JP2008216032A - Underground position detection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underground position detection method, by which the underground position of a drilling unit can be detected easily, using a simple structure, without being affected by obstructions on the ground. <P>SOLUTION: The underground position detection method is employed for detecting the underground position of the drilling unit 1. A magnet 2 is provided in the drilling unit 1; a rotating magnetic field is generated by rotating this magnet 2 on a plane containing an x-axis and a z-axis, orthogonal to a y-axis stretching in the axial direction of the drilling unit 1; the x-axis component and the z-axis component of the magnetic flux density of the rotating magnetic field generated by the magnet 2 are measured at, at least three measuring points P<SB>1</SB>, P<SB>2</SB>, P<SB>3</SB>, respectively as a time calendar; from the x-axis and z-axis components, phase differences among the individual measuring points P<SB>1</SB>, P<SB>2</SB>, P<SB>3</SB>are calculated respectively; each of the acquired phase differences is considered as a viewing angle, by which the position of the magnet 2 is viewed from each projection point which is a respectively projected point of each measuring point to an xz-plane containing an origin; and from this viewing angle the x coordinate and z-coordinate of the position of the magnet 2 are calculated, whereas, the y-coordinate of the position of the magnet 2 is calculated from the drilled distance of the drilling unit 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an underground position detection method for detecting an underground position of a drilling device such as a boring or a shield tunnel.

  Conventional methods for detecting the underground position of drilling equipment such as boring and shield tunnels include (1) a method using a gyroscope, (2) a method using a geomagnetic orientation sensor and an inclinometer, and (3) electromagnetic induction. And (4) a method using an elastic wave.

  The method using the gyroscope of (1) detects the position of the tip of the boring or shield tunnel by measuring the three-dimensional bending of the drilling hole by taking the gyroscope into and out of the borehole of the boring or shield tunnel. It is supposed to be.

  The method of (2) using a geomagnetic orientation sensor and inclinometer is to install a geomagnetic orientation sensor and inclinometer in the borehole of a borehole or shield tunnel and measure the position of the borehole or shield tunnel. The position of the tip or the like is detected.

  In the method using electromagnetic induction (3), a magnetic field is generated by passing a current through a coil installed at the tip of a boring or shield tunnel, and the strength of the magnetic field is measured on the ground. The position is detected.

  The method using elastic waves in (4) detects the position of the tip of the boring or shield tunnel by generating the elastic wave from the tip of the boring or shield tunnel and measuring the arrival time of the elastic wave on the ground or in the ground. It is supposed to be.

Further, as other position detection methods, there are methods as shown in Patent Document 1 and Patent Document 2. The position detection device of Patent Document 1 is a device for detecting the relative position of two underground excavators that are started to face each other, and a magnetic field generator is provided at the front of one of the underground excavators. The other underground excavator magnetic field detector is provided. Based on the difference in peak generation time of the magnetic field generated from the magnetic field generator, the angle between the magnetic field detectors as viewed from the magnetic field generator is obtained, and the relative position between the excavators in each place is obtained. In the position detection apparatus of Patent Document 2, a magnetic force generation source is built in an underground excavation body, and one detection unit capable of detecting three orthogonal components of a magnetic field generated by the magnetic force generation source is provided at a measurement point. Then, assuming that the measurement point is placed at the origin of the three-dimensional coordinates and the magnetic field generation source is placed in an arbitrary posture on the y-axis, the position of the magnetic force generation source is calculated using a predetermined calculation formula. It has become.
JP-A-3-257321 JP 2006-10628 A

  However, in the method using the gyroscope (1), since the apparatus is taken in and out of the mine, it is necessary to temporarily suspend the excavation work in order to detect the position, and the work efficiency is lowered. . In the method (2) using the geomagnetic azimuth sensor and inclinometer, a precision machine such as a geomagnetic azimuth sensor and inclinometer is installed at the tip of the boring or shield tunnel, and the measurement data is transmitted to the outside by wire or wirelessly. Therefore, there is a problem that the structure becomes complicated, and there is a problem that an error occurs in the measurement result if there is iron near the geomagnetic direction sensor. Furthermore, in the method using electromagnetic induction (3), since it is necessary to perform measurement directly above the coil, there is a problem that it is difficult to perform measurement below an existing structure. In addition, in the method using the elastic wave of (4), since an apparatus for generating an elastic wave is required in the pit, there is a problem that the structure becomes complicated, and when the elastic wave velocity of the formation is not uniform, There is also a problem that a large error occurs in the measurement result.

  Therefore, the present invention has been devised to solve the above-described problem, and the position detection device can be made simple in structure, and can be bored and shielded without being affected by obstacles on the ground. It is an object of the present invention to provide an underground position detection method capable of easily detecting the underground position of a tunnel.

  In order to solve the above-mentioned problem, the invention according to claim 1 is an underground position detection method for detecting an underground position of an excavator, wherein the excavator is provided with a magnet, and the magnet is disposed in an axial direction of the excavator. A rotating magnetic field is generated by rotating on a plane including the x-axis and z-axis orthogonal to the extending y-axis, and the x-axis component and the z-axis component of the magnetic flux density of the rotating magnetic field generated by the magnet at at least three measurement points. Are respectively measured as time calendar data, the phase difference between the respective measurement points is calculated from the x-axis component and the z-axis component, respectively, and the obtained phase difference is set on the xz plane including the origin. It is regarded as an expected angle at which the position of the magnet is expected from each projected point, and the x coordinate and the z coordinate of the magnet position are calculated from the estimated angle, while the y of the magnet position is calculated from the excavation distance of the excavator. seat A ground position detecting method characterized by calculating the.

  According to such a method, since it is only necessary to attach a magnet in the excavator, there is no need to install a power source or precision equipment in the excavator, and the position detection device has a simple structure. . In addition, the measurement of the rotating magnetic field only needs to measure the magnetic field from the magnet on the ground or in the ground, so that it is not limited by the measurement location and is not affected by obstacles on the ground. Furthermore, the underground position can be easily detected by calculating the position based on the measurement data.

  The invention according to claim 2 is an underground position detection method for detecting an underground position of an excavator, wherein the excavator is provided with a magnet, and the magnet is orthogonal to a y-axis extending in the axial direction of the excavator. A rotating magnetic field is generated by rotating on a plane including the axis and the z-axis, and the x-axis component and the z-axis component of the magnetic flux density of the rotating magnetic field generated by the magnet at at least three measurement points are measured as time calendar data, respectively. The phase difference between the measurement points is calculated from the x-axis component and the z-axis component, and the obtained phase difference is calculated from the projection points obtained by projecting the measurement points on the xz plane including the origin. Considering the expected angle as the expected position of the magnet, the x-coordinate and z-coordinate of the position of the magnet are calculated from the estimated angle. On the other hand, the excavator is provided with a magnet, which includes the y-axis and the z-axis. On the plane, Alternatively, a rotating magnetic field is generated by rotating on a plane including the x-axis and the y-axis, and the y-axis component and the z-axis component of the magnetic flux density of the rotating magnetic field generated by the magnet at at least three measurement points, or the x-axis Component and y-axis component are respectively measured as time calendar data, and the phase difference between the respective measuring points is calculated from the y-axis component and z-axis component, or the x-axis component and y-axis component, respectively. The phase difference is regarded as an expected angle at which the position of the magnet is estimated from each projection point obtained by projecting each measurement point on the yz plane or the xy plane including the origin, and the y coordinate and the z coordinate of the magnet position from the expected angle. Or an underground position detection method characterized by calculating x-coordinate and y-coordinate.

  The method of claim 1 calculates the y coordinate from the excavation distance of the excavator, while the method of claim 2 calculates the y coordinate from the magnetic flux density of the rotating magnetic field as well as the x coordinate and the z coordinate. It is a thing. According to such a method, as in the first aspect of the invention, the device necessary for position detection has a simple structure. Further, the measurement of the rotating magnetic field is not limited by the measurement location and is not affected by the obstacle on the ground. Furthermore, the underground position can be easily detected by calculating the position based on the measurement data.

  According to the present invention, an apparatus for position detection can have a simple structure, and it is possible to easily detect the underground position of a boring or shield tunnel without being affected by an obstacle on the ground. Show the effect.

  Next, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, when the rotation center of the magnet 2 is the origin O, and the magnet 2 rotates on a plane including the x axis and the z axis perpendicular to the y axis, the x direction of the N pole of the magnet 2 Is a three-direction component (B _x , B _y , B _z ) of the magnetic flux density of the rotating magnetic field at a certain point P (x, y, z), the following equations 1, 2 and 3 It is represented by

  In Expressions 1 to 3, r represents the distance from the origin O of the point P, and m represents the magnetic moment of the magnet 2.

Then, when calculating the function formula F ₁ shown in Equation 4 below, as shown in FIG. 2 (a), represented in a sine wave.

Here, as shown in FIG. 2B, the angle from the x-axis of the straight line OP ′ with respect to the projection point P ′ (x, 0, z) obtained by projecting the point P onto the xz plane including the origin O is expressed as follows. Assuming that θ, the relationship of the rotation angle φ _m of the magnet 2 and the angle θ when F ₁ is the maximum value holds the relationship as shown in the following Expression 5.

Also, when calculating the function formula F ₂ shown in Equation 6 below, as shown in FIG. 3 (a), expressed in sine wave.

Here, as shown in FIG. 3B, the angle from the x-axis of the straight line OP ′ with respect to the projection point P ′ (x, 0, z) obtained by projecting the point P onto the xz plane including the origin O. when theta, F ₂ is the angle of rotation phi ₀ and the angle of the magnet 2 at the time of F _{2 =} 0 theta when changes to the positive side from the minus side, the relationship of equation 7 below is established.

That is, the rotation angles φ _m and φ ₀ are equal to the angle θ formed by the straight line OP ′ and the x axis plus n times π (= 180 °). By utilizing this property, the magnet for the measuring point P can be obtained from the x component B _x and the z component B _z of the magnetic flux density of the rotating magnetic field measured as time history data on the ground or in the ground as described below. 2 x and z coordinates are obtained.

  As shown in FIG. 4, in the underground position detection method according to the present embodiment, a magnet 2 is provided in an excavating apparatus 1 such as a horizontal boring or a shield tunnel. A permanent magnet is used for the magnet 2. The magnet 2 is attached to a rotating part such as the rotating shaft of the excavator 1 so that the NS direction of the magnet 2 is orthogonal to the axial direction of the excavator 1. Here, the axial direction of the excavator 1 is taken as the y-axis, the horizontal direction perpendicular to the y-axis is taken as the x-axis, and the vertical direction perpendicular to the y-axis is taken as the z-axis. As a result, when the excavator 1 is activated and the rotation portion rotates, the magnet 2 rotates on a plane including the x-axis and the z-axis orthogonal to the y-axis extending in the axial direction of the excavator 1. As the magnet 2 rotates in this way, a rotating magnetic field is generated.

Then, the x component B _x and the z component B _z of the magnetic flux density of the rotating magnetic field are respectively measured as time calendar data at the three measurement points P ₁ and P ₂ on the ground and the measurement point P _{3 in} the ground. . Each measuring point P ₁ , P ₂ , P ₃ is provided with a measuring device such as a triaxial coil or a fluxgate magnetometer, and the measuring device measures the magnetic flux density of the rotating magnetic field. Then, F ₁ is calculated by substituting the measured x component B _x and z component B _z into Equation 4 or substituting into Equation 6 to calculate F ₂ . Then, F _{1 at} each of the measurement points P ₁ , P ₂ , and P ₃ has a sinusoidal shape as shown in FIG. 5, and F _{2 at} each of the measurement points P ₁ , P ₂ , and P ₃ is also shown in FIG. As shown in FIG.

Here, the phase time differences ΔT ₁₂ and ΔT ₂₃ between the measurement points of F ₁ or F ₂ (between P ₁ and P _{2 and} between P ₂ and P ₃ ) are measured. Assuming that one period of rotation of the magnet 2 is T, the phase differences φ ₁₂ and φ ₂₃ of the rotation angle of the magnet in the sine wave of the rotating magnetic field from the time differences ΔT ₁₂ and ΔT ₂₃ are expressed by the following equations 8 and 9. .

Phase difference phi ₁₂ of the rotation angle shown by the formula 8, each measuring points P _1, P _2, the position of the magnet 2 from each projection point P ₁ ', P _2' obtained by projecting each xz plane including the origin O Expected angle (angle formed by straight line OP ₁ ′ and straight line OP ₂ ′) θ ₁₂ (see FIG. 7). Further, the phase difference φ ₂₃ of the rotation angle shown in Expression 9 is calculated from the projection points P ₂ ′ and P ₃ ′ obtained by projecting the measurement points P ₂ and P ₃ onto the xz plane including the origin O, respectively. The expected angle (the angle formed by the straight line OP ₂ ′ and the straight line OP ₃ ′) θ ₂₃ (see FIG. 7) is estimated. Therefore, the phase difference φ ₁₂ , φ ₂₃ of the rotation angle in the sine wave of the rotating magnetic field between the measurement points P ₁ , P ₂ , P ₃ is read, and each projection point P ₁ projected on the xz plane including the origin O is read. ', _{P 2',} relative to the respective positions of _{P 3} 'prospective angle theta ₁₂ looking into position of the magnet 2 from that regarded as theta _23, the projection points _{P 1', P 2 ',} P 3' The position of the correct magnet 2 can be calculated and obtained.

Below, the method to calculate the position of the magnet 2 from each prospective angle (theta) ₁₂ , (theta) ₂₃ is demonstrated.

Each station coordinate is defined as P ₁ (x ₁ , y ₁ , z ₁ ), P ₂ (x ₂ , y ₂ , z ₂ ), and P ₃ (x ₃ , y ₃ , z ₃ ). As shown in FIG. 7, when the angle between the vertical line L from the position of the magnet 2 to the ground surface and the measuring point P ₂ ′ is θ ′ and the position of the magnet 2 to be obtained is (X, Z), Equations 10 to 12 are established.

If these formulas 10 to 12 are rearranged, they become a simultaneous equation consisting of the following formulas 13 and 14.

  By solving this simultaneous equation, the position (X, Z) of the magnet can be obtained.

The measurement points P ₁ , P ₂ , and P ₃ may be arranged only on the ground, or may be a combination of the ground and the ground, and can be installed at any position. In the above description, three measuring points are provided, but four or more measuring points may be provided. In this case, the magnet position (X, Z) is obtained by applying the least square method.

In the present embodiment, calculation is performed using one of F _{1 and} F ₂ , but an average value may be adopted by calculation using both functional expressions. In this way, the accuracy of the phase difference data is improved. In the case of calculating the F ₂ may be used selectively to detect a signal synchronized with the rotation of the rotary shaft drilling rig 2.

  Next, the y coordinate of the magnet 2 is calculated from the excavation distance of the excavator 2. Specifically, for example, the y coordinate can be calculated with high accuracy by obtaining the extended distance of the boring. As described above, the position of the magnet 2 can be detected three-dimensionally by obtaining each coordinate.

  When the excavator 2 is a shield tunnel excavator, as shown in FIG. 8, the excavator 1 is provided with a side excavator 3 that excavates sideways. The y-coordinate may be calculated according to the above method by providing a magnet 4 at the tip of the side excavator 3 and rotating it.

Specifically, the magnet 4 is rotated on a plane including the y-axis and the z-axis (or on a plane including the x-axis and the y-axis) to generate a rotating magnetic field, and at least three on the ground or in the ground The y-axis component obtained by measuring the y-axis component and the z-axis component (or the x-axis component and the y-axis component) of the magnetic flux density of the rotating magnetic field generated by the magnet 4 at a measurement point (not shown), respectively. And the z-axis component (or the x-axis component and the y-axis component) to obtain a sine function formula F ₁ or F _2, and calculate the phase difference from the time difference of the phase of the sine wave at each measurement point, respectively. The phase difference is regarded as an expected angle at which the position of the magnet 4 is estimated from each projection point obtained by projecting each measurement point onto the yz plane (or the xy plane) including the origin. Coordinates (or x-coordinate and Coordinate) is calculated. Thereby, the y coordinate is calculated, and the position of the magnet 4 can be detected three-dimensionally by combining the previously calculated x coordinate and z coordinate.

  According to the method as described above, the magnet 2 need only be attached to the excavator 1. There is no need to install precision equipment in the excavator 1. In particular, if the magnet 2 is attached to the rotating shaft of the excavator 1, there is no need to separately install a rotating mechanism and a power source for rotating the magnet in the excavator 1, and the apparatus for position detection is simple. It becomes a structure. Further, the measurement of the rotating magnetic field only needs to measure the rotating magnetic field due to the rotation of the magnet 2 on the ground or in the ground, so that it is not limited by the measurement location and is not affected by the obstacle on the ground. Furthermore, the underground position can be easily detected by calculating the position based on the measurement data.

As another detection method of the above-described underground position detection method, there is a method as described below. In this underground position detection method, a magnet is provided on the rotating shaft of the excavator, and a rotating magnetic field is generated by rotating the magnet on a plane including the x-axis and the z-axis orthogonal to the axial direction of the excavator. Alternatively, the three-direction components (B _x , B _y , B _z ) of the magnetic flux density of the rotating magnetic field are measured at arbitrary measurement points in the ground. Then, the three-direction components (B _x , B _y , B _z ) of the magnetic flux density, the separately measured rotation angle φ of the magnet, and the magnetic moment m of the magnet 2 measured in advance are expressed by the above-described equations 1, 2 and Substituting into Equation 3, the position of the magnet is calculated.

  Note that the rotation angle φ of the magnet is measured by detecting the rotation angle of the rotation shaft of the excavator. Further, the magnetic moment m of the magnet is obtained by measuring in advance the amplitude of the magnetic field at a certain distance from the magnet.

  Also by such a method, since it is only necessary to measure the rotating magnetic field due to the rotation of the magnet, there is no limitation on the measurement location and it is not affected by the obstacle on the ground. Furthermore, the underground position can be easily detected by calculating the position based on the measurement data.

  In addition to the detection method described above, there is a method for measuring the amplitude of the magnetic field. This direction is a method that can be applied when the magnetic field can be measured in the vicinity of the position directly above the excavator, and does not indicate the constituent requirements of the present invention. This method uses the property that the magnetic field is maximized at a position directly above the magnet.

As shown in FIG. 9, a magnet 2 is provided at the tip of the excavator 1 and rotated to generate a rotating magnetic field. Then, the z component B _z of the rotating magnetic field is measured on the excavation plan line near the position directly above the excavator 1. Here, the amplitude of the z component B _z of the rotating magnetic field increases as the magnet approaches the measurement point, and decreases as the magnet moves away from the measurement point. That is, the tip position of the excavator 1 is directly below the position where the amplitude of the z component B _z of the rotating magnetic field is maximized. Then, the depth of the excavator 1 is obtained by back calculation from the measured magnitude of the rotating magnetic field or distance attenuation. That is, the z component B _z of the rotating magnetic field is expressed as the following Expression 15, and is inversely proportional to the cube of the distance r between the magnet and the measuring point.

  Here, m is the magnetic moment of the magnet, and is obtained by measuring the amplitude of the magnetic field at a certain distance from the magnet in advance, and by substituting m into Equation 15, The distance r can be calculated.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to the said embodiment, In the range which does not deviate from the meaning of this invention, a design change is possible suitably. For example, in the above-described embodiment, the magnet 2 is composed of a permanent magnet, but may be another configuration such as an electromagnet.

It is the perspective view which showed the definition of the magnet and coordinate axis of the underground position detection method which concerns on this invention. (A) is a waveform diagram showing the waveform of the F _1, (b) is a projection plan view obtained by projecting the stations to the xz plane. (A) is a waveform diagram showing the waveform of the F _2, (b) is a projection plan view obtained by projecting the stations to the xz plane. It is the perspective view which showed the example of arrangement | positioning of the magnet of the underground position detection method which concerns on this invention, and a measuring point. Each measuring point F ₁ of the waveform shape is a waveform diagram illustrating respectively. Each measuring point F ₂ of the waveform shape is a waveform diagram illustrating respectively. It is the figure which showed the prospective angle which looked at the magnet from each measuring point. It is the schematic which showed the excavation apparatus in the case of calculating | requiring y coordinate. It is the schematic which showed the excavation state in the case of detecting an underground position using the amplitude of a magnetic field.

Explanation of symbols

1,3 drilling equipment 2,4 magnet

Claims (2)

In the underground position detection method for detecting the underground position of the excavator,
A magnet is provided in the excavator, and a rotating magnetic field is generated by rotating the magnet on a plane including an x-axis and a z-axis orthogonal to the y-axis extending in the axial direction of the excavator,
Measuring the x-axis component and the z-axis component of the magnetic flux density of the rotating magnetic field generated by the magnet at at least three measurement points as time calendar data,
Calculating a phase difference between the measurement points from the x-axis component and the z-axis component,
The obtained phase difference is regarded as a prospective angle for estimating the position of the magnet from each projection point obtained by projecting each measurement point on the xz plane including the origin,
Calculate the x-coordinate and z-coordinate of the magnet position from the expected angle,
On the other hand, the y-coordinate of the position of the magnet is calculated from the excavation distance of the excavator. In the underground position detection method for detecting the underground position of the excavator,
A magnet is provided in the excavator, and a rotating magnetic field is generated by rotating the magnet on a plane including an x-axis and a z-axis orthogonal to the y-axis extending in the axial direction of the excavator,
Measuring the x-axis component and the z-axis component of the magnetic flux density of the rotating magnetic field generated by the magnet at at least three measurement points as time calendar data,
Calculating a phase difference between the measurement points from the x-axis component and the z-axis component,
The obtained phase difference is regarded as a prospective angle for estimating the position of the magnet from each projection point obtained by projecting each measurement point on the xz plane including the origin,
Calculate the x-coordinate and z-coordinate of the magnet position from the expected angle,
On the other hand, a magnet is provided in the excavator, and a rotating magnetic field is generated by rotating the magnet on a plane including the y axis and the z axis, or on a plane including the x axis and the y axis,
Measuring the y-axis component and the z-axis component or the x-axis component and the y-axis component of the magnetic flux density of the rotating magnetic field generated by the magnet at at least three measurement points, respectively, as time calendar data;
Calculating a phase difference between the measurement points from the y-axis component and the z-axis component, or the x-axis component and the y-axis component, respectively;
The obtained phase difference is regarded as a prospective angle for estimating the position of the magnet from each projection point obtained by projecting each measurement point on the yz plane or the xy plane including the origin,
An underground position detection method characterized by calculating a y-coordinate and a z-coordinate or an x-coordinate and a y-coordinate of the position of the magnet from the expected angle.

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