JPS60262220A - Steering device of unmanned truck - Google Patents

Abstract

PURPOSE:To reset quickly an unmanned truck which is deviated from its route by controlling the steering angle after detecting two elements, i.e., the lateral deviated amount from the route and the angle of the truck body. CONSTITUTION:A truck 1 is running toward an arrow head on a route 5. When the truck 1 has deviation from the route 5 by some reason, a difference is produced between the outputs of detection of a detector 11 set at the side of a steering wheel and a detector 12 at the side opposite to the steering wheel. Based on this output difference, the steering angle S of the truck 1 is decided. Thus the truck 1 can be quickly reset to the correct route 5.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a steering device for an automatic guided vehicle that travels along a preset route.

(B) Prior art (generally unmanned) General transportation vehicles are equipped with a system that allows them to travel along a preset route. used.

The automated guided vehicle guides the vehicle while detecting the amount of deviation from the route. For example, in the case of an electromagnetic induction method, a detection output difference between a pair of pickups or the like, or an optical guidance method or laser In the beam guidance system, etc., a large number of light receiving elements are arranged to detect and compare the amount of reflected light from the path, and the steering angle is determined based on the output signal, and the vehicle is guided to travel.

Conventionally, the steering angle has been determined by detecting the angle θ (original angle) between the traveling direction of the automatic guided vehicle and the route, and by detecting the amount of lateral deviation between the center line of the automatic guided vehicle and the route. There is something that detects Y.

However, in the front section (vehicle angle detection method), the traveling trajectory of the automatic guided vehicle converges to a certain value with respect to the path X, as shown in FIG. 1(a), but there is a certain limit value y for that convergence.

On the other hand, in the latter case (deviation detection method in the lateral direction of the path), the travel trajectory of the automatic guided vehicle is such that the amount of deviation y changes with a constant amplitude as shown in Figure 1 (1)), and the automatic guided vehicle meanders. There is a tendency to run repeatedly.

In other words, in the former case, the vehicle travels while deviating from the route by a certain distance, and in the latter case, the vehicle runs in a so-called oscillating manner.

(C) Purpose The present invention has been made in view of the above circumstances, and it controls steering by simultaneously detecting the amount of lateral deviation y with respect to the travel path of the automatic guided vehicle and the angle θ formed between the path and the automatic guided vehicle. It is an object of the present invention to provide a steering device for an automatic guided vehicle, which allows the automatic guided vehicle to run smoothly.

(d) Configuration The present invention provides a steering device for an automatic guided vehicle that travels along a preset route, and the angle between the lateral deviation of the automatic guided vehicle with respect to the route and the center line of the automatic guided vehicle. The automatic guided vehicle is equipped with detection devices disposed at the front and rear parts of the automatic guided vehicle to detect each of It is a steering device.

(e) Embodiment FIG. 2 is a bottom view of an automatic guided vehicle showing an embodiment of the present invention, and 1 is a trolley of the automatic guided vehicle, with a steering wheel 2 at the front or rear part and a rear or rear part of the trolley. It is equipped with drive wheels 3.4 at the front.

Note that the steered wheels 2 are configured to freely turn around a vertical axis via a speed reduction mechanism by a steering motor (not shown).

Further, the drive wheels 3.4 are driven by a drive motor via a deceleration mechanism (not shown). 11.12 is a detector arranged at right angles to the traveling direction at the front and rear of the truck 1. Specifically, this detector has a plurality of light-receiving elements arranged and detects the reflected light from the path 5. A detection device is configured together with a light source (not shown). Reference numeral 5 indicates a reflective tape pasted on the floor, and represents the route along which the automatic guided vehicle should travel.

In addition, the trolley is equipped with a terry (not shown) and a control device, which will be described later.

FIG. 3 is an explanatory diagram showing the running situation of the automatic guided vehicle, in which the bogie 1 is running on the route 5 in the direction of the arrow, and when the bogie 1 is running on the route 5, the vehicle body angle is 0°, Detector 11
．． The detection output of 12 is 0. When the truck 1 begins to deviate from the path 5, a difference occurs between the detection outputs of the detectors 11 and 12.

The amount of lateral deviation of the steering wheel (jll) detector 11 is 01,
If the amount of lateral deviation of the detector 12 on the side opposite to the steering wheel is 01, and the distance between the two detectors is L, then the vehicle body angle θ is 80-(
e, -e, ) / L rad ...■.

If Δy is the lateral deviation of the truck, the steering angle S can be expressed as follows.

S = K, 2Δθ to Δy+...■However, 2,
K2 is a constant.

The clear steering angle S of the truck can be determined by detecting and calculating Δy, e, . Here, the amount of deviation is arbitrarily selected from a position signal or a detection voltage determined by the arrangement of the light-receiving elements.

Once the steering angle is determined as described above, the steering motor is controlled based on this. The traveling locus of the trolley according to this control device is shown in FIG. 5, and the error is within zero.

FIG. 4 is a block diagram of the control circuit. 10
0 is a control device that generates steering and running signals based on the output from the detector, 13 is a detection device consisting of two detectors 11 and 12, 2 is a steered wheel which is a driven wheel, This steering wheel 2 is connected to a steering motor 135.

Further, 3 and 4 are left and right drive wheels, and the drive motor 124 is connected to the drive motor 124 via a speed reduction mechanism 126 including a differential gear.
Further, an encoder 125 for measuring the rotational speed of the driving wheels is connected to the speed reduction mechanism 126 .

Next, to explain the flow of signals, the detector 11.
The deflection angle signal and the lateral deflection amount signal from 12 enter the control device 100, respectively, and are sent to A/D converters 111 and 112.
The steering angle and running conditions are determined according to the processing procedure inputted to the central processing unit 101t and stored in the storage device 102 via the central processing unit 101t.

Here, a steering signal from the central processing unit w101 drives the steering motor 135 via a synchronization circuit 131, a D/A converter 132, and a control circuit 134 to steer the steering wheels 2.

On the other hand, the running signal output from the central processing unit is transmitted to the synchronization circuit 12.
1. Drive the drive motor 124 via the D/A converter 122 and the control circuit 123, and drive the drive wheels 3.4 via the speed reduction mechanism 126 including the differential gear;
Let the automated guided vehicle run.

Furthermore, the rotational speed of the driving wheels is expressed as an output of the encoder 125, and this output is fed back to the central processing unit via the pulse counter 12@, thereby stabilizing the control.

In this embodiment, the explanation has been made using one drive motor, but a two-wheel drive type with two drive motors may also be used. Route detection is not limited to the optical guidance method, but may also include an electromagnetic induction method or other methods. This method may also be used. Further, in this embodiment, a guidance method is used, but the method 11,' where the route is memorized in advance and the vehicle travels autonomously may also be used.

(F) Effect According to the present invention, since the steering angle is controlled by detecting two elements, the amount of lateral deviation from the route and the vehicle body angle, when the automatic guided vehicle deviates from the route, the steering angle can be controlled. This has the effect of making corrections and quickly returning it to the path, allowing it to run smoothly without meandering.

[Brief explanation of drawings]

FIG. 1 is a traveling trajectory of an automatic guided vehicle in a conventional example, FIG. 2 is a bottom view of an automatic guided vehicle according to the present invention, FIG. 3 is an explanatory diagram of the traveling situation of an automatic guided vehicle, and FIG. The block diagram of the control circuit, FIG. 5, shows the traveling locus of the automatic guided vehicle in the embodiment of the present invention. ■...Bogie, 2...Steering wheel, 3.4...Drive wheel, 11.12...Detector, 100...Control device patent applicant Hitachi Kiden Kogyo Co., Ltd. Agent Patent attorney Dai Takaharu Nishi Figure 1 (a) (b) Figure 2 Figure 3 Figure 4; Figure 5

Claims (1)

[Claims] (1) In a steering device for an automated guided vehicle that travels along a preset route, the angle between the lateral deviation of the automated guided vehicle with respect to the route and the center line of the automated guided vehicle in the traveling direction of the automated guided vehicle is determined, respectively. An unmanned conveyance vehicle characterized by comprising: a detection device disposed at the front and rear portions of the automatic guided vehicle for detection, and a control device that outputs a drive signal and a steering signal, respectively, based on signals from the detectors. car steering system.