Work vehicle

Abstract

To provide a work vehicle that enables operation related to automatic steering to be performed with preferable operability.SOLUTION: A work vehicle includes: a steering part; a vehicle body capable of traveling by either manual steering by the steering part or automatic steering of the steering part based on a travel planned line; a steering switch operation tool for switching start or end of the automatic steering; and a set steering tool capable of at least switching travel setting of the automatic steering. The work vehicle does not accept start of the automatic steering unless a travel distance reaches a predetermined distance or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a work vehicle such as a rice transplanter. [Background technology]

[0002] There is known a rice transplanter that has a planting device attached to a vehicle body so that it can be raised and lowered, a steering motor that drives a steering handle, and a control device that causes the steering motor to drive the steering handle and assist the vehicle body in turning (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-24541 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-335720 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional transplanters such as the rice transplanter described above cannot allow the vehicle body's turning assistance to begin when the working implement is raised. They also have an automatic / manual changeover switch that serves as a mode changeover operation means for switching between automatic and manual driving modes. However, while this automatic / manual changeover switch can be used to switch between automatic and manual driving modes, it cannot perform other operations related to automatic steering. To perform other operations, a separate switch must be operated, resulting in poor operability.

[0005] For example, conventional transplanters are unable to allow the start of turning assistance for the vehicle body when the working device is lowered, the vehicle body moves forward while work is being performed using the working device, the vehicle body stops and moves backward, the working device is raised, and then the vehicle body stops.

[0006] The present invention takes into consideration the above-mentioned conventional problems and aims to provide a work vehicle that can easily perform multiple operations related to automatic steering and that can allow the start of turning assistance for the vehicle body when the work implement is raised. [Means for solving the problem]

[0007] The first invention is a work vehicle that includes a steering unit, a vehicle body that can travel either by manual steering using the steering unit or by automatic steering using the steering unit based on a planned travel line, a steering switching device that switches between starting and ending the automatic steering, and a switchable setting steering device that sets at least the travel settings for the automatic steering.

[0008] A second aspect of the present invention is the work vehicle according to the first aspect, characterized in that the start of the automatic steering is not accepted unless the work vehicle has traveled a predetermined distance or more.

[0009] The third invention is a work vehicle as described in the first or second invention, characterized in that the planned driving line is registered by acquiring a first reference point and a second reference point within the field, and the automatic steering is started when the vehicle body is parallel to the planned driving line and the steering wheel is straight. [Effects of the Invention]

[0010] The present invention makes it possible to perform a plurality of operations related to automatic steering with good operability. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view of a rice transplanter according to an embodiment of the present invention; [Figure 2] Block diagram of a power transmission system of a rice transplanter according to an embodiment of the present invention [Figure 3] Block diagram of a control system for a rice transplanter according to an embodiment of the present invention [Figure 4] FIG. 1 is an explanatory diagram of a back turn of a rice transplanter according to an embodiment of the present invention; [Figure 5] FIG. 1 is a partial perspective view of the vicinity of a straight-line assist lever of a rice transplanter according to an embodiment of the present invention; [Figure 6] FIG. 1 is a partial perspective view of the vicinity of an assist mode switch of a rice transplanter according to an embodiment of the present invention; [Figure 7] (a) is a partial front view of the vicinity of the GNSS antenna of the rice transplanter according to the embodiment of the present invention; (b) is a partial left side view of the vicinity of the GNSS antenna of the rice transplanter according to the embodiment of the present invention; [Figure 8] FIG. 1 is a partial perspective view of the GNSS antenna stay and its vicinity in a rice transplanter according to an embodiment of the present invention; [Figure 9] 1 is an explanatory diagram of the operation of the rice transplanter according to the embodiment of the present invention (part 1) [Figure 10] 1 is a diagram illustrating the operation of a rice transplanter according to an embodiment of the present invention (part 2); [Figure 11] 1 is a diagram illustrating the operation of the rice transplanter according to the embodiment of the present invention (part 3) DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0013] The rice transplanter of this embodiment is an example of a transplanter in the present invention.

[0014] The planting device 100 is an example of a working device in the present invention, the steering handle 52 is an example of a steering member in the present invention, and the steering motor 45 is an example of a steering member drive device in the present invention.

[0015] First, the configuration and operation of the rice transplanter of this embodiment will be specifically described with reference to FIGS.

[0016] FIG. 1 is a perspective view of a rice transplanter according to an embodiment of the present invention, and FIG. 2 is a block diagram of a power transmission system of the rice transplanter according to an embodiment of the present invention.

[0017] While explaining the operation of the rice transplanter of this embodiment, a turning assist method of an invention related to the present invention will also be explained.

[0018] The rice transplanter of this embodiment is a riding mat seedling rice transplanter for planting eight rows, and the planting device 100 has four planting units, each of which has a pair of two planting tools on the left and right.

[0019] Of course, the rice transplanter is not limited to a riding mat seedling rice transplanter that plants eight rows, but may also be, for example, a riding pot seedling rice transplanter that plants ten rows.

[0020] First, the basic configuration and operation of the rice transplanter of this embodiment will be explained. Therefore, the operation of the control device 200 will be explained in detail later.

[0021] The driving unit 50 has a seat 51 provided above the engine cover.

[0022] A steering handle 52 for operating the front wheels 31 is provided in front of the seat 51. Horizontal step floors are provided on both the left and right sides of the engine cover. Furthermore, spare seedling loading tables 101 are provided on both the left and right sides of the steering handle 52.

[0023] The traveling device 30 is a device that causes the vehicle body 10 to travel using front wheels 31 and rear wheels 32.

[0024] The soil leveling device 60 is a device that levels a field using a soil leveling rotor mechanism 61 and a soil leveling float mechanism 62.

[0025] The line-drawing marker 80 is a marker that is attached so as to be retractable to the vehicle body 10 and forms a straight line marking in the field as a guide for the next planting travel route.

[0026] The planting device 100 is attached to the rear side of the vehicle body 10 via a planting device lifting device 90.

[0027] The rotational power of the engine 20 attached to the main frame is transmitted to the main transmission mechanism 41, which is an HST (Hydro Static Transmission) mechanism. The rotational power, the speed of which is changed in the main transmission mechanism 41 and the sub-transmission mechanism 42, is separated into traveling power used in the traveling device 30 and the like, and externally extracted power used in the planting device 100 and the like.

[0028] A portion of the running power is transmitted to the left and right front wheel final cases to drive the pair of left and right front wheels 31, and the remainder of the running power is transmitted to the left and right rear wheel gear cases 43 to drive the pair of left and right rear wheels 32. Then, a portion of the running power transmitted to the rear wheel gear cases 43 is transmitted to the soil leveling device 60 and the fertilizing device 70.

[0029] Next, the configuration and operation of the rice transplanter of this embodiment will be described more specifically with reference mainly to FIGS.

[0030] Here, FIG. 3 is a block diagram of a control system of the rice transplanter according to the embodiment of the present invention, and FIG. 4 is an explanatory diagram of the back turn of the rice transplanter according to the embodiment of the present invention.

[0031] The control device 200 is a device that performs various controls using not only lever operation using the main speed change lever 53, sub-speed change lever 54 or straight-line assist lever 55, and switch operation using the assist mode switch 56, but also detection results from the rear wheel rotation speed sensor 210 or the planting device lifting / lowering sensor 220.

[0032] The positioning system 300 is a system that performs positioning by DGPS (Differential Global Positioning System) technology, which uses GPS (Global Positioning System), a typical GNSS (Global Navigation Satellite System).

[0033] For example, a straight-line control program for driving straight from point P0 to point P1 is stored in a straight-line control ECU (Electronic Control Unit) of the positioning system 300, while a turning control program for making U-turns and back turns at the edge of a field F, etc., is stored in a turning control ECU inside the hood.

[0034] Just as the straight-line control program is used to align the travel path to the next planting travel path in the final stage of the back turn from point P1 to point P5 via points P2, P3, and P4, the transition from turning control to straight-line control is performed between points P4 and P5. Regarding the control output to the steering motor 45, a control signal from the turning control ECU is output from the straight-line control ECU.

[0035] As shown in FIG. 5, the straight driving assist is started by operating the finger up lever of the straight driving assist lever 55 in the direction of the arrow Xu.

[0036] FIG. 5 is a partial perspective view of the vicinity of the straight-travel assist lever 55 of the rice transplanter according to the embodiment of the present invention.

[0037] Point A, which is the starting reference point for the straight driving assist, is obtained by operating the finger down lever of the straight driving assist lever 55 in the direction of arrow Xd, and point B, which is the ending reference point for the straight driving assist, is obtained by continuing to operate the finger down lever of the straight driving assist lever 55 in the direction of arrow Xd.

[0038] The operation of obtaining point A will be specifically described below with reference mainly to FIG.

[0039] FIG. 9 is a first explanatory diagram of the operation of the rice transplanter according to the embodiment of the present invention.

[0040] (1) When the operator on board operates the finger down lever using the straight driving assist lever 55 while the vehicle is moving or stopped, the A point acquisition operation is performed. At this time, the operating conditions conform to the straight driving assist conditions. Regarding the display and warning, the A point lamp is turned on, the B point lamp is turned on and off, the automatic lamp is turned off, the straight driving lamp is turned off, the U-turn lamp is turned off, the back turn lamp is turned on, and the electronic buzzer outputs one short buzzer sound. Regarding the signal output from the turning control ECU to the straight driving control ECU, an A point acquisition signal is output.

[0041] The operation of acquiring point B will be specifically described below with reference mainly to FIG.

[0042] (2) When the operator operates the finger down lever using the straight-line assist lever 55 while the vehicle is moving or stopped, the B-point acquisition operation is performed. At this time, the operating conditions conform to the straight-line assist conditions, but the auto-marker operation, which does not include the projection of both the left and right line drawing markers 80, must be performed. Regarding displays and warnings, the A-point lamp is turned on, the B-point lamp is turned on, and the automatic lamp is turned off. The operation of the straight-line lamp, U-turn lamp, and back-turn lamp conforms to the operation in the above-mentioned items, and the electronic buzzer outputs one short buzzer sound. Regarding signal output from the turning control ECU to the straight-line control ECU, not only the B-point acquisition signal is output, but also a left or right target line selection signal, which is the same as the auto-marker lamp output. Regarding signal output from the straight-line control ECU to the turning control ECU, the reference line acquisition operation is performed, and the target line generation operation is performed according to the working width and the target line selection signal output.

[0043] The standby operation will be specifically described below mainly with reference to FIG.

[0044] (3) When the operator operates the finger-up lever using the straight-line assist lever 55 while the vehicle is moving forward, the straight-line control operation begins and the turning control operation is put into standby. At this time, the straight-line assist conditions must be satisfied, the planting device 100 must be lowered, and straight-line assist must be performed. Regarding displays and warnings, the A-point lamp is turned on, the B-point lamp is turned on, the automatic lamp is turned on, the straight-line lamp, the U-turn lamp, and the reverse-turn lamp operate in accordance with the operations described above, and the electronic buzzer emits a single short buzzer sound. Signals output from the turning control ECU to the straight-line control ECU include not only an automatic steering signal but also a center target line selection signal, and the steering motor 45 is set to a rotational speed. Signals output from the straight-line control ECU to the turning control ECU control the output of the steering motor 45 to drive toward the target line. Note that automatic steering may not be initiated unless the vehicle has traveled a predetermined distance. Furthermore, unless the vehicle body is parallel to the intended travel line and the steering is straight, the output control operation of the steering motor 45 for traveling toward the target line will not be performed.

[0045] (4) When the vehicle is moving forward, the target line direction output operation is performed without any operation by the on-board operator. At this time, the edge warning buzzer must be sounding, and straight-line assist must be performed. Regarding displays and warnings, the A-point lamp is turned on, the B-point lamp is turned on, the automatic lamp is turned on, the straight-line lamp, the U-turn lamp, and the back-turn lamp operate in accordance with the operations described above, and the electronic buzzer outputs one short buzzer sound. Regarding signal output from the turning control ECU to the straight-line control ECU, a left or right target line selection signal is output, which is the same as the auto marker lamp output. Regarding signal output from the straight-line control ECU to the turning control ECU, the target line determination operation is performed according to the indicated direction.

[0046] (5) When the operator presses the ridge alarm cancel switch while the vehicle is moving forward, the ridge stop control is released and the ridge alarm buzzer stops sounding. At this time, the ridge alarm buzzer must be sounding and the straight-line assist must be in operation. Regarding displays and warnings, the A-point lamp is turned on, the B-point lamp is turned on, the automatic lamp is turned on, the straight-line lamp, the U-turn lamp, and the reverse turn lamp operate in accordance with the operations described above, and the electronic buzzer emits one short beep.

[0047] As shown in FIG. 6, an assist mode switch 56 has been added, so that not only the straight-line assist mode but also the U-turn assist mode and the back-turn assist mode can be selected, realizing highly convenient switching of turning patterns.

[0048] FIG. 6 is a partial perspective view of the vicinity of the assist mode switch 56 of the rice transplanter according to the embodiment of the present invention.

[0049] The control device 200 causes the steering motor 45 that drives the steering wheel 52 to drive the steering wheel 52, thereby assisting the vehicle body 10 in turning.

[0050] A mode is provided that allows the start of turning assistance for the vehicle body 10 when the planting device 100, which is attached to the vehicle body 10 so as to be able to rise and fall, is raised.

[0051] Such a mode that allows turning assist to begin when the planting device 100 is raised is utilized for back-turn assist, which will be described in detail later.

[0052] A mode is also provided that prohibits the start of turning assistance for the vehicle body 10 when the planting device 100 is raised.

[0053] Such a mode that prohibits the start of turning assistance when the planting device 100 is raised is used for U-turn assistance.

[0054] When the planting device 100 is raised, the planting device 100 is lowered, the vehicle body 10 moves forward while the planting device 100 performs work, the vehicle body 10 stops and moves backward, the planting device 100 is raised, and then the vehicle body 10 stops.

[0055] If the turning assist start condition is not satisfied, the start of turning assist is not permitted.

[0056] The turning assist start condition is a condition related to the vehicle body backward travel distance Db until the vehicle body 10 stops after the vehicle body 10 stops and moves backward and the planting device 100 is raised.

[0057] The turning assist start condition is a condition related to the forward distance Df of the vehicle body 10 after the planting device 100 is lowered and the planting device 100 performs work while the vehicle body 10 moves forward until the vehicle body 10 stops.

[0058] With reference mainly to FIG. 10, the reverse control operation for going from point P1 to point P2 when the back turn assist mode is selected will be specifically described below.

[0059] FIG. 10 is a second explanatory diagram of the operation of the rice transplanter according to the embodiment of the present invention.

[0060] (6) When the operator operates the main shift lever 53 so that the lever position of the main shift lever 53 is in the reverse position while the vehicle is stopped, the back-turn assist control operation is initiated. Specifically, the planting operation is turned off, the planting device 100 is raised, the vehicle body 10 moves backward, the rear wheel rotation speed sensor 210 detects pulses through the rear wheel pulse count operation, the vehicle speed is set according to the lever position of the main shift lever 53, and the steering wheel position of the steering handle 52 is returned to the center position for straight driving. At this time, the engine 20 must be running, the point A and point B acquisition operations must be completed, the positioning system 300 must be receiving signals normally, the deviation angle from the target line direction (the direction from point P1 to point P2) must be less than 30 degrees, the steering angle of the steering wheel 52 must be 30 degrees or less, the tilt angle of the vehicle body 10 must be less than 8 degrees, the lever position of the auxiliary gearshift lever 54 must be a planting speed position different from the road speed position, the automatic turning mode switch must be on to automatically perform lifting of the planting device 100 during turning, the auto-marker operation must be performed to deploy only the left and right line markers 80, and the difference between the vehicle body forward distance Df of the current planting travel path and the vehicle body forward distance Df of the immediately preceding planting travel path must be less than 5 meters. For example, if this difference exceeds 5 meters, the backturn assist control operation may be canceled. Regarding the displays and warnings, the A point lamp is turned on, the B point lamp is turned on, the automatic lamp is turned on, the straight ahead lamp, the U-turn lamp and the reverse turn lamp operate in accordance with the operations in the above items, and the electronic buzzer continuously outputs a short buzzer sound until the end of reverse. Regarding the signal output from the turning control ECU to the straight ahead control ECU, a steering signal is output at the center of the steering wheel, and the steering motor 45 outputs so that the steering wheel position of the steering wheel 52 is returned to the center position for straight ahead.

[0061] Regarding the count of the rear wheel rotation speed sensor 210, the count accumulation condition is that counting is always performed when reversing is performed, and there are no prohibition conditions. The reset condition is that resetting is performed when the automatic turning mode switch, which automatically performs operations such as raising the planting device 100 as the device turns, is turned on, and when the difference between the vehicle body forward distance Df on the current planting travel path and the vehicle body forward distance Df on the immediately previous planting travel path is 5 meters or less and the backturn assist control operation is initiated.

[0062] Because the vehicle body forward distance Df is not reset when the planting device 100 is raised, it can be determined that the difference between the vehicle body forward distance Df of the current planting travel path and the vehicle body forward distance Df of the immediately preceding planting travel path is 5 meters or less even when the planting device 100 is raised. Therefore, when the back-turn assist mode is selected by the assist mode switch 56, not only is the start of turning assistance for the vehicle body 10 appropriately permitted, but safety is also improved.

[0063] It is desirable that the back-turn assist control operation be performed only when a vehicle body reverse detection switch for detecting that the vehicle body 10 is moving backward is turned on. For example, it is desirable that the intermittent output of the buzzer sound described above is not performed if the vehicle body 10 is not moving backward. This is because, when the operator on board uses the main shift lever 53 to perform a backlift to supply seedlings at the edge of the paddy field F, the vehicle body 10 is not moving backward but is stopped, so the vehicle body reverse detection switch is not turned on and no meaningless buzzer sound is output.

[0064] The handle position of the steering wheel 52 may be fixed to the center position for straight ahead driving so that the back turn assist control operation by the rear wheel drive is stable.

[0065] When the straight-line driving assist is cancelled, the on-board operator must operate the steering wheel 52 to reach point P1. Therefore, it is desirable that the reverse control operation to get from point P1 to point P2 be performed based on the accurate direction from point P1 to point P2, and not rely on the on-board operator's steering operation, which may not always be accurate.

[0066] Since the upper limit of the trunnion opening of the main transmission mechanism 41, which is an HST mechanism, is regulated in order to regulate the upper limit of the vehicle speed as described above, point P2, where the vehicle stops, is less likely to shift, steering is stable, and safety is improved.

[0067] The vehicle may be stopped after reversing automatically by determining that the vehicle reversing distance Db obtained using the detection of the rear wheel rotation speed sensor 210 has reached 1 meter, or may be stopped manually by the operator operating the main shift lever 53.

[0068] In the latter case, since the operator on board may operate the main shift lever 53 so that the lever position of the main shift lever 53 is in the forward position, it is desirable that the vehicle reverse distance OK / NG determination be made based on the vehicle reverse distance Db. When the vehicle reverse distance Db is less than 1 meter or equal to or greater than 3 meters, the vehicle reverse distance NG determination is made, and the back-turn assist control operation is canceled. When the vehicle reverse distance Db is equal to or greater than 1 meter but less than 3 meters, the vehicle reverse distance OK determination is made, and the back-turn assist control operation is continued.

[0069] If the vehicle body reverse distance Db is too small, the turning vehicle body 10 may come into contact with the edge of the field F if the size of the vehicle body 10 is large.

[0070] If the vehicle body reverse distance Db is too large, turning accuracy may deteriorate. That is, in the first stage of turning from point P2 to point P3, the direction of the vehicle body 10 is mainly changed regardless of the position of the vehicle body 10, and in the second stage of turning from point P4 to point P5, the position of the vehicle body 10 is adjusted to align the travel path with the next planting travel path. However, if the vehicle body reverse distance Db is too large, deviations in the distance between the planting travel paths are likely to occur.

[0071] Not only the vehicle body reverse distance Db obtained by using the detection of the rear wheel rotation speed sensor 210, but also the determination of whether the vehicle body reverse distance is OK or NG may be displayed on a monitor or the like.

[0072] (7) When the vehicle is moving backward until it stops, if the operator operates the main shift lever 53 so that the lever position of the main shift lever 53 is in the neutral position or depresses the vehicle stop pedal, the vehicle 10 will stop according to the position of the main shift lever 53, but the back-turn assist control operation will not be stopped. Regarding displays and warnings, the operation of the A point lamp, B point lamp, automatic lamp, straight ahead lamp, U-turn lamp, back-turn lamp, and electronic buzzer will be the same as those described above. Regarding signal output from the turning control ECU to the straight ahead control ECU, the steering signal output will be maintained, but the output operation of the steering motor 45 will be stopped and the steering angle will be maintained.

[0073] (8) Also, when the vehicle is moving backward until it stops, if the operator operates the main shift lever 53 so that the lever position of the main shift lever 53 is in the forward position, the vehicle speed is set according to the lever position of the main shift lever 53, and the back-turn assist control operation is stopped. Regarding displays and warnings, the operation of the A-point lamp, B-point lamp, and automatic lamp is the same as that in the straight-line assist standby mode, the straight-line lamp is turned on and off, the U-turn lamp and back-turn lamp are the same as those in the above-mentioned items, and the electronic buzzer outputs one long buzzer sound. Regarding signal output from the turning control ECU to the straight-line control ECU, a steering signal is output waiting for steering wheel operation, and the steering motor 45 outputs so that the torque is turned off.

[0074] (9) Also, when the vehicle is moving backward until it stops, if the operator on board operates the finger-up lever using the straight-line assist lever 55, the back-turn assist control operation is stopped. Regarding displays and warnings, the operation of the A-point lamp, B-point lamp, and automatic lamp conforms to the operation in straight-line assist standby, the straight-line lamp is turned on and off, the U-turn lamp and back-turn lamp operate conforms to the operation in the above-mentioned items, and the electronic buzzer outputs one long buzzer sound. The signal output from the turning control ECU to the straight-line control ECU conforms to the signal output in the above-mentioned items.

[0075] (10) Furthermore, when the vehicle is moving backward until it stops, if the operator turns off the automatic turning mode switch, which automatically raises the planting device 100 as the vehicle turns, the back-turn assist control operation is stopped. At this time, the operating conditions correspond to the automatic turning interruption conditions. Regarding displays and warnings, the operation of the A-point lamp, B-point lamp, and automatic lamp conforms to the operation in the straight-line assist standby mode, the straight-line lamp is turned on and off, the U-turn lamp is turned on and off, the back-turn lamp operates in accordance with the operation described above, and the electronic buzzer outputs one long buzzer sound. Signal output from the turning control ECU to the straight-line control ECU conforms to the signal output described above.

[0076] (11) Furthermore, when the vehicle is moving backward until it stops, if the operator on board operates the steering wheel 52 or the like, the back-turn assist control operation may be stopped.

[0077] (12) When the vehicle is in reverse until it stops, reverse travel is stopped and the vehicle is stopped, even without any operation by the onboard operator, and the turning control operation is put into standby. At this time, the detection value of the rear wheel rotation speed sensor 210 must reach the first predetermined value. Regarding displays and warnings, the A-point lamp is turned on, the B-point lamp is turned on, the automatic lamp is turned on, the straight-ahead lamp is turned off, the U-turn lamp and reverse-turn lamp operate in accordance with the operations described above, and the electronic buzzer emits one short buzzer sound. Regarding the signal output from the turning control ECU to the straight-ahead control ECU, a left or right target line selection signal is output, which is the same as the auto marker lamp output. Regarding the signal output from the straight-ahead control ECU to the turning control ECU, the target line determination operation is performed according to the indicated direction.

[0078] With reference mainly to FIG. 11, the turning control operation for traveling from point P2 to point P5 via points P3 and P4 when the back turn assist mode is selected will be specifically described below.

[0079] FIG. 11 is a diagram (part 3) illustrating the operation of the rice transplanter according to the embodiment of the present invention.

[0080] (13) When the operator operates the main shift lever 53 while the vehicle is stationary, the vehicle speed is set to the forward position, with an upper limit of 0.9 meters per second (50 percent of the maximum speed) according to the position of the main shift lever 53. The steering motor 45 then controls the output of the steering wheel 52, rotating the steering wheel 52 in the indicated direction. At this time, the back-turn assist control must be active, and the planting device 100 must be raised. Regarding displays and warnings, the A-point lamp, B-point lamp, automatic lamp, straight ahead lamp, U-turn lamp, and back-turn lamp operate in accordance with the operations described above, and the electronic buzzer continuously emits a short buzzer sound until the turn is completed. Regarding signal output from the turn control ECU to the straight ahead control ECU, a steering signal for turning is output, and the steering motor 45 outputs power to move in the direction of the target line.

[0081] When the vehicle is stopped after reversing manually by the operator operating the main shift lever 53, the above-mentioned vehicle reversing distance OK determination is made, and when the back-turn assist control operation continues, an output operation of the steering motor 45 is performed to move the line drawing marker 80 of the current planting travel route in the direction of swinging out.

[0082] Since the upper limit of the trunnion opening of the main transmission mechanism 41, which is an HST mechanism, is regulated in order to regulate the upper limit of the vehicle speed as described above, even if the upper limit of the response speed of the steering motor 45 is 170 degrees per second, the turning radius when the steering wheel 52 is turned is unlikely to increase as the vehicle travel distance increases, resulting in stable steering and improved safety.

[0083] (14) When the vehicle is moving forward, the rotation of the steering motor 45 is stopped and the steering angle is maintained even if the operator does not operate it. At this time, the back-turn assist control operation must be performed, and the detection value of the transmission steering angle sensor, which is used as an automatic turning steering angle sensor to automatically perform operations such as raising the planting device 100 during turning, must be the set angle value. Regarding displays and warnings, the operation of the A-point lamp, B-point lamp, automatic lamp, straight ahead lamp, U-turn lamp, back-turn lamp, and electronic buzzer is the same as the operation in the items described above. Regarding signal output from the turning control ECU to the straight ahead control ECU, the steering signal output is maintained, but the output operation of the steering motor 45 is stopped and the steering angle is maintained.

[0084] In order to stabilize the steering by suppressing the vehicle speed at the beginning of a turn, the upper limit of the trunnion opening of the main transmission mechanism 41 described above may be increased as the steering angle approaches the target steering angle.

[0085] To reduce variation in the turning start point, which affects turning accuracy, the vehicle 10 may be driven straight from point P1 until it reaches the turning start point, which is, for example, a vehicle backward distance Db of 1 meter. Arrival at the turning start point may be determined by detecting the forward and backward vehicle distances using the rear wheel rotation speed sensor 210, and the steering angle may be fixed for straight driving. Alternatively, arrival at the turning start point may be determined by receiving DGPS data from the positioning system 300 from the time the planting device 100 is raised, and straight steering may be performed along the reference line direction, which is the direction from point P0 to point P1. In the former case, control is simplified by using a straight-line control ECU, while in the latter case, accuracy is improved by using a turning control ECU.

[0086] (15) When the vehicle is moving forward, if the operator operates the main shift lever 53 so that the lever position of the main shift lever 53 is in the neutral position or depresses the vehicle stop pedal, the vehicle 10 will stop according to the position of the main shift lever 53, but the back-turn assist control operation will not be stopped. Regarding displays and warnings, the operation of the A point lamp, B point lamp, automatic lamp, straight ahead lamp, U-turn lamp, back-turn lamp, and electronic buzzer will be the same as those described above. Regarding signal output from the turning control ECU to the straight ahead control ECU, the steering signal output will be maintained, but the output operation of the steering motor 45 will be stopped and the steering angle will be maintained.

[0087] (16) Furthermore, when the vehicle is moving forward, if the operator on board operates the finger-up lever using the straight-line assist lever 55, the back-turn assist control operation is stopped. Regarding displays and warnings, the operation of the A-point lamp, B-point lamp, and automatic lamp conforms to the operation in straight-line assist standby, the straight-line lamp is turned on and off, the operation of the U-turn lamp and back-turn lamp conforms to the operation in the above-mentioned items, and the electronic buzzer outputs one long buzzer sound. Regarding signal output from the turning control ECU to the straight-line control ECU, a steering signal is output waiting for steering wheel operation, and the steering motor 45 outputs so that the torque is turned off.

[0088] (17) Also, when the vehicle is moving forward and the operator operates the main shift lever 53 so that the lever position of the main shift lever 53 is in the reverse position, the vehicle speed is set according to the position of the main shift lever 53, and the back-turn assist control operation is stopped. Regarding displays and warnings, the operation of the A-point lamp, B-point lamp, and automatic lamp conforms to the operation in the straight-line assist standby mode, the straight-line lamp is turned on and off, the U-turn lamp and back-turn lamp conform to the operation in the above-mentioned items, and the electronic buzzer outputs one long buzzer sound. The signal output from the turning control ECU to the straight-line control ECU conforms to the signal output in the above-mentioned items.

[0089] (18) Furthermore, when the vehicle is moving forward, if the operator turns off the automatic turning mode switch, which automatically raises the planting device 100 while the vehicle is turning, the back-turn assist control operation is stopped. At this time, the operating conditions correspond to the automatic turning interruption conditions. Regarding displays and warnings, the operation of the A-point lamp, B-point lamp, and automatic lamp conforms to the operation in the straight-line assist standby mode, the straight-line lamp is turned on and off, the U-turn lamp is turned on and off, the back-turn lamp operates in accordance with the operation described above, and the electronic buzzer outputs one long buzzer sound. The signal output from the turning control ECU to the straight-line control ECU conforms to the signal output described above.

[0090] (19) When the vehicle is moving forward, the steering wheel position of the steering wheel 52 is returned to the center position for straight ahead driving without any operation by the operator. At this time, the back-turn assist control operation must be performed, and the detection value of the rear wheel rotation speed sensor 210 for the rear wheel 32 on the inside of the turn must reach the second predetermined value. Regarding displays and warnings, the operation of the point A lamp, point B lamp, automatic lamp, straight ahead lamp, U-turn lamp, back-turn lamp, and electronic buzzer conforms to the operation in the items described above. Regarding signal output from the turning control ECU to the straight ahead control ECU, a steering signal for the center of the steering wheel is output, and the steering motor 45 outputs so that the steering wheel position of the steering wheel 52 is returned to the center position for straight ahead driving.

[0091] Arrival at point P3, the end point of the first stage turn, is determined by determining whether the deviation angle from the target line direction, which is the direction from point P6 to point P5, is 70 degrees or more, without using the detection value of the rear wheel rotation speed sensor 210. Therefore, the effect of wheel slip in the field can be ignored.

[0092] In the temporary straight-line driving between the first stage and second stage of a so-called U-shaped turn, the handle position of the steering wheel 52 is returned to the center position for straight-line driving, and a temporary straight-line driving control operation is initiated in which the steering angle is fixed.

[0093] When the deviation angle from the target line direction, which is the direction from point P6 to point P5, is equal to or greater than 0 degrees and less than 90 degrees, the steering wheel 52 may be rotated at a constant angle that is the same as the turning direction angle even in the temporary straight-line control operation in response to the first-stage turn being too small. When the deviation angle from the target line direction, which is the direction from point P6 to point P5, is 90 degrees or greater, the steering wheel 52 may be rotated at a constant angle that is opposite to the turning direction angle even in the temporary straight-line control operation in response to the first-stage turn being too large. When the deviation angle from the target line direction, which is the direction from point P6 to point P5, is between 87 (= 90 - 3) degrees and 93 (= 90 + 3) degrees, the steering angle may be maintained to maintain a straight-line state.

[0094] Arrival at point P4, which is the end point of the temporary straight-line driving, is determined using the detection value of rear wheel rotation speed sensor 210. For example, arrival at point P4 is determined by determining that the rear wheel pulse count, which is the detection value of rear wheel rotation speed sensor 210 of rear wheel 32 on the inside of the turn, has reached 30 after the temporary straight-line driving control operation has started.

[0095] When the backturn assist control operation is initiated, a straight line extending from point P3 to point P4, perpendicular to the reference line extending from point P0 to point P1, may be set as the turning target line. The distance Δ between point P1, where the planting device 100 is raised, and the turning target line is approximately equal to the product of the distance between planting rows and half the number of planting rows (4 (= 8 / 2)). Therefore, the distance between the turning target line and the edge of the paddy field F is sufficiently large so that the turning vehicle body 10 does not come into contact with the edge of the paddy field F. Since the vehicle body moves forward after reversing toward this turning target line, which is accurately set using latitude and longitude, the accuracy of the U-shaped turn is improved.

[0096] Instead of a turning target line that is a straight line extending from point P3 to point P4, point P4 may be set as a turning target point between the reference line of the current planting travel route extending from point P0 to point P1 and the reference line of the next planting travel route extending from point P6 to point P5. The distance δ between the turning target point and the reference line of the next planting travel route is a distance that approximately matches the turning radius. The accuracy of the U-shaped turn is improved because temporary straight travel ends upon reaching such a turning target point, which is accurately set using latitude and longitude.

[0097] (20) When the vehicle is moving forward, the steering handle 52 is rotated according to a set angle value by utilizing an automatic turning steering angle sensor to automatically perform operations such as raising the planting device 100 during turning, without the operator's intervention. At this time, the back-turn assist control operation must be performed, and the detection value of the rear wheel rotation speed sensor 210 must reach the third predetermined value. Regarding displays and warnings, the operation of the A-point lamp, B-point lamp, automatic lamp, straight ahead lamp, U-turn lamp, back-turn lamp, and electronic buzzer is the same as the operation described above. Regarding signal output from the turning control ECU to the straight ahead control ECU, a turning steering signal is output, and the steering motor 45 outputs power to move in the direction of the target line.

[0098] (21) When the vehicle is moving forward, the rotation of the steering motor 45 is stopped and the steering angle is maintained even if the operator does not operate it. At this time, the back-turn assist control operation must be performed, and the detection value of the automatic turning steering angle sensor, which automatically performs operations such as raising the planting device 100 as the vehicle turns, must be the set angle value. Regarding displays and warnings, the operation of the A-point lamp, B-point lamp, automatic lamp, straight ahead lamp, U-turn lamp, back-turn lamp, and electronic buzzer is the same as the operation in the items described above. Regarding signal output from the turning control ECU to the straight ahead control ECU, the steering signal output is maintained, but the output operation of the steering motor 45 is stopped and the steering angle is maintained.

[0099] In this way, when the temporary straight running ends, the steering handle 52 is turned in accordance with the turning direction, and the second stage turning is performed.

[0100] (22) When the vehicle is moving forward, the steering wheel position of the steering wheel 52 is returned to the center position for straight ahead driving without any operation by the onboard operator. At this time, the back-turn assist control operation must be performed, and the deviation angle from the target line direction, which is the direction from point P5 to point P6, must be equal to or less than a predetermined angle value. Regarding displays and warnings, the operation of the point A lamp, point B lamp, automatic lamp, straight ahead lamp, U-turn lamp, back-turn lamp, and electronic buzzer conforms to the operation in the above-mentioned items. Regarding signal output from the turning control ECU to the straight ahead control ECU, a steering signal for the center of the steering wheel is output, and the steering motor 45 outputs so that the steering wheel position of the steering wheel 52 is returned to the center position for straight ahead driving.

[0101] In this way, for example, when the deviation angle based on the target line direction, which is the direction from point P5 to point P6, becomes less than 20 degrees, the steering position of the steering wheel 52 is returned to the straight-ahead center position, and the second-stage turning ends with the detection of straight-ahead steering.

[0102] Mainly with reference to FIG. 11, the straight ahead assist control operation for going from point P5 to point P6 will be specifically described below.

[0103] (23) When the vehicle is moving forward, the system transitions to straight-line assist control operation without any operation by the on-board operator. At this time, the steering angle of the steering wheel 52 must be 120 degrees or less, and the deviation angle from the target line direction, which is the direction from point P5 to point P6, must be 3 degrees or less. Regarding displays and warnings, the Point A lamp is turned on and off, the Point B lamp is turned on and off, the automatic lamp, straight lamp, U-turn lamp, and reverse turn lamp operate in accordance with the operations described above, and the electronic buzzer emits one short buzzer sound. Regarding signal output from the turning control ECU to the straight-line control ECU, an automatic steering signal is output. Regarding signal output from the straight-line control ECU to the turning control ECU, an output control operation of the steering motor 45 is performed to travel toward the target line.

[0104] (24) When the vehicle is moving forward, the vehicle speed is set according to the position of the main shift lever 53, without any operation by the onboard operator, and the straight-line assist control operation is performed, with the upper limit regulated by a 0.9 meter / second limit (50 percent of the maximum speed). At this time, the steering angle of the steering wheel 52 must be 30 degrees or less, and the deviation angle from the target line direction (the direction from point P5 to point P6) must be 3 degrees or less for at least three seconds. Regarding displays and warnings, the Point A lamp is turned on and off, the Point B lamp is turned on and off, the automatic lamp, straight-line lamp, U-turn lamp, and reverse-turn lamp operate in accordance with the operations described above, and the electronic buzzer emits one short buzzer sound. Signal output from the turning control ECU to the straight-line control ECU is in accordance with the signal output described above. Signal output from the straight-line control ECU to the turning control ECU is in accordance with the signal output described above.

[0105] In this way, the straight-line assist control operation is started in conjunction with the end of the turning control operation.

[0106] The straight-line assist control operation is performed by setting the reference line of the next planting travel route in the direction from point P6 to point P5 as the target line, so that automatic travel route alignment to the next planting travel route is achieved and deviations in the distance between planting travel routes are unlikely to occur.

[0107] Such target line setting may be performed automatically using linear parallel movement so that the distance between the reference line of the current planting travel path from point P0 to point P1 and the reference line of the next planting travel path from point P6 to point P5 approximately matches the product of the distance between planting rows and the number of rows planted by the rice transplanter, 8.

[0108] The back-turn assist control operation will be described in more detail below.

[0109] When the back-turn assist control operation is being performed, a short buzzer sound may be output intermittently and continuously so that the on-board operator can easily recognize that the vehicle speed or steering is being automatically controlled. If the back-turn assist control operation is stopped for some reason, a single long buzzer sound may be output so that the on-board operator can easily recognize that the automatic control has been interrupted.

[0110] It goes without saying that various conditions for interrupting the back-turn assist control operation can be considered as follows.

[0111] When the back-turn assist control operation is being performed, if the main shift lever 53 is operated in a manner that does not match the vehicle traveling direction during the back-turn assist control operation, the back-turn assist control operation may be interrupted. For example, if, with the vehicle traveling in reverse as described above, the operator operates the main shift lever 53 so that the lever position of the main shift lever 53 is in the forward position, the back-turn assist control operation may be interrupted.

[0112] When the back-turn assist control operation is being performed, the back-turn assist control operation may be interrupted if a switch operation is performed using the assist mode switch 56. For example, when the vehicle body is moving backward as described above, if the operator on board operates the assist mode switch 56 to select the U-turn assist mode, the back-turn assist control operation may be interrupted.

[0113] When the back-turn assist control operation is being performed, if a switch operation is performed using the automatic turning mode switch to automatically perform operations such as raising the planting device 100 in conjunction with turning, the back-turn assist control operation may be interrupted. For example, if, in the vehicle body reverse state described above, an operator on board performs a switch-off operation using the automatic turning mode switch, the back-turn assist control operation may be interrupted.

[0114] When a back-turn assist control operation is being performed, if an operation to turn off the auto-marker operation is performed, the back-turn assist control operation may be interrupted.

[0115] When a back-turn assist control operation is being performed, if a finger-up lever operation or a finger-down lever operation is performed using the straight-ahead assist lever 55, the back-turn assist control operation may be interrupted.

[0116] When the back-turn assist control operation is completed, the above-described restriction on the upper limit of the vehicle speed may be released. The restriction on the upper limit of the trunnion opening of the main transmission mechanism 41, which is an HST mechanism, is released, and the vehicle speed is set according to the lever position of the main transmission lever 53, even without the operator operating the main transmission lever 53 to decrease the vehicle speed, and the vehicle automatically returns to the target vehicle speed. To avoid a sudden increase in vehicle speed upon completion of the back-turn assist control operation, it is desirable that this automatic return to the target vehicle speed be carried out slowly, with a response speed different from the response speed caused by normal operation of the vehicle speed increase lever.

[0117] Next, the configuration and operation of the rice transplanter of this embodiment will be described more specifically with reference mainly to FIGS. 7(a), 7(b), and 8.

[0118] Here, Figure 7(a) is a partial front view of the vicinity of the GNSS antenna 310 of a rice transplanter according to an embodiment of the present invention, Figure 7(b) is a partial left side view of the vicinity of the GNSS antenna 310 of a rice transplanter according to an embodiment of the present invention, and Figure 8 is a partial oblique view of the vicinity of the GNSS antenna stay 320 of a rice transplanter according to an embodiment of the present invention.

[0119] The GNSS antenna stay 320 is a stay to which the GNSS antenna 310 of the positioning system 300 for realizing the rice transplanter automatic steering system is attached.

[0120] Since the GNSS antenna 310 is not located directly above the seat 51, even if the height of the GNSS antenna 310 is not very large, when the on-board worker stands up from the seat 51, the worker's head or other parts are unlikely to hit the GNSS antenna 310.

[0121] Since the height of the GNSS antenna 310 does not need to be very large, not only is the GNSS antenna 310 less likely to interfere with obstacles, but the ground clearance of the vehicle body 10 is also reduced. Furthermore, since the GNSS antenna stay 320 can be shortened, the rigidity of the GNSS antenna stay 320 is also improved.

[0122] The GNSS antenna 310 is located in the center of the vehicle body in the left-right direction, but is provided above the steering handle 52 and the head of the on-board operator sitting in the seat 51. Therefore, the field of view of the on-board operator is unlikely to be obstructed by the GNSS antenna 310.

[0123] A GNSS antenna stay reinforcing plate 321 is attached to the center of the GNSS antenna stay 320 in the vertical direction.

[0124] A monitor or the like for displaying the automatic steering status may be attached to the center of the GNSS antenna stay reinforcing plate 321 in the left-right direction of the vehicle body.

[0125] A space may be provided for attaching a logo mark label or the like to the GNSS antenna stay reinforcing plate 321.

[0126] The program of the invention related to the present invention is a program for causing a computer to execute all or part of the steps (or processes, operations and actions, etc.) of the turning assistance method of the invention related to the present invention described above, and is a program that operates in cooperation with a computer.

[0127] In addition, the recording medium of the invention related to the present invention is a recording medium that records a program for causing a computer to execute all or some of the steps (or processes, actions and functions, etc.) of the turning assistance method of the invention related to the present invention described above, and is a computer-readable recording medium in which the read program is used in cooperation with a computer.

[0128] It should be noted that the above-mentioned "some steps (or processes, operations, actions, etc.)" means one or some steps among the plurality of steps.

[0129] Furthermore, the above-mentioned "operations of steps (or processes, operations, actions, etc.)" means the operations of all or part of the above-mentioned steps.

[0130] Furthermore, one mode of use of the inventive program related to the present invention may be in the form of being transmitted through a transmission medium such as the Internet, light, radio waves, or sound waves, being read by a computer, and operating in cooperation with the computer.

[0131] The recording medium also includes a ROM (Read Only Memory).

[0132] Furthermore, a computer is not limited to pure hardware such as a CPU (Central Processing Unit), and may also include firmware, an OS (Operating System), and even peripheral devices.

[0133] As described above, the configuration of the present invention may be realized in software or hardware. [Industrial Applicability]

[0134] The transplanter of the present invention can allow the turning assistance of the vehicle body to begin when the working implement is raised, and is useful for use in transplanters such as rice transplanters. [Explanation of symbols]

[0135] 10. Body 20 Engine 30 Running gear 31 Front wheel 32 rear wheel 41 Main transmission mechanism 42 Sub-transmission mechanism 43 Rear wheel gear case 45 Steering motor 50 Operation Units 51 seats 52 Steering wheel 53 Main gear shift lever 54 Sub-gear lever 55 Straight-line assist lever 56 Assist mode switch 60 Ground leveling equipment 61 Leveling rotor mechanism 62 Leveling float mechanism 70 Fertilizer application equipment 80 Line Marker 90 Planting device lifting device 100 Planting device 101 Spare seedling tray 200 control device 210 Rear wheel rotation speed sensor 220 Planting device lifting sensor 300 Positioning System 310 GNSS antenna 320 GNSS antenna stay 321 GNSS antenna stay reinforcement plate

Claims

1. A work vehicle comprising a steering unit, a vehicle body capable of traveling either by manual steering using the steering unit or by automatic steering using the steering unit based on a planned traveling line, a steering switching device for switching between starting and ending the automatic steering, and a switchable setting steering device for setting at least the traveling settings of the automatic steering.

2. 2. The work vehicle according to claim 1, wherein the start of the automatic steering is not accepted unless the travel distance is equal to or greater than a predetermined distance.

3. The work vehicle according to claim 1 or 2, characterized in that the intended driving line is registered by acquiring a first reference point and a second reference point within a field, and the automatic steering is started when the vehicle body is parallel to the intended driving line and the steering wheel is straight.

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