JP2006010628A - Detector for detecting object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detector capable of detecting precisely a position and a posture of a cutting object, in particular, without occupying a wide ground surface in a non-excavating method, in the detector for detecting a detecting object. <P>SOLUTION: This detector for detecting the position and/or the posture of the detecting object has a magnetic field generating source built in the detecting object, one detecting means capable of detecting three-directional orthogonal components of a magnetic field generated by the magnetic field generating source, and a computing means for computing the position and/or the posture of the detecting object, based on a data detected by the detecting means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a detection apparatus for an object to be detected, and particularly relates to an apparatus suitable for detecting the position and posture of an underground excavation body used in a non-open cutting method or the like.

  When gas is newly supplied to a private area, a gas supply pipe (hereinafter referred to as a supply pipe) is connected to a gas main branch pipe (hereinafter referred to as a main branch pipe) embedded in a public road such as a roadway or a side road. It is necessary to connect and draw the supply pipe to the private side. The conventional method of laying a supply pipe is to cut a laying road that opens to the ground surface on the ground of a public road between the planned supply pipe withdrawal part on the private side and the connection part of this branch pipe. This is a so-called open-cut method, in which the supply pipe is connected to the branch pipe, and the opened laying path is backfilled. According to the open-cut method, when the laying road is provided so as to cross, for example, a public road, there is a problem that the traffic on the public road is obstructed during the laying work of the supply pipe.

  In recent years, non-cutting methods have attracted attention as methods for solving such problems. The non-cutting method is a method of excavating the ground on the private side where the supply pipe is drawn in or only the ground of the connecting part of this branch pipe, and laying the supply pipe by excavating only in the underground, public roads There is no need to excavate on a large scale. Therefore, there is an advantage that the construction of the supply pipe can be done in a short period of time without obstructing the traffic on the public road, and there is a tendency that it is frequently used especially in urban areas where the traffic is heavy.

In the non-open cutting method, excavation is performed in the ground, and thus a detection technique for detecting the position and posture of an underground excavation body (hereinafter also referred to as an excavation body) used for the excavation is necessary. As the detection technology, a magnetic detection device that is easy to handle and has a simple structure is used for detection while following the excavation body in accordance with the propulsion of the excavation body. What is detected by relative comparison is known, and an example thereof is disclosed in Patent Document 1 below. The detection method disclosed in Patent Document 1 is “an electromagnetic wave from a transmitting coil at a plurality of positions at equal distances within a plane perpendicular to a planned arrival direction at a predetermined arrival portion of a propulsion body (excavation body). A plurality of receiving coils are arranged with the axis in the planned arrival direction, and the propulsion direction of the propulsion body is set so that the electromagnetic wave reception intensity of each of the plurality of receiving coils becomes a value set individually. It is set and propelled. ”Is a method in which the position of the excavated body is identified while propagating while comparing the received intensity of electromagnetic waves received by a plurality of receiving coils.
Japanese Patent Laid-Open No. 8-100595

  According to the detection method of Patent Document 1, there is an advantage that propulsion can be performed without being deviated with respect to the planned arrival direction, but it is premised that the excavated body is not greatly separated from the planned propulsion line. Therefore, when the excavated body is separated from the propulsion planned line, it is difficult to correct the propulsion direction of the excavated body.

  Moreover, according to the detection technique of Patent Document 1, it must be arranged on the ground surface or in the ground while aligning the axes of the plurality of receiving coils with respect to the planned arrival direction of the excavated body, and still occupies the ground surface during work There is a problem of doing.

  An object of the present invention is to provide a novel device for detecting a detected object, and in particular, a detection device capable of detecting the position and posture of an excavated body more accurately without occupying the ground surface in a non-open cutting method. Its purpose is to provide.

  One aspect of the present invention is an apparatus for detecting the position and / or orientation of a detected object, and a magnetic field generation source built in the detected object and three directions orthogonal to the magnetic field generated by the magnetic field generation source It is an apparatus having one detection means capable of detecting a component and a calculation means for calculating the position and / or orientation of the detected object based on data detected by the detection means. An underground excavation body excavating underground can be used as the object to be detected. Further, it is preferable to use a triaxial coil in which three coils are combined so as to be orthogonal as the detection means.

  In addition, the arithmetic means is a magnetic flux M (Bx, By, Bz) that is a three-way component of magnetic flux density obtained by measuring the magnetic field generated by the magnetic field generation source having a predetermined magnetic moment, and the magnetic moment M. And the position (Xs, Ys, Zs) of the object to be detected is calculated, and / or the position (θ, φ) of the object to be detected is calculated by calculating the position (Xs, Ys, Zs) of the object. It is preferable to calculate.

  According to the above-described detection apparatus, since there is one detection means for detecting the detection target, a large space is not required for arranging the detection means. Furthermore, by using the above formulas (1) and (2), the position and orientation of the detected object can be specified with high accuracy even with a single detection means.

  The present invention will be described based on its embodiments. FIG. 1 is a schematic configuration diagram illustrating a position and orientation detection device 6 of an excavated body according to an embodiment of the present invention. 2-4 is a figure explaining the method to detect the position and attitude | position of an excavation body by the detection apparatus of FIG. FIG. 5 shows another embodiment of the present invention. FIG. 6 is a diagram showing still another embodiment of the present invention. 7 and 8 are diagrams for explaining an embodiment of the detection device of FIG.

  As shown in FIG. 1, the detection device 6 according to this aspect detects the position and posture of an excavated body 5 propelled toward the main branch pipe 4 embedded in the ground. A slant cutting head 51 is mounted at the tip of the excavating body 5 for excavating the ground while rotating and correcting the propulsion direction. At the rear end of the oblique cutting head 51, a guide lot 52 for transmitting propulsive force and rotational force generated in the excavator body (not shown) is attached. The guide lot 52 has a structure that can be bent in an arc shape so that the excavated body 5 can bend.

  The detection device 6 includes a magnetic field generation source 61 coaxially built in the oblique cutting head 51, one triaxial coil 62 capable of detecting three orthogonal components of the magnetic field generated by the magnetic field generation source 61, and a triaxial coil Based on the data detected at 62, a calculation means 63 for calculating the position and orientation of the oblique cutting head 51 is provided. Here, the three-axis coil 62 is a combination of three magnetic field detection coils having substantially the same characteristics in three orthogonal directions, and the magnetic flux density due to the magnetic field generated from the magnetic field generation source 61 is three orthogonal. Directional components (x direction, y direction, z direction) are detected by each coil.

  Processing performed by the calculation means 63 will be described with reference to FIGS. Here, the center point S of the magnetic field generation source 61 in FIG. 1 is referred to as the magnetic field generation point, the center point P of the triaxial coil 62 as the measurement point, and the excavation target point Q as the target point.

  As shown in FIG. 2, in a magnetic field having a predetermined magnetic flux distribution generated from the magnetic field generation source 61 of the oblique cutting head 5, the magnetic field generation point S is coordinate (xs, ys, zs) and the measurement point P is coordinate (xp, yp, zp). The magnetic flux density B in each axial direction represented by the equation (3) is measured at the measurement point P by the magnetic field generated by the magnetic field generation source 61.

  Here, symbols Mx, My, and Mz in Equation (3) are components in the respective axial directions of the magnetic moment M of the magnetic field generation source 61. Symbols x, y, and z are components in the respective axial directions represented by Expression (4) of the length (distance from the point P to the point S) r of the straight line from the measurement point P to the magnetic field generation point S.

Here, as shown in FIG. 3, assuming that the measurement point P is placed at the origin of the three-dimensional coordinates and the magnetic field generation source 61 is placed in an arbitrary posture on the y-axis, the coordinates of the measurement point P are (xp , Yp, zp) = (0, 0, 0), and the coordinates of the magnetic field generation point S are (xs, ys, zs) = (0, ys, 0). Further, the angle (yaw angle) in plan view of the magnetic field generation source 61 with respect to the propulsion direction is represented by the symbol θ, and the angle (elevation angle) in elevation view is represented by the symbol φ, and the attitude of the magnetic field generation source 61 is defined by θ and φ. In this case, the magnetic moment M of the magnetic field generation source 61 is (Mcosφsinθ, Mcosφcosθ, Msinφ).
Can be expressed as Substituting these into equation (3) yields equation (5).

  The distance from the measurement point P to the magnetic field generation point S is Equation (6).

  By rearranging equation (5) and substituting equation (6) into equation (5), equation (7) for each component of magnetic flux density B at measurement point P can be obtained.

  Here, when Expression (7) is expressed by θ and φ, Expression (8) indicating the attitude of the magnetic field generation source 61 is obtained.

  When Expression (7) is solved for ys, Expression (9) that is the distance in the y direction from the measurement point P to the magnetic field generation point S is obtained.

  Next, as shown in FIG. 4, it is assumed that the magnetic field generation source 61 is shifted from the y-axis by a distance xs from the position of FIG. In this case, the coordinates of the magnetic field generation point S are (xs, ys, 0), and the magnetic moment of the point S is M = (0, M, 0). Further, since the measurement point P is at the origin, its coordinates are (0, 0, 0). Therefore, Expression (4) becomes (x, y, z) = (xs, ys, 0), and the distance r from the measurement point P to the magnetic field generation point S is expressed by Expression (10).

If Expression (10) is used, Expression (3) can be rewritten as Expression (11).

  Solving the equation (11) for the distance xs in the x direction from the measurement point P to the magnetic generation point S, the equation (12) is obtained.

  Further, the distance zs in the z direction from the measurement point P to the magnetic generation point S when the magnetic field generation source 61 is displaced in the z direction is also expressed by the equation (13) as in the equation (12).

  The magnetic flux density B in each axis direction at the measurement point P can be measured by a triaxial coil 62 that detects a magnetic field generated from the magnetic field generation source 61. Further, the magnetic moment M in each axial direction of the magnetic source 61 is unique to the magnetic source 61 and is known. Accordingly, the calculation means 63 inputs the magnetic flux density B and the magnetic moment M in the respective axial directions into the above-described equations (8), (9), (12), and (13), and generates a magnetic field as viewed from the measurement point P. The position and posture of the point S (that is, the oblique cutting head 51) are specified. In FIG. 1, the measurement point P is arranged at a position distant from the target point Q. However, if the positional relationship of the three-axis coil 62 with respect to the target point Q is stored in the calculation means 63 in advance, the oblique cutting head 5 is moved. The position and posture can be specified.

  For example, as shown in FIGS. 5 and 6, the triaxial coil 62 can be disposed in the vicinity of the main branch 4 through a small-diameter vertical hole drilled immediately above the main branch 4. In this way, the excavated body 5 can be propelled more accurately.

  An experiment example in which the three-axis coil 62 is arranged as shown in FIG. 6 and the ground is excavated by the excavating body 5 while detecting the position and orientation by the above-described detection device will be described. The excavation conditions are that the horizontal distance from the excavation start point to the target point is 3.73 m, and the embedding depth of the main branch pipe 4 is 0.985 m. FIG. 7 shows the result of detecting the position in the axial direction of the excavated body 5 viewed from the measurement point in the process from the excavation start point to the target point.

It is a schematic block diagram of the detection apparatus of one embodiment of this invention. It is a figure explaining the detection method of the detection apparatus of FIG. It is another figure explaining the detection method of the detection apparatus of FIG. It is another figure explaining the detection method of the detection apparatus of FIG. It is a schematic block diagram of the detection apparatus of another embodiment of this invention. It is a schematic block diagram of the detection apparatus of another embodiment of this invention. It is a figure explaining the Example of the detection apparatus of FIG.

Explanation of symbols

4: main branch pipe 5: excavated body, 51: oblique cutting head, 52: guide rod 6: position and orientation detection device for underground excavated body 61: magnetic field generation source, 62: magnetic field detection coil (3-axis coil)
63: calculation means, 64: excavation target point 65: positional relationship between the detection coil and the main branch pipe

Claims (4)

  An apparatus for detecting the position and / or orientation of a detected object, wherein a magnetic field generation source built in the detected object and three orthogonal components of a magnetic field generated by the magnetic field generation source can be detected. A detection apparatus comprising: a detection unit; and a calculation unit that calculates a position and / or orientation of the detected object based on data detected by the detection unit.   The detection apparatus according to claim 1, wherein the detected object is an underground excavation body that excavates underground.   The detection device according to claim 1, wherein the detection means is a three-axis coil in which three coils are combined so as to be orthogonal to each other. 4. The detection device according to claim 1, wherein the calculation unit is a three-direction component of magnetic flux density obtained by measuring the magnetic field generated by the magnetic field generation source having a predetermined magnetic moment by the measurement unit. Bx, By, Bz) and the magnetic moment M are calculated in the equation (1) to calculate the position (Xs, Ys, Zs) of the detected object and / or in the equation (2). A detection device for calculating the posture (θ, φ) of the detected object.

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