Work vehicles

Abstract

Conventional work vehicles such as rice transplanters are unable to control the turning of the vehicle body. [Solution] A work vehicle comprising a steering member drive device that drives a steering member and a control device that controls the steering member drive device, wherein the control device performs straight-line control when the vehicle body (10) is made to travel straight, performs turning control when the vehicle body (10) that has been made to travel straight is made to turn, and performs straight-line control after the turn when the turned vehicle body (10) is made to travel straight again, and is characterized in that the size of the turning trajectory is determined based on the vehicle travel distance and vehicle orientation.

Description

[Technical field]

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

[0002] A rice transplanter is known that has a planting device that is attached to the vehicle body so that it can be raised and lowered, a steering motor that drives a steering handle, and a control device that controls the straight-line movement of the vehicle body by having the steering motor drive the steering handle (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-24541 A [Patent Document 2] JP 2002-335720 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, work vehicles such as the above-mentioned conventional rice transplanters are not capable of controlling the turning of the vehicle body.

[0005] SUMMARY OF THE PRESENT DISCLOSURE In consideration of the above-mentioned problems, an object of the present invention is to provide a work vehicle capable of controlling the turning of the vehicle body. [Means for solving the problem]

[0006] The first aspect of the present invention is a steering member drive device (44) for driving a steering member (52); A control device (200) for controlling the steering member drive device (44); Equipped with a control device (200) for controlling a vehicle body (10) to travel straight when the vehicle body (10) is caused to travel straight, a turning control for turning the vehicle body (10) that has been travelling straight or for stopping the vehicle body (10) that has been travelling straight, moving it backward, and turning it again after stopping the vehicle body, and a straight running control after the turning is performed for the work vehicle when the vehicle body (10) that has been turned is caused to travel straight again, The size of the turning trajectory is determined based on the aircraft travel distance and the aircraft heading; The timing for returning the steering to make the turning vehicle body (10) go straight again is determined by measuring the distance traveled by the vehicle from the start of the turn until the vehicle heading reaches a predetermined heading, and changing the timing for returning the steering based on the distance traveled by the vehicle; The control device (200) uses a first regulation speed and a second regulation speed which is smaller than the first regulation speed in the turning control. car By regulating the speed car Control the speed, Using the second speed limit at the timing of returning the steering car Regulating the speed, When the vehicle body (10) is reversed, the control device (200) uses a third speed limit not exceeding the second speed limit. car Regulating the speed, This work vehicle is characterized in that, when the vehicle is reversed and then stopped again, the steering member (52) is oriented in the turning direction.

[0007] (delete)

[0008] (delete)

[0009] (delete) Effect of the Invention

[0010] According to the first aspect of the present invention, it is possible to control the turning of the vehicle body. Also, it is possible to realize highly precise control.

[0011] (delete)

[0012] (delete)

[0013] (delete) [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of a rice transplanter according to an embodiment of the present invention; [Diagram 2] Block diagram of a power transmission system of a rice transplanter according to an embodiment of the present invention. [Diagram 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 turning control of a rice transplanter according to an embodiment of the present invention; [Diagram 5] FIG. 1 is an enlarged explanatory diagram of the turning control of a rice transplanter according to an embodiment of the present invention; [Figure 6] FIG. 1 is an explanatory diagram of back-turn control of a rice transplanter according to an embodiment of the present invention; [Figure 7] FIG. 1 is a partial perspective view of a rice transplanter according to an embodiment of the present invention; [Figure 8] FIG. 1 is a partial plan view of a rice transplanter according to an embodiment of the present invention; [Figure 9] FIG. 1 is an enlarged partial plan view of the vicinity of an auxiliary wheel of a rice transplanter according to an embodiment of the present invention; [Figure 10] FIG. 2 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention (part 2) [Figure 11] FIG. 3 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 12] FIG. 4 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 13] FIG. 5 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 14] FIG. 6 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 15] FIG. 7 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 16] FIG. 8 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 17] FIG. 9 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 18] FIG. 10 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 19] FIG. 11 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 20] FIG. 12 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 21] FIG. 13 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 22] FIG. 14 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 23] FIG. 15 is an explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention. [Figure 24] FIG. 1 is a partial perspective view of the vicinity of an operating unit of a rice transplanter according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the drawings, an embodiment of the present invention will be described in detail.

[0016] The same applies below, but some components may not be shown in the drawings, or may be shown in a perspective or simplified manner.

[0017] The rice transplanter of this embodiment is an example of a work vehicle in the present invention or an invention related to the present invention.

[0018] In an alternative embodiment, for example, the work vehicle of the present invention or of a related invention may be an agricultural tractor.

[0019] The steering wheel 52 is an example of a steering member in the present invention or an invention related to the present invention. The steering motor 44 is an example of a steering member drive device that drives the steering wheel 52 in the present invention or an invention related to the present invention.

[0020] The control device 200 is an example of a control device for controlling the steering motor 44 in the present invention or an invention related to the present invention.

[0021] The vehicle body 10 is an example of a vehicle body in the present invention or an invention related to the present invention. The rear wheel rotation speed sensor 210 and the positioning system 300 are an example of a detection mechanism that detects the turning state of the vehicle body 10 in the present invention or an invention related to the present invention.

[0022] The auxiliary wheel 33 is an example of one or more auxiliary wheels attached to at least one of the inside and outside sides in the left-right direction of the vehicle body 10 in the present invention or an invention related to the present invention.

[0023] The rear wheel 32 on the inside of the turn is an example of a predetermined wheel in the present invention or in an invention related to the present invention.

[0024] First, the configuration and operation of the rice transplanter of the present embodiment will be specifically described with reference to Figs. 1 and 2.

[0025] 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 the embodiment of the present invention.

[0026] While explaining the operation of the rice transplanter of this embodiment, a travel control method of an invention related to the present invention will also be explained.

[0027] 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, and each planting unit has a pair of two planting tools, one on the left and one on the right.

[0028] The rice transplanter is not limited to a riding mat seedling rice transplanter for planting eight rows, but may be, for example, a riding pot seedling rice transplanter for planting ten rows.

[0029] First, the basic configuration and operation of the rice transplanter of this embodiment will be described. Therefore, the turning control and the like will be described in detail later.

[0030] The driving unit 50 has a seat 51 provided above the engine 20 .

[0031] A steering handle 52 for operating the front wheel 31 is provided in front of the seat 51. A horizontal step floor is provided on both the left and right sides of the engine 20. Furthermore, the vehicle body 10 is provided with a spare seedling carrying platform 101.

[0032] The traveling device 30 is a device that causes the vehicle body 10 to travel using front wheels 31 and rear wheels 32.

[0033] The soil leveling device 60 is a device that levels a farm field using a soil leveling rotor mechanism 61 and a soil leveling float mechanism 62.

[0034] A line-drawing marker 80, which forms straight markings in the field as a guide for the next planting travel route, is attached to the vehicle body 10 so as to be retractable.

[0035] The planting device 100 is attached to the rear side of the vehicle body 10 via a planting device lifting device 90.

[0036] 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, etc. The rotational power changed in speed by the main transmission mechanism 41 and the sub-transmission mechanism 42 is separated into running power used by the traveling device 30, etc., and externally taken power used by the planting device 100, etc.

[0037] A part 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 rest 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 part 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.

[0038] Next, the configuration and operation of the rice transplanter of the present embodiment will be described more specifically with reference mainly to FIGS.

[0039] FIG. 3 is a block diagram of a control system of the rice transplanter according to the embodiment of the present invention.

[0040] The control device 200 is a device that performs various controls using not only lever operation using the main speed change lever 53, the sub speed change lever 54 or the 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 sensor 220.

[0041] The positioning system 300 is, for example, a system that performs positioning by DGPS (Differential Global Positioning System) technology that uses GPS (Global Positioning System), which is a typical GNSS (Global Navigation Satellite System).

[0042] Since driving control requires consideration of a comprehensive range of factors, including the size of the vehicle body 10, the responsiveness of the steering motor 44, and the condition of the field, even if the positioning system 300 were extremely accurate, it is difficult to achieve precise driving control, and various attempts are known.

[0043] In the straight-line control, the coordinates of point A, which corresponds to the start point of straight-line driving for planting work, and point B, which corresponds to the end point of straight-line driving, are registered in advance using the positioning system 300 that acquires current orientation information of the vehicle body 10. Then, the straight-line control is realized by driving the steering motor 44 to perform steering so that straight-line driving is performed based on an imaginary line connecting points A and B.

[0044] However, since the straight-line control must be turned on and off every time a turn requiring manual steering is made, the burden on the operator is not small, and operability and workability are not necessarily sufficient.

[0045] Therefore, it is desirable to realize not only straight-line control but also turning control that automatically aligns rows based on the distance between planting rows, and the following basic turning control is considered.

[0046] Of course, it goes without saying that the method of turning control described below can be used in various turning controls. Specifically, one of the various turning controls is, for example, turning control in which a straight-line movement during turning is not included, the steering angle is kept almost constant during turning, and the turning path of the vehicle body 10 is a path having an approximately semicircular shape.

[0047] (A1) Next, the configuration and operation of the rice transplanter of the present embodiment will be described more specifically with reference mainly to FIGS.

[0048] Here, FIG. 4 is an explanatory diagram (part 1) of the turning control of the rice transplanter according to the embodiment of the present invention, and FIG. 5 is an enlarged explanatory diagram of the turning control of the rice transplanter according to the embodiment of the present invention.

[0049] The rice transplanter of the present embodiment is a rice transplanter in which the control device 200 performs turning control when turning the vehicle body 10 that has been traveling straight.

[0050] The control device 200 determines the turning state based on the result of the detection, and controls the steering angle based on the turning state determination.

[0051] For example, in the automatic turning control of a rice transplanter, the steering angle is fixed at a constant α (for example, 45 degrees) during automatic turning so that the machine does not move straight during the turn. When a turning route is set using GPS and the machine turns along that route, the control can be difficult and unstable. In addition, moving the steering wheel during turning changes the rotation of the rear wheel on the inside of the turn, which makes so-called Z-turns and other controls unstable. By keeping the steering angle constant, control is easy and the system is highly versatile for machines with various specifications. Since the steering angle is constant, the rotation of the rear wheel on the inside of the turn is stable, and it is easy to determine, without additional sensors, that if the rotation rate of the rear wheel on the inside of the turn is low, the machine is making a tight turn, and if the rotation rate is high, the machine is making a wide turn.

[0052] The control device 200 controls the steering angle by changing the timing of returning the steering angle based on the turning state determination in order to make the turning vehicle body 10 move straight again.

[0053] The steering angle return timing is the timing at which the difference between the direction of the turned vehicle body 10 and the direction in which the vehicle body 10 is made to move straight again falls below a predetermined steering angle return level.

[0054] For example, the steering angle return level is 30 degrees.

[0055] The steering angle return timing is adjustable based on a manual operation that adjusts a predetermined steering angle return level.

[0056] For example, the steering angle return level may be decreased to 25 degrees or increased to 35 degrees by dialing the threshold adjustment device 400 based on the operator's experience.

[0057] The timing at which the turning state is determined is the timing of the position of arrow A, which is determined based on the direction such as the aircraft direction or the aircraft perpendicular direction, distance, time, GNSS position, vehicle speed, etc. The turning state is determined based on the direction, distance, time, GNSS position, vehicle speed, etc.

[0058] For example, the magnitude of the turning trajectory is determined with sufficient time to spare at a timing when the aircraft heading is 45 degrees, which is the difference between the direction of the vehicle body 10 being turned and the direction in which the vehicle body 10 is made to move straight again.

[0059] When the turning trajectory of the vehicle body 10 starting from the turning start position Ps on the straight line Lv0, which is the previous process line, is determined to be a standard size turning trajectory C0, the steering angle is returned to the standard 30 degree steering angle return level position P0 without changing the steering angle return timing. Even without changing the steering angle return timing, the vehicle body 10 can enter the straight control handover zone Z upon reaching the virtual line Lh0 just before the planting start line Lh, so a smooth handover to the straight control is performed to automatically move the vehicle body 10 straight again along the straight line Lv.

[0060] The handover from turning control to straight-line control is performed, for example, at the timing when entry into the straight-line control handover zone Z is recognized based on the GNSS position.

[0061] In order to achieve a smooth handover to the straight-line control, it is desirable that, as the vehicle approaches the next process line, the straight-line line Lv, the entry angle to the straight-line line Lv as well as the steering angle be not too large just before the straight-line control handover zone Z.

[0062] The inventors have arrived at the idea of ​​ensuring a smooth transition to such straight-line control, regardless of the turning condition, which is easily affected by factors such as field conditions, by changing the timing at which the steering angle is returned based on a judgment of the turning condition.

[0063] Specifically, based on the determination of the size of the turning trajectory, the steering angle return timing is changed as follows.

[0064] When the turning trajectory is determined to be a sharp turning trajectory C1, the steering angle is returned not at the timing of position P1 of the standard 30 degree steering angle return level, but, for example, at the timing of position Q1 of the steering angle return level of 35 degrees, which is greater than 30 degrees. Then, even if the turning trajectory is a sharp turning trajectory C1, the vehicle body 10 approaches the straight line Lv and can enter the straight running control handover zone Z, so that a smooth handover to the straight running control is performed in the same manner.

[0065] When the turning trajectory is determined to be a wide turning trajectory C2, the steering angle is returned not at the timing of position P2 of the standard 30 degree steering angle return level, but, for example, at the timing of position Q2 of the steering angle return level of 25 degrees, which is smaller than 30 degrees. Then, even if the turning trajectory is a wide turning trajectory C2, the vehicle body 10 can enter the straight-line control handover zone Z without moving away from the straight-line line Lv, so that a smooth handover to the straight-line control is performed in the same manner.

[0066] Of course, the timing of steering angle return may be changed based on the direction in this way, but it may also be changed based on distance, time, GNSS position, vehicle speed, etc. so that the movement path is corrected for a smooth transition to straight-line control.

[0067] In the turning assist correction control using the rear wheel pulse, the pulse of the inner rear wheel is measured from the start of automatic turning control to the time of turning in order to know the rear wheel rotation speed used to determine the size of the turning trajectory. The number of pulses of the inner rear wheel during automatic turning is less affected by slippage, etc., and it can be determined whether the turning operation is normal.

[0068] In the automatic turning control of rice transplanters, the number of pulses of the rear wheel on the inside of the turn is measured from the start of automatic turning control until the machine's heading reaches the specified heading (θ0). θ0 must be 45 degrees or more. The number of rear wheel pulses at the time when the machine's heading is θ0 is used to determine whether or not to add corrections to the automatic turning control. If θ0 is 45 degrees or less, even if corrections are added to the automatic turning control, the control may not be able to keep up and turning accuracy may deteriorate.

[0069] If the number of pulses at this time is between p1 and p2, it is determined that the turning is normal and no correction control is performed. By setting the range from p1 to p2 for the appropriate pulse value for the rear wheel on the inside of the turn during automatic turning control, unnecessary correction control is not performed and turning accuracy can be improved.

[0070] If the pulse count p is p ≥ p2, it is determined that the turn is wide, and the steering return start direction is delayed to move the aircraft closer to the inside and align the start of the turn. If it is determined that a wide turn is occurring based on the rear wheel rotation speed, the steering return start direction is controlled so that the aircraft moves to the inside, and the start of the turn can be aligned, improving turning accuracy.

[0071] When the pulse number p is p≦p1, it is determined that the turning is tight, and the steering return start direction is delayed or advanced so that the aircraft moves to the outside and the start of the turn is synchronized. If it is determined that the turning is tight from the rear wheel rotation speed, the steering return start direction is controlled so that the aircraft moves to the outside, so that the start of the turn can be synchronized and the turning accuracy can be improved.

[0072] The magnitude of the turning trajectory may be determined based on the magnitude of the rear wheel rotation number at the timing of the position where the aircraft heading reaches a predetermined angle, but conversely, it may be determined based on the magnitude of the aircraft heading at the timing of the position where the rear wheel rotation number reaches a predetermined number. For example, if the magnitude of the aircraft heading at the timing of the position where the rear wheel rotation number reaches a predetermined number is small, it may be determined that the turning is a large turn, and the steering return start direction may be delayed so that the aircraft start to move inward and be aligned.

[0073] Ultimately, the timing at which the turning state determination is performed is determined based on one or more physical quantities selected from the heading, distance, time, GNSS position, vehicle speed, etc., and the turning state is determined based on similar physical quantities, but the combination of these physical quantities is arbitrary. For example, the timing at which the turning state determination is performed may be determined based on the distance and the GNSS position, and the turning state determination may be determined based on the heading and vehicle speed.

[0074] The steering angle return timing is changed based on one or more physical quantities selected from the direction, distance, time, GNSS position, vehicle speed, etc., but the physical quantity on which the control of the steering angle is based, such as the change in the steering angle return timing, may be determined independently of or dependent on the combination of the physical quantities described above. For example, the timing at which the turning state determination is made may be determined based on time, the turning state determination may be determined based on the vehicle speed, and the steering angle return timing may be changed based on the direction and the GNSS position.

[0075] The control device 200 may maintain the steering angle at a constant angle until the turning state determination timing at which the turning state is determined, and then control the steering angle by changing the constant angle based on the turning state determination.

[0076] When the number of pulses p is p≧p2, it is determined that the vehicle is making a wide turn, and the steering angle α, which is a fixed angle, is turned more to make the vehicle turn more tightly. When it is determined that the vehicle is making a wide turn based on the rear wheel rotation speed, the steering control is performed to make the vehicle turn more tightly, thereby improving the turning accuracy.

[0077] When the number of pulses p is p≦p1, it is determined that the vehicle is making a tight turn, and the constant steering angle α is turned back to make a wide turn. When it is determined that the vehicle is making a tight turn based on the rear wheel rotation speed, the steering control is performed to make a wide turn, thereby improving the turning accuracy.

[0078] It goes without saying that a change to a certain angle, such as increasing or returning the steering angle α, may be performed simultaneously with the determination of the turning state, or may be performed, for example, 0.2 seconds after the determination of the turning state.

[0079] The control device 200 may control the steering angle by changing the steering angle return speed at which the steering angle is returned based on the turning state determination in order to make the turning vehicle body 10 move straight again.

[0080] Of course, the steering angle return speed may be changed instead of or in conjunction with the change in the timing of returning the steering angle so that the path of travel can be properly corrected. For example, the aircraft heading at which the steering angle is returned may be constant, and only the steering angle return speed may be changed.

[0081] It goes without saying that the steering angle may be returned simultaneously with the determination of the turning state, or may be returned, for example, 0.2 seconds after the determination of the turning state.

[0082] In a configuration in which the steering angle return speed is adjustable, even if the timing for determining the turning state is quite close to the steering angle return timing, the steering angle can be returned without delay by increasing the steering angle return speed.

[0083] (A2) Next, the configuration and operation of the rice transplanter of this embodiment will be described more specifically with reference mainly to FIG.

[0084] FIG. 6 is an explanatory diagram of the back-turn control of the rice transplanter according to the embodiment of the present invention.

[0085] The rice transplanter of the present embodiment is a rice transplanter in which the control device 200 performs turning control when the vehicle body 10 that has been moving straight is stopped, moved backward, stopped again, and then turned.

[0086] After backing straight from point S1 to point S2, a turn from point S2 via points S3 and S4 to point S5 is performed automatically or semi-automatically.

[0087] Of course, it is also possible to configure the system not to start turning assist control when the turning control is in a mode where the HST is automatically controlled, such as the so-called "pitched planting control" or "pitched approach control." This is because if turning assist is started by mistake during pitted approach, the HST may operate unintendedly. Therefore, it is desirable to prevent unintended HST operation.

[0088] Here, the first to eighth reverse patterns in the back-turn control, in which the vehicle body 10 that has been traveling straight is stopped, reversed, stopped again, and then turned, will be described.

[0089] (First reverse pattern) The first reverse movement pattern is a reverse movement pattern in which the vehicle moves backward in a straight line.

[0090] In the rice transplanter turning assist control, during back-turn control, a configuration is considered in which the motor control keeps the steering wheel moving straight from the start of reverse movement to the stop of reverse movement (1.1 m). By moving backwards straight when backing up, it is possible to prevent position deviation until the next target line is reached during turning.

[0091] (Second reverse pattern) The second reverse pattern is a reverse pattern in which the steering wheel is turned in front of the vehicle.

[0092] When the vehicle body 10 is reversed, the control device 200 maintains the steering angle at zero until a predetermined timing, and then changes the steering angle toward the turning direction by a predetermined steering angle amount.

[0093] In other words, during back-turn control in the rice transplanter turning assist control, a configuration is considered in which the steering wheel is kept in a straight line by motor control from the start of reverse movement to 30 cm before the reverse stop (1.1 m). By moving backwards in a straight line when backing up, position deviation is prevented until the next target line is reached during turning.

[0094] In the rice transplanter turning assist control, during the back-turn control, after the above control, that is, from 30 cm before the reverse stop (1.1 m) to the reverse stop (1.1 m), a configuration is considered in which the steering wheel is turned at a certain angle in the turning direction by motor control. If the steering wheel is turned when the vehicle starts moving forward, the traveling trajectory will not be stable depending on the vehicle speed. The vehicle may make a wide turn and hit the bank. Also, if the steering wheel is not turned while moving, the motor may not be able to turn the steering wheel because it will be unable to withstand the load of the field. By turning the steering wheel to a certain degree in the turning direction before turning, the traveling trajectory when moving forward and turning can be stabilized and wide turns can be prevented. Therefore, it is preferable to turn the steering wheel while moving backward.

[0095] The predetermined steering angle is a steering angle at which the transmission of driving force to the rear wheel 32 on the inside of the turn attached to the vehicle body 10 is not cut off.

[0096] In other words, the steering angle should be set to a level where the rear wheel clutch is not disengaged (220 degrees). This is because if the steering wheel is turned until the rear wheel clutch is disengaged, the running path will change suddenly as if the vehicle was quick, and the vehicle will move backwards, which will not only damage the planting area with the tires, but also cause stalks to be missing and make the running path unstable when turning.

[0097] (Third reverse pattern) The third reverse pattern is a reverse pattern in which the vehicle backs up in the final straight heading direction.

[0098] In the rice transplanter turning assist control, during the backturn control, a configuration is considered in which the steering wheel is steered based on the direction of the last straight-line assist from the start of reverse to the stop of reverse (1.1 m). This is because the straight-line assist control usually forces the vehicle to stop 3 m before the bank, so a person must manually plant at least 3 m, and the manually planted area may deviate from the straight-line assist path, and there is a risk that the path after the turning assist and the path before it will not be 30 cm between rows (depending on the model). In particular, with deformed rice fields, people have a habit of turning the steering wheel to enter the bank perpendicularly, so they enter in a bow shape and back up in that state, and back up in a direction different from the original planting path, which reduces the disadvantage of an unstable turning path.

[0099] (Fourth backward pattern) The fourth reverse pattern is a reverse pattern that is aligned with the final straight path line.

[0100] In the rice transplanter turning assist control, during backturn control, a configuration is considered in which the steering wheel is steered based on the path on which the last straight-line assist was performed from the start of reverse movement to the stop of reverse movement (1.1 m).

[0101] (Fifth reverse pattern) The fifth reverse movement pattern is a reverse movement pattern that is aligned with the ideal reverse stop position coordinates obtained from the final path.

[0102] In the rice transplanter turning assist control, during backturn control, a possible configuration is to steer the steering wheel from the start of reverse movement to the stop of reverse movement (1.1 m) to a coordinate point that is moved an arbitrary reverse distance (1.1 m) in the reverse direction of the last straight path from a coordinate point that is perpendicular to the last straight path and a perpendicular line obtained by rotating the last straight path 90 degrees from the current machine position.

[0103] (Sixth reverse pattern) The sixth reverse pattern is a reverse pattern in which a period is intentionally provided in which the steering wheel is turned in the opposite direction to the turning direction.

[0104] In the rice transplanter turning assist control, a configuration can be considered in which during backturn control, a period is set in which the steering wheel is turned a certain angle in the opposite direction to the turning direction by motor control between the start of reverse movement and the stop of reverse movement (1.1 m).

[0105] (Seventh Reverse Pattern) The seventh reverse pattern is a reverse pattern in which a period is intentionally set aside to turn in a different direction.

[0106] In the rice transplanter turning assist control, a configuration can be considered in which, during backturn control, a period is set up in which the steering wheel is steered in a direction shifted by an arbitrary angle from the direction in which the last straight-line assist was performed between the start of reverse travel and the stop of reverse travel (1.1 m).

[0107] (Eighth reverse pattern) The eighth reverse pattern is a reverse pattern in which a period is intentionally set aside to switch to a different route.

[0108] In the rice transplanter turning assist control, a configuration is conceivable in which, during backturn control, the steering wheel is steered to a path that is shifted in any direction from the path on which the last straight-line assistance was performed between the start of reverse movement and the stop of reverse movement (1.1 m) (e.g., 10 cm closer to or farther from the travel path or turning path).

[0109] In the reverse patterns such as the first to eighth reverse patterns when turning backward, the vehicle is controlled to automatically stop after moving backward for a certain distance (1.1 m), but if the vehicle stops suddenly when moving backward at high speed, the shock of stopping is large and it may be dangerous for the operator. In addition, between 30 cm before the reverse stop (1.1 m) and the reverse stop (1.1 m), the vehicle is controlled to turn the steering wheel ahead of the vehicle in the direction of turning so that the rear wheel clutch is not disengaged (aiming for 220 degrees of steering). However, if the steering wheel is turned while driving at high speed, the driving path becomes unstable, and the vehicle may reach the reverse stop (1.1 m) position before the steering wheel is turned completely, and the vehicle may have to turn the steering wheel while stopped. In particular, in the case of deep wet rice fields, the motor may not be able to turn the steering wheel when the vehicle is stopped because of the load of the field. Therefore, when controlling the back turn, it is desirable to control the vehicle speed while taking safety into consideration.

[0110] When the vehicle is operated forward after reverse drive is completed in the various configurations described above, a configuration is considered in which the steering wheel is turned at a certain angle in the turning direction by motor control. By turning the steering wheel in the turning direction, automatic turning becomes possible without the need for a human to operate the steering wheel.

[0111] In other words, when the turning start is made, the steering wheel is already turned.

[0112] Here, a description will be given of turning assist handle steering for so-called U-shaped turning control, which includes a straight-ahead movement during turning.

[0113] A U-turn is a turn such as a turn from point S2 to point S5 via points S3 and R4, regardless of whether the above-mentioned backing straight ahead is performed.

[0114] The following describes the step of completing steering control for starting a turn (1). When the steering state has already been achieved at the start of a turn in the previous step, if the deviation of the aircraft's heading from the target heading exceeds a certain angle (75 degrees), a configuration is considered in which steering operation is completed. The steering operation end condition is clarified, and the start condition for an 8-row U-shaped turn is given.

[0115] The steering wheel center control step during turning (2) will be explained. When the steering wheel turning operation is completed in the previous step, a configuration is considered in which the steering wheel is driven by the motor in a straight-ahead state. When making a U-shaped turn, the steering wheel is turned a certain distance to turn, and then the steering wheel is straightened once. This realizes a clear turning operation.

[0116] The steering wheel center control completion step during turning (2) will be described. A configuration is conceivable in which the steering wheel straight operation is completed when the counter of the rear wheel rotation sensor reaches a certain value or more in the previous step, that is, when the straight-line portion of the U-shaped turn is completed. This clarifies the condition for completing the steering wheel straight operation.

[0117] The steering control step for starting turning (2) will now be described. When the steering wheel has been operated to go straight in the previous step, a configuration is considered in which the steering wheel is turned a certain angle in the direction of the turn (final turning in the direction of the turn). When making a U-shaped turn, the steering wheel is turned after driving straight for a certain distance, which allows for a clear turning operation.

[0118] The steering control completion step of (3) at the start of turning will now be described. In the immediately preceding step, when the vehicle is traveling in the direction of travel after turning, if the deviation of the vehicle's orientation from the target orientation becomes less than a certain angle (depending on conditions), the steering operation can be completed. This clarifies the conditions for ending the steering operation.

[0119] The turning start (4) steering straight control step will be explained. When the steering wheel turning operation is completed in the previous step, the steering wheel is driven to go straight. When the U-shaped turn is completed, the steering wheel is made to go straight. This realizes a clear turning operation.

[0120] The step of completing the steering straight-line control for the start of turning (4) will now be described. When the steering wheel returns to within a certain straight-line range in the previous step, a configuration is possible in which the steering straight-line operation is completed. This clarifies the conditions for ending the turning assist operation.

[0121] The straight-line assist control start step is explained below. A possible configuration is to start straight-line assist after the handlebars have been moved straight in the previous step. Turn start (4) When the handlebars straight-line control is completed, the machine will automatically start straight-line assist after the turn is completed based on the path after the turn, allowing the machine to continue turning and planting work by simply operating the HST lever. In addition, the travel path is based on the path after the turn, so that the distance between adjacent rows of 30 cm (depending on the model) is appropriately maintained.

[0122] The turning assist control completion step will be described. When one turning operation is completed in the immediately preceding step, the turning assist control may be considered to be completed. This clarifies the turning assist operation end condition.

[0123] In the straight-line assist control start step, the straight-line assist after turning can be configured to automatically steer with parameters different from the steering parameters of the normal straight-line assist until the machine is on the target line. If the machine deviates from the target path after turning assist, it may take time to return to the target path by steering the steering wheel, but by making the steering parameters stronger (increasing the steering amount) after turning assist, the machine can return to the target path more quickly and the planting marks will be neater.

[0124] It is possible to configure the steering parameters to be changeable by operating a checker, dial, switch, etc. The return response can be changed according to the field conditions.

[0125] The steering parameters can be configured to return to normal straight-line assist steering parameters once the vehicle is on the target line. If the steering remains hard even after the vehicle is on the target line, the steering wheel may hunt (diverge). However, by clarifying the parameter switching conditions, automatic steering with normal steering parameters becomes possible once the vehicle is on the target line without the need for any operation.

[0126] It is possible to configure the counter setting of the rear wheel rotation sensor in the straight-line range to be arbitrarily changed in the (2) steering wheel center control completion step during turning. By setting the counter to 0, the process from the (1) steering wheel turning control completion step to the (2) steering wheel turning control step at the start of turning can be skipped, making it possible to make a large one-point turn.

[0127] A configuration that omits the steps from the step of completing steering control at the start of turning (1) to the step of controlling steering at the start of turning (2) is conceivable. When making a U-shaped turn, the turning trajectory may become unstable depending on the field conditions (slippage, etc.), but by omitting the U-shaped turn in the first place, the stability of the turn is increased. In addition, the wheel marks during the turn are also cleaned up, and the field is not damaged.

[0128] In the step of completing the steering control at the start of turning (3), the angle of the end of turning can be reduced if the vehicle speed is slow. If the vehicle speed is slow, the distance traveled from turning the steering wheel to returning it to the center position is short, which may result in a wide turn. However, by reducing the end of turning angle and delaying the timing of returning the steering wheel to the center position when the vehicle speed is slow, the turning path can be appropriately adjusted toward the target path.

[0129] A possible configuration is to increase the turning end angle in the steering wheel turning control completion step (3) when the vehicle speed is high. When the vehicle speed is high, the distance traveled from turning the steering wheel to returning to the center becomes long, resulting in tighter turning. When the vehicle speed is low, the turning end angle is increased and the timing of returning the steering wheel to the center is accelerated, making it possible to appropriately steer the vehicle toward the target path.

[0130] At the start of turning (3) steering control completion step, the turning end angle can be changed depending on the number of threads on the aircraft. The turning radius and working width differ depending on the number of threads, so the target route differs. By changing the turning end angle depending on the number of threads, the turning route can be appropriately adjusted toward the target route.

[0131] When the turning end angle is set to 7 stripes at the steering control completion step (3), a configuration is possible in which it is changed between 3 stripes and 5 stripes. Since the turning radius and working width differ depending on the number of stripes that are straddled in 7 stripes, the target route may differ, but by changing the turning end angle depending on the number of stripes, it is possible to appropriately adjust the turning route toward the target route.

[0132] At the step of completing the steering control after starting turning (3), the turning end angle can be corrected (-2 degrees) if the vehicle has an internal auxiliary wheel. When auxiliary wheels are attached, the turning radius becomes larger, which may result in a larger turn and a different turning trajectory. However, by changing the turning end angle by setting the auxiliary wheels, the turning trajectory can be adjusted appropriately to the target path. At the step of completing the steering control after starting turning (3), the turning end angle can be corrected (-2 degrees) if there are external auxiliary wheels. When auxiliary wheels are attached, the turning radius becomes larger, which may result in a larger turn and a different turning trajectory. However, by changing the turning end angle by setting the auxiliary wheels, the turning trajectory can be adjusted appropriately to the target path. When both internal and external auxiliary wheels are attached (triple configuration), an external priority configuration can be considered, which prioritizes the external auxiliary wheel settings and performs corrections. In the case of a triple configuration, the influence of the external wheels is large, but double corrections by the internal and external wheels are prevented. By changing the turning end angle depending on the auxiliary wheel settings, it is possible to make an appropriate turning path toward the target path.

[0133] When both internal and external auxiliary wheels are attached (triple configuration), a triple setting configuration that performs dedicated correction for the turning end angle is possible. By changing the turning end angle by the auxiliary wheel setting, the turning path can be appropriately adjusted toward the target path, making it possible to set correction settings unique to the triple configuration. The correction value can be changed to any value using a checker or monitor settings, allowing users to change parameters to their liking depending on field conditions.

[0134] Not only in such a turning assist handle steering for U-shaped turning control, but also in the first to eighth reverse patterns in the back-turn control described above, a configuration is conceivable in which the timing for starting to turn the steering wheel is changed depending on the number of teeth. In the case of six teeth, the steering wheel is turned 60 cm before the target, and in the case of seven or eight teeth, the steering wheel is turned 30 cm before the target. This is because, if the steering wheel is turned 30 cm before the target in the case of six teeth, the turning trajectory does not match, and it may not be possible to properly enter the target route after turning.

[0135] (B) Next, the configuration and operation of the rice transplanter of the present embodiment will be described more specifically with reference mainly to Figs.

[0136] Here, Figure 7 is a partial oblique view of a rice transplanter according to an embodiment of the present invention, Figure 8 is a partial plan view of a rice transplanter according to an embodiment of the present invention, and Figure 9 is an enlarged partial plan view of the vicinity of auxiliary wheel 33 of the rice transplanter according to an embodiment of the present invention.

[0137] The rice transplanter of the present embodiment is a rice transplanter in which the control device 200 performs turning control when turning the vehicle body 10 that has been traveling straight.

[0138] The control device 200 changes the timing for returning the steering angle to the original position based on the mounting state of the auxiliary wheels 33 in order to make the vehicle body 10 that has been turned go straight again.

[0139] The standard steering angle return timing is provided as the steering angle return timing when the auxiliary wheels 33 are not attached.

[0140] In the automatic turning control of a rice transplanter, the pulse number p of the rear wheel on the inside of the turn is measured from the start of the automatic turning control until the machine heading becomes θ0. If the pulse number at this time is between p1 and p2, it is determined that the turn is normal and no correction control is performed.

[0141] When the auxiliary wheel 33 is attached to the inside in the left-right direction of the vehicle body but not to the outside in the left-right direction of the vehicle body, the control device 200 changes the steering angle return timing so that the steering angle return timing is delayed compared to the standard steering angle return timing.

[0142] When the internal auxiliary wheels 33 are installed, the appropriate values ​​p1 to p2 change, so when the internal auxiliary wheels 33 are installed, the controller settings may be made to adjust the standard for determining the turning state without adjusting the standard steering angle return timing itself, and the appropriate values ​​p1 and p2 may be changed. By setting a width from p1 to p2 for the appropriate value of the rear wheel pulse on the inside of the turn during automatic turning control, unnecessary correction control is not performed and turning accuracy can be improved. In addition, when the internal auxiliary wheels 33 are installed, the rear wheel resistance during turning changes and the appropriate rear wheel rotation speed also changes. By changing the values ​​p1 and p2 in the controller settings, highly accurate automatic turning control is possible even when the internal auxiliary wheels 33 are installed.

[0143] When the auxiliary wheel 33 is attached to the outside in the left-right direction of the vehicle body but not to the inside in the left-right direction of the vehicle body, the control device 200 changes the steering angle return timing so that the steering angle return timing becomes earlier than the standard steering angle return timing.

[0144] When the external auxiliary wheels 33 are attached, the appropriate values ​​p1 to p2 change, so when the external auxiliary wheels 33 are attached, the controller settings may be made to adjust the standard for determining the turning state without adjusting the standard steering angle return timing itself, and the appropriate values ​​p1 and p2 may be changed. By setting the width from p1 to p2 for the appropriate value of the rear wheel pulse on the inside of the turn during automatic turning control, unnecessary correction control is not performed and turning accuracy can be improved. In addition, when the external auxiliary wheels 33 are attached, the rear wheel resistance during turning changes and the appropriate rear wheel rotation speed also changes. By changing the values ​​p1 and p2 in the controller settings, high-precision automatic turning control is possible even when the external auxiliary wheels 33 are attached.

[0145] When the auxiliary wheels 33 are attached to the inside and outside in the left-right direction of the vehicle body, the control device 200 changes the steering angle return timing so that the steering angle return timing is earlier than the standard steering angle return timing.

[0146] The control device 200 judges the turning state based on the result of the detection, and changes the steering angle return timing not only based on the mounting state of the auxiliary wheels 33 but also based on the turning state judgment.

[0147] (C) Next, the configuration and operation of the rice transplanter of the present embodiment will be described in more detail with reference mainly to FIGS.

[0148] The rice transplanter of the present embodiment is a rice transplanter in which the control device 200 performs turning control when turning the vehicle body 10 that has been traveling straight.

[0149] The control device 200 controls the vehicle speed during turning control.

[0150] In rice transplanter turning assist control, during U-turn control, after control is started by the planting lift operation, that is, during turning from planting lift, a configuration is considered in which the maximum forward speed is normally 1.86 m / s (depending on the model) but is restricted to 0.9 m / s. This is because the travel distance from the start of forward movement until the steering wheel is turned to the target position varies depending on the vehicle speed, and if the steering wheel is turned while moving forward at high speed, the vehicle will naturally make a wide turn and the travel trajectory will not be stable. By regulating the vehicle speed, the vehicle's driving trajectory during cornering is stabilized.

[0151] During U-turn control, the maximum forward speed limit is not limited to a flat cap of 0.9 m / s or more, but rather it can be configured to be gradually limited to 0.9 m / s when the HST lever is in the maximum forward speed position. This is because if the speed limit is set to a flat cap of 0.9 m / s or more, the HST lever may reach the upper limit of 0.9 m / s at an intermediate position, making fine adjustments difficult and resulting in a poor operating feel as the vehicle speed does not change even when the lever is operated. This makes it easier to fine-tune the vehicle speed even when the vehicle speed is limited, improving the operating feel.

[0152] The control device 200 controls the vehicle speed by regulating the vehicle speed using a first speed limit and a second speed limit that is lower than the first speed limit. The second vehicle speed regulation period in the turning control, during which the vehicle speed is regulated so as not to exceed the second speed limit, is a period following the first vehicle speed regulation period in the turning control, during which the vehicle speed is regulated so as not to exceed the first speed limit.

[0153] At least near the turning control end timing at which the turning control is ended, the vehicle speed is restricted so as not to exceed the second restricted speed.

[0154] During U-turn control, if the turning ends during the above-mentioned control and the difference between the heading of the aircraft and the target heading while proceeding in the direction of the next turning target line becomes equal to or less than a specified angle (50 degrees), a configuration is conceivable in which the maximum forward speed limit of 0.9 m / s (first speed limit) is further restricted to 0.6 m / s (second speed limit). This is because, as a control specification, when the aircraft approaches the direction of the target line, the steering wheel is returned to the center and automatic steering is started toward the turning target line, but if the aircraft is traveling at high speed while turning the steering wheel, the traveling path may become unstable and the entry angle to the target line may become unstable. Restricting the vehicle speed stabilizes the traveling trajectory during turning.

[0155] The control device 200 performs straight running control after turning when making the turning vehicle body 10 go straight again. At least near the start timing of the straight running control after turning, when the straight running control after turning is started, the vehicle speed is restricted so as not to exceed a second restricted speed.

[0156] Of course, an embodiment may be considered in which the vehicle speed is restricted so as not to exceed the second restricted speed even after the straight ahead control start timing.

[0157] For example, during U-turn control, the maximum forward speed of 0.6 m / s is restricted by automatic steering after the turn, and the vehicle speed is restricted until the vehicle reaches the target line, even during trajectory correction toward the target line. This is because if the vehicle speed restriction is released after automatic steering is engaged after the turn, the vehicle speed will be high until the vehicle reaches the target line, and the distance until the planting mark becomes straight may be longer. By restricting the vehicle speed even after the turn, the driving trajectory until the vehicle reaches the target line is stabilized.

[0158] When the vehicle body 10 reaches the vicinity of the straight-line control target line for the straight-line control after turning, the restriction on the vehicle speed is released.

[0159] Of course, an embodiment is also possible in which the restriction on the vehicle speed is not released even after the vehicle body 10 reaches the vicinity of the straight-line control target line of the straight-line control after turning.

[0160] For example, during U-turn control, the maximum forward speed of 0.6 m / s is restricted by automatic steering after the turn, and continues to be restricted until the planting clutch is engaged during trajectory correction toward the target line, so that a configuration can be considered in which the vehicle speed is restricted with planting engaged. This is because if the vehicle speed restriction is released after automatic steering is engaged after the turn, the vehicle speed will be high until it reaches the target line, and the distance until the planting mark becomes straight may be long accordingly. By restricting the vehicle speed even after the turn, the driving trajectory until it reaches the target line is stabilized.

[0161] During the first vehicle speed regulation period, the regulation of the vehicle speed takes priority even if a manual operation is performed to adjust the vehicle speed so that the vehicle speed exceeds the first regulation speed.

[0162] During the second vehicle speed regulation period, the regulation of the vehicle speed takes priority even if a manual operation is performed to adjust the vehicle speed so that the vehicle speed exceeds the second regulation speed.

[0163] During U-turn control, the HST's vehicle speed recovery response speed when the vehicle speed restriction is released can be configured to return more slowly than during normal lever operation. This is because, although there is a possibility of endangering the operator if the vehicle speed were to return suddenly after control ends, this ensures safety.

[0164] For vehicle speed regulation, a configuration is considered in which the HST trunnion opening is restricted based on the theoretical vehicle speed at the HST lever position. This clarifies the method of vehicle speed regulation, and since it is determined only by the lever position, vehicle speed regulation can be easily achieved.

[0165] A possible configuration is to use a rear wheel rotation sensor to detect the current vehicle speed during speed regulation, and if it is determined to be slower than the target vehicle speed, increase the trunnion opening to increase the vehicle speed. Depending on the field conditions, the vehicle speed may fluctuate even with the same trunnion opening, but this allows the vehicle to turn at a stable speed depending on the field conditions.

[0166] A possible configuration is to use a rear wheel rotation sensor to detect the current vehicle speed during speed regulation, and if it is determined to be faster than the target vehicle speed, the trunnion opening is reduced to slow down the vehicle speed. Depending on the field conditions, the vehicle speed may fluctuate even with the same trunnion opening, but this allows the vehicle to turn at a stable speed depending on the field conditions.

[0167] A possible configuration is to use GPS to detect the current vehicle speed during speed restrictions, and if it is determined to be slower than the target vehicle speed, increase the trunnion opening to increase the vehicle speed. Depending on the field conditions, the vehicle speed may fluctuate even with the same trunnion opening, but this allows the vehicle to turn at a stable speed depending on the field conditions.

[0168] A possible configuration is to detect the current vehicle speed using GPS during speed restrictions, and if it is determined to be faster than the target vehicle speed, reduce the trunnion opening to slow down the vehicle speed. Depending on the field conditions, the vehicle speed may fluctuate even with the same trunnion opening, but this allows the vehicle to turn at a stable speed depending on the field conditions.

[0169] A possible configuration is to use the average value over a certain period of time (0.5 seconds, 1 second, etc.) for GPS detection. GPS speed is not very stable, so if it is judged based on an instantaneous value, there will be some fluctuation, but using the average value improves the accuracy of speed detection.

[0170] When calculating the average value of the GPS vehicle speed obtained at regular intervals (0.1 seconds), the maximum and minimum values ​​are omitted, and the vehicle speed average is calculated. GPS vehicle speed is unstable, so if it is judged based on the instantaneous value, there will be fluctuations, and due to its characteristics, abnormal values ​​may be received momentarily, but the vehicle speed detection accuracy can be improved by thinning out the maximum and minimum values.

[0171] If the currently calculated average GPS vehicle speed Vn is significantly different from the average GPS vehicle speed Vn-1 calculated one cycle ago (by 1.0 m / s or more), the currently calculated average GPS vehicle speed Vn is judged to be abnormal, and the average GPS vehicle speed Vn-1 calculated one cycle ago is treated as the positive value for control. A possible configuration is to perform detection using GPS. Since GPS vehicle speed is unstable, if it is judged based on the instantaneous value, there will be fluctuations, and due to its characteristics, it may receive an abnormal value momentarily, but the accuracy of vehicle speed detection can be improved by thinning out the abnormal values.

[0172] One possible configuration is to monitor vehicle speed (whether it is fast or slow) at fixed intervals (0.5 seconds, 1 second, etc.) rather than at the main control interval (10 ms, etc.).This is because if the monitoring interval is too short, the vehicle speed will not be stable and the HST will be constantly under feedback control, which will cause hunting and reduce comfort.

[0173] One possible configuration is to set a certain threshold value (such as allowing up to ±0.1 m / s) as the appropriate range for vehicle speed monitoring (fast or slow).This is because if the appropriate range for vehicle speed is too narrow, the HST will be constantly under feedback control, which will tend to cause hunting and reduce comfort.

[0174] One possible configuration would be to monitor the vehicle speed (whether it's fast or slow) and adjust the HST opening to a certain vehicle speed range (0.1 m / s). It is necessary to determine the appropriate value for how much correction should be made at one time, so the vehicle speed can be adjusted gradually without making the correction all at once.

[0175] When the current vehicle speed is significantly different from the target vehicle speed, the above-described process may be repeated at regular intervals. By repeating the feedback control, the vehicle speed can be smoothly corrected.

[0176] The HST opening to be corrected may be stored in a non-volatile manner in the controller, and the correction opening may be changed in a non-volatile manner using a checker or a dial on a monitor panel, etc. The response of the vehicle speed correction may be made faster or slower depending on the situation.

[0177] The opening of the HST to be corrected can be changed by operating an external dial, and a configuration in which the correction opening can be changed with a dial is conceivable. Although it can be cumbersome to operate the checker or to go into a deep hierarchy on the monitor, it makes it easy to speed up or slow down the response of the vehicle speed correction depending on the situation.

[0178] One possible configuration is to simultaneously feedback control the engine speed by controlling the electric accelerator as well as the trunnion opening of the electric HST. This is because in deep farm fields such as wet paddy fields, if the HST opening is increased alone, the engine may stop due to engine drop.

[0179] It is possible to configure the system to perform feedback control of the HST and electric accelerator even during normal driving, not just when cornering is in progress. This would enable driving control according to the HST lever position even during normal driving, regardless of the field conditions.

[0180] A possible configuration is that feedback control is not performed when the sub-transmission is at travel speed. This is because if control that automatically corrects the HST opening works while driving on the road, it may result in driving that is different from what the operator intended (automatic acceleration), which may lead to a dangerous situation, so it is desirable not to perform automatic driving correction while driving on the road.

[0181] A possible configuration is one in which feedback control is not performed when the planting section is raised. This is because if the control to automatically correct the HST opening works when the sub-transmission is at planting speed while driving on the road, there is a risk that the driving will differ from what the operator intended (automatic acceleration), which could lead to a dangerous situation, so it is desirable not to automatically correct the driving when not working.

[0182] A possible configuration is that feedback control is not performed when the planting clutch is off. This is because if the control to automatically correct the HST opening works when the sub-transmission is at planting speed while driving on the road, there is a risk that the driving will be different from what the operator intended (it will automatically accelerate), which could lead to a dangerous situation, and there is also the possibility that the planting part will be lowered below a certain height depending on the situation, such as to avoid obstacles, and the vehicle will be driven on the road, so it is desirable that the driving correction is not performed automatically when not working, and the control is not effective unless the planting clutch is engaged, in other words, when rice planting is in progress.

[0183] A possible configuration is to store the feedback control on / off switch in a non-volatile manner held by the controller, and to change the setting on / off in a non-volatile manner by using a checker or a dial on a monitor panel, etc. This is because some users do not want to correct the vehicle speed because it changes the feeling, and it is desirable to be able to turn the vehicle speed correction on and off depending on the situation.

[0184] A configuration in which feedback control can be switched on or off by operating an ON / OFF switch or the like is conceivable. This is because some users do not want to correct the vehicle speed because it changes the feeling, and it is desirable to be able to turn the vehicle speed correction on or off depending on the situation.

[0185] During the second vehicle speed regulation period, the vehicle speed is regulated to coincide with the second regulation speed. During the first and second vehicle speed regulation periods, if a manual operation is performed to adjust the vehicle speed so that the vehicle speed falls below the second regulation speed, the vehicle body 10 is stopped.

[0186] One possible configuration is to fix the HST opening to a neutral position during U-turn control at very low forward speeds, preventing driving. This is because when turning assistance is performed at very low speeds, the GPS information varies widely and the vehicle is easily affected by the field, making turning unstable. When automatic steering is turned on after the turn is completed, if the vehicle is not traveling at a certain speed or higher, an error at low speeds may cause the automatic steering to be cut off. By restricting turning assistance at unstable speeds, the vehicle can make turns with a stable driving trajectory and prevent automatic steering errors from occurring after the turn.

[0187] A possible configuration is to restrict the maximum forward speed from 1.86 m / s (depending on the model) to 0.9 m / s when the ridge warning starts during U-turn control (approximately 8 m before the ridge). This is because, as described above, when U-turn control starts while driving at high speed, the distance traveled from the start of forward movement until the steering wheel is turned to the target position varies depending on the vehicle speed, and turning the steering wheel while driving at high speed naturally results in a wide turn and an unstable driving trajectory. Smooth U-turn control is possible by reducing the vehicle speed to a certain extent before the start of U-turn control.

[0188] A possible configuration is to restrict vehicle speed in stages according to the distance from the ridge. In one example, the restricted vehicle speed is set every 2m in accordance with the ridge-edge warning, at 1.3m / s above 8m, 1.2m / s from 6m to 8m, 1.1m / s from 4m to 6m, 1.0m / s from 2m to 4m, and 0.9m / s below 2m. This is because if the vehicle speed is restricted too far in advance, it will take longer than necessary to reach the target ridge-edge position.

[0189] The response speed of the HST when the vehicle speed restriction starts can be configured to return more slowly than during normal lever operation. This is to ensure safety, since a change in vehicle speed could pose a danger to the operator.

[0190] A possible configuration is to continue the vehicle speed restriction control at the edge of the field until the HST lever is returned to the vehicle speed restriction position. This is because the vehicle cannot actually drive to the desired position for a U-turn because the vehicle is set to automatically stop 3m before the field, and if the vehicle continues to drive after the field stop control has been activated, it is meaningless if the vehicle speed restriction does not work when the driver turns off the automatic steering wheel at the edge of the field. If the driver turns off the automatic steering wheel at the edge of the field, the vehicle speed restriction can continue until the driver operates the lever voluntarily, even if the HST lever position remains the same until the vehicle starts to turn, allowing for smooth U-turn control.

[0191] A configuration is considered in which the vehicle speed restriction control at the edge of a field is released when U-turn control is started. This is because if the vehicle speed restriction at the edge of a field is continued for a long time, it will collide with the vehicle speed restriction during turning assistance and the control will not be effective. This clarifies the conditions for releasing the vehicle speed restriction at the edge of a field.

[0192] A possible configuration is to release the vehicle speed restriction control on the edge of a field when the U-turn control is turned off (U-turn switch OFF). This is because if the vehicle speed restriction on the edge of a field continues for a long time, it may collide with the vehicle speed restriction during turning assistance, or the restriction may continue even though it should be released when turning assistance is turned off. This clarifies the conditions for releasing the vehicle speed restriction on the edge of a field.

[0193] The control device 200 also performs turning control when the vehicle body 10 that has been traveling straight is stopped, moved backward, stopped again, and then turned. When the vehicle body 10 is moved backward, the control device 200 restricts the vehicle speed by using a third restricted speed that does not exceed the second restricted speed.

[0194] Of course, an embodiment is also conceivable in which, when the vehicle body 10 is reversed, the control device 200 regulates the vehicle speed by utilizing a third regulated speed that does not exceed the first regulated speed.

[0195] For example, in the rice transplanter turning assist control, a configuration can be considered in which the maximum reverse speed is normally 1.2 m / s and is restricted to 0.9 m / s from the start of reverse movement during backturn control until 30 cm before the reverse stop (1.1 m). This is because, in a control that automatically stops after reversing a certain distance (1.1 m) when turning backward, if the vehicle suddenly stops when reversing at high speed, the stopping shock is large and there is a possibility of danger to the operator, but safety is ensured.

[0196] In the rice transplanter turning assist control, during the back-turn control, after the above-mentioned control, that is, from 30 cm before the reverse stop (1.1 m) to the reverse stop (1.1 m), a configuration is considered in which the maximum reverse speed limit of 0.9 m / s is further restricted to 0.5 m / s (third restricted speed). This is because, from 30 cm before the reverse stop (1.1 m) to the reverse stop (1.1 m), there is a control to turn the steering wheel in advance to the extent that the rear wheel clutch is not disengaged toward the turning direction (aiming for 220 degrees of steering), but if the steering wheel is turned while traveling at high speed, the traveling path may not be stable, and the reverse stop (1.1 m) position may be reached before the steering wheel is completely turned, which may cause a problem that the steering wheel must be turned while the vehicle is stopped (especially in the case of deep wet rice fields, there is a risk that the motor will not be able to turn the steering wheel when the vehicle is stopped because it will be unable to handle the load of the field). In addition, the above-mentioned control makes it possible to travel a certain distance without restricting the vehicle speed too much, and by restricting the vehicle speed to a certain extent when leading the vehicle, it is possible to suppress the shock of shifting gears 30 cm before the reverse stop (1.1 m) while also suppressing the stopping shock when reversing to a stop (1.1 m).

[0197] It goes without saying that the various controls described above in the U-turn control can be used not only in the U-turn control but also in the back-turn control.

[0198] For example, during backturn control in rice transplanter turning assist control, after the reverse control for backing straight ahead as described above, that is, during turning from a stop in reverse, a configuration can be considered in which the maximum forward speed is normally 1.86 m / s (depending on the model) and limited to 0.9 m / s.

[0199] (D) Next, the configuration and operation of the rice transplanter of the present embodiment will be described more specifically with reference mainly to FIGS.

[0200] The rice transplanter of this embodiment is a rice transplanter in which the control device 200 performs straight-line control before turning when making the turning vehicle body 10 go straight, performs turning control when turning the vehicle body 10 that has been going straight, and performs straight-line control after turning when making the turning vehicle body 10 go straight again.

[0201] The changeover from the straight line control to the turning control before the turn is performed based on a manual operation.

[0202] Of course, embodiments are possible in which the switch from straight-line control before a turn to turning control is performed automatically, as is the switch from turning control to straight-line control after a turn, and embodiments are also possible in which the switch from turning control to straight-line control after a turn is performed based on manual operation.

[0203] The timing for returning the steering angle to return the steering angle in order to make the vehicle body 10 that has been turned go straight again is set as a timing before the timing for starting straight-line control for starting straight-line control after turning.

[0204] The steering angle return timing is the timing at which the difference between the direction of the turned vehicle body 10 and the direction in which the vehicle body 10 is made to move straight again falls below a predetermined steering angle return level.

[0205] As described above, for example, the steering angle return level is 30 degrees.

[0206] The steering angle return timing is adjustable based on a manual operation that adjusts a predetermined steering angle return level.

[0207] As described above, for example, the steering angle return level may be reduced to 25 degrees or increased to 35 degrees by, for example, dial operation of the threshold adjustment device 400 based on the operator's experience.

[0208] (E) Next, with reference mainly to FIGS. 10 to 24, the configuration and operation of the rice transplanter according to the present embodiment will be described in more detail.

[0209] Here, FIGS. 10 to 23 are explanatory views (from the second to the fifteenth) of the turning control of the rice transplanter according to the embodiment of the present invention, and FIG. 24 is a partial perspective view of the vicinity of the operation unit 50 of the rice transplanter according to the embodiment of the present invention.

[0210] <Turn assist correction control using a Z-turn (1)>(see FIG. 10) In the automatic turning control of the rice transplanter, during automatic turning, the steering angle is fixed at a constant α and the turning is controlled. Also, for the Z-turn, it is designed to give a planting part lowering signal when turning 135°.

[0211] The control is to set the turning path with GPS and turn along it, but there is a problem that the control is difficult and unstable.

[0212] By setting the steering angle constant, the control is easy and the versatility is great for various types of machines. Since the steering angle is constant, the rotation of the rear inner wheel during turning becomes constant, and the Z-turn control accuracy is improved.

[0213] <Turn assist correction control using a Z-turn (2)>(see FIG. 10) During the automatic turning control of the rice transplanter, the orientation of the machine body is measured by the IMU. When the planting part lowering signal is not output when the machine body reaches the angle of θ1 (when the rear inner wheel on the turning inner side does not rotate more than the designed value), it is determined that the machine is turning in a small circle, and a correction control is performed to return the steering angle α and turn in a large circle.

[0214] By utilizing the control of the Z-turn to correct the turning assist control, it is possible to easily determine whether correction of the turning radius is necessary with the existing program and sensors, and the turning accuracy can be improved.

[0215] <Turning Assist Correction Control Using Z-Turn (3)>(See Figure 10) During the automatic turning control of the rice transplanter, the orientation of the machine body is measured by the IMU. When the machine body reaches the angle of θ2 and the planting part lowering signal is output (when the rear wheel on the inside of the turn rotates too much compared to the design value), it is determined that the machine is turning in a large circle, and correction control is performed to increase the steering cut-off angle α and make a smaller turn.

[0216] By utilizing the control of the Z-turn to correct the turning assist control, it is possible to easily determine whether correction of the turning radius is necessary with the existing program and sensors, and the turning accuracy can be improved.

[0217] <Turning Assist Correction Control Using Z-Turn (4)>(See Figure 11) During the automatic turning control of the rice transplanter, the orientation of the machine body is measured by the IMU. When the machine body reaches the angle of θ1 and the planting part lowering signal is not output (when the rear wheel on the inside of the turn does not rotate more than the design value), it is determined that the machine is turning in a small circle, and control is performed to advance the starting orientation of returning the steering so that the planting tracks are aligned.

[0218] By utilizing the control of the Z-turn to correct the turning assist control, it is possible to easily determine whether correction of the turning radius is necessary with the existing program and sensors, and the turning accuracy can be improved.

[0219] <Turning Assist Correction Control Using Z-Turn (5)>(See Figure 12) During the automatic turning control of the rice transplanter, the orientation of the machine body is measured by the IMU. When the machine body reaches the angle of θ2 and the planting part lowering signal is output (when the rear wheel on the inside of the turn rotates too much compared to the design value), it is determined that the machine is turning in a large circle, and control is performed to delay the starting orientation of returning the steering so that the planting tracks are aligned.

[0220] By correcting the turning assist control by utilizing the control of the Z-turn, it is possible to easily determine whether correction of the turning radius is necessary with the existing program and sensors, and the turning accuracy can be improved.

[0221] <Turning Assist Correction Control Using Z-Turn (6)>(See Fig. 13) Regarding the angles θ1 and θ2 for determining whether to perform the turning assist correction control, they shall be 140° or less.

[0222] By setting θ1 and θ2 to 140° or less, even if the correction control is activated, it is possible to prevent the correction from being in time and the turning accuracy from deteriorating.

[0223] <Turning Assist Control from Three Points (1)>(See Fig. 14) In the automatic turning control of the rice transplanter, during automatic turning, the control is such that it turns while fixing the steering cut-off angle at a constant α.

[0224] The control is to set the turning path with GPS and turn along it, and there is a problem that the control is difficult and unstable.

[0225] By setting the steering cut-off angle to be constant, the control is easy and it has great versatility for aircraft of various specifications.

[0226] <Turning Assist Control from Three Points (2)>(See Fig. 14) In the automatic turning control of the rice transplanter, the control is to obtain the coordinates at the turning angles θ1, θ2, and θ3 of the aircraft during automatic turning with a constant steering cut-off angle from the GNSS antenna information.

[0227] By obtaining the coordinates, it is possible to confirm whether the aircraft is turning as planned.

[0228] <Turning Assist Control from Three Points (3)>(See Fig. 15) In the automatic turning control of the rice transplanter, the coordinates of the aircraft turning angle, θ1, θ2, and θ3 during automatic turning with a constant steering angle are obtained from the GNSS antenna information. The coordinates of the three obtained points are substituted into the following equation, and the simultaneous equations are solved to obtain the turning radius R1 and monitor whether the turning radius is being controlled as planned (x 2 +y 2 +lx+my+n=0).

[0229] By calculating the turning radius, it is possible to determine whether the aircraft is turning with the planned turning radius.

[0230] <Three-point turning assist control (4)> (see Figure 15) In the automatic turning control of the rice transplanter, the coordinates of the aircraft turning angle, θ1, θ2, and θ3 during automatic turning with a constant steering angle are obtained from the GNSS antenna information. The coordinates of the three obtained points are substituted into the following equation, and the simultaneous equations are solved to obtain the turning radius R1 and monitor whether the turning radius is being controlled as planned (x 2 +y 2 +lx+my+n=0). If the calculated turning radius R1 is within the range of Ra (lower limit of proper turning radius) ≦ R1 ≦ Rb (upper limit of proper turning radius), it is determined that the turning is normal, and the turning continues without any correction.

[0231] By determining whether a turn is being made normally or not for each turn from the measured turning radius, the accuracy of the turn can be improved.

[0232] <Three-point turning assist control (5)> (See Figure 15) In the automatic turning control of the rice transplanter, the coordinates of the aircraft turning angle, θ1, θ2, and θ3 during automatic turning with a constant steering angle are obtained from the GNSS antenna information. The coordinates of the three obtained points are substituted into the following equation, and the simultaneous equations are solved to obtain the turning radius R1 and monitor whether the turning radius is being controlled as planned (x 2 +y 2+lx+my+n=0). If the calculated turning radius R1 is Rb≦R1, it is determined that the vehicle is making a wide turn, and the steering angle is controlled to be increased to make the vehicle turn tighter.

[0233] When it is determined from the measured turning radius that the vehicle is making a large turn, the steering is controlled to make the turn a small one, thereby improving turning accuracy.

[0234] <Three-point turning assist control (6)> (See Fig. 15) In the automatic turning control of the rice transplanter, the coordinates of the aircraft turning angle, θ1, θ2, and θ3 during automatic turning with a constant steering angle are obtained from the GNSS antenna information. The coordinates of the three obtained points are substituted into the following equation, and the simultaneous equations are solved to obtain the turning radius R1 and monitor whether the turning radius is being controlled as planned (x 2 +y 2 +lx+my+n=0). If the calculated turning radius R1 is R1≦Ra, it is determined that the vehicle is making a tight turn, and the steering angle is controlled to return to a larger turning angle.

[0235] When it is determined from the measured turning radius that the turning is becoming tighter, the steering is controlled to make the turning turn wider, thereby improving the turning accuracy.

[0236] <Three-point turning assist control (7)> ​​(see Figure 16) In the automatic turning control of the rice transplanter, the coordinates of the aircraft turning angle, θ1, θ2, and θ3 during automatic turning with a constant steering angle are obtained from the GNSS antenna information. The coordinates of the three obtained points are substituted into the following equation, and the simultaneous equations are solved to obtain the turning radius R1 and monitor whether the turning radius is being controlled as planned (x 2 +y 2 +lx+my+n=0). When the calculated turning radius R1 is Rb≦R1, it is determined that the turn is wide, and the steering return direction at the end of the turn is delayed so that the planting marks are on the inside, and the tillage marks are controlled to be aligned.

[0237] If the measured turning radius indicates that the turn is becoming wider, the steering return direction at the end of the turn is delayed to align the tilling start position with the previous process, thereby improving the accuracy of the turning assist control.

[0238] <Three-point turning assist control (8)> (see Figure 17) In the automatic turning control of the rice transplanter, the coordinates of the aircraft turning angle, θ1, θ2, and θ3 during automatic turning with a constant steering angle are obtained from the GNSS antenna information. The coordinates of the three obtained points are substituted into the following equation, and the simultaneous equations are solved to obtain the turning radius R1 and monitor whether the turning radius is being controlled as planned (x 2 +y 2 +lx+my+n=0). When the calculated turning radius R1 is R1≦Ra, it is determined that the vehicle is turning in a tight circle, and the steering return direction at the end of the turn is accelerated so that the planting marks are on the outside, and the tillage marks are controlled to be aligned.

[0239] If it is determined from the measured turning radius that the turning is becoming tighter, the steering return direction at the end of the turn can be accelerated to align the start of tilling with the previous process, thereby improving the accuracy of the turning assist control.

[0240] <Three-point turning assist control (9)> (see Figure 18) In the automatic turning control of the rice transplanter, the coordinates of the machine turning angles θ1, θ2, and θ3 during automatic turning with a constant steering angle are obtained from GNSS antenna information. The position information is obtained so that the values ​​of θ1, θ2, and θ3 are 30° or more apart.

[0241] If three points are obtained at small angles to calculate the turning radius, there is a high risk that the error will be large and the turning radius will not be calculated accurately.

[0242] By acquiring position coordinates that are 30° or more away and calculating the turning radius, a highly accurate turning radius can be calculated, thereby improving the accuracy of turning assist control.

[0243] <Three-point turning assist control (10)> (see Figure 19) In the automatic turning control of the rice transplanter, the coordinates of the machine turning angles θ1, θ2, and θ3 during automatic turning with a constant steering angle are obtained from GNSS antenna information. The control is to obtain position information so that θ1, θ2, and θ3 are values ​​that are 30° or more apart. In addition, θ3 is 120° or less.

[0244] Even if you try to correct turning control based on a turning radius obtained at 120° or more, the control may not be able to keep up, and turning accuracy may decrease.

[0245] By determining whether or not to correct the turning control before the vehicle has turned 120 degrees, the effect of making the correction can be fully exerted, and the accuracy of the turning assist control can be improved.

[0246] <Straight-line assist control (1)> In a straight-line assisted rice transplanter, the inclination of the machine in the rolling direction is detected by the IMU. If the machine continues to tilt in one direction for a certain period of time, it is determined that the wheels are stuck in a rut, and the steering amount dial value is automatically changed to the larger side.

[0247] If the steering amount remains small when the vehicle is stuck in a rut, the amount of steering control during straight-line control will be small, and straight-line accuracy will deteriorate. Also, the vehicle will not be able to get out of the rut.

[0248] By automatically increasing the amount of steering, the accuracy of straight-line driving is improved. It also allows the vehicle to escape from ruts earlier and improves straight-line driving.

[0249] <Straight-line assist control (2)> In the straight-line assisted rice transplanter, if the tilt of the machine in the rolling direction is detected by the IMU and the machine continues to tilt in one direction for a certain period of time, it is determined that the wheels are stuck in a rut and the steering amount dial value is automatically changed to the larger side. Also, if it is determined that the machine has remained horizontal for a certain period of time, the steering amount is automatically returned to the original value.

[0250] If the steering angle remains large even after the vehicle has left the rut, the steering control amount may be too large, causing the vehicle to snake.

[0251] Straight-line accuracy is improved by automatically returning to the original steering amount when the vehicle returns to a horizontal position.

[0252] <Improvement of turning assist control (1)> (See Fig. 20) In the turning assist control, a steering angle α is set according to a turning target distance for each model, and during turning control, the vehicle is turned at the fixed steering angle α.

[0253] In the past, the tiller was fixed in place, and the steering wheel was returned midway through the turn to allow the tiller to run sideways, but the lateral running distance was unstable depending on the field conditions, and the row alignment was not always correct. This eliminates the unstable factor caused by lateral running. In addition, turning with the steering wheel fixed is simpler and more stable than using a method of specifying a route using GNSS, etc., and is not affected by GNSS sensitivity.

[0254] By fixing the steering angle during turning according to each model and number of rows, unstable factors caused by lateral running are eliminated, row alignment can be stabilized, and the control is simple and highly versatile. In addition, turning can be stabilized without being affected by GNSS.

[0255] It is now possible to change from a U-shaped turn to a U-shaped turn.

[0256] <Improvement of turning assist control (2)> (See Fig. 20) In the turning assist control, when the steering angle is set for each vehicle type, the turning radius differs for each vehicle type, and the control is such that the back amount L during a back turn is changed according to the turning radius.

[0257] Changing the steering angle changes the turning radius, but if the amount of backing up when backing up is constant, there is a problem that when the turning radius becomes large, the vehicle may run onto a ridge or back up too far and crush seedlings.

[0258] Changing the steering angle changes the turning radius, and by setting the back amount accordingly, optimal turning can be performed, improving work efficiency.

[0259] <Improvement of turning assist control (3)> (See Fig. 20) In the turning assist control, a steering angle α is set according to a turning target distance for each model, and during turning control, the vehicle is turned at a fixed steering angle α. The turning angle α can be set for right turns and left turns, respectively.

[0260] Due to variations in parts, the turning radius differs from aircraft to aircraft even with the same steering angle, so the accuracy of turning assist control can be improved by configuring the system to be able to set the turning angle to suit each aircraft.

[0261] <Improvement of turning assist control (4)> (See Fig. 20) In the turning assist control, the steering angle α is set according to the turning target distance for each model, and during turning control, the vehicle is turned at a fixed steering angle α. The steering angle α can be set separately for right and left turns. The value can also be adjusted with a dial on the monitor (e.g., 1 memory steering 5°).

[0262] By configuring it so that it can be fine-tuned to suit field conditions, the accuracy of turning assistance can be improved.

[0263] <Improvement of turning assist control (5)> (See Fig. 20) In the turning assist control, a steering angle α is set according to the turning target distance for each model, and during turning control, the vehicle is turned at a fixed steering angle α. The turning angle α can be set for right and left turns, respectively. The value can also be adjusted using a dial on the monitor. The vehicle is also configured to automatically change the appropriate amount of backing according to the adjusted turning angle.

[0264] L´: Back amount L: Specified back amount K: Adjustment factor α: Cutting angle J: Turn angle adjustment value using the dial L´=L K (α+J) As the turning radius increases, it is necessary to keep a distance to the ridge, and if the backing distance is constant, there is a problem of running over the ridge when the turning radius is increased.

[0265] By changing the amount of backing up in conjunction with changing the steering angle, it is possible to prevent the vehicle from running onto ridges while turning or crushing seedlings when backing up, and it is possible to stabilize the turning assistance.

[0266] <Improvement of turning assist control (6)> (See Fig. 21) In the turning assist control, the steering angle α is set according to the turning target distance for each model, and during turning control, the vehicle is turned at a fixed steering angle α. The steering angle α can be set separately for right and left turns. In addition, in order to adjust the turning accuracy to suit the field conditions, the vehicle azimuth angle β at which the steering wheel (circled number 4 in the figure) begins to return to a straight ahead state can be adjusted with a dial on the monitor.

[0267] By configuring the system to allow fine adjustment of the timing at which the steering starts to return to a straight-ahead state, turning assistance can be performed according to the field conditions, improving accuracy.

[0268] <Improvement of turning assist control (7)> ​​(See Fig. 21) In the turning assist control, the steering angle α is set according to the turning target distance for each model, and during turning control, the vehicle is turned at a fixed steering angle α. The steering angle α can be set separately for right and left turns. The value can also be adjusted with a dial on the monitor (e.g. 1 memory steering 5°). The aircraft azimuth angle β, at which the steering wheel (number 4 in a circle in the figure) begins to return to a straight ahead state, is changed in conjunction with the adjusted steering angle.

[0269] β´: Aircraft azimuth angle when steering starts β: Steering return start aircraft direction setting value K: Adjustment factor J: Turn angle adjustment value using the dial β´=β·K·(α+J) The accuracy of turning assistance can be improved by changing the timing at which the steering begins to return to a straight-ahead position in conjunction with the steering angle.

[0270] <Improvement of turning assist control (8)> (See Fig. 21) In the turning assist control, the steering angle α is set according to the turning target distance for each model, and during turning control, the vehicle is turned at a fixed steering angle α. The turning angle α can be set separately for right and left turns. The value can also be adjusted with a dial on the monitor (e.g., 1 memory steering 5°). In accordance with the adjusted turning angle, the aircraft azimuth angle β at which the steering wheel (number 4 in a circle in the figure) begins to return to a straight ahead state is changed in conjunction with the steering angle, and the amount of backing up during a back turn is also changed in conjunction with the steering angle.

[0271] The accuracy of turning assistance can be improved by changing the timing at which the steering begins to return to a straight-ahead position and the amount of backing up in conjunction with the steering angle.

[0272] <Improvement of turning assist control (9)> (See Fig. 22) In the turning assist control, the steering angle α is set according to the turning target distance for each model, and the vehicle is turned at a fixed steering angle α during turning control. The turning angle α can be set separately for right and left turns. The vehicle speed during turning is also detected, and the turning angle α is changed in conjunction with the vehicle speed. The higher the vehicle speed V, the larger the turning angle α is set, thereby suppressing the change in turning radius due to the vehicle speed.

[0273] α´: Turning angle C: Adjustment factor V: Vehicle speed during turning α: Specified steering angle α´=C·V·α The turning radius can be stabilized by changing the steering angle according to the vehicle speed.

[0274] <Improvement of turning assist control (10)> (See Fig. 23) In the turning assist control, the steering angle α is set according to the turning target distance for each model, and the vehicle is turned at a fixed steering angle α during turning control. The turning angle α can be set separately for right and left turns. In addition, the angular velocity γ during turning is detected, and the turning angle α is changed in conjunction with the angular velocity. The higher the vehicle speed V, the larger the turning angle α is set, thereby suppressing the change in turning radius due to the vehicle speed.

[0275] α´: Turning angle C: Adjustment factor γ: Angular velocity during turning α: Specified steering angle α´=C·γ·α The turning radius can be stabilized by changing the steering angle according to the angular velocity during turning.

[0276] <Improvement of turning assist control (11)> (See Fig. 23) In the turning assist control, the steering angle α is set according to the turning target distance for each model, and the vehicle is turned at a fixed steering angle α during turning control. The turning angle α can be set separately for right and left turns. The system also detects the HST lever opening during turning, and changes the turning angle α in conjunction with the HST lever. The larger the HST lever opening R, the larger the turning angle α can be, which can suppress changes in the turning radius due to vehicle speed.

[0277] α´: Turning angle C: Adjustment factor R: HST lever opening α: Specified steering angle α´=C·R·α The turning radius can be stabilized by changing the steering angle according to the opening degree of the HSTB lever.

[0278] <Improvement of turning assist control (12)> (See Fig. 21) In the turning assist control, a steering angle α is set according to the turning target distance for each model, and during turning control, the vehicle is turned at a fixed steering angle α. The turning angle α can be set for right and left turns, respectively. The value can also be adjusted using a dial on the monitor. The vehicle is also configured to automatically change the appropriate amount of backing and the timing to start returning the steering wheel in accordance with the adjusted turning angle.

[0279] L´: Back amount L: Specified back amount K: Adjustment factor α: Cutting angle J: Turn angle adjustment value using the dial L´=L K (α+J) β´: Aircraft azimuth angle when steering starts β: Steering return start aircraft direction setting value K: Adjustment factor J: Turn angle adjustment value using the dial β´=β·K·(α+J) As the turning radius increases, it is necessary to keep a distance to the ridge, and if the backing distance is constant, there is a problem of running over the ridge when the turning radius is increased.

[0280] By changing the amount of backing up in conjunction with changing the steering angle, it is possible to prevent the vehicle from running onto ridges while turning or crushing seedlings when backing up, and it is possible to stabilize the turning assistance.

[0281] <Turning Assist Z-Turn Correction (1)> During turning assistance in the rice transplanter Z-turn control, a correction (+20pls) is made to the planting section lowering timing N1, which is determined by detection by the rear wheel rotation sensor.

[0282] Because the turning assist control results in a larger turn than a normal turn, the timing of the Z-turn is not right (it is too early). If you want to time the Z-turn, the user has to operate the checker or monitor themselves.

[0283] During turning assistance, Z-turn correction is automatically performed, reducing the user's effort.

[0284] <Turning Assist Z-Turn Correction (2)> During turning assistance in the rice transplanter Z-turn control, a correction (+20pls) is made to the planting clutch engagement timing N2, which is determined by detection by the rear wheel rotation sensor.

[0285] Because the turning assist control results in a larger turn than a normal turn, the timing of the Z-turn is not right (it is too early). If you want to time the Z-turn, the user has to operate the checker or monitor themselves.

[0286] During turning assistance, Z-turn correction is automatically performed, reducing the user's effort.

[0287] <Turning Assist Z-Turn Correction (3)> In the configuration of turning assist Z turn correction (1), the N1 correction is configured to change depending on the number of threads on the aircraft.

[0288] The turning radius and working width vary depending on the number of rows, so the target route also differs.

[0289] By changing the amount of Z-turn correction depending on the number of threads, appropriate turning assistance and Z-turns are possible.

[0290] <Turning Assist Z-Turn Correction (4)> In the configuration of the turning assist Z-turn correction (1), when the N1 correction is set to 7 lanes, the configuration is changed between 3 lanes and 5 lanes.

[0291] The turning radius and working width vary depending on the number of rows that are straddled, so the target route also varies.

[0292] By changing the amount of Z-turn correction depending on the number of straddle strips, appropriate cornering assistance and Z-turns can be achieved.

[0293] <Turning Assist Z-Turn Correction (5)> In the configuration of turning assist Z-turn correction (1), the N1 correction is changed (+30pls) when an internal auxiliary wheel is used.

[0294] The turning radius and working width differ depending on the auxiliary wheels, so the target route also differs.

[0295] By changing the amount of Z-turn correction using the auxiliary wheels, appropriate cornering assistance and Z-turns are possible.

[0296] <Turning Assist Z-Turn Correction (6)> In the configuration of turning assist Z-turn correction (1), the N1 correction is changed (+30pls) when external auxiliary wheels are used.

[0297] The turning radius and working width differ depending on the auxiliary wheels, so the target route also differs.

[0298] By changing the amount of Z-turn correction using the auxiliary wheels, appropriate cornering assistance and Z-turns are possible.

[0299] <Turning Assist Z-Turn Correction (7)> In the configuration of the turning assist Z-turn correction (1), N1 correction is configured to prioritize the external auxiliary wheel setting when both internal and external auxiliary wheels are attached (triple) (external priority version).

[0300] In the case of triple suspension, the influence of external wheels is large. This prevents double compensation by internal and external wheels.

[0301] By changing the amount of Z-turn correction using the auxiliary wheels, appropriate cornering assistance and Z-turns are possible.

[0302] <Turning Assist Z-Turn Correction (8)> In the configuration of the turning assist Z-turn correction (1), the N1 correction is a configuration (triple setting version) that performs dedicated correction when both internal and external auxiliary wheels are attached (triple).

[0303] By changing the amount of Z-turn correction using the auxiliary wheels, appropriate turning assistance and Z-turns are possible. Triple's own unique correction settings are possible.

[0304] <Turning Assist Z-Turn Correction (9)> In the configuration of the turning assist Z turn correction (2), the N2 correction is changed depending on the number of threads on the aircraft.

[0305] The turning radius and working width vary depending on the number of rows, so the target route also differs.

[0306] By changing the amount of Z-turn correction depending on the number of threads, appropriate turning assistance and Z-turns are possible.

[0307] <Turning Assist Z-Turn Correction (10)> In the configuration of the turning assist Z-turn correction (2), when the N2 correction is set to 7 lanes, the configuration is changed between 3 lanes and 5 lanes.

[0308] The turning radius and working width vary depending on the number of rows that are straddled, so the target route also varies.

[0309] By changing the amount of Z-turn correction depending on the number of straddle strips, appropriate cornering assistance and Z-turns can be achieved.

[0310] <Turning Assist Z-Turn Correction (11)> In the configuration of turning assist Z-turn correction (2), the N2 correction is changed (+40pls) when an internal auxiliary wheel is used.

[0311] The turning radius and working width differ depending on the auxiliary wheels, so the target route also differs.

[0312] By changing the amount of Z-turn correction using the auxiliary wheels, appropriate cornering assistance and Z-turns are possible.

[0313] <Turning Assist Z-Turn Correction (12)> In the configuration of the turning assist Z-turn correction (2), the N2 correction is changed (+40pls) when external auxiliary wheels are used.

[0314] The turning radius and working width differ depending on the auxiliary wheels, so the target route also differs.

[0315] By changing the amount of Z-turn correction using the auxiliary wheels, appropriate cornering assistance and Z-turns are possible.

[0316] <Turning Assist Z-Turn Correction (13)> In the configuration of the turning assist Z-turn correction (2), when both internal and external auxiliary wheels are attached (triple), the N2 correction is configured to give priority to the external auxiliary wheel setting and perform correction (external priority version).

[0317] In the case of triple suspension, the influence of external wheels is large. This prevents double compensation by internal and external wheels.

[0318] By changing the amount of Z-turn correction using the auxiliary wheels, appropriate cornering assistance and Z-turns are possible.

[0319] <Turning Assist Z-Turn Correction (14)> In the configuration of the turning assist Z-turn correction (2), the N2 correction is a configuration (triple setting version) that performs dedicated correction when both internal and external auxiliary wheels are attached (triple).

[0320] By changing the amount of Z-turn correction using the auxiliary wheels, appropriate turning assistance and Z-turns are possible. Triple's own unique correction settings are possible.

[0321] <Turning Assist Z-Turn Correction (15)> The correction values ​​of the turning assist Z-turn corrections (1) to (14) can be changed to any value using a checker or monitor settings.

[0322] Users can change parameters to suit their preferences depending on field conditions.

[0323] <Rice transplanter turning assist monitor guidance display (1)> (see Fig. 24) In the rice transplanter turning assist control, the marker monitor lamp during left turning is configured to flash the left lamp in the turning direction periodically (on time 500 ms, period 1 second, etc.) from the start to the end of turning assist.

[0324] During auto marker (turn assist condition), the marker monitor lamp does not move in the direction of turning when the planting section rises, but lights up the lamp in the opposite direction to the direction it is currently in. In other words, when turning left, the marker is out on the left and the lamp is on the left, but when turning back, the marker lamp automatically lights up in the opposite direction. When this happens, the direction to turn the steering wheel is to the left, but the lamp is on the right, which makes the worker feel uncomfortable (it is actually the marker lamp, not the turning direction lamp, so the operation is correct but it feels strange).

[0325] When turning assist is enabled, the marker lamps can be used as turning guidance lamps.

[0326] <Rice transplanter turning assist monitor guidance display (2)> In the rice transplanter turning assist control, the marker monitor lamp when turning right is configured to flash the right lamp in the turning direction periodically (on time 500 ms, period 1 second, etc.) from the start to the end of the turning assist.

[0327] During auto marker (turn assist condition), the marker monitor lamp does not move in the direction of turning when the planting section rises, but lights up the lamp in the opposite direction to the direction it is currently in. In other words, when turning left, the marker is out on the left and the lamp is on the left, but when turning back, the marker lamp automatically lights up in the opposite direction. When this happens, the direction to turn the steering wheel is to the left, but the lamp is on the right, which makes the worker feel uncomfortable (it is actually the marker lamp, not the turning direction lamp, so the operation is correct but it feels strange).

[0328] When turning assist is enabled, the marker lamps can be used as turning guidance lamps.

[0329] <Rice transplanter turning assist monitor guidance display (3)> The rice transplanter turning assist control is configured to display "Turning assist: turning left" during left turning from the start to the end of turning assist.

[0330] During auto marker (turn assist condition), the marker monitor lamp does not move in the direction of turning when the planting section rises, but lights up the lamp in the opposite direction to the direction it is currently in. In other words, when turning left, the marker is out on the left and the lamp is on the left, but when turning back, the marker lamp automatically lights up in the opposite direction. When this happens, the direction to turn the steering wheel is to the left, but the lamp is on the right, which makes the worker feel uncomfortable (it is actually the marker lamp, not the turning direction lamp, so the operation is correct but it feels strange).

[0331] I know the direction of rotation now.

[0332] <Rice transplanter turning assist monitor guidance display (4)> The rice transplanter turning assist control is configured to display "Turning assist: turning right" when turning right from the start to the end of turning assist.

[0333] During auto marker (turn assist condition), the marker monitor lamp does not move in the direction of turning when the planting section rises, but lights up the lamp in the opposite direction to the direction it is currently in. In other words, when turning left, the marker is out on the left and the lamp is on the left, but when turning back, the marker lamp automatically lights up in the opposite direction. When this happens, the direction to turn the steering wheel is to the left, but the lamp is on the right, which makes the worker feel uncomfortable (it is actually the marker lamp, not the turning direction lamp, so the operation is correct but it feels strange).

[0334] I know the direction of rotation now.

[0335] <Rice transplanter turning assist monitor display (1)> During back-turn control using the rice transplanter turning assist control, the monitor will display an interrupt message saying "Please move the main shift lever to the reverse side" from the start of back-turn until back-turn is completed.

[0336] At first, it is difficult for the operator to understand what operations to perform during turning assistance.

[0337] Inform operators how to operate the equipment.

[0338] <Rice transplanter turning assist monitor display (2)> During the rice transplanter turning assist control, after the backturn is completed during the backturn control, the monitor will display an interrupt message "Turning assist in progress" from the forward operation to the completion of the turning assist control.

[0339] The operator is informed that turning assist control is currently in progress and that the HST and steering operation is different from normal.

[0340] <Rice transplanter turning assist monitor display (3)> When the rice transplanter turning assist control is set to make a U-turn, if the conditions for starting the U-turn control are met (if only the planting part needs to be raised), an interrupt message will be displayed on the monitor saying "Start turning by operating the planting part up while moving forward."

[0341] At first, it was difficult for the operator to understand what to do during turning assistance. In particular, it was difficult to understand the difference between back-turn and U-turn control, because the starting conditions are different.

[0342] Inform operators how to operate the equipment.

[0343] <Rice transplanter turning assist monitor display (4)> During U-turn control using rice transplanter turning assist control, the monitor will display an interrupt message saying "Turning assist in progress" from the start of the U-turn until the turning assist control is completed.

[0344] The operator is informed that turning assist control is currently in progress and that the HST and steering operation is different from normal.

[0345] <Rice transplanter turning assist monitor display (5)> If the rice transplanter turning assist control interrupts the turning assist control during backturn control, the message "Turning assist has been canceled" is displayed.

[0346] To inform an operator that turning assistance has been canceled.

[0347] <Rice transplanter turning assist monitor display (6)> If the rice transplanter turning assist control is interrupted during U-turn control, the message "Turning assist has been canceled" is displayed.

[0348] To inform an operator that turning assistance has been canceled.

[0349] In addition, 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, actions, etc.) of the driving control method of the invention related to the present invention described above, and is a program that operates in cooperation with a computer.

[0350] In addition, the recording medium of the invention related to the present invention is a recording medium having recorded thereon a program for causing a computer to execute all or part of the operations of all or part of the steps (or processes, operations and actions, etc.) of the driving control 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.

[0351] In addition, the above-mentioned "some steps (or processes, operations, actions, etc.)" means one or some steps among the multiple steps.

[0352] In addition, the above-mentioned "operation of a step (or process, operation, action, etc.)" means the operation of all or a part of the above-mentioned steps.

[0353] 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.

[0354] Furthermore, the recording medium includes a ROM (Read Only Memory) and the like.

[0355] 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.

[0356] As described above, the configuration of the present invention may be realized in software or in hardware. [Industrial Applicability]

[0357] The work vehicle of the present invention is capable of controlling the turning of the vehicle body, and is useful for use as a work vehicle such as a rice transplanter. [Explanation of symbols]

[0358] 10. Body 20 Engine 30 Running gear 31 Front wheel 32 Rear wheel 33 Auxiliary wheels 41 Main transmission mechanism 42 Sub-transmission mechanism 43 Rear wheel gear case 44 Steering motor 50 Operation Unit 51 seats 52 Steering wheel 53 Main gear shift lever 54 Sub-gear shift 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 stand 200 Control device 210 Rear wheel speed sensor 220 Planting device lift sensor 300 Positioning System 400 Threshold adjustment device

Claims

[Claim 1] A steering member drive device (44) that drives the steering member (52); A control device (200) for controlling the steering member drive device (44); Equipped with A work vehicle in which the control device (200) performs straight-line control when moving a vehicle body (10) straight, performs turning control when turning the vehicle body (10) that has been moving straight, or when stopping the vehicle body (10) that has been moving straight, moving it backward, and turning it after stopping it again, and performs straight-line control after turning when making the turning vehicle body (10) move straight again, The size of the turning trajectory is determined based on the aircraft travel distance and the aircraft heading, The timing of returning the steering to make the turning vehicle body (10) go straight again is determined by measuring the vehicle travel distance from the start of the turn until the vehicle heading reaches a predetermined heading, and changing the timing of returning the steering based on the vehicle travel distance; The control device (200) controls the vehicle speed by regulating the vehicle speed using a first regulation speed and a second regulation speed lower than the first regulation speed in the turning control, The vehicle speed is restricted by utilizing a second restricted speed at the timing of returning the steering wheel; When the vehicle body (10) is reversed, the control device (200) regulates the vehicle speed using a third regulation speed not exceeding the second regulation speed; When the work vehicle is reversed and then stopped again, the steering member (52) is oriented in the turning direction.

Images