is insufficient despite the engine 12 or other device being set to a predetermined traveling speed, the driving abnormality determination means 303B determines that an abnormality has occurred in the traveling gear or due to slippage of the wheels 6, 7 in the field. It is preferable to reduce false positives by comparing the period (sampling interval, the time it takes for the rear wheels 7 to rotate a predetermined angle α) at ​​which the rotation speed sensor SN4 detects the rotation of the rear wheels 7 with the vehicle speed to determine whether the abnormality is due to vibration of the traveling vehicle body 1 (abnormal) or due to forward / reverse movement (normal). Therefore, if the detection period of the actually detected rotation exceeds the range of the target detection period corresponding to the traveling speed controlled by automatic traveling or other means, it can be determined to be an abnormality. In addition, by arranging two rotation speed sensors on the axis of the rear wheel 7 with a phase difference, it is possible to distinguish between forward and reverse, and for example, if the vehicle is detected as moving backward even though it should be moving forward at a low speed due to the influence of vibration, it can be determined that this is an abnormality.

[0048] The gear shift abnormality determination means 303C has an asynchronous determination means 303C1 and a clutch disengagement determination means 303C2, and determines whether an abnormality has occurred in the HST, which is the gear shift device, or in the members 101-117 around it. The asynchronous determination means 303C1 determines whether the operations of the trunnion arm 102 and the trunnion motor 111 are not synchronized (asynchronous) based on the detection results of the first potentiometer SN1 and the second potentiometer SN2. As an example, asynchronous operation is determined when the first potentiometer SN1 detects the rotation of the trunnion motor 111 but the second potentiometer SN2 does not detect the movement of the trunnion shaft 101 or the trunnion arm 102, or when the amount of movement of the trunnion arm 102 detected by the second potentiometer SN2 differs from the amount of rotation of the trunnion motor 111 detected by the first potentiometer SN1. Note that in this embodiment, even if 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 also become asynchronous as a result.

[0049] The clutch disengagement determination means 303C2 determines whether clutch disengagement has occurred based on the detection result of the clutch disengagement sensor SN3. Therefore, if the trunnion arm 102 and the trunnion motor 111 become out of sync due to clutch disengagement, the clutch disengagement determination means 303C2 can identify that this is the case. Note that in the embodiment, the clutch disengagement sensor SN3 is installed to detect clutch disengagement, but this is not limiting. For example, it is also possible to use a configuration in which the clutch disengagement sensor SN3 is not installed, and a large deviation is determined to be clutch disengagement based on the detection results of the two potentiometers SN1 and SN2.

[0050] The working machine abnormality determination means 303D determines whether an abnormality has occurred in the seedling planting device 3, which is a working machine, based on the detection results of the lifting sensor SN6. As an example, if the height of the seedling planting device 3 does not descend to a predetermined height during work, or does not rise to a predetermined height during rotation, it is determined that an abnormality has occurred. Alternatively, sensors can be provided in 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.

[0051] The abnormality level determination means 303E determines whether the detected abnormality is mild or severe. In the embodiment, the abnormality level determination means 303E determines whether the abnormality is mild, which allows for the possibility of resuming autonomous driving, or severe, which makes it difficult to resume autonomous driving. For example, if the steering abnormality determination means 303A, the driving abnormality determination means 303B, or the work equipment abnormality determination means 303D determine an abnormality, the abnormality is determined as severe. Furthermore, if the gear shift abnormality determination means 303C determines an abnormality as asynchronous, the abnormality is determined as severe if the deviation of the movement amount of the trunnion arm 102 relative to the rotation amount of the trunnion motor 111 is greater or smaller than a predetermined allowable deviation range, and the abnormality is determined as mild if the deviation is within the allowable range. Furthermore, the abnormality level determination means 303E in the embodiment determines an abnormality as mild if the position acquisition means 301 cannot acquire the current position, for example, if communication with a satellite is temporarily interrupted or if communication with a distribution server or tablet terminal is interrupted.

[0052] In this embodiment, when the clutch disengagement determination means 303C2 determines that mild clutch disengagement has occurred (the deviation is within the allowable range and the clutch has disengaged), the abnormality detection means 303 controls the trunnion motor 111 so that the value detected by the first potentiometer SN1 is in 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 after the trunnion motor 111 is activated, 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 mild is maintained. That is, by performing the operation of returning to the neutral position, it is determined that the clutch disengagement has been resolved (automatic recovery from clutch disengagement).

[0053] On the other hand, if the detection value of the first potentiometer SN1 does not reach the neutral state even after a predetermined time has elapsed since the trunnion motor 111 started operating so that the first potentiometer SN1 is in neutral, if the detection value of the second potentiometer SN2 indicates that the trunnion arm 102 or trunnion shaft 101 has not returned to the neutral state, or if the speed at which the trunnion shaft 101 moves is too slow, the system determines that the abnormality is serious. In other words, even if the neutral position is returned, the clutch disengagement is not resolved, and it is determined that continuing to travel poses a safety or operability problem.

[0054] Even when it is determined that the clutch disengagement has been resolved, it is desirable to perform a check after automatic recovery from the clutch disengagement, for example, by checking whether the detected values ​​of the potentiometers SN1 and SN2 are the maximum forward speed value with the HST in the maximum forward speed position, checking whether the detected values ​​of the potentiometers SN1 and SN2 are the maximum reverse speed value with the HST in the maximum reverse speed position, and checking whether the detected values ​​of the potentiometers SN1 and SN2 are the neutral value with the HST in the neutral position. Note that in the check operation, if clutch disengagement has occurred on the forward side, it is preferable to first check at the maximum reverse speed, and if clutch disengagement has occurred on the reverse side, to first check at the maximum forward speed, as this is expected to resolve the clutch disengagement. If the clutch disengagement is not resolved by the check operation, it is preferable to perform the operation to resolve the clutch disengagement again. Also, if the clutch disengagement is not resolved even after performing the clutch disengagement resolution operation a predetermined number of times (for example, three times), it is preferable to determine that the abnormality is serious.

[0055] In addition, taking into consideration the possibility of deviations in detection by potentiometers SN1 and SN2 during the check operation, it is also possible to 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 ​​at the new maximum forward speed position or maximum reverse speed position, and then terminate the check operation. Furthermore, if the clutch disengagement is not resolved even after performing the clutch disengagement resolution operation a predetermined number of times, it is possible to try to resolve the clutch disengagement by intermittently moving the trunnion motor 111 in a predetermined pattern, performing sudden or slow acceleration / deceleration, and causing the traveling vehicle body 1 to sway.

[0056] The travel control means 304 has an automatic travel control means 304A and a manual travel control means 304B, and controls the travel of the riding rice transplanter. In the embodiment, the travel control means 304 stops the traveling body 1 for safety when an abnormality is detected by the abnormality detection means 303. In the embodiment, when stopping the traveling body 1, the HST is returned to the neutral position to stop the traveling body 1. Therefore, in the embodiment, even if clutch disengagement occurs, the traveling body 1 is braked and stopped by returning the HST to the neutral position.

[0057] Note that when stopping the traveling vehicle body 1, it is possible to stop the traveling vehicle body 1 not only by returning the HST to the neutral position, but also by operating the brake pedal and activating the brake (braking device). In particular, even when control to stop the traveling vehicle body 1 is performed, if the rotation speed sensor SN4 detects rotation even after the time that should have been sufficient for the traveling vehicle body 1 to stop has passed, or if the position acquisition means 301 detects a movement of the current position, i.e., if the traveling vehicle body 1 is moving, it is preferable to activate the brake to ensure safety. Note that when detecting rotation using the front wheels 6, if the front wheels 6 have a configuration in which the clutches can be switched on and off, there is a possibility that only one of the inner and outer wheels will rotate. Therefore, when stopping the traveling vehicle body 1, by forcibly engaging the clutch connecting the left and right front wheels regardless of the turning angle of the steering wheel 16, the left and right wheels will rotate identically, and the movement of the traveling vehicle body 1 can be detected by the rotation speed sensor of the front wheels 6.

[0058] Furthermore, when restarting or switching back to automatic driving mode after being automatically stopped, a specific operation can be performed to prompt the operator to confirm the operation. For example, by preventing restarting until the brake pedal is moved to the locked position (fully depressed position), it is possible to prevent the vehicle from suddenly moving immediately after restarting, thereby improving safety. Furthermore, by disabling restart until an abnormal stop release operation is performed, such as performing a specific screen operation two or more times on the touch panel 201, removing a check fuse, requiring an operation on the terminal side as well as the touch panel 201, turning the key off once, or operating a safety switch, safety can be ensured compared to when restart is possible simply. It is also possible to perform different abnormal stop release operations depending on the type of abnormality that has occurred.

[0059] Furthermore, by using password management, etc., it is possible to prevent use in unsafe conditions by restricting the operation to cancel the abnormal stop to operators with specific authority. Also, from a safety perspective, it is preferable to prevent switching to automatic driving mode if an abnormality continues to be detected even after the operation to cancel the abnormal stop is performed.

[0060] When a user selects the 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 devices), etc. based on the work information stored in the work information storage means 302 to automatically control (automatic driving and automatic operation) the traveling speed and steering of the traveling vehicle body 1, as well as the activation / stop and elevation of the seedling planting device 3. Therefore, the traveling vehicle body 1 travels at a traveling speed along the traveling route, and if the current position deviates from the traveling route, the traveling vehicle body 1 is steered to stay along the traveling route. Because speed and gear change control are performed automatically by the trunnion motor 111, it is desirable to prevent the automatic driving mode from starting unless the gear change lever 17 is in the neutral position. This is because switching to the manual driving mode while the automatic driving mode is running with the gear change lever 17 in a position other than the neutral position may result in sudden acceleration / deceleration depending on the setting of the gear change lever 17, thereby reducing safety.

[0061] When the manual driving mode is selected from the user's touch panel 201 or tablet terminal, etc., the manual driving control means 304B controls the engine 12, etc. in accordance with the operator's driving operations such as the steering wheel 16, gear shift lever 17, accelerator pedal, brake pedal, etc., to control the driving speed and steering of the traveling vehicle body 1, and the raising and lowering of the seedling planting device 3.

[0062] The driving mode switching means (switching means) 305 switches between the automatic driving mode and the manual driving mode. In this embodiment, the driving mode switching means 305 switches the driving mode between the automatic driving mode and the manual driving mode in response to input from the touch panel 201, a tablet terminal, or the like. In principle, the driving mode does not switch automatically until an operator inputs from the touch panel 201, or the like.

[0063] In the embodiment, when the abnormality detection means 303 detects an abnormality while the vehicle is traveling in the automatic traveling mode, if the degree of the abnormality is minor, the traveling mode switching means 305 maintains the automatic traveling mode when the traveling vehicle body 1 is stopped, i.e., does not switch to the manual traveling mode. On the other hand, if the abnormality is severe, when the traveling vehicle body 1 is stopped, the engine 12 is also stopped and the traveling mode is forcibly switched to the manual traveling mode. Therefore, the automatic traveling mode cannot be resumed by operating the tablet terminal alone, and the automatic traveling mode can be resumed only after an operator goes to the traveling vehicle body 1 and checks for safety. It is also possible to perform the aforementioned clutch disengagement resolution operation and check operation after the engine is stopped. In this case, it is preferable for safety reasons to perform the clutch disengagement resolution operation when conditions for performing the operation are met, such as the brake pedal being depressed or the gear shift lever 17 being in neutral. It is also possible to perform the clutch disengagement resolution operation while the engine is stopped, and if the clutch disengagement is resolved, to release the engine 12 from stop and return to the autonomous driving mode simply by remote operation from a tablet terminal.

[0064] In manual driving mode, if an operator is on board and the engine 12 suddenly stops and the vehicle suddenly decelerates, the operator may be injured, so it is preferable not to stop the engine 12. Also, when driving manually, detection results that differ from those obtained during normal driving may be obtained when climbing a ridge or loading a truck, and an abnormality may be erroneously detected. If the engine 12 stops while climbing a ridge, workability will be impaired, so it is preferable not to stop the engine 12. Similarly, even in the automatic driving mode, it is preferable not to immediately stop the engine 12 when an abnormality is detected, for example, when the gear shift lever 17 is manually operated or when an operator is on board, so as to prevent sudden deceleration, etc. Therefore, when an operator is present, it is preferable to stop the engine after an abnormality is detected while decelerating to a certain speed or below, or after traveling a certain distance. At this time, it is preferable to leave the operator informed by voice guidance, a buzzer, a display on the screen, etc. that the engine 12 will soon stop. Note that when the operator is unmanned, immediately stopping the engine 12 can shorten the distance traveled in an abnormal state, ensuring safety and reducing the need to redo work.

[0065] In the seedling transplanter of the embodiment having the above configuration, if an abnormality occurs while traveling in automatic traveling mode, such as a minor abnormality such as loss of the GNSS signal or minor clutch disengagement, the traveling vehicle 1 stops, but the automatic traveling mode is maintained. Therefore, once the GNSS signal loss is recovered or the clutch disengagement is resolved, the automatic traveling mode can be resumed 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 traveling gear, it is important for the operator to go to the traveling vehicle 1 to confirm safety, so the mode is forcibly switched to manual traveling mode. Therefore, compared to the prior art, which forcibly switches to manual traveling mode when an abnormality occurs regardless of the severity of the abnormality and requires the operator to go to the traveling vehicle 1 to confirm safety, workability and work efficiency are improved while ensuring safety.

[0066] (Example of change) The work vehicle of the present invention is not limited to rice transplanters, but can also be applied to seedling transplanters that transplant vegetable seedlings. Also, although a rice transplanter that uses so-called mat-shaped seedlings has been exemplified, the work vehicle is not limited to this, and can also be applied to rice transplanters that use pot-shaped seedlings. Furthermore, although a riding seedling transplanter has been exemplified, the present invention is not limited to this and can also be applied to an autonomously moving work vehicle.

[0067] In addition, although the above example shows a configuration in which all the processing of the means 301 to 305 is centralized in the seedling transplanter, the present invention is not limited to this. One or more of the means 301 to 305 may be provided in a server or computer device connected by a communication line, and a configuration in which processing is distributed may be adopted. [Explanation of symbols]

[0068] 1...Traveling vehicle body, 3...Work equipment, 6,7...Travel gear, 12...Engine, 16...Steering control member, 101... Trunnion axis, 102... Trunnion arm, 107...clutch, 107b...first transmission part, 107c...second transmission part, 111... Trunnion motor, 300...control unit, 301...position acquisition means, 303...Abnormality detection means, 304...Travel control means, 305...switching means, HST: Hydrostatic continuously variable transmission, SN1: first sensor, SN2: second sensor, SN3: Separation detection member.

Claims

1. a traveling vehicle body (1) having an engine (12) and traveling devices (6, 7) that travel by transmitting drive from the engine (12); a work machine (3) supported by the traveling vehicle body (1) and performing work on a farm field; a control unit (300) having a position acquisition means (301) for acquiring the current position of the traveling vehicle body (1); a switching means (305) for switching between an automatic traveling mode in which the traveling vehicle body (1) is automatically traveling in a field based on the information of the current position acquired by the position acquisition means (301) and a manual traveling mode in which the traveling vehicle body (1) is traveling in accordance with the driving operation of a worker; an abnormality detection means (303) for detecting an abnormality related to the work vehicle; and a traveling control means (304) for stopping the traveling vehicle body (1) when an abnormality is detected by the abnormality detection means (303), and for maintaining the automatic traveling mode when the traveling vehicle body (1) is stopped when an abnormality is detected by the abnormality detection means (303); A work vehicle comprising:

2. a steering control member (16) that steers and controls the traveling direction of the traveling vehicle body (1) in the automatic traveling mode; the control unit (300) that stops the engine (12) and switches to a manual driving mode when an abnormality in the steering control member (16) is detected; 2. The work vehicle according to claim 1, further comprising:

3. the control unit (300) that stops the engine (12) and switches to a manual driving mode when an abnormality is detected in the driving device (6, 7); 2. The work vehicle according to claim 1, further comprising:

4. A hydrostatic continuously variable transmission (HST) that changes speed by changing the angle of the swash plate; A trunnion shaft (101) connected to the swash plate to change the angle of the swash plate when rotated; a trunnion arm (102) connected to the trunnion shaft (101) to rotate the trunnion shaft (101); a trunnion motor (111) for moving the trunnion arm (102); a first sensor (SN1) for detecting the rotational position of the trunnion motor (111); a second sensor (SN2) for detecting the position of the trunnion arm (102); the control unit (300) stopping the engine (12) and switching to a manual travel mode when it is determined that the operations of the trunnion arm (102) and the trunnion motor (111) are not synchronized based on the detection results of the first sensor (SN1) and the second sensor (SN2); 2. The work vehicle according to claim 1, further comprising:

5. a clutch (107) disposed between the trunnion motor (111) and the trunnion arm (102) for turning on and off transmission; the control unit (300) that brakes the traveling vehicle body (1) when it is determined that a deviation in transmission by the clutch (107) has occurred based on the detection result of the first sensor (SN1) and the detection result of the second sensor (SN2); 5. The work vehicle according to claim 4, further comprising:

6. the control unit (300) that, when a deviation in transmission by the clutch (107) is within a predetermined range based on the detection result of the first sensor (SN1) and the detection result of the second sensor (SN2), operates the trunnion motor (111) so that the detection value of the first sensor (SN1) is in a neutral state, thereby braking the traveling of the traveling vehicle body (1); 6. The work vehicle according to claim 5, further comprising:

7. the control unit (300) stopping the engine (12) when the detection value of the first sensor (SN1) does not reach the neutral state even after a predetermined time has elapsed since the trunnion motor (111) started to operate so that the detection value of the first sensor (SN1) reaches the neutral state; 7. The work vehicle according to claim 6, further comprising:

8. the clutch (107) having a first transmission part (107b) to which drive from the trunnion motor (111) is transmitted, and a second transmission part (107c) connected to the trunnion arm (102) and capable of contacting and separating from the first transmission part (107b), wherein when the first transmission part (107b) and the second transmission part (107c) come into contact with each other, power from the trunnion motor (111) is transmitted to the trunnion arm (102); a separation detection member (SN3) that detects movement of the second transmission part (107c) in a direction away from the first transmission part (107b); 6. The work vehicle according to claim 5, further comprising:

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