JPH07210246A - Steering controller for automated guided vehicles - Google Patents

Abstract

(57) [Summary] [Purpose] The direction of the automated guided vehicle and the direction of the guide line are quickly matched. [Construction] Guidance sensors 5f and 5b are provided on the front end side and the rear end side of a vehicle body 4 of an automated guided vehicle 1. The guidance sensors 5f and 5b detect the positions P _f and P _b of the guidance line 10. The control device 6 obtains the deviation amounts Z _f and Z _b at the front and rear ends and the posture angle θ based on the positions P _f and P _b . Then, the steering control of the front wheels 2 is performed so that the deviation amounts Z _f and Z _b and the attitude angle θ are zero.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering control device for an automated guided vehicle, which controls the steering in consideration of the attitude angle of the automated guided vehicle.

[0002]

2. Description of the Related Art An automated guided vehicle is a device for transporting parts, products, small articles, etc. in various factories, warehouses, offices and the like.
An automated guided vehicle uses a guide line (electric wire or light-reflective tape) installed along the road to guide the sensor (magnetic sensor or optical sensor).
Detected at, drive along the guide line.

An example of an automatic guided vehicle will be described with reference to FIG. The automated guided vehicle 1 shown in FIG. 5 is of a tricycle type having one front wheel 2 for rotational driving and steering, and two rear wheels 3 functioning as driven wheels. An inductive sensor 5f is installed on the front part of the vehicle body 4. When the vehicle travels, the guide wire 5 is detected by the guide sensor 5f, and the vehicle travels while the steering control is performed so that the central portion of the guide sensor 5f, that is, the central portion of the vehicle body 4 is positioned directly above the guide wire 10. In addition, including steering control,
Various controls for traveling are performed by commands from the control device 6.

In the automatic guided vehicle 1 described above, the guidance sensor 5 is used.
The guide wire 10 is detected by f, the distance (deviation amount) between the guide wire 10 and the center of the vehicle body 4 is sensed, and the steering angle is determined according to the deviation amount. The relationship between the deviation amount and the steering angle is preset in the control device 6.

[0005]

By the way, as shown in FIG. 6, even if the direction A of the automatic guided vehicle 1 and the direction of the guide wire 10 are different, the center of the guide sensor 5f is directly above the guide wire 10. When the vehicle is in the position, steering control is not performed. Then, from the state of FIG. 6, the automatic guided vehicle 1 is further added.
Is running and the center of the guidance line 5f and the guidance 1
After the amount of deviation from the position where 0 is detected is detected, steering control is started, and by steering, finally, the direction A of the automatic guided vehicle 1 and the direction of the guide wire 10 become equal. Note that here, the direction A of the automated guided vehicle 1
The angle formed by the guide line 10 and the guide line 10 is referred to as “attitude angle θ”.

As described above, in the prior art, even if the attitude angle θ is large, when the deviation amount is zero, steering control is not performed, so that it takes a long time until the attitude angle θ becomes zero.

In view of the above-mentioned prior art, the present invention provides a steering control device for an automatic guided vehicle, which controls the direction of the automatic guided vehicle so as to promptly match the direction of the guide line.

[0008]

The structure of the present invention for solving the above-mentioned problems includes a pair of induction sensors which are separated in the vehicle length direction and extend in the vehicle width direction to detect the position of a guide line.
Based on the steering motor that changes the steering angle of the steered wheels and the position of the guide line detected by the pair of guide sensors, the angle between the direction of the automated guided vehicle and the direction of the guided line is obtained, and the automated guided vehicle and the guided line are obtained. The amount of deviation from
And a control device for controlling the steering motor so that the obtained angle and displacement amount become zero.

[0009]

Operation: The pair of induction sensors detect the position of the induction line. The shift amount and the posture angle are obtained based on the detected position, and the steering control is performed so that the shift amount and the posture angle are zero.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. It should be noted that parts having the same functions as those of the conventional art are designated by the same reference numerals and described.

As shown in FIG. 1, an automated guided vehicle 1 according to an embodiment of the present invention includes a pair of induction sensors 5f and 5b. The guidance sensor 5f is located on the front end side of the vehicle body 4 and extends in the vehicle width direction, and the guidance sensor 5b is located on the rear end side of the vehicle body 4 and extends in the vehicle width direction. . Both inductive sensors 5f and 5b are located at positions P _f and P of the inductive wire 10.
_b (see FIG. 2) is detected. The front wheels 2 are steered by the drive of the steering motor 7 and rotationally driven by the drive of the drive motor 8. The pair of rear wheels 3 are driven wheels.

As shown in FIG. 3, inductive sensors 5f and 5b.
Guide line position P detected in_f, P _bIs sent to the controller 6.
To be The control device 6 controls the guide line position P._f, P_bBased on
Between the center of the vehicle body and the guide line 10 on the front end side.
Deviation amount Z_fAnd the center of the body and the guide line 1 on the rear end side
Deviation amount Z from 0_bAsk for. Further, the control device 6 is
In position P_f, P_bIs applied to the following equation (1) to obtain the posture angle θ
Ask.

[0013]

[Equation 1]

The inductive sensor 6 uses the calculated deviation amounts Z _f and Z _b.
And the steering motor 7 so that the posture angle θ becomes zero.
To control the steering angle of the front wheels 2. That is, the action of approaching the guiding line 10 (Z _f and Z _b are made zero) and the action of adjusting the direction to the guiding line 10 (making θ zero) are simultaneously controlled. Therefore, even if one of the deviation amounts Z _f and Z _b is zero (the state of FIG. 2), the steering control is performed based on the posture angle θ, so that the direction A of the automatic guided vehicle 1 and the guide line 10 are not changed. The convergence time until the directions match becomes shorter, and the extra traveling space required for convergence becomes unnecessary. Therefore, it is effective when used in a place where the direction A of the automatic guided vehicle is largely displaced due to transfer or the like, and the flexibility of the layout of the guide line 10 is increased.

If the inter-sensor distance L is shortened as shown in FIG. 4, the steering control can be performed by obtaining the posture angle θ even for a guide line provided along a sharp curve.

[0016]

As described above in detail with reference to the embodiments, according to the present invention, the attitude angle is obtained, and the steering is performed so that the attitude angle becomes zero. Can be matched quickly.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a plan view showing an example.

FIG. 3 is a block diagram showing a control system of the embodiment.

FIG. 4 is a plan view showing a modified side of the embodiment.

FIG. 5 is a perspective view showing a conventional automated guided vehicle.

FIG. 6 is a plan view showing a conventional automatic guided vehicle.

[Explanation of symbols]

 1 Automated guided vehicle 2 Front wheel 3 Rear wheel 4 Body 5f, 5b Inductive sensor 6 Control device 7 Steering motor 8 Drive motor 10 Induction line

Claims (1)

[Claims] 1. A pair of inductive sensors that are separated in the vehicle length direction and extend in the vehicle width direction to detect the position of a guide line, a steering motor that changes a steering angle of steered wheels, and the pair of inductive sensors. Based on the detected position of the guide line, the angle between the direction of the automatic guided vehicle and the direction of the guide line is calculated, and the deviation amount between the automatic guided vehicle and the guide line is calculated, and the calculated angle and the deviation amount are set to zero. A steering control device for an automatic guided vehicle, comprising: a control device for controlling the steering motor.