JPS62244306A - Steering apparatus in moving agricultral machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a steering device for a mobile agricultural machine that can be applied to a self-propelled rice transplanter, tractor, etc.

[Traditional technique]

In this type of mobile agricultural machine in which a working part is attached to a four-wheeled traveling body, when controlling the machine to move straight, the steering is controlled by steering the steering wheels.

However, in the conventional mobile H7t 1m in which the steering is controlled by steering the steering wheels, the working parts are unevenly located in the front or rear away from the turning center of the wheels, so it is difficult to carry out the work. There is a problem that once the reference position of the part deviates from the target trajectory, accurate positioning becomes impossible. [Object of the Invention] The present invention solves these problems in view of the above-mentioned conventional situation. The object of the present invention is to provide a steering device for a mobile agricultural machine that can quickly and accurately align a mobile machine that has deviated from a target trajectory to the target trajectory.

[Structure of the Invention] A steering device for a mobile agricultural machine of the present invention that achieves the above object is a four-wheeled mobile agricultural machine equipped with a working part, in which movement atJl that deviates from the target trajectory is controlled by the steering device when the reference position of the working part is It is configured to return to the target trajectory through combined control of parallel movement to move on the target trajectory and turning movement to maintain the reference position of this working part on the target trajectory and move the front side of the aircraft onto the target trajectory. It is characterized by:

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Below, drawings showing the present invention as an embodiment will be described.

As shown in Figures 1 and 2, the central part of the aircraft I (Y
-Y line) Below is the front fulcrum shaft 2 and the rear fulcrum shaft 4.
A front axle frame 3 is rotatably supported on the fulcrum shaft 2, and a rear axle frame 5 is rotatably supported on the fulcrum shaft 4. Hydraulic motors 6.6 whose rotations are independently controlled are fixed to each of the wheels, and the front wheels 7.7 supported on the front axle frame 3 are driven and rotated by the hydraulic motors 6.6. Further, hydraulic motors 8, 8 whose rotations are independently controlled are fixed to the left and right sides of the rear axle frame 5, respectively, and the rear wheels 9°9 supported on the rear axle frame 5 are driven by the hydraulic motors 8°8. It is designed to be rotated. Note that the front axle frame 3 is configured to swing around a center bin 2a arranged in the longitudinal direction.

The fuselage 1 is provided with a front hydraulic expansion mechanism lO and a rear hydraulic expansion mechanism 11 whose one ends are mutually pivotally supported on the fuselage I, and the other end of the front hydraulic expansion mechanism 10 is connected to the front axle frame 3. The other end of the rear hydraulic expansion/contraction mechanism 11 is pivotally connected to the rear axle frame 5, and the front axle frame 3
and the rear axle frame 5 have respective hydraulic expansion and contraction mechanisms 10.
-Q and + centered on the neutral position by expansion and contraction of 11.
It is possible to steer independently or in conjunction with each other over the steering angle with Q.

An engine 12 is disposed at the front of the aircraft I in the north, and a transmission mechanism 13 is disposed behind the engine 12. Between the transmission mechanism 13 and the output shaft of the engine 12, A hydraulic pump 15 is connected and fixed to the rear of the transmission mechanism 13 by a coupling 14, and this hydraulic pump 15 is connected to each of the hydraulic motors 6.8 for driving the wheels via a control valve 16. It is also connected via a switching valve or the like to hydraulic telescoping mechanisms TO, TI that control the steering angle, and a hydraulic telescoping mechanism that raises and lowers the working machine 21.

Furthermore, a control unit (CPU) 17 is disposed above the transmission mechanism 13 and the hydraulic pump 15, and the control valve 1
An oil tank 18 is arranged above the engine 1.
A battery 19 is installed in the front of the machine body 2, and a working part 21 such as a rice transplanter is attached to the rear of the machine body 2 via a parallel link 20 that is raised and lowered by a hydraulic expansion mechanism (not shown). 25 are configured.

As shown in FIG. 4(A), by controlling the steering of the front wheel frame 3 and the rear wheel frame 5 at mutually opposite angles, the aircraft 1 can be turned with a predetermined turning radius. Furthermore, as shown in FIG. 4(B), by controlling the steering so that both the front wheel frame 3 and the rear wheel frame 5 are in a parallel state at the same angle and in the same direction, the aircraft 1 can be moved in parallel. It has become.

Furthermore, as shown in FIG. 4(C), by controlling the steering of only the front wheel frame 3 to a predetermined steering angle, the aircraft body 1 can be moved in the direction of the arrow. ), the aircraft body can be moved in the direction of the arrow by controlling the steering of only the rear wheel frame 5 to a predetermined steering angle.

Therefore, in the mobile agricultural machine 25 that moves in the field while performing rice planting work, in order to maintain the target trajectory during rice planting, straight-line control is used to correct deviations from the target trajectory at any position, and at the planting end. The basic operation is turning control to change direction. Therefore, first, the aircraft turning at the end of planting will be explained separately as follows.

(Turning the aircraft using both axes) As shown in FIG. 3, the front axle frame 3 and the rear axle frame 5 are steered at opposite angles so that they are oriented toward the turning center O. In this case, the steering angles of the front axle frame 3 and the rear axle frame 5 are both Q, and the turning relational expression is as follows, with the left rotation being (-) and the right rotation being (+).

RCsinQ=S/2 * RC=S/2 sin Q----------------------
--(1) R-RC-T/2゜RO=RC+T/2-...-1--------
−−−−−・−(II) V=Rω−πD/60·N.

VO−ROω=πD/60・No −−−−−τ−(
I[[)VC-RCω-πD/120 ・ (N+N
0)-shi or ω-πD/60R-N=πD/60RO-N.

=πD/120 RC・(N+NO)・=(lla
) is given by However, ω is the angular velocity of turning, and when the inner ring is rotated at N and the outer ring is rotated at No, the turning radius of the inner ring is obtained by formula (II).

(Body turning by one axis) As shown in FIG. 5, a state in which only one of the front axle frame 3 or the rear axle frame 5 is independently steered will be described.

When the front axle frame 3 and the rear axle frame 5 are rotated in opposite directions for 9 seconds, the turning center is at the O position. When the angle is set to 0, the center of rotation is at 01, and the following relational expression holds.

P 1 =S/lan Q-T/ 2゜PCI=P1+
T/2゜P O1= P 1 + T −・−・−−−・・・・
-----(IV) P 2 = S/lan Q-T/ 2
゜PC2=P2+T/2゜PO2=P2+T −・−・−・−・・−・−(V)
ω−πD/60P1・N=πD/60P OI −N.

=πD/120PCI・(N+N0)=πD/60P
2・N=πD/60PO2・NO=πD/120P
C1・(N+N0)−・−・(VT) In other words, when the front axle frame 3 is steered by 10 degrees, in order for the aircraft 1 to turn at an angular velocity ω, the relationship of equation (Vl) must be established. All you have to do is rotate each wheel 7.9.

[Steering angle and wheels]

As shown in FIG. 5, the maximum value of the steering angle Q of the front axle frame 3 and the rear axle frame 5 is t when the center distance MS is small.
When is the outer width of the lug, points A and A intersect at point B. Therefore, the distances 2 to A+4 to A between the fulcrum shafts 2 and 4 and point A determine angles ±Q that do not interfere when 2A+4A>S.

Further, when <S, Qfc can be selected on the angle unconditionally.

As shown in FIG. 5, when turning using both axles that steer the front axle frame 3 and the rear axle frame 5, the turning center is above the zero point, and the turning radius can be minimized. Further, in a single-axis turning in which only either the front axle frame 3 or the rear axle frame 5 is steered, the turning center is on 01 or 02 for the same steering angle Q. These turning center regions exist within the range of 01 and 0.02, and the steering angle Q
It is determined by the combination of and the selection operation of one or both axes.

(Aircraft direction correction operation during work) Next, we will explain how to correct the aircraft direction during work.

As shown in FIG. 6, the machine 1 is supposed to move on the target trajectory Y-Y line, but at a certain point it is on the Z-Z line and the reference point E of the work machine is a distance H from the target trajectory Y-Y line. Suppose that there is a deviation. The direction of the aircraft l is offset from the Y-Y line by an angle α, and the front wheels 7 and rear wheels 9 are also moving in this direction.

In order to correct the movement from this state to the target trajectory Y-Y line, it is sufficient to correct two elements: <11 position deviation H from the reference line (2) deviation angle α with respect to the reference line.

That is, there are various methods for modifying <11, (2) above, independently or in combination, but in FIG. 6, (
This is a case in which correction is performed in steps 1) and (2), and is performed in the following steps.

(Position deviation I] and deviation angle α correction process) ■) Initial position Z
In -Z, the front axle frame 3 and the rear axle frame 5 are translated in parallel so that they each have an angle of -β (parallel shift/correction of I]).

2) Due to this parallel movement, the reference point E of the working section moves to 〇El on the target upward trace Y - Y line -. (At this time, move to 2--28+4-4 a and E--E 1 respectively.) 3) Set the steering angle of the front axle frame 3 and the rear axle frame 5 so that the deflection angle α-0. Control. At this time, if you make a turn as shown in Figures 3 and 5, the reference point El will deviate from the target trajectory Y-Y line, so it is necessary to steer so that it does not deviate.To do this, the following conditions must be met. Steer so that it holds true.

4a; As shown in FIG. 7(A), point 4a continues to move straight in the T2 direction at a speed of ■2. Assuming that V2 is at a constant speed, the relationship between V2 and the rotational speed N2 of the rear wheel 7 is as follows: V2=πD/60·N2.

8 points: Move on the target trajectory Y-Y line.

Point 2a: 4a-El enters a turning state by moving in the direction of the arc 2a2b at an instantaneous speed Vl.

Figure 7 (B) shows that such a relationship holds true.

As shown in Figure 7(C), V 1-yrD/60・N L.

■2-πD/60・N2−・ (■) ωcX−V2/L・5inr2 −−1−・−:V
1=S+L/L-ωα+V2 -1111= (Vl
)T2−β−α −1−−−−−−−−−−−
−−−−−−−・r2=β+α
Knee (IX) = β 1 ω α skewer 1 ------・-・
−・−・−・・・Par However, ωα is controlled in a relationship similar to the turning angular velocity when correcting the declination α to α−〇.

This is for the case where the control is performed using the steps 1) to 3) as described above, but there is no need to limit it to this, and the control may be performed in a composite/alternate series manner.

Therefore, if the steering mechanism is controlled by such a method, arbitrary control in the field, such as straight-line control along the target trajectory and turning on the headland, is possible, and a simple mechanism can be used to freely perform indoor steering. Trajectory control is possible.

The basic control described above is as follows: A: The front wheels 7 and the rear wheels 9 are automatically controlled to have independent rotational speeds according to their conditions.

(All-Wheel Independent Drive Control) B: Each hydraulic motor 6.6 that drives the front wheels 7 and the hydraulic motor 8.8 that drives the rear wheels 9 are provided independently.

C: This drive is automatically controlled by a computer.

This can be done by:

Next, FIG. 8 will be explained. The example shown in Fig. 8 is
Already planted seedling rows X-X on both left and right sides of aircraft 1 as a target trajectory
A comb-shaped front seedling sensor 22 and a rear seedling sensor 23 are provided to detect the
There is a front distance sensor 27 for detecting the distance 1iitiLF (see FIG. 9) between the headland distance ii! and the headland distance ii! A rear distance sensor 28 is provided to detect the iLR (see FIG. 9).

The double-image sensors 22 and 23 have a central conductive contact facing in the direction of travel, and a plurality of contacts on the left and right sides of this contact, which are arranged in a direction intersecting the direction of travel. and a mounting rod made of an insulating material, each of which is connected to a computing device (not shown) to control the steering of the hydraulic expansion/contraction mechanism 10, 11 so that the central contact and the seedling continue to be in contact with each other. This computing unit receives signals from each seedling sensor 22 and 23, calculates the operating angle, and controls the steering of the aircraft in one direction by issuing a signal to operate the hydraulic expansion/contraction mechanism 10.11 according to the operating angle. It is supposed to be done.

Then, the distance between the center line Y-Y of the body 1 and the line of the planted seedling row The detection distance with X-ray is G on the rear side,
The front side is designated as 02. In this Fig. 8 (A), the deviation ΔG from the line X-X of the planted seedling row, which is the target trajectory.
is ΔG=G-01, and the aircraft direction deviation ΔG2 is ΔG2=02-
It becomes G.

Figure 8 (B) shows the direction deviation of the aircraft I (G=G2°ΔG2=
0), but it shows a case where the distance is outside the standard distance ■], and it shows a case where G>Gl and the distance is away from the planted seedling row X-X line which is the target trajectory.

Contrary to FIG. 8(B), FIG. 8(C) shows a case where the target trajectory is too close to the line X--X of the planted seedling row. (G=G2.G<Gl) Figure 8 (D) shows a state in which the direction and distance of the aircraft are shifted and the aircraft 1 is moving along the line X-X of the planted seedling row, which is the target trajectory. It shows. (ΔG=0.ΔG2=0) FIG. 8(E) shows an example where the direction of the aircraft is opposite to that of FIG. 8(A), and G=01.

Figure 9 shows the turning and reversal state of the headland part during planting work, where LR is the headland width, LF is the ridge distance from the front end of the fuselage 1 to the ridge 26 within LR, and LP is the stroke pitch. (Number of planted rows x row spacing) is shown for each, and this ridge distance LF
is detected by a front distance sensor 27 provided at the front of the machine body 1, and the headland width LR is detected by a rear distance sensor 28 provided at the rear of the working machine 21. Both distance sensors 27 and 28 start the planting work when the rear distance sensor 28 detects the headland width LR, and stop the planting work when the front distance sensor 27 detects the ridge distance LF. , are linked to the aforementioned control unit 17 so that the aircraft 1 starts turning.

Figure 10 shows a basic series of work control flowcharts for planting work, and the planting work is performed according to the order of initial setting step, initial process step, and main work step. The code of ■ is the first
It shows the relationship and continuation with FIGS. 1 to 13.

In FIG. 10, the planting method is first selected from among the initial modes, and in this mode, folding planting is usually selected except in special cases. When planting four rows and planting three rows, the stroke pitch must be changed. In addition, the reversal rotation due to the telescoping operation of the hydraulic telescoping mechanisms 10 and 11 is
It is detected by the gyro mounted on the aircraft, the ground reference coordinates, or the wheel rotation speed, and this detection signal activates the computing unit, so that the wheel rotation speed during this reverse turn is adjusted to the wheel rotation speed according to the turning radius. It's about to be controlled. Furthermore, when the vehicle returns straight after the reversal is completed, the rotational speed of the wheels is simultaneously controlled so that the axle frame 3.5 returns to the neutral position.

11 is a control flowchart connected to the symbol ■ in FIG. 10 for control, and FIG. 12 is a control flowchart connected to FIG. 11 for control, as shown in FIG. Flowchart 1 shows a correction operation when the position of the rear seedling sensor 23 differs from the position of the already planted seedling row X-X when the aircraft I turns. Before reaching the end, the front seedling sensor 22
The judgment is controlled by a judgment device that controls the positioning of the front wheel frame 3, and depending on the result of detecting the deviation from the A computing unit that calculates the steering direction and steering angle calculates the rotational direction and rotational speed of the vehicle Mt70 that correspond to the steering angle of the front wheel frame 3, and drives and controls the hydraulic motor 6.

FIG. 13 shows a case where the detection position of the rear seedling sensor 23 is different from that of the front seedling sensor 22 (the direction is not parallel to the X-X axis), and when the reference distance is different (G<Gl or G>Gl).
), which is also related to FIGS. 6 and 7. In this example, as shown in FIGS. 8(A) and 8(E), G>02 determines whether the aircraft direction is not parallel to the target trajectory X-X axis. fA8 diagram (B) by Gl
As shown in FIG. 8(C), the control can be performed by a signal from a determining device that determines in which direction of the X-X axes the reference position E of the working machine 21 is located.

Based on the judgment signal of this judgment device, the moving angle when the front frame 3 and the rear frame 5 both move in parallel is calculated by the calculation unit. G2.Gl in Figure 8 (A) corresponds to ΔG=G-01).

Then, based on the calculation signal of this movement angle, the aircraft 1 is moved by ΔG=G-at parallel to the direction of the aircraft 1, and ΔG=
It is designed to move in parallel so that it becomes 0. When this parallel movement is completed and G=G1, the direction of the machine body 1 is still not parallel to the X-X axis, so the working part 2
Maintaining the state in which the reference point E of 1 is G=G1, use the hydraulic expansion/contraction mechanism 10°11 to align the aircraft 1 with the main body of the front wheel frame 3 as shown in Figure 7 (A). The aircraft 1 returns to the target trajectory XX line by turning by controlling the travel angle and controlling the rotational speed of the hydraulic motor 6.8, so that G2=G=01.

Therefore, the mobile Q aircraft 2 deviates from the target trajectory X-X line.
5, first, the reference position E of the working part is quickly and accurately moved on the target trajectory X-X line by parallel movement of the machine body 1, without steering the machine direction by the speed difference between the left and right wheels as in the conventional case. be able to.

Furthermore, by rotating the front side of the machine body 1 while maintaining the reference position E of this working part on the target trajectory XX line, the entire mobile agricultural machine 25 can be positioned on the target trajectory XX line. , even if the mobile agricultural machine 25 with the working part 21 mounted on the front or rear deviates from the target trajectory It can be adjusted to

(Effect of the invention) In short, the steering device for the mobile agricultural machine of the present invention has the following features:
In a four-wheeled mobile agricultural machine equipped with a working part, the target g
'Parallel movement in which the reference position of the working part moves to the target trajectory of the mobile agricultural machine that has come off the L trace, and turning in which the reference position of the working part is maintained on the target trajectory and the front side of the machine moves on the target trajectory. Because it is configured to return to the target trajectory through combined control with movement, it is possible to move the agricultural machine that has deviated from the target trajectory without having to steer the machine direction by steering the left and right wheels as in the past. The reference position of the working part can be moved quickly and accurately onto the target trajectory by parallel movement, and the front side of the machine can be rotated while maintaining the reference position of the working part on this target trajectory. Since the entire aircraft can be positioned on the target trajectory,
Even if a mobile agricultural machine whose working part is attached to the front or rear of the machine deviates from the target trajectory, the mobile agricultural machine can be quickly and accurately aligned with the target trajectory by moving the shortest distance.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a plan view of a mobile agricultural machine with a planting section attached to the traveling machine body, Fig. 2 is a side view of Fig. 1, and Fig. 3 is a view of the machine body. Fig. 4 is an action explanatory diagram showing each steering mode separately. Fig. 5 is an action explanatory diagram showing a comparison of the aircraft's turning reversal state. Fig. 6 is an action explanatory diagram showing the aircraft's turning reversal state. Fig. 7 is an action explanatory diagram showing the main parts of Fig. 6 in an enlarged manner, Fig. 8 is an action explanatory diagram showing individual directional control of the aircraft, Fig. 9 1 is an action explanatory diagram showing the turning of the machine on a headland, and FIGS. 10 to 13 are flowcharts showing a series of work controls in a planting work. l...Body, 3...Front axle frame, 5...Rear axle frame, 6, 8...Hydraulic motor, 7...Front wheel,
9... Rear wheel, 10.11... Hydraulic expansion and contraction device, 21.
... Working part, 22... Front seedling sensor, 23... Back seedling sensor, 25... Mobile agricultural machine, 27... Front distance sensor, 28... Back distance sensor.

Claims (1)

[Claims] In a four-wheeled mobile agricultural machine equipped with a working part, the mobile agricultural machine that has deviated from the target trajectory can be moved in parallel to move the reference position of the working part onto the target trajectory, and the reference position of this working part can be moved onto the target trajectory. 1. A steering device for a mobile agricultural machine, characterized in that the steering device is configured to return to a target trajectory through combined control with turning movement in which the front side of the machine body maintains the position and moves on the target trajectory.