JPH0222721Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a programmable steering control device for turning an unmanned vehicle.

[Prior art] When an unmanned vehicle traveling along a guidance cable or the like is to be transferred by turning to another guidance cable that intersects with the guidance cable, the unmanned vehicle must be moved away from the guidance of the guidance cable. I am trying to release it and rotate the program. This programmed turning means that the steering angle necessary for turning is programmed in advance as a function of the distance traveled, and during the turn, the distance traveled is detected and the steering angle is automatically controlled using the above function. be.

[The problem that the idea aims to solve]

When turning using a general four-wheeled vehicle (two steered wheels) as an unmanned vehicle, the same function can be used for left and right turns (however, the polarity of the steering angle is reversed). If the same function is used in a vehicle that has only one steering wheel, such as a lift, and its mounting position is offset from the center of the vehicle, it will not be possible to transfer to the guide cable during one of the turns. This is because the turning radius of the steered wheels is different when turning to the right and when turning to the left.

This idea was made in view of the above points,
When an unmanned vehicle that has only one steering wheel and is installed offset from the center line of the vehicle is programmed to make a turn, the unmanned vehicle can change from one driving course to the other in either turn. The present invention aims to provide a steering control device for a vehicle.

[Means and actions for solving problems]

According to this invention, in an unmanned vehicle steering control device in which there is one steering wheel and the steering wheel is installed to be shifted by a predetermined distance to the right or left side from the center line of the vehicle body, the unmanned vehicle is a travel distance detection means for detecting the travel distance of the vehicle; and one trapezoidal function indicating a relationship between the travel distance of the unmanned vehicle and the steering angle corresponding to either a right turn or a left turn of the unmanned vehicle. function generating means for storing a signal indicating a steering angle in response to the distance traveled by the unmanned vehicle detected by the distance detecting means; and determining whether the unmanned vehicle turns left or right. and an amplifying means for amplifying the signals indicating the steering angle generated from the function generating means with different gains, respectively, in response to the signals indicating the steering angle amplified by the amplifying means. It is configured to perform steering control of a vehicle.

〔Example〕

Hereinafter, this invention will be explained in detail based on an embodiment of the accompanying drawings.

In FIG. 1, lines a and b are the normal running course of the unmanned vehicle 1, and these are, for example, induction cables through which an alternating current is passed, and the vehicle 1 detects this alternating current. It is now possible to travel along lines a and b. During a turn, the guidance provided by lines a and b is released. Fixed wheels 3 and 4 are installed on the front left and right sides of the unmanned vehicle 1, respectively, and a steering wheel 2 is installed on the rear left side.

As shown in FIG. 1, when the unmanned vehicle 1 on line a is rotated to the right around point A and transferred to the position indicated by dotted line 1a on line b, the trajectory of the steered wheel 2 is on line La. The trajectory of the steered wheel 2 when turning to the left around point B, which is symmetrical with respect to line a at point A, and transferring to the position shown by the dashed-dotted line 1b on line b, is as shown by line Lb. . The reason why the curve sizes of line La and line Lb are different is that the steering wheel 2 is installed at a position offset from the center line of the vehicle body. In other words, the locus La of a right turn is centered around point A.
It is a circular arc whose radius is the length of the center point O of the steering wheel 2, and the locus Lb of the left turn is centered at point B and whose radius is the length between point B and point O. . Therefore, in order to successfully move the vehicle 1 onto line b in both left and right turns, it is necessary not only to simply reverse the steering direction, but also to control the magnitude of the steering angle according to the trajectory that the steered wheels 2 should draw. You must do so. In addition, in FIG. 1, the length of the trajectory of the steered wheels 2 differs between turning to the right and turning to the left.
The traveling distance of the vehicle 1, that is, the traveling distance on the center line of the vehicle body is the same when turning to the right and turning to the left.

FIG. 2 shows an example of the relationship between the steering angle and travel distance in left and right turns. In this figure, a right turn is shown by a solid line X, and a left turn is shown by a dashed line Y.

A right turn will be explained. First, the position of the vehicle 1 at the point where it starts turning is defined as a distance x ₀ , and from this point the vehicle runs while gradually turning the steering wheel to the right, until the steering angle θ ₁ is reached when the vehicle 1 has traveled a distance x ₁ . When the steering angle reaches θ ₁ at a distance of x ₁ , the vehicle maintains that steering angle and travels to a distance of x ₂ . When the distance reaches x ₂ , gradually return the steering wheel to the left and control the steering angle so that when the steering angle reaches 0 at a distance of x ₃ , it reaches the position shown by dotted line 1a on line b (Figure 1). do.

In a left turn, the steering wheel is gradually turned to the left from distance x ₀ , and the steering angle becomes -θ ₂ when the vehicle travels to distance x ₁ . When the steering angle reaches -θ ₂ at a distance of x ₁ , the vehicle maintains that steering angle and travels up to a distance of x ₂ . When the distance reaches x ₂ , the steering wheel is gradually returned to the right, and the steering angle is controlled so that when the steering angle reaches 0 at a distance of x ₃ , the steering angle reaches the position shown by the dashed line 1b on line b.

In this figure 2, distance x ₀ to x ₃ , steering angle θ ₁ , −θ ₂
The value of is determined in advance according to the turning radius, the position of the steering wheel 2 on the vehicle body, etc.

FIG. 3 shows a control system for performing the steering control as shown in FIG. 2.

The distance detector 10 is for detecting the traveling distance of the unmanned vehicle 1 on the center line of the vehicle body from the turning start point. Therefore, this detector 10
For example, it should be installed on the center line of the vehicle body. If it is not possible to attach it on the center line due to the structure of the vehicle body, it may be attached to the left and right fixed wheels 3 and 4, respectively, to detect the distance traveled by each, and the average value thereof may be taken as the distance traveled by the vehicle. The turning start point of the unmanned vehicle 1 is detected, for example, based on the output of a pickup coil (not shown) that is disposed in the unmanned vehicle 1 and detects when the guidance signal from the guidance cable reaches a predetermined level. be able to.

The function generator 11 stores a trapezoidal function as shown by the solid line X (or the dashed line Y) in FIG. 2, and outputs a signal corresponding to the distance information from the distance detector 10. This output signal is applied to amplifier 14 via resistor r. The amplifier 14 includes a first feedback circuit via a resistor R ₁ and a switch S ₁ , and a resistor R ₂ ,
A second feedback circuit via switch _S2 is provided, and when the first feedback circuit is closed by turning on switch _S1 , it operates as an amplifier with a predetermined gain _G1 ,
When the second feedback circuit is closed by turning on the switch _S2 , it operates as an amplifier with another gain _G2 (> _G1 ). Further, switch _S1 is turned on by a right turn signal, and switch _S2 is turned on by a left turn signal. In other words, if the switch _S3 is closed by the right turn signal, the gain of the amplifier 14 will be reduced, and the line
The steering angle indicated by the signal led to l ₂ becomes as shown by the solid line X in Figure 2, and the steering angle indicated by the left turn signal is
When _S4 is closed, the gain increases and the steering angle indicated by the signal guided to line _l2 becomes as indicated by the dashed line Y in the figure. The steering angle of the steering (not shown) is controlled based on the signal guided to this line _l2 .

[Effect of idea]

As explained above, according to this invention, it is possible to successfully transfer from one guide cable to the other guide cable regardless of whether the cable is turned to the right or to the left or to the left. Also, since the functions are shared between forward and reverse, the configuration is simplified.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view showing how the unmanned vehicle turns to the right or left at the point where the guidance cables intersect, Fig. 2 is a graph showing an example of the function used in the programmed turning according to this invention, and Fig. 3 FIG. 1 is a block diagram showing one embodiment of a control system applied to this invention. 1...Unmanned vehicle, 2...Steering wheel, 3, 4...
Fixed wheel, 10... Distance detector, 11... Function generator.

Claims (1)

[Scope of Claim for Utility Model Registration] In an unmanned vehicle steering control system in which there is only one steering wheel and the steering wheel is installed a predetermined distance to the right or left of the center line of the vehicle body, a distance detecting means for detecting a distance traveled by the unmanned vehicle; and a distance detecting means for detecting a distance traveled by the unmanned vehicle; and a distance detecting means for detecting a distance traveled by the unmanned vehicle; function generating means for storing a trapezoidal function and generating a signal indicating a steering angle in accordance with the distance traveled by the unmanned vehicle detected by the distance detecting means; and whether the unmanned vehicle turns left or right. and amplifying means for amplifying the signals indicative of the steering angle generated by the function generating means with different gains, respectively, corresponding to the signals indicative of the steering angle amplified by the amplification means. A steering control device for an unmanned vehicle that performs steering control of the unmanned vehicle.