JPS62266606A - Guide system for unattended carriage - Google Patents

Abstract

PURPOSE:To detect systems both for running guide and for auxiliary control by widening the prescribed spot part of a ferrite marker with a constant width provided as guide marker, and detecting the systems according to a change in the output voltage of a detection coil. CONSTITUTION:The ferrite marker 2 with a constant width is continuously provided along the running path of an unattended carriage 1, and a widening part 21 is provided on the spot of increasing and decreasing the speed and the spot of stopping or branching. Detection devices 3 and 4, which are provided with a left detection air core coil 7 and a right detection air core coil 8 with an excitation air core coil 6 generating a magnetic flux by an excitation from a high-frequency oscillator as a center, are provided in front and behind the unattended carriage 1. The widening part 21 detects that the output voltage of the left detection air core coil 7 and the right detection air core coil 8 are equal and that the voltage level increases compared to the part of the ferrite guiding body 2 with a constant width, and attains auxiliary (acceleration/ deceleration, stop, branch, etc.,) signals from the change.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a guidance system for automatic guided vehicles used mainly for transporting cargo within premises such as factories and warehouses.

(Prior Art) In recent years, automatic guided vehicles have been widely adopted from the viewpoint of streamlining cargo transportation, and various guidance systems have been put into practical use.

Among these, for example, Japanese Patent Application Laid-Open No. 57-130200 (Automatic Driving Control System for Vehicles) and Japanese Patent Application No. 1891-1982
As disclosed in Publication No. 26 (Detection device for ferrite markings), ferrite markings of a certain width are laid along the driving route, and magnetic flux is generated by excitation from a high-frequency oscillator attached to the vehicle. The guidance system, which guides the vehicle while detecting changes in the magnetic field using a so-called 3-coil sensor that is installed with one coil and two detection coils engaged, is attracting attention because of its economic efficiency and ease of maintenance. has been done.

[Problem that the invention seeks to solve]

In the guidance system for automated guided vehicles, in addition to the guidance markings that guide the vehicle along a ferrite marking of a certain width,
Auxiliary markers are placed at necessary points to accelerate or decelerate the vehicle, stop it, enter or exit a curved road, freeze or branch steering control, and detect it with a detection device mounted on the vehicle to control the vehicle. .

This auxiliary marker is separated from the guiding marker and its detection device by a different means, such as optical detection, to avoid mutual interference.

Therefore, the detection device on the vehicle side becomes complicated, and there is a drawback that it is difficult to install the detection device of the auxiliary marker at a suitable position.

The present invention has been improved in view of the above points, and provides an automatic guided vehicle that is simple and highly accurate by easily detecting both vehicle travel guidance and auxiliary control such as acceleration, deceleration, and stopping. The purpose is to provide a guidance system.

(Means for Solving the Problems) As a means for solving the above-mentioned problems, the present invention provides ferrite markings of a constant width laid along the driving route as guidance markings for acceleration, deceleration, and stopping of vehicles. The output voltage of two detection coils at that point can be simultaneously increased to a large level by widening the predetermined point where the detection is performed, etc., and using the detection device of the guidance sign for vehicle running, without separately providing a detection means for the auxiliary sign. The feature is that it is detected by a jump change.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

FIG. 1 and FIG. 2 show the ferrite labeled body according to the present invention.
This is an explanatory diagram showing the entire guidance system of an automatic guided vehicle equipped with a detection device, in which ferrite markings 2 of a certain width are continuously laid along the travel path of the automatic guided vehicle 1, and are used to accelerate, decelerate, stop, or branch. It has widened portions 21 at certain points.

On the other hand, detection devices 3.4 for detecting the ferrite marker 2 and its widened portion 21 are mounted approximately in the center of the front and rear portions of the automatic guided vehicle 1, respectively.

The detection devices 3.4 are the same and are activated depending on the direction of travel of the automatic guided vehicle. In other words, the direction of travel is F
If the vehicle is traveling in the opposite direction, the detector @3 is activated, and if the vehicle is traveling in the opposite direction, the detector 4 is activated.

The configuration of the detection devices 3 and 4 is a so-called 3-coil sensor as shown in FIGS.
Left and right detection air-core coils 7 and 8 are disk-shaped left and right detection air-core coils 8 on the left and right with respect to the direction of travel of the vehicle, centering on a square plate-shaped excitation air-core coil 6 that generates magnetic flux by excitation from a magnet (as shown in the figure). are respectively provided in a predetermined manner with the excitation air-core coil 6. The left detection air-core coil 7 and the right detection air-core coil 8 are each connected to an amplifier 9 (shown in FIG. 2).

The amplifier 9 amplifies the signal output from the left detection air-core coil 7 and the right detection air-core coil 8, and outputs the signal from the ferrite labeled body 2.
deviates from the center of the vehicle body of the automated guided vehicle 1, the left steering control device @10 (shown in Figure 2) or the right steering control device 11 (
(Illustrated in Figure 2). This changes the rotational speed of either the left drive motor 12 (shown in FIG. 2) or the right drive motor 13 (shown in FIG. 2).

That is, steering is performed by creating a difference in the rotational speed of the left and right running wheels 14, 15.

If the distance from the ferrite marker 2 to the excitation air-core coil 6 and the specifications of the ferrite marker detection device 3.4 are selected as shown in Table 1, the deviation of the excitation air-core coil 6 in the width direction of the ferrite marker 2 The output change characteristics are as shown in FIG.

Table 1 In other words, for the width direction distance of the left half of the running center line of the ferrite marker 2, the output of the left detection air-core coil 7 is always greater than the output of the right detection air-core coil 8, and the output of the right detection air-core coil 7 is always greater than the output of the right detection air-core coil 8. 8 decreases monotonically, and for the width direction distance of the right half, the output of the air-core coil 8 for right detection is always larger than the output of the air-core coil 7 for left detection, and the output of the air-core coil 7 for left detection town is decreasing monotonically. Further, on the center line of the ferrite marker 2, the outputs of the right detection air-core coil 8 and the left detection air-core coil 7 are equal.

Viewed as a whole, the output diagrams of the left detection air-core coil 7 and the right detection air-core coil 8 have the same substantially trapezoidal shape and overlap in the center.

For example, the output SL (y) of the left detection air-core coil 7 is 5L.
(V2>, the output SR(y) of the right detection air-core coil 8 is S
If it is obtained as R<V2), then SL (￥2
)>SR(V2), it can be detected that the excitation air-core coil 6 is y2 minutes &i odd to the right of the center of the ferrite marker 2.

Therefore, in this case, the rotational speed of the left traveling wheel 14 may be instructed to be lower than the rotational speed of the right traveling wheel 15.

Next, the output characteristics of the detection device at the widened portion 21 of the ferrite marker 2 will be explained with reference to FIGS. 6 and 7.

FIG. 6 is an enlarged view of the widened portion 21, and shows Bit!
The width dimension at point i, ie, c13 of the widened portion 21, is approximately three times as large as that at point A.

Figure 7 shows the output characteristics of the detection device.
The output voltage characteristics at the point are SL as explained above.
(y) and SR(y), but at point B of the widening section, they change to SSL (y) and SSR(y).

This is because the total amount of magnetic flux increases greatly by widening the ferrite label.

Therefore, for example, if the center of the excitation air-core coil 6 of the detection device and the center of the ferrite marker 2 are misaligned and the center of the excitation air-core coil 6 is at yn, then at point A, the left detection air-core coil 7 and the right The output voltages of the detection air-core coil 8 are 5L (Vn) and 5R (Vn), respectively, and 5R (
Vn) > 5L (Vn), but when they reach point B, the output voltages of the left detection air-core coil 7 and the right detection air-core coil 8 become SSL (Vn) and 88R(
Vn), and SSL (yn)=SSR(Vn
). and SSL(yn)=SSR(Vn)
>SR(Vn) >SL(Vn).

That is, at point B of the widened part, the output voltages of the air-core coil 7 for left detection and the air-core coil 8 for right detection are both equal, and the voltage level is increased compared to point A. ) can be identified as a signal.

If the center of the excitation air-core coil 6 coincides with the center of the ferrite marker 2, SL (Vo) at point A
=SR(yo), and at point B, SSL(Vo
)=SSR(Vo). And 881 (Vo
)=SSR(Yo)>SL(Vo)=SR(V
o), it can be determined that there is a widened portion.

Note that the voltage level in the widened portion 21 in this case is preferably set to twice or more that in the normal case.

Then, the automatic guided vehicle 1 detects the widened portion 21 and stops.
Acceleration and deceleration are performed, but it is stored in advance at which widened portion the vehicle is to be stopped.

Note that by changing the width of the widened portion of the ferrite marker, the thickness of the ferrite marker, or the magnetic permeability, the voltage level can be controlled as an absolute address by varying the voltage level for stopping, accelerating, decelerating, branching, etc.

Further, in the above embodiment, an air-core coil was used as the detection device, but an iron-core human coil may also be used.

〔Effect of the invention〕

As explained above, in the automatic guided vehicle guidance system according to the present invention, the ferrite marking body is provided with an enlarged part to obtain the output characteristics as shown in FIG. Since both of the auxiliary controls such as stopping and branching are easily detected and controlled, a highly reliable, simple and economical guidance system is obtained.

[Brief explanation of drawings]

Figures 1 and 2 show the entire guidance system for an automatic guided vehicle equipped with a ferrite marker detection device according to the present invention. Figure 1 is a perspective view of the entire system, and Figure 2 shows a control mechanism. Figure 3 is a front view of the ferrite 8X detection device, Figure 4 is a plan view, Figure 5 is a diagram showing the output characteristics of the ferrite marker detection device, and Figure 6 is an enlarged view of the ferrite marker. (■ is a plan view, (b) is a side view, and FIG. 7 is a diagram showing the output voltage characteristics at the widened part. 1... Automatic guided vehicle 2... Ferrite mark body 21
... widening part 3.4 ... detection device for ferrite marker 2 5 ... high frequency oscillator 6 ... air-core coil for excitation 7 ... air-core coil for left detection 8 ...
Air link for right detection, 9...Amplifier 10...
・Left steering control device 11...Right steering control device 1
2...Left drive motor 13...Right drive motor
, 14...Left running wheel 15...Right running wheel Patent applicant: NEC Co., Ltd.
Patent attorney representing Nippon Sharyo Manufacturing Co., Ltd.
Hiroshi Kido Room
Kido - intention
Makoto Ogawa - Fig. 1, Fig. 2, Upper Section, Section 3, Section 4, Section 5

Claims (1)

[Claims] 1. A ferrite marker of a certain width is laid along the driving path, and a total of three markers are engaged: one excitation coil and two detection coils that generate magnetic flux through excitation from a high-frequency oscillator attached to the vehicle. In a guidance system for an automated guided vehicle that guides the vehicle while detecting the ferrite marker using a coil sensor detection device installed in 1. A guidance system for an automatic guided vehicle, characterized in that the width of the detection coil is widened and the detection device determines this by a change in which the output voltages of two detection coils simultaneously become large.