JPS60122409A - Automatic operation control system of car - Google Patents

Abstract

PURPOSE:To improve the tracking performance of a running course to an external disturbance by driving a car in a guideless way and also applying feedback control of a lateral displacement and an attitude angle to the steering control so as to simplify the constitution of the drive control system. CONSTITUTION:An on-vehicle controller 11 provided onto a car body is provided with a setting section 12, an operation control section 13 and a memory section 14 and a data of each running course and various constants of the car body for drive control are preset to the setting section 12. Moreover, the car body 15 is provided with a potentiometer 16 detecting the steering angle can an encoder 17 counting the number of revolutions, and a signal representing the steering angle and the number of revolutions from them is fetched to the control section 13 of the controller 11. The control section 13 computes the data at each running course preset to the setting section 12 and the various constants of the car body and also the inputted steering angle and number of revolutions. Then the feedback control for lateral displacement and attitude angle is applied to the steering control, the car is driven in a guideless way, the constitution of the system is simplified and the tracking performance against external disturbance is improved.

Description

[Detailed Description of the Invention] This invention provides a guideless (guideless here refers to a vehicle that does not use an electromagnetic induction method, an optical guidance method, a visual guidance method, etc.) and is capable of automatic operation. Regarding automatic driving control methods.

Conventionally, methods for automatically driving a vehicle include laying guide wires, guide rails, optical reflective tape, etc. along the driving course and driving the vehicle while detecting these, or using radio waves, light, ultrasonic waves, etc. There is a method of detecting the absolute position of the vehicle within the operating plane using a method, and moving the vehicle based on the positional deviation between this detected position information and the traveling course.

However, providing special guide wires, guide rails, optical reflective tapes, etc. is costly, and when using propagating waves such as radio waves, light, and ultrasound, propagation obstacles may occur depending on the environment. There was a risk that detection accuracy would be reduced.

Also, as for other conventional automatic driving control methods.

A plurality of positions are set on the running course, and changes in position and attitude angle are stored in a memory for each of these positions, and each of the positions is used as a target position when running.

Clear the target position and move it one by one along the driving course.

Also, the target position is the origin on the virtual xy plane.

The y-axis is aligned with the tangential direction at each point, the angle formed with the y-axis is taken as the attitude angle, and the deviation from the current position and attitude angle of the running vehicle is sequentially determined, and the vehicle speed and steering angle are determined according to this deviation. Calculate and drive the vehicle.

There is a method in which the target position is tracked while the attitude angle is set to zero. But this method.

When the virtual x-y plane changes (the target position moves one step forward), coordinate transformation must be performed to obtain the quantities that represent the vehicle body position and direction on the new virtual x-y plane, but it is not possible to memorize it. Since the data being used is the change in the origin position of the virtual x-y plane and the direction of the y-axis in the real X-Y plane, the calculation of the coordinate transformation becomes complicated. In order to drive accurately.

This method has disadvantages in that it is necessary to take many target positions, it takes time and effort to set the target positions and attitude angles, and it requires a large memory capacity.

The purpose of the present invention is to solve the deficiencies of the conventional methods described above, and to realize an automatic driving method for vehicles that is guideless, can be realized at relatively low cost, is easy to control, and does not require a large memory capacity. It is said that it provides.

In order to achieve the above object, the automatic driving control system for a vehicle of the present invention configures a driving course to consist of linear elements and circular arc elements, assumes a reference coordinate axis for each course element, and separately sets the road surface. Assuming a road surface fixed coordinate axis that is fixedly determined, data specifying the reference coordinate axis with respect to the road surface fixed coordinate axis and command positions of a vehicle speed command and a continuous speed command are stored in a storage means for each of the reference coordinate axes. , and while the vehicle is running, the lateral displacement and attitude angle of the moving object are detected from the rotation speed and steering angle detected by the rotation speed detection means and the steering angle detection means,
Steering control is performed so that the lateral displacement and attitude angle become zero, and when the vehicle body reaches a vehicle speed command position, a vehicle speed command value corresponding to that position is output.

Hereinafter, this invention will be explained in more detail with reference to Examples.

In the example described below, the vehicle body itself calculates its own positional deviation (lateral displacement) and direction deviation (attitude angle) with respect to the assumed driving course so that the car body travels along the previously assumed driving course. Calculate it.

A steering output is applied so that this lateral displacement and attitude angle become zero, and when the vehicle reaches a predetermined position on the travel course.

It outputs a vehicle speed command value and performs travel steering control.

The travel course assumed in advance is composed of a combination of linear elements and circular arc elements. Then, on each element m, a reference coordinate axis (referred to as a reference coordinate axis) xm-ym is assumed.

This reference coordinate axis aligns the X axis with the course element when the course element is a straight line.

If the course element is an arc, the y-axis passes through the center of the arc,
Make sure the X-axis touches the arc. In addition to the reference coordinate axes fixed to each course element, coordinate axes xy fixed to the road surface (referred to as road surface fixed coordinate axes) are assumed.

When these reference coordinate axes and road surface fixed coordinate axes are illustrated for traveling course example M, they are as shown in FIG.

In the figure, the driving course M is a straight line element rr+1. Arc element m2. Consisting of straight line elements m3, these course elements m1
．． m2. The reference coordinate axes of m3 are xl-yl as shown in Figure 2.
+x2-y2. x, 3-y3.

Data regarding the reference coordinate axes is stored in advance in the memory of the on-vehicle control device as travel course data.

The data to be stored is ■The position of each reference coordinate axis relative to the road surface fixed coordinate axes (Xm
, Ym) and rotation angle Φm.

■Distinguish whether course element m is a straight line or an arc.

■End point of course element m ('□, i).

■Central coordinates of the arc element (0, y'm).

■Vehicle speed command position and its command value, where m=L, 2, 5. ...Next, during driving, the position and direction of the vehicle body relative to the reference coordinate axes are calculated.

This calculation of the position and direction of the vehicle body is performed cyclically at every minute unit time by the on-vehicle control device. In other words, it is assumed that the turning center position of the vehicle body does not change in a minute unit time.
The current position and direction of the vehicle body with respect to the reference coordinate axes are calculated by geometrically determining the amount of change in the position and direction of the vehicle body and adding them sequentially.

Now, as shown in Figure 2, the vehicle body is fixed wheels W21°w22.
and steering wheel W11. It is a four-wheeled vehicle having W12, the fixed wheel w21 and the steering wheel w12 are driven wheels, and the fixed wheel w22
When the steering wheel w12 is a driving wheel, the position and direction of the vehicle body are calculated using one of the following methods.

■Calculated from the detected values of the rotation speed and steering angle of the two driven wheels (W12 and W21).

■Calculated from the rotation speed of the two fixed wheels (w21, w22).

Here, the method of the above equation 0 will be explained in detail.

In addition, when calculating, as shown in the diagram, the turning center position of the vehicle body is determined by the axis of the steering side drive wheel W11 and the fixed wheel w.
It is the intersection point P of the axes of 21 and w22.

The point where the position of the car body is determined (the representative point of the car body) is fixed on the fixed wheel w21.
, is calculated as the intersection point B of the axis of w22 and the center line of the vehicle body.

(xi-i, yi-1): Vehicle position before minute unit time (xi, yi): Vehicle position 0 after minute eye position time has passed
1-1: Vehicle direction θI before minute unit time has elapsed: Vehicle direction Δxi, Δy1 after minute unit time has elapsed - Amount of change in vehicle body position in minute unit time △θI: Amount of change in vehicle body direction in minute unit time ψI: Steering angle in minute unit time (potentiometer detection value) W - Rud of the vehicle body, L: Wheel vane of the vehicle body, C: Wheel offset amount.

r: Wheel effective radius.

Δ#i: Distance traveled by the vehicle body in minute unit time P: Number of pulses per rotation of wheel rotation speed detection encoder P12i, P21i: Wheel W12. Let it be the number of rotation pulses of the encoder in a minute unit time of V121.

The vehicle body position (xi, yi) and vehicle body direction after a minute unit of time has elapsed can be calculated using the following formula.

Using equation (1) above, the position and direction of the vehicle body can be calculated for each minute unit of time, but as the course elements change as the driving progresses, the reference coordinate axes also change, so the above is calculated at the point where the course elements change. It is necessary to convert the position and direction of the vehicle body calculated by equation (1) onto the new reference coordinate (9) axis.

Next, the coordinate conversion method will be explained.

In this example, from the reference coordinate axis Xm-Xm-1-y.

To perform coordinate transformation to xm-ym, directly use the reference coordinate axis
Instead of converting from m-1,, -Y m-1 to x m -y m, the reference coordinate axis x m -1-y m-1
After converting the coordinates from to the road surface fixed coordinates X-Y, the reference coordinates @
The coordinates are transformed to x m - y m. If you do it like this.

The data stored in memory for coordinate conversion is the position of the origin of the reference coordinate axis (xm-
x, ym-t), (xm, ym) and rotation angle Φm-1゜Φ
m, the reference coordinate axis x m −i ”−y m−
Xm required when directly converting from i to xm-ym
This is because the data is easier to create than the position of the origin and rotation angle of x m -y m with respect to -] and -ym-1.

Near (1o) (x, y): Vehicle body position with respect to the road surface fixed coordinate axis X-Y during coordinate transformation.

β: Road surface fixed axis X-Y during coordinate transformation direction of the vehicle relative to If so.

First, the position and direction of the vehicle body are determined by the reference coordinate axis x
m −1 −ym−1 is converted to the road surface fixed coordinate axis XY.

Next, from the linear equation, from the road surface fixed coordinate axis x-y, the reference coordinate axis x
Convert to m-.yml.

In addition, the timing of performing the above coordinate transformation, that is, the course element changes from m-1 to m, and the reference coordinate axis xm-1-
Conditions for performing coordinate transformation from ym-1 to xm-ym are determined as follows.

■When course element m-1 is a straight line.

The stored position of the end point of course element m-1 with respect to the reference coordinate axis is compared with the vehicle body position xm-1.

If x m-1≧蔀i (4), the coordinates are transformed to a new reference coordinate axis xm-ym.

■When course element m-1 is a circular arc.

The end point of the stored course element m-1 and the position of the arc center with respect to the reference coordinate axis Xm-Xm-1-y (xm-1°3'm-1) + ym-1 and the vehicle body position (xm-1 ,y
From m-1).

If satisfied, the coordinates are transformed to the reference coordinate axes xm-ym.

As described above, the vehicle body position and direction with respect to the reference coordinate axes are calculated for each minute unit of time.

Based on this vehicle body position and direction, the positional deviation (lateral displacement) and directional deviation (attitude angle) of the vehicle body with respect to the traveling course can be calculated.

Next, a method of calculating the lateral displacement 4 and attitude angle ψ of the vehicle body with respect to the traveling course will be explained.

■If the course element is a straight line As shown in Figure 4, if the course element m is a straight line, the representative point B of the car body is located at x, y) with respect to the reference coordinate axis X-y, and the direction angle θ is If there.

The lateral displacement l and attitude angle ψ are You can read more.

■If the course element is an arc The course element m is a circular arc as shown in FIG.

Representative point B of the vehicle body relative to the reference coordinate axis x-y
) and the tangent of the center point (0, Y') of one circular arc and the point that intersects the course element on the line connecting B to the representative of the car body and (1
3) ra.

Let the angle with the X axis be β and the direction angle of the vehicle body be θ.

Lateral displacement and attitude angle ψ are You can charge a fee.

Now, in order to ideally automatically drive the vehicle on a predetermined travel course M, it is necessary to bring the lateral displacement l and attitude angle ψ to 0 while driving. Therefore, as shown in the control block diagram of Fig. 6, the lateral displacement l and attitude angle ψ calculated by equation (7) are gain-adjusted by a gain adjuster, and their combined amount e-Gβ·l
Ten Gψ・ψ is fed back. And the target value e
The deviation between =o and this combined amount e is the steering output, and
As a compensation element, the steering angle ψ is fed back and added to the steering direction. Steering output E is added to the power amplifier.

The output drives the steering motor and performs steering control. Note that if the course element is a straight line and the vehicle body is on the (14) − path, the composite amount of the lateral displacement l and the attitude angle ψ is zero, the steering angle ψ is zero, and the vehicle body moves straight on the course. However, if the course element is an arc and the car body is on the course, the steering angle ψ is zero and the car body will immediately deviate from the course if it goes straight. Steering angle offset amount ψ according to the radius of the arc.

Calculate.

Gψ (ψ−ψ.) is fed back to the operation output. In the end, the steering output value E is calculated using the following equation.

E=-GQ-1-G'f)・(P-Gψ(9'-ψo)
...(8) However, G2: Lateral displacement feedback gain.

Gψ: Attitude angle feedback gain Gψ: Steering angle feedback gain.

FIG. 7 is a block diagram showing an automatic driving control system for implementing the present invention. In the figure, an on-vehicle control device 11 provided on the vehicle body.

Setting section 12. An arithmetic control section 13 and a memory 14 are provided.

The setting unit 12 is configured to previously input and set data for each course element of the driving course and various constants of the vehicle body to be controlled. The memory 14 stores various data inputted from the setting section 12 regarding the running speed, vehicle body, etc., as well as calculated values during driving.

The calculation control unit 12 calculates various data stored in the memory 13 and a steering angle detected from the vehicle body, which will be described later.

In response to the wheel rotation speed, various calculations are performed according to a predetermined program to derive steering output and vehicle speed output in order to move the vehicle along a travel course at a predetermined speed.

The vehicle body 15 includes a potentiometer 16 for detecting the steering angle and an encoder 17 for detecting the number of rotations of the wheels.
are provided, and these potentiometers 16. Signals indicating the steering angle and wheel rotation speed from the encoder 17 are taken into the arithmetic control section 12 of the on-vehicle control device 11.

Next, the overall operation of this automatic driving control system during running will be explained with reference to the flowchart shown in FIG.

When starting the car body from a fixed point, the number of the course element at Sadahiro and the position and direction data on the reference coordinate axes where the car body should be at the fixed point are stored in advance, so the car body can be set up accordingly. and start it. When starting at an arbitrary position, data such as the above-mentioned course element number of that position is input as start point data using the ten keys of the setting section 12, and the start is started.

After the operation is complete, first, the steering angle ψi from the potentiometer 16 and the wheel rotation speed P12i from the encoder 17 are determined.
, P21i is read (step 5T1). continue,
The above calculation (1) is performed based on the steering angle ψi, the wheel rotation speeds P12i, P2ti, constants stored in the memory 13 in advance, the vehicle body position at the time of the previous calculation, the vehicle body direction, etc., and the vehicle body position (xi, yi) and the direction θi (step ST2). Next, from the detected vehicle body position, the above (4)
Step ST3) calculates the equation or equation (5) to determine whether or not the current vehicle body position has reached the change point of the course element.
The calculations of equations (2) and (3) above are executed as shown in (17) to perform coordinate transformation (step s'r4).

After the coordinate transformation or following the determination of course element change No. in step ST3, the vehicle speed is output based on the vehicle speed command at that point (step 5T5).

Next, referring to the course element data currently being traveled stored in the memory 13, it is determined whether the course element is a straight line or an arc (step ST6). As a result of the determination, if the course element is a straight line, the lateral displacement l and attitude angle ψ of the vehicle body on the straight course are calculated using the above equation (6) (step ST7
). If the course element is a circular arc, the lateral displacement l and attitude angle ψ of the vehicle body in the first circular arc course are calculated using the above equation (7) (step 5T3). Next, when the course element is a circular arc, the steering angle offset amount ψ is determined according to the radius of the two circular arcs.

is calculated (step 5T9). Then, a steering output is calculated and outputted so that the composite amount of the calculated lateral displacement and attitude angle is 0 (steps 5T10 and 5T11). Finally, it is determined whether or not the operation is finished (Step 5T12).

If not finished, return to start. And from then on,
A series of processes from step ST1 to (18) to step 5T12 are repeated every minute unit time until the end of the operation. By carrying out the above control, the vehicle body follows and advances on a travel course determined in advance.

According to this invention, it is possible to proceed with the guide V, and since the steering control is feedback control of lateral displacement and attitude angle, the traveling course can be followed well even in response to external disturbances.

It is possible to create two different driving courses by combining straight course elements and arc course elements.

Furthermore, the data regarding the driving course that is stored in advance in the memory may be for each course element.

This method has the advantage that arithmetic processing is simplified, data input for storing courses is simple, and the memory capacity required for storing courses is relatively small.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a running course of an embodiment of the present invention, and FIG. 2 is a diagram showing fixed wheels and steered wheels of a vehicle body. Figure 6 is a diagram for explaining the turning center of the vehicle body, Figure 4 is a diagram for explaining the calculation of the lateral displacement and attitude angle of a straight course element, and Figure 5 is a diagram for explaining the lateral displacement of an arcuate course element. Fig. 6 is a diagram explaining the calculation of attitude angle and attitude angle, and the steering control □
□ is a control block diagram for explaining □, and FIG. 7 is a block diagram of an automatic driving control system for implementing this invention.
FIG. 8 is a flowchart for explaining the operation of the automatic operation control system. M: Driving course, ml, m2. m3: course element, xi
-yl・x2-y2・x3-y3: Reference coordinate axes. X-Y: Road surface fixed coordinate axis, 13: Arithmetic control unit. 14: Memory, 16: Potentiometer. 17: Encoder. Patent Applicant Nippon Yusoki Co., Ltd. Agent Patent Attorney Shigeru Nakamura Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) Configure the driving course to consist of linear elements and circular arc elements, and assume a reference coordinate axis that serves as a reference for each course element, and also assume a road surface-fixed coordinate axis that is fixedly fixed to the road surface. With respect to the coordinate axes, the data specifying the reference coordinate axes, the vehicle speed command, and the command position of the continuous speed command are stored in a storage means for each of the reference coordinate axes, and during driving, the rotation speed detection means and the steering angle detection means The lateral displacement and attitude angle of the moving body are detected from the rotational speed and steering angle detected by , and the steering is controlled so that the lateral displacement and attitude angle become zero, and when the vehicle body reaches the vehicle speed command position, An automatic vehicle driving control system that outputs a vehicle speed command value corresponding to that position.