JPH0212409A - Magnetic induction system - Google Patents

Abstract

PURPOSE:To surely detect the deviation of the running direction of a vehicle to control the running direction by providing a magnetic detecting means which is wound symmetrically with respect to the middle between both ends of a magnetic field generating means provided with magnetic poles in both ends in the breadthwise direction of a magnetic marker. CONSTITUTION:When the vehicle is left or right deviated from the running center line of a magnetic marker 7, the magnetic flux generated from one magnetic pole of a core 2 crosses a magnetic detecting coil 5 and reaches the magnetic marker 7. The magnetic flux generated from the other magnetic pole less crosses the magnetic detecting coil 5 or does not cross it. As the result, an output signal is generated in the magnetic detecting coil 5 in accordance with the change of the crossing magnetic flux. That is, the output signal where the polarity is inverted is obtained from the magnetic detecting coil 5 in accordance with the direction in which the vehicle is deviated from the running center line of the magnetic marker 7. Thus, the running position deviation of the vehicle is corrected.

Description

Detailed Description of the Invention ((Industrial Application Field) The present invention is directed to 2) controlling the movement of a vehicle such as an unmanned vehicle operated unmanned, or a semi-submerged transport vehicle such as a pallet (hereinafter collectively referred to as a vehicle). , relates to a magnetic induction system for guiding.

(Prior art) In order to guide vehicles, magnetic signs made of magnetic materials such as ferrite are installed on or under the road surface along the vehicle driving course, and the positional deviation of the vehicle from the magnetic signs is detected. ,
For example, Japanese Patent Application Laid-open No. 57 (1983) describes how to make a vehicle run automatically by detecting it with a plurality of magnetic sensors mounted on the vehicle.
It is publicly known from the publication No.-130200. Japanese Patent Application Laid-Open No. 62-49409 discloses that a detection device for detecting a marker is equipped with an excitation air-core coil that generates magnetic flux by excitation from a high-frequency oscillator, and a vehicle is moved with the excitation air-core coil in the center. On the left and right sides of the direction, a left detection air-core coil for detecting a positional deviation to the left and a right-detecting air-core coil for detecting a positional deviation to the left are provided symmetrically and overlapping the excitation air-core coil. It is shown. With this detection device, when the vehicle deviates from the center line of travel of the ferrite marker in the left half width direction, the output signal amount of the left detection air-core coil is always smaller than the output signal amount of the right detection air-core coil. Therefore, when the right half is displaced in the width direction, the output signal amount of the right detection air-core coil becomes smaller than the output amount of the left detection air-core coil. Therefore, based on the opposite action performed by each detection air-core coil in response to left and right positional deviations, and furthermore, based on the fact that the output signal amount of each left and right detection air-core coil is equal on the center line, it is possible to determine the vehicle's running position. I'm trying to correct the discrepancies.

(Problem to be Solved by the Invention) However, the above means uses a first-order method to detect a deviation in the running position of the vehicle by comparing the output signal amounts of the left detection air-core coil and the right detection air-core coil. There were some challenges.

That is, (1) the left and right detection air-core coils must have the same electromagnetic characteristics;

It must be placed correctly and symmetrically with respect to the excitation air-core coil. However, in order to perform good running direction control, highly accurate magnetic detection is essential, and with normal mechanical precision it is difficult to balance the output characteristics of the left and right detection air-core coils.

In addition to this problem (1), (2) the left and right detection air-core coils, when deviated from the edge of the magnetic marker,
The signal level is gradually reduced according to the amount of deviation, so
The level of the output signal obtained by comparing the output signal amounts of the left and right detection air-core coils also changes gradually in accordance with the deviation in the running position of the vehicle. For this reason, it has been impossible to improve the accuracy with respect to deviations between the left and right running paths, and it has been difficult to control the running direction favorably. Furthermore, (3) the characteristics of the peripheral circuits that calculate and amplify the output signals of each detection air-core coil usually vary by a few percent, making it impossible to accurately adjust left and right for deviations in the running track. It is not possible to completely avoid the risk of the situation going out of control. There were other issues.

(Means for Solving the Problems) The present invention solves the problems in the prior art, and includes a magnetic sign of a predetermined width provided along a lane for one vehicle, and a magnetic sign mounted on a vehicle. and a magnetic field generating means having magnetic poles at both ends in the width direction.

A magnetic label system characterized by a magnetic detection means having a magnetic detection means with a single coil winding placed parallel to the magnetic field generation means and wound symmetrically about midway between the ends of the magnetic field generation means. It is something.

The present invention will be explained below with reference to the drawings. FIG. 1 is an explanatory diagram of the system of the present invention, where 1 is an oscillator, and 2 is a core having a pair of magnetic poles at both ends made of a magnetic material such as ferrite. This core has 1 oscillator l and an excitation coil 3 connected to it.
is wound.

4 is a winding frame provided close to and parallel to the core 2;
A magnetic detection coil 5 is wound around the winding frame 4 in a direction parallel to the axial direction of the core 2 and the surface of a magnetic marker 7 provided on the travel path. 6 is a terminal of the coil, and this core 2. Excitation coil 31 winding frame 4° Magnetic coil 5 is a vehicle (not shown)
It is installed in.

(Function) Next, the function of the present invention will be explained with reference to FIGS. 1 and 2. In addition, in FIG. 2, the horizontal axis represents the amount of deviation (ΔL) of the vehicle from the center line of travel, and the vertical axis represents the output signal 1 (V) of the air bleed detection coil 5.

When the vehicle is placed on the center line of the magnetic sign 7 in the traveling direction and the oscillator 1 is operated, the core 2 around which the excitation coil 3 is wound is excited, and as a result, the magnetic sign 7 is emitted from the magnetic poles at both ends of the core 2. Magnetic fluxes directed in opposite directions to each other are generated, and a spatial magnetic field is formed [indicated by broken lines in FIG. 1(b)]. Therefore.

When the vehicle is located on the running center line of the magnetic sign 7, induced currents that cancel each other out occur in the magnetic detection coils interlinking the magnetic flux, and no output signal is generated at the terminal 6 of the magnetic detection coil 5 ( (See symbol A in Figure 2).

Next, the case where the vehicle deviates to the left or right from the center line of travel of the magnetic sign 7 will be explained [Fig. 1 (a) (c)
)reference〕. The magnetic flux generated from one of the magnetic poles of the core 2 interlinks with the magnetic detection coil 5 and reaches the magnetic label 7. The magnetic flux generated from the other magnetic pole has less or no linkage with the magnetic detection coil 5. As a result, an output signal is generated in the magnetic detection coil 5 in response to changes in the interlinking magnetic flux.

That is, an output signal with reversed magnetism is obtained from the magnetic detection coil 5 in accordance with the direction in which one vehicle deviates from the traveling center line of the magnetic sign 7. In addition, the drive signal (E) of the excitation coil 3
Waveform 5 Phase and output signal of magnetic detection coil 5 (S
) are shown in FIGS. 3(a) and 3(b).

In this way, the present invention allows the output of the magnetic detection coil 5 to be adjusted to the zero point cross signal, so that the vehicle can detect the magnetic marker (
Deviation from trajectory) 7 can be detected quickly and accurately. Also, the amount of deviation of the vehicle from the magnetic sign 7 (△
Amount of change (ΔV) in the output signal with respect to L), (ΔV/ΔL
), it is possible to perform highly accurate vehicle driving control. Furthermore, by detecting the phase change of the output signal (S) of the magnetic detection coil 5 with respect to the drive signal (E) of the excitation coil 3, the vehicle.

Since it is possible to detect whether the vehicle is deviated to the left or right with respect to the center line of travel, there is no need to use multiple detection coils as in conventionally known methods.

Since only a single coil is required, it is mechanically simple.

(Example) As a magnetic detection coil, a wire diameter of 0.3 is placed on a winding frame with an outer diameter of 60 mm.
A 2 mm copper wire wound with 10 turns per turn was used. In addition, the excitation coil is 3.5 mm long, 15.5 mm wide,
It was constructed by winding a 132 mmΦ copper wire 80 times around a rod-shaped ferrite core having a length of 60 mm.

Furthermore, as a magnetic marker, the width is 5Qmm, and the material is Fe5llN.
An amorphous magnetic alloy ribbon consisting of 12°crsB+zc<(atomic %) was used and laid along the running path. The distance between the magnetic label and the magnetic detection coil was adjusted to 18.25 mm. When an alternating current signal of 100 kHz was supplied from the oscillator to the excitation coil, output signals as shown in FIG. 2 were detected in the magnetic detection coil as the signal gradually moved away from the center of the magnetic marker. As is clear from this figure, the output signal generated from the magnetic detection coil is a zero-point cross signal with an output value of zero when the vehicle is located on the center line of travel, so that the left-right shift of the vehicle can be detected with high accuracy. As a result, the vehicle can be accurately controlled against deviations in the direction of travel, allowing it to run away.

We were able to completely prevent the runaway.

In addition, in the description of the above embodiment, the core forming the excitation coil is rod-shaped, but the shape of the core is not limited to the rod-shape, and may be, for example, U-shaped. Further, the outer diameter of the magnetic detection coil and the core length of the excitation coil do not necessarily have to be equal. Furthermore, in the description of the above embodiment, an alternating current signal is applied to the excitation coil to generate a magnetic flux of a constant frequency, but the present invention is not limited to this. A detection signal may be detected when the vector direction of the magnetic flux interlinking the magnetic detection coil changes in accordance with the left-right deviation of the vehicle from the center line of the magnetic sign.

(Effects of the Invention) As explained above, the present invention can reliably detect deviations in the running direction of a vehicle and control the running direction. Moreover, since it is mechanically simple, it is extremely effective when applied to unmanned vehicles.

[Brief explanation of the drawing]

FIGS. 1(a), (b), and (c) are explanatory diagrams of the system of the present invention. 2 and 3(a) and 3(b) are clear diagrams showing the operation of the present invention. 1; Oscillator; 2; Rod-shaped core; 3; Excitation coil 4; Winding frame;
5: Magnetic detection coil, 6; Terminal 7; Magnetic label, E;
Excitation coil drive signal S; output signal of the magnetic detection coil. Patent applicant Nippon Steel Corporation

Claims (2)

[Claims] (1) A magnetic sign with a predetermined width provided along a vehicle running route, a magnetic field generating means mounted on the vehicle and having magnetic poles at both ends in the width direction of the magnetic sign, and a magnetic field generating means parallel to the magnetic field generating means. 1. A magnetic induction system having a magnetic detection means with a single coil winding located at and wound symmetrically about the middle of the ends of the magnetic field generating means. (2) The magnetic induction system according to claim 1, wherein the coil winding of the magnetic detection means is wound on a winding surface that interlinks magnetic flux directed toward the magnetic label from each magnetic pole at both ends of the magnetic field generation means. .