JPS6113311A - Automatic steering controlling method - Google Patents

Abstract

PURPOSE:To improve both the response property and stability of an unmanned carrier car, by establishing the relation between the size of a steering command to the unmanned carrier car to the deviation between its running course and the car in proportion to the (n)-th (n>1) power of the deviation and not in linear proportion. CONSTITUTION:When a target value is set at epsilon0=0 which makes the deviation from a running course to zero, the position P of an unmanned carrier car at an optional moment is given to a steering controller 5 as a deviation epsilon from the running course through a feedback element 3 and comparator 4. The steering controller 5 has a transmission function ¦S¦=K2, epsilon<n> (n>1) against the deviation epsilon and outputs a steering command S. A steering driving device 6 drives a steering device 7 in accordance with the steering command S and corrects the car position by transmitting the drive to the unmanned carrier car. By making the steering command S proportional to the (n)-th power of the deviation epsilon (n>1), the response property when the deviation epsilon is large and the stability when the deviation epsilon is small are improved. It is practical to set the (n) at 2 (n=2) so as to obtain ¦S¦=K2epsilon2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic steering control method for an automatic guided vehicle that automatically travels along an instructed travel course.

[Traditional technique]

In this type of automatic steering control, the magnitude of the steering command given to the automatic guided vehicle to correct the deviation of the automatic guided vehicle from the traveling course (Figure 1) is given by a linear proportional function to the deviation. (Figure 2).

〔the purpose〕

As a result, the steering control system becomes unstable due to an insufficient amount of steering at a position where the deviation is large and an excessive amount of steering at a position where the deviation is small, which causes the vehicle to wobble.

This problem becomes more significant as the vehicle weight increases, and the purpose of the present invention is to solve the problem that adjusting the proportionality constant alone is insufficient to stabilize the control system.

〔composition〕

In order to solve the above-mentioned drawbacks, the present invention makes the magnitude of the steering command proportional to the nth power of the deviation (n>1).

〔Example〕

FIG. 1 is a diagram showing the deviation of the automatic guided vehicle 2 from the traveling course 1, where 1 is the traveling course, 2 is the automatic guided vehicle that automatically travels along the traveling course 1 instructed by the guidance device, and E is the diagram showing the deviation of the automatic guided vehicle 2 from the traveling course 1. Show deviation.

FIG. 2 is a diagram showing the magnitude 151 of the steering command with respect to the deviation ε according to the conventional steering control method, where ε is the deviation, +5
1 indicates the magnitude of the steering command, and K1 indicates the proportionality constant.

FIG. 3 shows an embodiment of the present invention (FIG. 81 is a block diagram of the steering control system, 3 is a feedper target value, ε
is the deviation, and S is the steering command. (The bl diagram represents the transfer function of the steering control device 5, ε is the deviation, 151
is the magnitude of the steering command, and K2 is a proportionality constant.

Now, the target value ε that makes the deviation from the running course 0
, -0, the vehicle body position P at any time is given to the steering control device 5 through the feed bank element 3 and the comparator 4 as the deviation ε with respect to the traveling course. The steering control device 5 sets the transfer function 1Sl=2·ε (however, n>l) shown in FIG. 3(b) for the deviation 6.
-(1) and outputs a steering command S. The steering drive unit N6 drives the steering unit W7 according to the steering command S, transmits the command to the automatic guided vehicle, and corrects the vehicle body position.

As shown in FIG. 3 (bl and equation (1)), the steering command S
By making it proportional to the nth power of the deviation ε (n>1.),
The response when the deviation ε is large and the stability when the deviation ε is small are improved.

Here, it is practical to set n=2 and 1sl=2 ε −−m−−−−・−11111−−−−−−−−−−・−(2) .

〔effect〕

As mentioned above, the deviation of the steering command to the nth power (n > 1)
By making it proportional to , it is possible to improve both responsiveness and stability, which previously had to be sacrificed or compromised by adjusting only the linear proportionality constant. This is more effective as the weight of the vehicle increases.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the deviation of the automatic guided vehicle from the traveling course, FIG. 2 is a diagram showing the relationship between the steering command and the deviation according to the conventional steering control method, and FIG. 3(a) is a steering control block diagram of the present invention. FIG. 3(b) is a diagram showing the relationship between the steering command and the deviation (transfer function of the steering control device) according to the present invention. 1--------One driving course 2--Automated guided vehicle 3--Feedback element 4--One comparator 5--Steering control device 6----- --- Steering drive device 7 --- One steering device ε--・-- Deviation S --- One --- Steering command + 51-- One --- Steering command magnitude ε, -- Target value 1. 2 ----One proportional constant P-...Vehicle body position

Claims (1)

[Claims] In an automatic guided vehicle that automatically travels along a travel course instructed by a guidance device, the relationship between the magnitude of the steering command to the automatic guided vehicle and the deviation between the travel course and the automatic guided vehicle is not linearly proportional, but is calculated based on the deviation. An automatic steering control method in which a steering command is proportional to the nth power (n>1).