JPH0914959A - Method for detecting position - Google Patents

Abstract

PURPOSE: To provide a method for detecting position by which the direction to an object to be measured from an arbitrary observation point can be accurately detected with a high efficiency without requiring much labor. CONSTITUTION: First and second transmission coils 16 and 17 having magnetic field transmitting surfaces in the same plane are arranged at an observation point. An orthogonal reception coil 6 in which coaxial first and second reception coils 6A and 6B intersect each other at right angles are inserted into a pipe 1 buried underground. The position of the pipe 1 is detected by observing the magnetic field intensity values from the transmission coils 16 and 17 received by means of the reception coils 6A and 68 by changing the arranging directions of the transmission coils 16 and 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention measures the magnetic field strength to
The present invention relates to a position detecting method for detecting a position between points, and particularly to a technique effective when applied to a position detecting method for detecting a position of an underground buried pipe or the like.

[0002]

2. Description of the Related Art Conventionally, as this kind of position detecting method,
Japanese Patent Laid-Open No. 57-133373 discloses, for example, Japanese Laid-Open Patent Publication No. 57-133373, in which a magnetic field measuring device is moved and scanned on the ground to measure a vertical component of a magnetic field emitted from the ground to detect the position of a underground pipe. In addition, the magnetic field generating element is attached to the excavator so that the central magnetic field line always faces in the vertical direction, and the substrate is provided with a linear magnetic field detecting element guide fixed horizontally.
The magnetic field detection element guide is provided with a magnetic field detection device in which the interlinking plane is vertical and at right angles to the moving direction, and the magnetic field detection element is movably attached to the magnetic field detection element guide. For example, Japanese Patent Application Laid-Open No. 59-153112 discloses a device for measuring the position where is zero.

[0003]

However, the present inventor has found that the above-described position detecting method has the following problems. That is, JP-A-57-
In the position detection method of Japanese Patent No. 133373, if there is an obstacle such as an implant, a guardrail, or a utility pole on the ground just above the magnetic field generation element, measurement becomes impossible. It requires a large number of measurements and requires a lot of time and effort.

Further, in the position detecting method disclosed in Japanese Patent Laid-Open No. 59-153112, there is a position where a zero value is obtained even if the transmitting coil and the receiving coil are not exactly orthogonal to each other, so that a measurement error occurs. easy. It is possible to detect only in the horizontal direction, that is, only the position on the pipe axis of the underground buried pipe can be detected,
Since the direction in which the pipe is buried cannot be detected from arbitrary measured values, for example, when a branch pipe is to be constructed in the main sewer without non-open cutting, it cannot be determined in which direction the excavation should start from the construction start position.

Further, in both of the above-mentioned two methods, it is necessary to adjust the transmission surface of the transmission coil so that the central magnetic field is orthogonal to the observation point, which is labor-intensive and causes an error. In view of the above-mentioned problems, an object of the present invention is to provide a position detection method capable of accurately detecting the direction in which an object to be measured is located from an arbitrary observation point without requiring a great deal of labor. To provide.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0007]

The outline of the invention disclosed in the present application will be briefly described as follows.
In the position detecting method of the present invention, a plurality of transmitting coils having a magnetic field transmitting surface on the same plane or a center of the magnetic field transmitting surface on the same straight line are arranged at an observation point, and the first concentric first coil is provided inside the object to be measured. An orthogonal type receiving coil in which the receiving coil and the second receiving coil are orthogonal to each other is inserted, and the magnetic field strength value from the transmitting coil received by the first receiving coil and the second receiving coil is changed in the arrangement direction of the transmitting coils. Then, the position of the object to be measured is detected by observing.

[0008]

[Operation] According to the above-mentioned means, the magnetic field is generated by changing the arrangement direction of a plurality of transmission coils having the magnetic field transmission surface on the same plane or the center of the magnetic field transmission surface on the same straight line. Since the intensity value is received by the orthogonal receiving coil inserted in the DUT and the position of the DUT is detected, the position of the DUT from any observation point can be accurately detected by simple work. It

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. Here, FIG. 1 is a schematic configuration diagram of a position detection system according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of an operation principle of a position detection method according to an embodiment of the present invention. Also, components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof will be omitted.

In FIG. 1, in the position detecting system, a movable carriage 2 which is movable in the longitudinal direction is introduced into an underground buried pipe 1 which is an object to be measured, and a wheel 3 of the movable carriage 2 has a rotary encoder or the like. A wheel rotation amount sensor (not shown) is attached, and a control device 4 for measuring the traveling distance of the moving carriage 2 by a signal output from the wheel rotation amount sensor is connected via a signal line 5.

On the moving carriage 2, as magnetic detection means,
A quadrature type receiving coil 6 is mounted. The quadrature receiving coil 6 is composed of a first receiving coil 6A and a second receiving coil 6B which are concentric, and the first receiving coil 6A and the second receiving coil 6B are orthogonal to each other. First receiving coil 6A
Is connected via a signal line 9 to a signal measuring device 10 arranged outside the underground buried pipe 1. Second receiving coil 6
B is provided on the central axis X of the underground buried pipe 1 and is connected to the signal measuring instrument 10 via the signal line 8.

On the other hand, a magnetic generator 11 is movably arranged at an observation point on the ground. Magnetic generator 11
Is provided with a pair of support plates 13 standing upright on the base 12, and a displacement plate 14 is provided between the pair of support plates 13 by the moving means 15 so as to be aligned with the central axis X of the underground buried pipe 1. It is supported so as to rotate about parallel axes and move in a direction perpendicular to the plate surface of the displacement plate 14.

At both ends of the displacement plate 14, a first transmission coil 16 and a second transmission coil 17 each having a magnetic field transmission surface on the same plane as the displacement plate 14 are mounted as magnetic field generation coils. Also, the first and second transmission coils 1
6, 17, a signal supply device 18 for supplying an alternating current,
The signal measuring device 10 is sequentially connected by the signal line 19, and the first and second transmitting coils 16 and 17 and the signal supplying device 18 are connected.
A switch 20 is connected to the signal line 19 between and.

Next, a position detecting method by the position detecting system will be described with reference to FIG. First, the moving carriage 2 is moved so that the central positions of the first and second receiving coils 6A and 6B are located on the central axis X of the underground buried pipe 1. The switch 20 alternately switches the supply of the alternating current from the signal supply device 18 to the first transmission coil 16 and the second transmission coil 17. By switching the switch 20, magnetic fields are alternately generated from the first transmitting coil 16 and the second transmitting coil 17, and after the magnetic field strength is received by the first and second receiving coils 6A and 6B,
Output to the signal measuring device 10. The signal measuring device 10 synchronously detects the signals received by the first and second receiving coils 6A and 6B and the reference signal transmitted from the signal supply device 18, and receives the received signal level V _1A of the first receiving coil 6A. , V _2A and the reception signal levels V _1B and V _2B of the second reception coil 6B are observed.

Here, the received signal level V_1A, V_2A,
V_1B, V_2BCan be expressed by the following equations (1) to (4). Note that V
₁Is the magnetic field strength vector of the magnetic field lines 21 of the second transmission coil 17.
Toll, V _TwoIs the magnetic field of the magnetic field lines 22 of the first transmission coil 16.
Intensity vector, θ₁Is the magnetic field strength vector V₁And the first receiving
Angle with the signal coil 6A, θ_TwoIs the magnetic field strength vector
V _TwoIs the angle formed by the first receiving coil 6A. V_1A= V₁cos θ₁ (1) V_1B= V₁sin θ₁ (2) V_2A= V_Twocos θ_Two (3) V_2B= V_Twosin θ_Two (4) From the above equations (1) to (4), V₁And V_TwoErase
Then, the following equations (5) to (8) are obtained.That is, the phase difference Δθ = θ_Two−θ₁Is expressed in the following equation (9).
LetSince the denominator of the above equation (9) is denominator> 0, the following equation (1
0) is led. V_2B・ V_1A-V_1B・ V_2A= 0 (10) That is, the displacement plate 14 is rotated or translated, and the first
And changing the arrangement direction of the second transmission coils 16 and 17,
Δθ = 0, that is, V_2B・ V_1A-V_1B・ V_2A= 0
By doing so, the first and second transmission coils 1 at that time
The arrangement directions of 6, 17 are the first and second receiving coils 6
It shows the center direction of A and 6B, and underground buried pipe 1
Is detected.

As described above, according to this embodiment, the first and second transmitting coils 1 having the magnetic field transmitting surfaces on the same plane.
6 and 17 are arranged, and the first concentric first
The orthogonal receiving coil 6 in which the receiving coil 6A and the second receiving coil 6B are orthogonal to each other is inserted, and a magnetic field is generated from the first and second transmitting coils 16 and 17 while changing the arrangement direction thereof, and the magnetic field strength value thereof is generated. Since the position of the underground buried pipe 1 is detected by receiving the first receiving coil 6A and the second receiving coil 6B, the position of the underground buried pipe 1 from an arbitrary observation point can be detected with good workability. To be done.

As described above, the inventions made by the present inventor are
Although the present invention has been specifically described based on the embodiments, it goes without saying that the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention.
In this embodiment, the first and second transmission coils 16 and 17 are
Are arranged so that their magnetic field transmitting surfaces are located on the same plane. Instead, the first and second transmitting coils 16 and 1 are arranged so that the centers of the magnetic field transmitting surfaces are located on the same straight line.
Even if 7 are arranged, the same effect can be expected.

[0018]

Advantageous effects obtained by typical ones of the inventions disclosed by the present application will be briefly described as follows.
It is as follows. According to the present invention, a plurality of transmission coils having the magnetic field transmission surface on the same plane or the center of the magnetic field transmission surface on the same straight line, while changing the array direction,
Generates a magnetic field and receives the magnetic field strength value with a quadrature receiver coil inserted in the DUT, and detects the position of the DUT, so the direction in which the DUT is located from any observation point is accurately determined. In addition, the detection can be performed with high efficiency without requiring a lot of labor.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a position detection system that is an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation principle of a position detecting method which is an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Underground piping 2 Mobile trolley 3 Wheels 4 Control device 5,8,9,19 Signal line 6 Orthogonal receiving coil 6A 1st receiving coil 6B 2nd receiving coil 10 Signal measuring device 11 Magnetic generator 12 Base 13 Support plate 14 Displacement Plate 15 Moving Means 16 First Transmission Coil 17 Second Transmission Coil 18 Signal Supply Device 20 Switch 21, 22 Magnetic Field Line

Claims (1)

[Claims] 1. A plurality of transmitting coils having a magnetic field transmitting surface on the same plane or a center of the magnetic field transmitting surface on the same straight line are arranged at an observation point, and a concentric first receiving coil and An orthogonal receiving coil in which the second receiving coil is orthogonal is inserted, and the magnetic field strength values from the transmitting coil received by the first receiving coil and the second receiving coil are
A position detecting method comprising the step of detecting the position of the object to be measured by changing the arrangement direction of the transmission coils and observing.