JPH0354601A - Steering controller for self-traveling vehicle - Google Patents

Abstract

PURPOSE:To smoothly shift from a turning stroke to a straight line traveling stroke by dividing a working block into a plural areas, selecting one of plural feedback gains based on the area where a self-traveling vehicle is positioned, and deciding a steering angle to correct deviation for a course between the current position and a progressive direction. CONSTITUTION:A means which sets the block with respect to the work of the self-traveling vehicle by dividing into the plural areas, a means 23 which judges at which are among the plural areas the self-traveling vehicle is positioned are provided, and means 24 and 26 which set scheduled feedback gains corresponding to the output of the means 23 are provided. At such a case, since the feedback gains can be set at different values at every area, steering control can be performed by moderating the change degree of a reference steering angle for steering control at the area where high hunting is predicted, and setting that of the steering angle at a comparatively large value at the area where it is predicted that the degree of hunting is low. In such a way, it is possible to shift the self-traveling vehicle smoothly from the turning stroke to the straight line traveling stroke.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a steering control device for self-propelled vehicles, and particularly for self-propelled vehicles such as automobiles, unmanned transport devices in factories, agricultural and civil engineering machinery, etc. The present invention relates to a steering control device for a self-propelled vehicle that causes the vehicle to travel according to a predetermined travel course.

(Prior Art) In the steering control for causing the self-propelled vehicle to travel along a planned course, the steering control is performed based on the deviation between position information indicating the current position of the self-propelled vehicle and the planned travel course. The system is designed to determine a standard steering wheel for the vehicle.

Conventional techniques for detecting the current position of the self-propelled vehicle include means for scanning a light beam generated by a movable body such as the self-propelled vehicle in a circumferential direction centering on the movable body; A device has been proposed that is fixed at at least three locations apart from the moving body and includes a light reflecting means for reflecting light in the incident direction and a light receiving means for receiving the reflected light from the light reflecting means. (Japanese Unexamined Patent Publication No. 59-67-47-6)
.

In this conventional device, the opening angle between three light reflecting means centered on the moving body is detected based on the light receiving output of the light receiving means, and the detected opening angle and the preset optical return means are calculated. The position of the moving body is calculated based on the position information.

Steering control of the self-propelled vehicle includes steering control during running on a straight course and steering control during running on a turning course for transitioning from the straight course to the next straight course.

The steering amount (steering angle) φ of the self-propelled vehicle while traveling on a straight course is calculated by the following equation (1).

φ−kx●Δx+ka·Δθ (1) The symbols ΔX and Δθ in the equation are as shown in the explanatory diagram of the self-propelled vehicle, the deviation of the traveling course, and the steering angle in FIG. 6. In the same figure, a preset driving course CL and a self-propelled vehicle 1
The difference from the current α position is indicated by ΔX, and the angular difference between the travel course and the traveling direction of the self-propelled vehicle is indicated by Δθ. Furthermore, in equation (1), the gain for feedback control, which is determined by taking into account the running speed of the self-propelled vehicle, has the symbols kx and ka.
Indicated by

As shown in equation (1), the steering angle φ of a self-propelled vehicle running on a straight course is determined by the deviation between the current position and traveling direction of the self-propelled vehicle and the set traveling course, and the value given to this deviation. It is determined based on the feedback gain given.

On the other hand, in steering control during turning, for example, feedback control may not be performed, and the steering amount may be fixed and controlled in order to simplify the control.

This control method is often used in situations where a self-propelled vehicle can achieve its purpose if it can travel along a planned course with high accuracy only in the straight course portion.

(Problem to be Solved by the Invention) The planned course and the actual self-propelled vehicle when the self-propelled vehicle is run while performing the above-mentioned steering control along the planned course that is a combination of the straight course and the turning course. An example of the trajectory traveled by the car is shown in FIG. 7(a). Figure 7(b) shows the seventh
It is an enlarged view of the main part of figure (a).

In FIG. 7(a), the planned travel course is shown by a solid line CL, and the actual travel trajectory is shown by a dotted line TL.

The light reflecting means is arranged at three reference points A, B, and C around the area S where the driving course CL is set. The self-propelled vehicle 1 travels along the straight portion of the travel course CL under the feedback control, and then travels through the turning portion according to the fixed steering angle.

Figure 7(a). As shown in (b), during the turning portion (turning stroke), the steering angle is fixed at a constant value, so at the end of the turning stroke, the position of the self-propelled vehicle deviates from the set course. ΔdO occurs.

On the other hand, in the transition portions Y and Z from the turning stroke to straight-line travel (straight-line traveling stroke), hunting occurs along with the steering to transition from the turning stroke to the straight-line traveling stroke, and the planned traveling course CL and There is a phenomenon in which it takes a while for the position of the self-propelled vehicle to match.

One of the reasons why such a hunting phenomenon occurs is that, for example, when transitioning from a turning stroke to a straight traveling stroke, the deviation ΔdO is large, so the steering angle is increased quickly according to the corresponding feedback gain. There are points that are controlled to return to the planned straight course. As a countermeasure for this problem, it is thought that hunting can be reduced by controlling the feedback gain by setting it to a small value so as to gradually shift to a straight-line travel stroke. However, the transition portion Y
If the feedback gain is set small according to
Although the degree of hunting is reduced in this transition portion Y, there is a problem in that the degree of hunting is not necessarily reduced in the other transition portion Z.

This is due to the fact that in addition to the hunting occurrence factors, the reference point A
- The point is that there are places where the error in position detection of the self-propelled vehicle 1 is large and small depending on the t-eye positional relationship between C and the self-propelled vehicle 1, that is, the distance and direction from the self-propelled vehicle 1 to the reference point. This is thought to be due to the following.

In other words, depending on the magnitude of the position detection error of the self-propelled vehicle 1, the point at which the transition from the turning stroke to the straight traveling stroke starts may be regarded as point p or point m even if it is actually at point h. It may be considered. Then, the amount of deviation in this case is considered to be a value Δd1 greater than ΔdO or a value Δd2 smaller than ΔdO.

Therefore, as a result of steering control being performed using a feedback gain commensurate with these deviation amounts Δdl or Δd2, a phenomenon occurs in which hunting is not reduced as described above.

Furthermore, the current position detection error of the self-propelled vehicle 1 is divided into an error in a direction along the set straight running course direction and an error in a direction perpendicular to this running course, and the error in each direction and the magnitude of hunting are calculated. Focusing on the relationship, hunting during the transition from the turning stroke to the straight traveling stroke is large in the portion where the error in the direction orthogonal to the planned travel course is large.

This is also supported by the simulation results shown in FIG.

In Figure 10, in a coordinate system in which the straight line connecting reference points B and C is the X axis, and the straight line connecting reference points A and B is the y axis, a straight running course parallel to the y axis and a turning course connecting these are defined. Set.

The position of the self-propelled vehicle recognized by the conventional control device when the self-propelled vehicle 1 is steered at a steering angle of 10'' at each sample point on this course is shown in the figure.

As you can see from the figure, near the X axis (lower position in the figure)
The deviation between the sample point and the recognized position of the self-propelled vehicle, especially in the X direction, is large.

The portion where the deviation in the direction perpendicular to the straight running course is large is due to the traveling speed of the self-propelled vehicle 1, the rotation direction and rotation speed of the light beam generating means, the relative positional relationship between the reference point and the self-propelled vehicle 1, etc. Determined by factors.

Normally, during the straight-line stroke before transitioning to the turning stroke, sudden steering control by increasing the steering angle is rarely performed, so this does not pose a problem in actual driving, but when transitioning from the turning stroke to the straight-line stroke In this case, the steering angle is large and the vehicle moves in a straight line, which causes large hunting as described above.

Note that, in order to clarify the results of the simulation, the size of the deviation is shown enlarged twice in the figure.

As described above, unlike the turning stroke, the straight-line traveling stroke requires high followability to the planned traveling course, so such hunting phenomenon is a problem in performing highly accurate steering control.

SUMMARY OF THE INVENTION An object of the present invention is to provide a steering control device for a self-propelled vehicle that eliminates the problems of the prior art described above and allows a smooth transition from a turning stroke to a straight traveling stroke.

(Means and effects for solving the problem) In order to solve the above-mentioned problems and achieve the object, the present invention divides the area related to work by self-propelled vehicles into a plurality of areas, and One of a plurality of preset feedback gains is selected depending on the position of the self-propelled vehicle, and the deviation in the current position and traveling direction of the self-propelled vehicle relative to the planned travel course is corrected according to the selected gain. The feature is that the steering angle is determined for the purpose.

In the present invention having the above structure, since the feedback gain can be changed to a different value for each region, the degree of change of the reference steering angle for steering tin can be made gentler in regions where the degree of hunting is expected to be large. In a region where the degree of hunting is expected to be small, control can be performed by setting the degree of change in the steering angle relatively large. As a result, the degree of hunting can be made equal and smaller in the regions Y and 2. As a result, the self-propelled vehicle can smoothly transition from a turning stroke to a straight traveling stroke.

(Implementation M) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 is a perspective view showing a self-propelled vehicle equipped with the control device of the present invention and a state of arrangement of front reflectors disposed in the travel area of the self-propelled vehicle.

In the figure, a self-propelled vehicle 1 is, for example, a self-propelled vehicle for agricultural work such as a lawn mower. A rotary table 4 driven by a motor 5 is provided on the top of the self-propelled vehicle 1. and,
The rotary table 4 is equipped with a light emitter 2 that generates a light beam and a light receiver 3 that receives reflected light from the light beam. The light emitter 2 includes a light emitting diode that generates light, and the light receiver 3 includes a photodiode that receives incident light and converts it into an electrical signal (both not shown).

Further, the rotary encoder 7 is provided so as to be interlocked with the drive shaft of the rotary table 4, and by counting the pulses output from the rotary encoder 7, the rotation angle of the rotary table 4 can be detected.

Reflectors 6 are arranged at reference points around the working area of the self-propelled vehicle 1. The reflector 6 has a reflecting surface that reflects incident light in the direction of incidence, and a so-called corner cube prism or the like which is conventionally available on the market can be used.

Next, the structure of the control device of this embodiment will be explained according to the block diagram shown in FIG. In FIG. 1, a light beam emitted from a light emitter 2 is scanned in the rotating direction of a rotary table 4 and reflected by a reflector 6. The light beam reflected by the reflector 6 is incident on the light receiver 3, and is detected as information representing the azimuth angle of the anti-1.1 beam 6 with respect to the traveling direction of the vehicle body.

The counter 9 counts the number of pulses output from the row encoder 7 as the rotary table 4 rotates.

The pulse count value is transferred to the angle detection section 10 each time the light receiver 3 receives reflected light. The angle detection unit 10 calculates the opening angle between each reflector 6 with respect to the traveling direction of the self-propelled vehicle 1 based on the count value (unidirectional angle) of the pulses transferred every time reflected light is received.

In the position/direction calculation unit 13, each detected reflector,
In other words, based on the opening angle between each reference point where each reflector is arranged, the coordinates of the self-propelled vehicle 1 in the x-y coordinate system described below, in which the X axis is a straight line connecting two of the reference points. and the direction of travel are calculated. The formula for calculating the coordinates and the traveling direction will be described later.

The x-y coordinate system is set based on the position information of each reference point measured in advance by a known means.

The calculation results of the position/progressing direction calculation section 13 are input to the comparison section 25 and the area determination section 23.

The comparison unit 25 compares the data representing the driving course set in the driving course setting unit 16 with the position/direction calculation unit 1.
The coordinates and traveling direction of the self-propelled vehicle 1 calculated in 3.11 are compared, and the position difference ΔX of the self-propelled vehicle 1 with respect to the traveling course is calculated.
and the angular difference Δθ in the traveling direction are detected.

In addition, the area determination unit 23 uses position data indicating the area where the position detection error of the self-propelled vehicle 1 in the direction perpendicular to the driving course is large and the other areas, and the position data of the self-propelled vehicle 1.
Based on the position information of the self-propelled vehicle 1 supplied from the traveling direction 7fl't calculator 13, it is determined in which region the self-propelled vehicle 1 is located. In response to this determination result, the first
Feedback gains set respectively are supplied from the gain setting section 24 or the second gain setting section 26 to the steering section 14.

The front wheels of the self-propelled vehicle 1 are controlled by the steering section 14 based on the position difference ΔX and the angular difference Δθ in the traveling direction detected by the comparison section 25 and the feedback gain set to a predetermined value depending on the area where the self-propelled vehicle 1 is located. 17 steering angles are determined.

A steering motor (not shown) connected to the front wheels 17 of the self-propelled vehicle is driven based on the determined steering angle. The steering angle of the front wheels 17 by the steering motor is detected by a steering angle sensor 15 provided on the front wheels with a self-running width 1, and is fed back to the steering section 14.

The drive unit 18 controls starting and stopping of the engine 19 and the operation of a clutch 20 that transmits the power of the engine 19 to the rear wheels 21.

It should be noted that among the components shown in FIG. 1, the parts within the range shown by the chain lines can be configured by a microcomputer.

The basic principle for detecting the position and traveling direction of the self-propelled vehicle 1 will be explained using this embodiment having the above configuration. 8 and 9 show the arrangement positions of the self-propelled vehicle 1 and the reflector 6 in a coordinate system for indicating the work range of the self-propelled vehicle 1. FIG.

In FIGS. 8 and 9, light reflectors 6 are placed at reference points A, B, and C in the working range of the self-propelled vehicle 1. The position of each light reflector 6 is represented by an xy coordinate system with reference point B as the origin and a line connecting reference points B and C as the X axis.

The position of the self-propelled vehicle 1 is indicated by a point T (x, y).

As can be seen from the figure, the position T of the self-propelled vehicle 1 is the triangle AT
7I exists on the circumcircle of triangle B and at the same time on the circumcircle of triangle BTC. Therefore, the position of the self-propelled vehicle 1 can be determined by calculating the two intersections of the circumscribed circles Q and P of the triangle ATB and the triangle BTC.

Here, since the reference point B is the origin, the position of the self-propelled vehicle 1 can be determined by calculating the other intersection T of the circumscribed circles P and Q according to the following procedure.

First, regarding the circumcircle P of the triangle BTC, its center is P
Then, P is on the perpendicular bisector of the line segment BC, and from the relationship between the central angle and the circumferential angle, BPW''-β.

However, it is assumed that W' is a point on the perpendicular bisector of the line segment BC, and is sufficiently far away from the straight line BC on the opposite side of the point T.

Now, focusing on triangle BPW (W is the midpoint of line segment BC), the coordinates of the center of circle P are (xc/2, (xc/2)cotβ} and the radius is lxc
/(2sinβ)1, and the circumscribed circle P is expressed by the following formula.

(x-xc/2) 2+ (y- (xc/2)cot
βl 2=fxc/(2s inβ)}2 Further, by rearranging this equation, the following equation is obtained.

x2-xc*x+y2 -xcey'cotβ-0 ・- ・- (1) Also, if the center of the circumcircle Q of the triangle ATB is Q, Q is on the perpendicular bisector of the line segment AB, ZCQV
−1 α.

However, V' is a point on the perpendicular bisector of the line segment AB, and is sufficiently far away from the line AB on the opposite side of the point T.

Now, focusing on triangle BQV (V is the midpoint of line segment AB), the coordinates of the center of circle Q are fxa/2+ (ya/2) cota, ya/2 −
(xa/2) cotal radius is l Xa”+Ya
”/(2·sirzr), and the circumscribed circle Q is expressed by the following formula.

x2-x (xa+ya●cotα)+y"-y (
ya-xa◆cotα) 10・・・・・・(2) Above (
From equations 1) and (2), the coordinates (x, y
) is calculated using the following formula.

x−xc (C1+k−cotβ)/(1+k”)・
・・・・・・(3) y−kx ・・・・・・・・・・・・・・・
・・・・・・・・・〈4〉However, k= (xc-xa-
ya IIco tα)/(ya-xa*cota-x
c*cotβ) (5) and represents the slope of the straight line BT.

} Furthermore, the traveling direction of the self-propelled vehicle 1 is calculated as follows. In FIG. 9, the angle between the traveling direction of the self-propelled vehicle 1 and the
, C to θa. In the case of θb and θC, the slope of the line segment BT is k.
An example has been shown in which the position and traveling direction of the self-propelled vehicle 1 are detected based on the positions of three reference points. Besides this,
Among the reference points placed at four or more locations, three reference points are selected that are expected to be able to accurately detect the position and traveling direction of the self-propelled vehicle based on the current location of the self-propelled vehicle. In some cases, the position and traveling direction of the self-propelled vehicle 1 may be detected.

Next, a description will be given of area setting within the work area, which is a criterion for switching the feedback gain.

FIG. 4(a) is an explanatory diagram of setting the region for determining feedback gain when detecting the position and traveling direction of the self-propelled vehicle 1 based on the positions of reference points A to C provided at three locations in the work area. It is. In addition, FIG. 4(b) shows that three reference points are selected from four reference points A to D provided in the work area according to the current position of the self-propelled vehicle 1, and the positions of the reference points are FIG. 2 is an explanatory diagram of setting a region for determining a feedback gain when detecting the position and traveling direction of the self-propelled vehicle 1 based on .

In FIG. 4(a), for example, the area t1 is the driving course C.
This is a region where it has been experimentally confirmed that the position detection error of the self-propelled vehicle 1 in the direction perpendicular to the straight line portion of L is large, and this region t
1 is set as a region in which the feedback gain is reduced, and extreme steering that involves sudden direction changes is avoided here. On the other hand, in area t2, self-propelled vehicle 1
This is a region in which the position detection error is expected to be small, and here the steering control is performed using a feedback gain larger than that in the region t1.

In Fig. 4(b), among the four reference points, reference point A,
In the work area surrounded by B and C, the position and traveling direction of the self-propelled vehicle 1 are detected based on the positions of these reference points A-C, and in the work area surrounded by reference points A, C, and D, the The (M position and traveling direction of vehicle 1 are based on these reference points A, C,
Detection is performed based on the position of D.

In this way, when the reference point is arbitrarily selected depending on the current position of the self-propelled vehicle, the area designation for determining the feedback gain is also switched together with the switching of the reference point.

In other words, when detecting the position and traveling direction of the self-propelled vehicle 1 using the reference points A, B, and C, the region t3 is set as the region where the feedback gain is reduced, and the reference point A
, C, and D to detect the position and traveling direction of the self-propelled vehicle 1, the 6a region t4 is set as the region in which the feedback gain is reduced. In the region t5, the feedback gain is made larger than in the regions t3 and t4.

In both cases of Fig. 4 (a) and (b), among the straight lines connecting each base point used to detect the position and traveling direction of the self-propelled vehicle 1, the straight part of the traveling course CL or this straight line The feedback gain is set to be small in the vicinity of the straight lines that are substantially orthogonal to each other, that is, the line segment BC and the line segment AD. Note that the width H of the area is set based on experimental values.

Next, steering control of the self-propelled vehicle 1 based on the position information of the self-propelled vehicle 1 calculated by the above procedure will be described. Second
The figure is a flowchart of steering control, and FIG. 3 is a diagram showing the traveling course of the self-propelled vehicle 1 and the arrangement of the reflectors 6.

In FIG. 3, points A, B, and C indicate the placement positions of the reflector 6, and the coordinate system of the self-propelled vehicle 1 with point B as the origin and the line passing through points B and C as the X axis. Location and working area 2
It represents 2.

(Xret, Yret) indicates the return position of the self-propelled vehicle 1,
The work area 22 has the coordinates (Xs t, Ys t), (Xs
This is an area connecting the points indicated by t, Ye), (Xe, Ys t), and (X e, Ye). Here, the position T of the self-propelled vehicle 1 is indicated by (Xp, Yp).

In addition, in FIG. 3, in order to simplify the explanation,
Although the example in which the four sides of the work area 22 are parallel to the X-axis or the y-axis is shown, as long as the reflector 6 is provided around the work area 22, the orientation of each side of the work area 22 and the The shape of the work area 22 is arbitrary.

The control procedure will be explained according to the flowchart shown in FIG.

In the procedure shown in this flowchart, an example is shown in which the area is divided as shown in Figure 4(a) based on reference points placed at three locations.

First, in step S1, the current position (Xre, Y
ret) and the coordinates (Xst, Yst) of the work start position set in the travel course setting section 16,
Set the movement course to the work start position.

In step S2, the engine is started by the drive unit 18, the clutch is connected, the self-propelled vehicle 1 is steered, and the self-propelled vehicle 1 is moved along the movement course to the work starting position.

In step S3, Xs is set as the X coordinate Xn of the driving course.
Set t and determine the driving course.

In step S4, when the self-propelled vehicle 1 starts traveling to start work, the self-propelled vehicle 1 calculates its own position (Xp, Yp) and the traveling direction θf (step S5).

In step S6, the deviation amount (ΔX, Δ
θf) is calculated.

In step S7, the self-position of the self-propelled vehicle 1 (cxp, Yp)
and based on the traveling direction θf, the self-propelled vehicle 1 moves to the area t1.
or t2 is determined. If the self-propelled vehicle 1 exists in the area t1, the process advances to step S8.

In step S8, kxl is set as the feedback gain.
and kal, and this feedback gain kx
The reference steering angle φ is determined by l and kal, and the deviation amounts ΔX and Δθf.

In step S9, steering control is performed based on this reference steering angle φ.

Further, if the self-propelled vehicle 1 exists in the area t2, step S
Proceed to IO. In step S10, gains kx2, ka2 larger than the gains kxl and kal are read as feedback gains, and a reference steering angle φ is determined based on the feedback gains kx2, ka2 and the deviation amounts ΔX, Δθf. Steering angle control is performed based on the reference steering angle φ.

In step S12, it is determined whether the self-propelled vehicle 1 is traveling in a direction away from the origin (going direction) or in a direction approaching the origin (returning direction) in the y-axis direction.

If it is in the forward direction, it is determined in step S13 whether one stroke is completed (Yp>Ye), and if it is in the return direction, it is determined in step S14 that one stroke is completed (Yp<Ye).
Ys t) It is determined whether or not. Step S13
Alternatively, if it is determined in S14 that one stroke has not been completed, the process returns to step S5.

If it is determined in step S13 or 514 that one stroke has been completed, then in step 515 it is determined whether all strokes have been completed (Xp>Xe).

If the entire stroke has not been completed, the process moves to step 516 and the U-turn control of the self-propelled vehicle is performed. The U-evening control includes step 85 of feeding back the position information of the self-propelled vehicle 1 calculated by the position/direction calculation unit 13 to the steering unit 14.
This is performed in a different manner from the straight-line travel steering control performed by the processing of ~Sll.

As U-turn control, for example, in a turning stroke, the self-propelled vehicle 1 is run with the steering angle fixed at a preset angle, and the steering angle as seen from the self-propelled vehicle 1 is determined based on the opening angle detected by the angle detection unit 10. When at least one of the azimuth angles of each of the reference points A, B, and C matches within the predetermined angle range, the process returns to the straight-line travel steering control performed by the processing from step 85 to Sll. Good (Special application 1986-1)
49619).

In step S17, Xn+L is set to Xn, and the next travel course is set. Once the next travel course is set, the process returns to step S5 and the above-mentioned process is performed.

When the entire stroke is completed, the return position (Xret, Yre
t) (step 318), the travel is stopped (
Step S19).

In the above flowchart, an example has been described in which the reference points are arranged at three locations, but the same process can be performed when three reference points are selected and used from among the reference points arranged at four locations. That is, based on the position information of the three selected reference points, the current position of the self-propelled vehicle 1 is at t3 in the area.
- t5 is determined in step S7, and based on the result of this determination, the self-propelled vehicle l is located in the region t3.
, t4, the small gain kx 1,kal
If the self-propelled vehicle 1 is located at t5 in the region, a large gain kx2,
The reference steering angle φ may be determined according to ka2.

Regarding the control method of selecting and using three of the four reference points, for example, Japanese Patent Application No. 63
It is detailed in No.-262191.

In this example, the feedback gain is reduced in the straight line part of the travel course and the area close to the straight line that is almost orthogonal to this extension line among the straight lines connecting each reference point. Not limited to standards.

The position detection error in the direction perpendicular to the straight line portion of the traveling course occurs in relation to the rotating direction of the light emitter 2 and the light receiver 3 and the traveling speed of the self-propelled vehicle 1. The region where the position detection error in the direction perpendicular to the straight line portion of the course is large may be determined experimentally, and a feedback gain set to be small may be selected in that region.

As explained above, in this example, there are areas within the work area where the error in the position i information of the self-propelled vehicle 1 is expected to be large depending on the positional relationship with the reference point, and areas where the error is expected to be small. The feedback gain for determining the steering angle is changed to a different value depending on the region in which the steering angle is determined.

Therefore, it is possible to reduce hunting caused by an error in the position information of the self-propelled vehicle when transitioning from a turning stroke to a straight traveling stroke.

In addition, the switching of the feedback gain is not only determined based on which of a plurality of divided regions the self-propelled vehicle 1 is located, but also the determination of the region where the self-propelled vehicle 1 is located and the turning stroke of the self-propelled vehicle 1. It is also possible to use the judgment that the process has ended and transitioned to the straight-line traveling process as a criterion for switching the feedback gain.

Furthermore, the switching of the feedback gain may not be performed according to a preset region, but may be performed only according to the judgment of the timing of transition from the turning stroke to the straight traveling stroke. In other words, since feedback gain switching is mainly required until some time has passed after the transition from the turning stroke to the straight-line traveling stroke, the position detection error in the direction perpendicular to the straight-line portion of the traveling course is large. The steering control may be performed using a small feedback gain at the time of transition from the turning stroke to the straight traveling stroke in the area where the vehicle is expected to move, and until a scheduled time has elapsed or the vehicle has traveled a scheduled distance.

By using such a judgment criterion for switching, the effect of suppressing hunting to a small level becomes greater in the transition process from the turning stroke to the straight traveling stroke, where hunting is expected to be greatest.

The coordinate system may be set by measuring the positional relationship between each reference point in advance as in this embodiment, but the coordinate system may be set by measuring the positional relationship between each reference point in advance, but the coordinate system may be set by measuring the positional relationship between each reference point in advance. The distance between the self-propelled vehicle 1 and the reflector 6 is measured based on the difference between the phase of the light beam scanned by the light beam and the phase of the reflected light from each reference point returning to the light receiver 3, and this distance information and It is also possible to detect the position of the reference points from the opening angle between each reference point and set the coordinate system (see Japanese Patent Application No. 116689/1989).
.

In addition, during the turning process, the steering angle is fixed and the self-propelled vehicle
The steering control is not limited to this embodiment in which the vehicle is caused to travel in a straight line, but the steering control may be performed using feedback control in the same manner as in the straight travel stroke.

(Effects of the Invention) As is clear from the above description, according to the present invention, the feedback gain when calculating the steering angle, which is a reference for performing steering control of a self-propelled vehicle, can be adjusted to multiple scheduled regions. You can select different values and switch between them. As a result, it is possible to reduce hunting when transitioning from a turning stroke to a straight-line traveling stroke, and it is possible to accurately transition to a planned straight-line traveling course in a short period of time.

Self-propelled vehicle transitions from turning left or turning right to driving in a straight line 2
Since the difference in the magnitude of /X-nching can be made small in the two different transition states, unevenness in work is eliminated when the self-propelled vehicle performs work.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a flowchart of steering control, Fig. 3 is a diagram showing the traveling course of a self-propelled vehicle and the arrangement of the counter device, and Fig. 4 is a diagram showing the arrangement of the counter device. An explanatory diagram of the area setting for feedback gain determination, Fig. 5 is a perspective view showing a self-propelled vehicle and a reversible vehicle, Fig. 6 is a diagram showing the relationship between the position of the self-propelled vehicle and the traveling course, and Fig. 7 is a self-propelled vehicle. A relationship diagram of a vehicle's traveling trajectory and a traveling course, Figure 8 is a principle diagram of position detection of a self-propelled vehicle, Figure 9 is an explanatory diagram of the principle of detecting the traveling direction of a self-propelled vehicle, and Figure 1
FIG. 0 is a diagram showing simulation results for explaining the problems of the conventional technology.

Claims (6)

[Claims] (1) A means for detecting the current position and direction of travel of a self-propelled vehicle with respect to reference points installed at least three locations around the work area, and a complex scheduled travel course that combines straight sections and turning sections. a steering control device for a self-propelled vehicle, comprising: a steering control means for feedback-controlling a steering angle of the self-propelled vehicle based on detection information of the detection means and information on the traveling course in order to cause the self-propelled vehicle to travel along the means for dividing and setting the area related to the work into a plurality of regions; means for determining in which region of the plurality of regions the self-propelled vehicle is located; and according to the output of the determining means. A steering control device for a self-propelled vehicle, comprising means for setting a scheduled feedback gain. (2) A means for detecting the current position and direction of travel of the self-propelled vehicle with respect to reference points installed at at least three locations around the work area, and a complex planned travel course that combines straight sections and turning sections. a steering control device for a self-propelled vehicle, comprising: a steering control means for feedback-controlling a steering angle of the self-propelled vehicle based on detection information of the detection means and information on the traveling course in order to cause the self-propelled vehicle to travel along the , means for dividing and setting the area related to the work into a plurality of areas; means for determining in which area of the plurality of areas the self-propelled vehicle is located; What is claimed is: 1. A steering control device for a self-propelled vehicle, comprising: means for setting a predetermined feedback gain according to an area in which the self-propelled vehicle is located when moving to a certain area. (3) The self-propelled vehicle according to claim 1 or 2, wherein the work-related area is divided based on the magnitude of a self-propelled vehicle position detection error in a direction perpendicular to a straight line portion of the travel course. steering control device. (4) A means for detecting the current position and direction of travel of the self-propelled vehicle with respect to reference points set at at least three locations around the work area, and a complex scheduled travel course that combines straight sections and turning sections. a steering control device for a self-propelled vehicle, comprising: a steering control means for feedback-controlling a steering angle of the self-propelled vehicle based on detection information of the detection means and information on the traveling course in order to cause the self-propelled vehicle to travel along the , a means for determining whether traveling in a straight section following a turning section is traveling in a straight section following a turning in either the left or right direction, and a means for determining whether a self-propelled vehicle is traveling in a straight section following a turning section, and a means for determining whether a self-propelled vehicle is traveling in a straight section following a turning section, and until a scheduled time elapses after the self-propelled vehicle finishes turning. The vehicle is characterized by comprising a means for setting a scheduled feedback gain for each of traveling in a straight line after a left turn and traveling in a straight line after a right turn until the vehicle travels a distance of . Steering control device for self-propelled vehicles. (5) The steering control means includes a light beam generating means provided on the self-propelled vehicle, a light beam scanning means for scanning the light generating means in a rotational direction with the self-propelled vehicle as a center, and a light-receiving means for receiving reflected light from light-reflecting means provided on a vehicle and disposed at at least three locations away from the self-propelled vehicle and reflecting light in an incident direction; and the light-receiving means as seen from the self-propelled vehicle. The present invention is characterized by comprising an opening angle detecting means between the vehicle and a position calculating means for calculating the position of the self-propelled vehicle based on the opening angle detected by the opening angle detecting means and the position information of the light reflecting means. A steering control device for a self-propelled vehicle according to any one of claims 1, 2, 3, and 4. (6) The self-propelled vehicle according to any one of claims 1, 2, 3, 4, and 5, wherein the traveling of the turning portion is not based on feedback control but is steering controlled according to a fixed steering angle. steering control device.