JPH10239001A - Detecting device for position of travel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately obtain a drift quantity even when a gap value is changed. SOLUTION: A pair of gap detecting coils 5a, 5b arranged above and below are installed above a pair of drift detecting coils 3a, 3b arranged in parallel on the same plane, and AC currents are fed to the gap detecting coils 5a, 5b. A metal mark plate 2 is installed on a travel road surface 1. The drift quantity (positional drift in the y-direction) between a travel device and the mark plate 2 is obtained based on the induced voltage difference of the drift detecting coils 3a, 3b. A gap value is obtained based on the induced voltage difference of the gap detecting coils 5a, 5b. The obtained drift quantity is corrected with the gap value by a gap correcting circuit 14, the corrected drift signal Szh not affected by the change of the gap value is obtained, and steering control is applied based on the corrected drift signal Szh.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling device position detecting device, and more particularly to a displacement of a traveling device (for example, a direction orthogonal to a traveling direction) when a traveling device (for example, a vehicle or a tire traveling crane) is automatically traveled. (The amount of misalignment along the line) can be accurately detected, and the installation work is simplified.

[0002]

2. Description of the Related Art In order for a traveling device to automatically travel along a traveling route, a deviation between the traveling device and the traveling route (a positional deviation along a direction orthogonal to the traveling direction) is detected.
It is necessary to steer the vehicle so as to make the detected deviation amount zero.

Conventionally, in order to detect the amount of displacement of the traveling device, as shown in FIG. 6 which is a plan view and FIG. 7 which is a front view, a guide line 01 is buried below the traveling road surface along the traveling route. A high-frequency current is passed through the induction wire 01,
A magnetic field is generated. On the other hand, the traveling device 02
A pair of search coils 03 and 04 are arranged along a direction (deviation direction: y direction) orthogonal to the traveling direction. Guidance line 0
When the magnetic field generated from 1 is linked to the search coils 03 and 04, an induced voltage is generated in the search coils 03 and 04. In addition, since the induced voltage generated in the search coils 03 and 04 changes according to the distance from the induction wire 01 as shown in FIG.
As shown in (b), it corresponds to the shift amount. The displacement amount detector 05 provided in the traveling device 02 determines the difference between the induced voltages generated in the search coils 03 and 04, and determines the displacement amount from the difference voltage.

[0004]

However, the above-mentioned prior art has the following disadvantages. (1) In order to draw the guide line 01 below the traveling road surface, burying work is necessary in advance, and this burying work takes a lot of trouble. (2) When the guide wire 01 is additionally installed, it is necessary to dig a concrete road surface, and traveling is impossible during this construction period. (3) If the road surface sinks, the guide line 01 may be cut, and the position shift may not be detected.

[0005] In view of the above prior art, the present invention can accurately detect the amount of displacement, and can eliminate the guide wire, and can be used as an object to be identified (in the prior art, a guide wire, but in the present invention, a metal mark ( It is an object of the present invention to provide a traveling device position detecting device that can easily perform the marking plate) and that does not cause trouble such as breakage even if the ground subsides.

[0006]

According to a first aspect of the present invention, there is provided a first coil group in which two coils are juxtaposed in a traveling device on a same plane along a direction orthogonal to a traveling direction. And a second coil group provided with two coils above and below the first coil group, and connecting the respective coils of the first coil group and the second coil group to a bridge circuit, An AC voltage applying means is provided for the coils of the second coil group, and an induced voltage generated in each coil of the first coil group when the traveling device travels on a metal mark provided on a predetermined path on a traveling road surface. The difference between the mark and the traveling device along the direction perpendicular to the traveling direction is detected based on the difference between the marks, and the difference between the induced voltages generated in the coils of the second coil group is detected based on the difference between the marks. Circuit means for detecting a gap value that is a distance between a traveling device and the mark, and correcting the shift amount based on the detected gap value to obtain a corrected shift amount that eliminates the influence of the gap. .

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a traveling device position detecting device according to the present embodiment from the front side. The traveling device itself is not shown.

As shown in FIG. 1, on a traveling road surface 1 on which a traveling device travels, mark plates 2 are arranged (attached) along a traveling route (along a direction perpendicular to the paper surface of FIG. 1) in a point array. ) Has been. The mark plate 2 is a metal plate and has a circular or rectangular shape. In FIG. 1, reference numeral 2 "denotes the position of the travel device and the mark plate when the travel device is displaced in the shift direction (y direction: left / right direction).

FIG. 1 shown from the front side and FIG. 2 shown in a plan view
As shown in (1), the traveling device is provided with a pair of displacement detection coils 3a and 3b that form a first coil group. The displacement detecting coils 3a and 3b are rectangular coils, and are arranged on the same plane along the displacement direction y. The displacement detecting coils 3a and 3b are connected in series and also connected to the resistors 4a and 4b to form a bridge circuit.

The traveling device is provided with a pair of gap detection coils 5a and 5b that form a second coil group above the first coil group (displacement detection coils 3a and 3b). The gap detection coils 5a and 5b are rectangular coils, and are configured by disposing the gap detection coil 5a on the lower side and disposing the gap detection coil 5b on the upper side. Moreover, the gap detection coils 5a and 5b are wider than the deviation detection coils 3a and 3b in the deviation direction y (two to three times the width of the deviation detection coils 3a and 3b). The detection coils 3a and 3b are covered above. The gap detection coils 5a and 5b are connected in series and also connected to the resistors 6a and 6b to form a bridge circuit. The AC power supply 7 is provided to the gap detection coils 5a and 5b arranged vertically (two-tiered).
, An AC voltage is applied.

The balance circuit 8 includes a shift detecting coil 3a,
It is connected to a bridge circuit composed of 3b and resistors 4a and 4b, cancels the offset generated in the displacement detection coils 3a and 3b, and outputs the offset canceled displacement signal Sz. Note that the displacement signal Sz is a difference voltage between the induced voltage generated by the displacement detection coil 3a and the induced voltage generated by the displacement detection coil 3b. Amplifier 9
Amplifies the deviation signal Sz and sends it to the peak detection circuit 10. The peak detection circuit 10 detects the maximum value (positive maximum value) or the minimum value (negative maximum value) of the shift signal Sz.

The balance circuit 11 is connected to a bridge circuit composed of the gap detection coils 5a and 5b and the resistors 6a and 6b, cancels the offset generated in the gap detection coils 5a and 5b, and generates the offset canceled gap signal Sg. Is output. The gap signal Sg is a difference voltage between the induced voltage generated by the gap detection coil 5a and the induced voltage generated by the gap detection coil 5b. The amplifier 12 amplifies the gap signal Sg and sends it to the peak detection circuit 13. Peak detection circuit 13
Detects the maximum value of the gap signal Sg.

The gap correction circuit 14 generates a gap signal S
Based on g, the value of the shift signal Sz is corrected, and a corrected shift signal Szh is output.

The operation and operation of the traveling device position detecting device according to the present embodiment having the above-described configuration will be described.

In the present embodiment, the gap detecting coil 5
An AC magnetic field is generated from gap detection coils 5a and 5b by applying an AC voltage to a and 5b and flowing an AC current. When the metal mark plate 2 is located below each coil, the AC magnetic field acts on the mark plate 2 (magnetic flux penetrates) and an eddy current flows through the mark plate 2, and the eddy current weakens the AC magnetic field. Is generated, and the magnetic field (magnetic flux amount) linked to the coil is reduced. In this case, the magnetic field (magnetic flux amount) linked to the coil decreases in proportion to the projected area of the mark plate 2 with respect to the coil.

Therefore, when the mark plate 2 is located below the displacement detecting coil 3a, the displacement detecting coil 3a
The magnetic field (the amount of magnetic flux) linked to the coil 3a decreases, and the induced voltage generated in the coil 3a decreases. In addition, the displacement detection coil 3
When the mark plate 2 is located below the position b, the magnetic field (the amount of magnetic flux) linked to the displacement detection coil 3b decreases, and the induced voltage generated in the coil 3b decreases. Although the details will be described later, the displacement amount (displacement detection signal Sz) of the traveling device is detected from the difference between the induced voltages of the displacement detection coils 3a and 3b.

Similarly, when the mark plate 2 is located below the gap detection coils 5a and 5b, the magnetic field (the amount of magnetic flux) interlinking the gap detection coils 5a and 5b decreases, and The induced voltage generated in 5a and 5b decreases. In this case, the upper gap detection coil 5b
Since the lower gap detection coil 5a is closer to the mark plate 2 as compared with the above, the decrease in magnetic flux in the lower gap detection coil 5a is larger than that in the upper gap detection coil 5b, and the upper gap detection coil The induced voltage of the lower gap detection coil 5a is smaller than the induced voltage of the coil 5b. Although the details will be described later, the size of the gap (the distance between the coil and the traveling road surface) is detected from the difference between the induced voltages of the gap detection coils 5a and 5b.

Next, a method of detecting a shift amount, a method of detecting a gap value, and a method of correcting by the traveling device position detecting device according to the present embodiment will be specifically described.

First, a method of detecting a shift amount will be described with reference to FIG. Note that FIG. 3 shows a state where the mark plate 2 is relatively moved from the left side to the right side with respect to the coils 3a, 3b, 5a, 5b.

In FIG. 3, when the mark plate 2 is located at the position (A) on the left side of the displacement detecting coil 3a, the induced voltages generated in the displacement detecting coils 3a and 3b become the same, and both induced voltages become equal. The voltage difference (voltage value corresponding to the deviation signal Sz) becomes zero. When the mark plate 2 reaches a position below the displacement detection coil 3a, an eddy current begins to flow through the mark plate 2 and the magnetic flux linked to the detection coil 3a starts to decrease, and the displacement signal Sz increases. Mark plate 2 is misalignment detection coil 3
When the mark plate 2 is located at the position (B) just below
A large eddy current flows and the magnetic flux linked to the displacement detection coil 3a is minimized, the induced voltage of the displacement detection coil 3a is minimized, and the displacement signal Sz is maximized. When the mark plate 2 is located at the position (C) between the displacement detection coils 3a and 3b, the gap detection coils 3a,
The induced voltage of 3b becomes the same, and the displacement signal Sz becomes zero.

When the mark plate 2 is located at the position (D) immediately below the displacement detecting coil 3b, the induced voltage of the displacement detecting coil 3b becomes minimum, and the displacement signal Sz becomes minimum (negative maximum). When the mark plate 2 is located at the position (E) on the right side of the displacement detection coil 3b, the displacement signal Sz
Becomes zero.

As described above, the displacement of the gap detection coils 3a and 3b (that is, the traveling device) with respect to the mark plate 2 is as follows.
It corresponds to the shift signal Sz, and the shift amount (that is, the shift amount in the y direction with respect to the mark plate 2) can be detected based on the shift signal Sz.

Next, a method of detecting a gap value will be described. The gap value is a distance between the lower end surface of the displacement detection coil 3a and the traveling road surface. As shown in FIG. 3 (4), the magnetic field generated by the gap detection coils 5a and 5b is y
The directions are almost the same. The eddy current flowing through the mark plate 2 (2 ") is determined by the magnetic field generated by the gap detection coils 5a and 5b and the gap value.
When the mark plate 2 is located below 5b, the magnetic field demagnetized by the eddy current becomes constant.

As described above, the gap detection coils 5a,
5b, the mark plate 2 is positioned below the mark plate 2b.
Since the magnetic flux caused by the eddy current generated on the upper side shift detection coil 5b acts more on the lower side shift detection coil 5b than on the upper side shift detection coil 5b, the magnetic flux of the lower shift detection coil 5a lower than the induced voltage of the upper shift detection coil 5b. The induced voltage is smaller. This voltage difference changes according to the gap value. That is, FIG.
As shown in (1), when the gap becomes small, the ratio of the magnetic flux due to the eddy current acting on the lower displacement detection coil 5a increases, and the induced voltage of the displacement detection coil 5a decreases. , 5b, which is the difference between the induced voltages, becomes large. Conversely, when the gap increases, the rate at which the magnetic flux due to the eddy current acts on the lower displacement detection coil 5a decreases, and the induced voltage of the displacement detection coil 5a decreases, and the induced voltages of the displacement detection coils 5a and 5b decrease. The gap signal Sg, which is the difference between the two, becomes smaller. Therefore, the gap value can be detected from the magnitude of the gap signal Sg.

Next, a description will be given of a correction method for correcting the shift amount (shift signal Sz) based on the gap value (gap signal Sg). When the mark plate 2 is below the gap detection coils 5a and 5b, the value of the gap signal Sg changes only by a change in the gap value even if there is a deviation, and FIG.
As shown in the figure, the value changes in inverse proportion to the gap value. The shift signal Sz changes in inverse proportion to the gap value as shown in FIG. 4B, but the form of the signal accompanying the shift hardly changes.

Therefore, if the ratio (Sz / Sg) between the shift signal Sz and the gap signal Sg is calculated, as shown in FIG. 4C, the corrected shift signal Szh which is not affected by the change in the gap value. Is obtained. Gap correction circuit 14
Performs such a calculation and outputs a correction shift signal Szh which is not affected by a change in the gap value.

Next, a signal form when the traveling device position detecting device according to the embodiment of the present invention travels on the mark plates 2a to 2d arranged as shown in FIG. explain. As shown in the figure, when the center of the detection device comes on the mark plate, the gap signal Sg becomes the maximum, and the shift signal Sz changes according to the shift amount (the shift amount in the y direction) from the mark traveling direction (x direction). Although it changes in the plus direction or the minus direction, its absolute value becomes maximum at the maximum value point (the center of the mark plate in the x direction) of the gap signal Sg.

Therefore, in the embodiment of the present invention, the maximum value of the gap signal Sg is fetched by the peak detection circuit 13, and the peak value of the shift signal Sz is fetched by the peak detection circuit 10 at this timing. The gap correction circuit 14 corrects the shift signal Sz based on the gap signal Sg, and outputs a corrected shift signal Szh that is not affected by a change in the gap value.

The thus obtained correction shift signal Szh
Since the deviation accurately represents the deviation amount without being affected by the gap value, by performing the steering control based on the corrected deviation signal Szh, it is possible to perform automatic traveling while performing excellent steering control.

[0030]

As described above in detail with the embodiments, in the present invention, the first coil is provided on the traveling device by arranging two coils side by side on the same plane along the direction perpendicular to the traveling direction. A coil group; and a second coil group having two coils provided above and below the first coil group, and each of the first and second coil groups is connected to a bridge circuit. In addition, an AC voltage applying means is provided for the coils of the second coil group, and is generated in each coil of the first coil group when the traveling device travels on a metal mark installed on a predetermined path on the traveling road surface. Based on the difference between the induced voltages, the amount of deviation between the traveling device along the direction perpendicular to the traveling direction and the mark is detected, and the induced voltage generated in each coil of the second coil group is detected. A configuration including a circuit unit that detects a gap value that is a distance between the traveling device and the mark based on the difference, and corrects the deviation amount based on the detected gap value to obtain a corrected deviation amount that eliminates the influence of the gap. And

As described above, according to the present invention, the gap value and the displacement amount can be detected simultaneously by installing the mark plate on the traveling road surface and integrating the displacement detection coil and the gap detection coil. By correcting the received shift signal based on the gap value, it is possible to prevent the shift detection accuracy from being lowered due to the gap change, and to detect the shift with high accuracy. That is, even if there is a gap change, the displacement can be detected without being affected by the gap change.

Further, since the mark plate (metal mark) is installed on the traveling road surface, unlike the conventional guide wire, even if it is additionally installed, it is not necessary to dig the road surface and the installation is easy. Also, even if there is land subsidence or the like, it is not cut, and the reliability is high.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a traveling device position detection device according to an embodiment of the present invention from the front side.

FIG. 2 is a configuration diagram showing a coil portion in the present embodiment in a plan view.

FIG. 3 is an explanatory diagram showing a coil portion and a signal state according to the embodiment.

FIG. 4 is an explanatory diagram showing a coil portion and a signal state according to the embodiment.

FIG. 5 is an explanatory diagram showing a traveling route and a signal state of the traveling device according to the embodiment.

FIG. 6 is a plan view showing a conventional technique.

FIG. 7 is a front view showing a conventional technique.

FIG. 8 is a characteristic diagram showing a signal state according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Road surface 2,2 "mark board (metal mark) 3a, 3b Deviation detection coil 4a, 4b Resistance 5a, 5b Gap detection coil 6a, 6b Resistance 7 AC power supply 8,11 Balance circuit 9,12 Amplifier 10,13 Peak Detection circuit 14 gap correction circuit y shift direction z traveling direction Sz shift signal Szh correction shift signal Sg gap signal

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshimi Oda 4-2-2 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Inside the Hiroshima Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Toshio Taguchi 4-chome Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture No. 6-22 Mitsubishi Heavy Industries, Ltd. Hiroshima Works

Claims (1)

[Claims] 1. A first device comprising a traveling device and two coils arranged in parallel on a same plane along a direction orthogonal to a traveling direction.
A coil group, and a second coil group including two coils provided above and below the first coil group, and each of the first and second coil groups is connected to a bridge circuit. AC voltage applying means is provided for the coils of the second coil group, and is generated in each coil of the first coil group when the traveling device travels on a metal mark provided on a predetermined path on a traveling road surface. Detects the amount of deviation between the traveling device and the mark along the direction perpendicular to the traveling direction based on the difference between the induced voltages, and detects the deviation between the traveling device and the traveling device based on the difference between the induced voltages generated in each coil of the second coil group. Circuit means for detecting a gap value, which is a distance from the mark, and for correcting a shift amount based on the detected gap value to obtain a corrected shift amount by removing the influence of the gap. Traveling device position detecting device characterized by comprising.