JPH02120906A - Magnetic guiding system for vehicle - Google Patents

Abstract

PURPOSE:To facilitate the production of a magnetic sensor and the adjustment of attaching of the sensor to a vehicle and to improve the stability of automatic traveling of the vehicle by providing the magnetic sensor to be attached to the vehicle with a single dislocation detecting coil and a magnetic field generating means. CONSTITUTION:A magnetic field generating means 32 on the magnetic sensor 3 attached to the vehicle 1 forms space magnetic flux to be extended in the lateral direction of a magnetic mark 2 from two magnetic poles and converged into the magnetic mark 2 and a part of the space magnetic flux intersects with the single dislocation detecting coil 31. Thereby, the vehicle 1 is dislocated from the center of the magnetic mark 2, and when the magnetic sensor 3 is positioned out of the center of the mark 2, both spatial magnetic flux bands are not formed symmetrically about the center of the mark 2, similarly arranged out of the center and allowed to asymmetrically intersect with each other about the right and left of the coil 31. Thereby the polarity of the coil 31 is inverted and an output variable is changed. Consequently, the traveling state of the vehicle 1 can be detected and the dislocation of the vehicle 1 from the magnetic mark 2 can be corrected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic guidance system that enables a vehicle to automatically travel along magnetic signs installed on a vehicle travel route, and particularly relates to a magnetic guidance system attached to a vehicle that This relates to a magnetic sensor that detects markings.

[Conventional technology] Recently, in order to improve the efficiency of logistics transportation and make production systems more flexible, factories and warehouses have been using transport vehicles, towing vehicles,
In addition, the importance of unmanned transportation systems that automatically move pallets (hereinafter referred to as vehicles) is increasing.

Traditionally, the guidance methods for making vehicles run automatically and unmanned include optical methods that detect the route optically and make the vehicle travel automatically, and guidance methods that make the vehicle travel automatically by detecting the magnetic field of a guidance cable buried in the route. A magnetic field method is known.

In particular, the magnetic marking method, in which magnetic signs made of magnetic material are laid down on the driving road, a magnetic sensor is installed in the vehicle to detect the magnetic sign, and the vehicle automatically runs along the magnetic sign, is effective in reducing the effects of dirt on the driving path. magnetic signs, and it is easy to install magnetic signs.
It has excellent features such as no consumption of induced current.

Typical conventional techniques for such magnetic labeling methods are explained below.

In other words, it is known that ferrite blocks are arranged on the driving path, the arrangement information is read by a total of four magnetic sensors arranged on the front, rear, left, and right sides of the vehicle, and the vehicle automatically runs based on this arrangement information. (Unexamined Japanese Patent Publication No. 57-130
Publication No. 200).

In addition, as a magnetic sensor attached to a vehicle, a left detection coil and a right detection coil are provided which are symmetrical to the left and right in the traveling direction of the vehicle with the excitation coil as the center, and the relative outputs of these two detection coils are It is known that the position of the vehicle relative to the ferrite marker is specified based on the size relationship between the two and the vehicle automatically travels (Japanese Patent Application Laid-open No. 49409/1983).

[Problems to be Solved by the Invention] However, according to the above-mentioned prior art, it is not possible to automatically operate a vehicle based on the relative magnitude relationship between the outputs of a plurality of magnetic sensors or a plurality of detection coils provided in the vehicle. Since the vehicle is driven, the configuration of the control circuit is not only complicated and adjustment is troublesome, but also requires high precision and special skill in manufacturing the magnetic sensor, installing it on the vehicle, and adjusting it.

Moreover, since it is virtually impossible to make the individual electromagnetic performance of multiple magnetic sensors and detection coils completely the same, variations in the characteristics of individual magnetic sensors and detection coils can result in autonomous driving of vehicles. deteriorate performance.

Furthermore, when a running vehicle shakes from side to side, so-called rolling, the floor surface of the vehicle tilts from side to side, and the distances between the individual magnetic sensors or detection coils and the road surface on which the vehicle is traveling become uneven. As a result, the vehicle misinterprets the left-right sway as a deviation from its driving position from the magnetic sign, making automatic driving unstable and sometimes causing the vehicle to drive out of control.

In general, conventional techniques have unresolved problems such as destabilizing the automatic running of vehicles because they are equipped with a plurality of magnetic sensors and detection coils.

[Means for Solving the Problems] In view of the instability of automatic driving performance of vehicles based on the above-mentioned conventional technology, the present invention provides a magnetic sensor attached to a vehicle with a single positional deviation detection coil and a magnetic field generating means. , the winding surface of the winding of the positional deviation detection coil is arranged parallel to the width direction of the magnetic label, and the two magnetic poles of the magnetic field generating means are arranged a predetermined distance apart in the width direction of the magnetic label. , the center line connecting both magnetic poles and the winding axis of the positional deviation detection coil are arranged so as to intersect at right angles with a predetermined distance apart, thereby attempting to solve the above problem.

[Function] According to the configuration of the present invention, the magnetic field generating means of the magnetic sensor provided in the vehicle generates a spatial magnetic flux that extends from two magnetic poles in the width direction of the magnetic sign and is focused on the magnetic sign, and the spatial magnetic flux is Some are linked to a single misalignment detection coil.

When the vehicle normally travels along the center of the magnetic sign and the magnetic sensor is located directly above the center of the magnetic sign, the above-mentioned spatial magnetic flux has a magnetic flux distribution that is symmetrical with respect to the center of the magnetic sign. , and also symmetrically interlinks with the positional deviation detection coil located directly above the center of the magnetic label. As a result, the positional deviation detection coil does not produce an output because the induced electromotive force induced in the winding is canceled out every turn.
figure.

However, if the vehicle is misaligned from the center of the magnetic sign and the magnetic sensor is located away from the center of the magnetic sign, the spatial magnetic flux will not be symmetrical with respect to the center of the magnetic sign. Rather, it interlinks asymmetrically with the positional deviation detection coil, which is also located off-center.

As a result, an induced electromotive force is generated in the winding of the misalignment detection coil that is not canceled out every turn, and the misalignment detection coil
An output whose polarity is reversed depending on the direction of positional deviation of the vehicle and whose output amount changes according to the amount of positional deviation is generated.

Therefore, the magnetic induction system of the present invention detects the running state of the vehicle using a single positional deviation detection coil included in the magnetic sensor, corrects the positional deviation of the vehicle from the magnetic sign, and enables the vehicle to travel automatically. It works like this.

[Embodiment] The configuration and operation of an embodiment of the present invention will be explained below based on FIGS. 1 to 4.

FIG. 1 is a perspective view showing the overall configuration of a magnetic guidance system for an unmanned vehicle, which is an embodiment of the present invention.

A magnetic sign 2 is laid along the route of the unmanned vehicle 1 as a vehicle, and a magnetic sensor 3 is installed under the floor of the unmanned vehicle 1 with a predetermined gap left above the surface of the magnetic sign 2. It is being Note that the unmanned vehicle 1 is equipped with a normal traveling device, a traveling control device, etc., and a magnetic sensor 3 is connected to the traveling control device.

Each magnetic sensor 3 includes - positional deviation detection coils 31.
and magnetic field generating means 32 are provided.

The positional deviation detection coil 31 is an air-core circular coil with a winding diameter of BO mm, and an insulated copper wire with a wire diameter of 0.32+nm is wound 100 times around a cylindrical bobbin.

Further, the winding direction thereof is arranged at 1-j with respect to the sign surface of the magnetic sign 2.

The magnetic field generating means 32 has a cross section of approximately 130 square meters.
It is a cored coil in which an insulated copper wire with a wire diameter of 0.32 m + w is wound 120 times around a type ferrite core, and the length is BOm.
The cores of m are arranged to extend in the width direction of the magnetic label 2 and parallel to the magnetic label 2. The magnetic field generating means 32 is connected to the traveling control device of the vehicle 1, and the winding has a frequency of 10
A sinusoidal excitation current of 0kllz is supplied.

That is, the positional deviation detection coil 31 and the magnetic field generation means 32 are
A line connecting the winding axis of the positional deviation detection coil 31 and the magnetic poles at both ends of the core of the magnetic field generating means 32, the so-called center line of the core, intersects perpendicularly at an interval of 50 mm at the position 15III11 on the surface of the magnetic label 2, and is integral with each other. magnetic sensor 3
It consists of

The output terminal of the positional deviation detection coil 31 is connected to a running control device (not shown) that receives the output and controls the running direction, running speed, etc. of the vehicle. An excitation circuit (not shown) that supplies current is connected.

Next, the operation of the above embodiment will be explained below with reference to FIGS. 2 to 4.

FIG. 2 is a plan view showing the positional relationship between the main parts of the magnetic sensor 3 and the magnetic sign 2. When the vehicle 1 normally automatically travels along the center of the magnetic sign 2 (FIG. 2(b)), When the vehicle 1 deviates to the right from the center of the magnetic sign 2 (as shown in the same figure)
a)) and when the vehicle 1 shifts to the left (see figure (
C)) are shown respectively.

In addition, in the figure, the spatial magnetic flux is shown by a broken line for easy understanding.

The magnetic field generating means 32 of the magnetic sensor 3 generates spatial magnetic flux from both ends of the core extending in the width direction of the magnetic label 2, and the spatial magnetic flux is focused on the magnetic label 2. At the same time, part of the spatial magnetic flux is
It interlinks with a single positional deviation detection coil 31.

When the vehicle 1 is normally traveling along the center of the magnetic sign 2, the magnetic flux distribution of the spatial magnetic flux is distributed symmetrically with respect to the center of the magnetic sign 2. This spatial magnetic flux also interlinks with the positional deviation detection coil 31 symmetrically (see Fig. 2).
b)).

When the vehicle 1 deviates from the center of the magnetic sign 2 to the right, the spatial magnetic flux converging on the magnetic sign 2 is disturbed and becomes asymmetric, and the positional deviation detection coil 31 has a magnetic field generating means 3.
The magnetic flux converging on the right magnetic pole of 2 is mainly interlinked (see Figure 2(a)).

On the other hand, when the vehicle 1 is displaced to the left, the displacement detection coil 31 is mainly interlinked with the magnetic flux that focuses on the left magnetic pole of the magnetic field generating means 32 (see FIG.
c).

FIG. 3 shows the signal waveform (
Figure (a)) and the positional deviation detection coil 3 of the magnetic sensor 3
1 is a waveform diagram showing the signal waveform ((b) to (d) in the same figure) of the output S (Sc, Sr, 5JI)) of No. 1.

When the vehicle 1 is normally traveling along the center of the magnetic sign 2, the spatial magnetic flux generated by the magnetic field generating means 32 intersects the positional deviation detection coil 31 symmetrically, so that the positional deviation detection coil The induced electromotive voltage induced in the winding is canceled out every turn, and as a result, no output is generated in the positional deviation detection coil 31 (see FIG. 3(b)).

When the vehicle 1 is misaligned to the right from the center of the magnetic sign 2, the asymmetrically distorted spatial magnetic flux interlinks mainly to the right side of the misalignment detection coil 31, causing an induction that is not canceled out each time the winding turns. By inducing an electromotive force, the positional deviation detection coil 31
In this case, an output Sr having the same polarity as the excitation current waveform of the magnetic field generating means 32 and an output amount corresponding to the amount of positional deviation of the vehicle is generated (see FIG. 3(c)).

On the other hand, when the vehicle 1 is displaced to the left, the spatial magnetic flux mainly interlinks to the left of the displacement detection coil 31, induces an induced electromotive force in the winding that is not canceled out, and causes the displacement detection coil 31 to In this case, an output s4) is generated which is opposite in polarity to the excitation current waveform of the magnetic field generating means 32 and has an output amount corresponding to the positional deviation amount (see FIG. 3(d)).

FIG. 4 is a characteristic diagram showing the output characteristics of the magnetic sensor 3. The horizontal axis of the figure shows the direction of displacement of the vehicle 1 with respect to the magnetic sign 2 (g indicates the leftward displacement, and "g" indicates the displacement to the right) and the amount of displacement, and the vertical axis shows the displacement amount. The peak value V and polarity of the output waveform are shown.

According to the illustrated output characteristics, the vehicle 1 runs normally,
When the magnetic sensor 3 is located directly above the center of the magnetic sign 2, the displacement detection coil 31 does not produce an output, and when the vehicle 1 is displaced from side to side, the polarity is reversed depending on the direction of displacement. , and supplies an output to the outside with the output amount changed according to the amount of positional deviation.

Furthermore, the output characteristics have good linearity with respect to left and right positional deviations between the centers, and the positional deviation detection accuracy is high. In addition, even if the vehicle 1 loses its agility with respect to the running surface, it is not affected much.

Furthermore, the ferrite core of the magnetic field generating means 32 does not saturate in a practical range even if the excitation current value is increased, so that the positional deviation detection sensitivity of the magnetic sensor 3 can be adjusted freely.

An embodiment of the present invention has been described above, but the winding shape of the positional deviation detection coil 31 is made rectangular, the winding surface is set at a predetermined angle with respect to the extending direction of the magnetic sign 2, etc. Various modifications are also possible.

Further, various changes can be made, such as changing the material of the core of the magnetic field generating means 32 to another magnetic material, or changing the shape of the core to a U-shape.

Furthermore, it is not only possible to arrange the winding surface of the positional deviation detection coil 31 and the magnetic field generating means 32 on the same plane, but also to arrange them on different parallel planes.

[Effects of the Invention] As described above, according to the present invention, a magnetic sensor that detects a positional deviation of a vehicle from a magnetic sign has a single coil whose winding surface is parallel to the width direction of the magnetic sign. A positional deviation detection coil is provided, and the winding axis is arranged perpendicular to the line connecting the magnetic poles of the magnetic field generating means, making the structure of the magnetic sensor simple and easy to install on the vehicle. Since the amount of positional deviation can be uniquely detected, not only can the configuration of the vehicle travel control device be simplified, but also the excellent effect of significantly increasing the stability of automatic vehicle travel can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the overall configuration of an embodiment of the present invention, FIGS. 2(a) to (C) are plan views showing the positional relationship between the main parts of the magnetic sensor and the magnetic label, and FIG. 3 (a) to (d)
4 is a waveform diagram showing the excitation current waveform of the magnetic field generating means and the output waveform of the positional deviation detection coil, and FIG. 4 is a characteristic diagram showing the output characteristics of the magnetic sensor 3. 1... Vehicle 2... Magnetic sign 3... Magnetic sensor 31... Positional deviation detection coil 32...
・Representative of magnetic field generating means Tatsuo Chanoki, patent attorney Figure 1? ! Figure 2 J/: Ax deviation detection boiler 32° magnetic field generating means (a) (b) (C) 10Vs VS 4ν Director General 8FF1 Wen Yi D.1.・Is f! Indication of 1986 Patent Application No. 273079 2 Name of the invention Magnetic induction system for vehicles 3 Person making the amendment/Relationship with 19 cases Patent applicant address 2-6-3 Otemachi, Chiyoda-ku, Tokyo Name ( 6
65) Nippon Steel Corporation Representative Hiroshi Saito 44th Director (I Address: 3-4-5 Kuramae, Taito-ku, Tokyo March 6, 1999 Target of 11-11- Figure 3

Claims (1)

[Claims] 1. A magnetic sign 2 installed along the route of the vehicle 1;
In a magnetic guidance system for a vehicle that includes a magnetic sensor 3 attached to a vehicle 1 to detect a magnetic sign 2 and enable the vehicle 1 to automatically travel along the magnetic sign 2, the magnetic sensor 3 includes:
A single misalignment detection coil 31 whose winding surface is arranged parallel to the width direction of the magnetic sign 2, and two magnetic poles arranged at a predetermined distance apart from each other in the width direction of the magnetic sign 2. , a magnetic induction system for a vehicle comprising a magnetic field generating means 32 in which a center line connecting both magnetic poles is misaligned and intersects the winding axis of a detection coil 31 at a right angle with a predetermined distance therebetween. 2. The magnetic induction system for a vehicle according to claim 1, wherein the positional deviation detection coil 31 of the magnetic sensor 3 is an air-core coil, and the magnetic field generating means 4 is a coil provided with a magnetic core.