JP2002303516A - Propulsion head position and direction measurement method and device for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure the position of a propulsion head in spite of spatial turbulence of magnetism. SOLUTION: This propulsion head position direction measurement device is provided with first and second magnetic field detectors 102 and 103 arranged in the same propulsion head 100 along the propulsion direction, a propulsion distance measurement device 120 measuring a propulsion distance of the propulsion head, a magnetic field azimuth estimation part 224 estimating a magnetic field azimuth of an imaginary point in the propulsion directional front part from magnetic field azimuths measured by the magnetic field detectors 102 and 103, and a horizontal position direction computing 230 computing a horizontal direction change in the propulsion head on the basis of the magnetic field azimuth estimated by the magnetic field azimuth estimation part 224 and the magnetic field azimuths found by the magnetic field detectors 102 and 103.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion head position / direction measurement method and a propulsion head position / direction measurement device in a propulsion method for laying pipes underground without digging.

[0002]

2. Description of the Related Art In a propulsion method for laying pipes underground without excavation, detecting the position and direction of the tip of a propulsion pipe during the construction involves correcting the propulsion direction and correcting the path of the pipeline. This is important information for controlling within a predetermined management range.

Heretofore, there has been a technology for measuring the position of a propulsion head using geomagnetism. This technique will be described with reference to FIG. As shown in FIG.
At the tip of the detector, a terrestrial magnetic field detector 701 for determining the azimuthal angle of terrestrial magnetism with respect to the propulsion head, an angle detector 702 for detecting an inclination angle of the propulsion direction with respect to the horizontal direction and a rotation angle about the propulsion direction as an axis, It is composed of In this apparatus, the displacement amount is calculated according to the propulsion distance from the detected azimuth angle and inclination angle of the propulsion head 100 and integrated to obtain the propulsion head position. The position in the propulsion direction is
It is obtained by managing the length of the propulsion pipe being propelled. Therefore, in this method, a horizontal position and a depth position are obtained with respect to the propulsion direction.

Conventionally, as a technique for measuring the position of the propulsion head, there has been a technique using an artificial magnetic field as disclosed in Japanese Patent Application Laid-Open No. 9-72192. This technique will be described with reference to FIG. As shown in FIG. 8, a magnetic field generating coil 802 is installed on the propulsion planning line of the propulsion work, the propulsion distance is managed by a propulsion distance measuring device 808, and when the underground propulsion head 801 reaches a position immediately below the coil 802, Power supply 8
From 07, a DC or rectangular alternating current is supplied to the coil 802 to generate an artificial magnetic field in the ground. The computing unit 810 calculates the horizontal position of the propulsion head from the three-axis magnetic field strength obtained by subtracting the three-axis magnetic field strength when the coil is not energized from the three-axis magnetic field strength when the coil is not energized, and the posture angle of the tip measured separately. And the depth position.

[0005]

The apparatus shown in FIG. 7 utilizes geomagnetism, but particularly in an urban area.
Geomagnetism is often spatially disturbed by the influence of automobiles, structures, and other buried pipes made of a magnetic material existing near the measurement location. Therefore, the azimuth angle has an error. Even if this error is small, there is a problem that the propulsion head position obtained by integrating the displacement amounts obtained using the error has a large error and is not practical in urban areas.

Further, in the apparatus shown in FIG. 8, the direction of the propulsion head cannot be measured only by obtaining the position of the propulsion head from the artificial magnetic field. The depth direction can be measured using an inclinometer or the like, but the horizontal direction is unknown. When correcting the direction of propulsion in actual propulsion work,
Information about the direction of the propulsion head as well as the propulsion head position is effective. Therefore, in this prior art,
There has been a problem that the measurement device is not sufficient for such a modification of the propulsion work.

An object of the present invention is to provide a propulsion head position / direction measurement method and a propulsion head position / direction measurement device capable of accurately measuring the position of a propulsion head even when the magnetism is spatially disturbed. is there.

[0008]

Means for Solving the Problems [Configuration] The present invention is configured as follows to achieve the above object.

(1) The propulsion device according to the present invention (claim 1)
The head position direction measurement method is based on the propulsion direction in the propulsion head.
Each magnetic field detection using multiple magnetic field detectors provided
Direction of the magnetic field with respect to the propulsion direction at the position where the vessel is installed
Steps for determining each angle and a plurality of determined magnetic fields
Magnetic field selected from multiple magnetic field detectors using azimuth
A virtual position at a distance L 'away from the detector forward in the propulsion direction
Magnetic field azimuth φ with respect to the propulsion direction at P_pPush
Measuring the propulsion distance of the propulsion head.
And the measured propulsion distance has become the distance L '
At this point, using the selected magnetic field detector, the propulsion
Magnetic field azimuth angle φ with respect to head propulsion direction _βSeeking for
And the magnetic field azimuth φ_pAnd magnetic field azimuth φ_βCompare with
To calculate the change in the horizontal direction of the propulsion head.
And a tip.

Further, a method for measuring the position and direction of a propulsion head according to the present invention (claim 2) when there are two magnetic field detectors is provided.
Determining a first magnetic field azimuth using a first magnetic field detector provided on the propulsion head; measuring a propulsion distance of the propulsion head; and a first magnetic field provided on the propulsion head. Determining a second magnetic field azimuth using a second magnetic field detector located behind the detector;
Estimating a third magnetic field azimuth at a virtual position near the first magnetic field detector from the first magnetic field azimuth and the second magnetic field azimuth; and a first magnetic field azimuth and a second magnetic field azimuth. After the third magnetic field azimuth is estimated from the above, when the measured propulsion distance of the propulsion head becomes the distance between the second magnetic field detector and the virtual position, the second magnetic field detector again determines Comparing the obtained main magnetic field azimuth with the third magnetic field azimuth to calculate a change in the horizontal direction of the propulsion head.

A preferred embodiment of the present invention will be described below.
Measuring a tilt angle of a propulsion head provided with a magnetic field detector when measuring a magnetic field azimuth angle, and measuring a change in a depth direction of the propulsion head based on the measured tilt angle.

[0012] A horizontal position of the propulsion head is measured by integrating changes in the horizontal direction of the propulsion head measured a plurality of times. Each time the main magnetic field azimuth is measured, the inclination angle of the propulsion head provided with the magnetic field detector is measured, and the change in the depth direction of the propulsion head is measured a plurality of times based on the measured inclination angle, The position of the propulsion head is measured by integrating changes in the horizontal direction and the depth direction of the propulsion head measured a plurality of times. The magnetic field detector is fixed to the propulsion head, detects the magnetic field with the magnetic field detector, measures the rotation angle and the inclination angle of the propulsion head, and based on the measured magnetic field, rotation angle, and inclination angle, Find the azimuth. To detect the azimuth of geomagnetism as the magnetic field azimuth. An artificial magnetic field is generated by a magnetic field generator installed on the ground, and the azimuth of the artificial magnetic field is detected as a magnetic field azimuth.

(2) A propulsion head position / direction measuring apparatus according to the present invention comprises: a plurality of magnetic field detectors provided in a propulsion direction on an underground propulsion head; a propulsion distance detector for measuring the propulsion distance; An arithmetic processor for calculating a change in the horizontal direction of the propulsion head based on the detection result.

A preferred embodiment of the present invention will be described below.
A magnetic field detector fixed to the propulsion head, a posture detector for detecting a rotation angle and a tilt angle of the propulsion head, a magnetic field measured by the magnetic field detector, and a rotation angle and / or a rotation angle detected by the posture detector. An arithmetic processing unit for obtaining a magnetic field azimuth angle based on the inclination angle. An artificial magnetic field generating means provided on the surface of the earth is further provided.

[Operation] The present invention has the following operation and effects by the above configuration.

By measuring the magnetic field a plurality of times and measuring the inclination angle of the propulsion head at substantially the same place, even if there is turbulence in the geomagnetism due to nearby magnetic structures, the propulsion is performed irrespective of the turbulence in the space. The azimuth angle of the terrestrial magnetism or artificial magnetic field of the head unit can be obtained, converted into a displacement according to the propulsion distance, and integrated, whereby the position of the propulsion head unit can be accurately measured.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a diagram showing a schematic configuration of a propulsion head position / direction measuring apparatus according to a first embodiment of the present invention. As shown in FIG.
Numeral 0 is made of a highly rigid columnar body, and its tip has an excavating function and is propelled underground. The propulsion head 100 includes the propulsion pipe 10
3 attached to the tip. The propulsion pipe 103 is made of a pipe or a rod, and transmits rotation and propulsion to the propulsion head 100. The propulsion pipe 103 has more flexibility than the propulsion head 100.

A first magnetic field detector 101 and a second magnetic field detector 102 are installed in the underground propulsion head 100. The first magnetic field detector 101 is installed on the propulsion head 100 and the second magnetic field detector 102 is connected to the first magnetic field detector 10.
It is installed at a position separated by a distance L behind one. In order to obtain high accuracy, it is preferable that the first magnetic field detector 101 is installed at a position near the tip. In the propulsion head 100, a gravitational acceleration direction detector 110 is installed. From the gravitational acceleration in three axial directions measured by the gravitational acceleration direction detector 110, the inclination angle and the rotation angle of the propulsion head are obtained. Furthermore, by using the obtained inclination angle and rotation angle, the coordinate values of the measured values of the geomagnetism in the three axial directions are converted,
The azimuth angle of geomagnetism with respect to the propulsion direction of the propulsion head 100 can be measured. In the following, the propulsion head 10
The azimuth of geomagnetism with respect to the thrust direction of 0 is abbreviated as the azimuth of geomagnetism.

A propulsion distance measuring device 120 for measuring the propulsion distance of the propulsion head 100 is provided on the ground. The first and second magnetic field detectors 101 and 102, the gravitational acceleration direction detector 110, and the propulsion distance measurement device 120 include an arithmetic processing unit 130 that calculates the horizontal position and the depth position of the propulsion head from the respective measurement results. Is provided. Here, the position of the propulsion head refers to the position of a part necessary for the construction to proceed, such as the tip or center of the propulsion head. Set arbitrarily as needed. Usually, the tip position of the propulsion head is used. The arbitrarily set position is calculated using the positional relationship between the propulsion head and the first magnetic field detector and / or the second magnetic field detector (and, if necessary, the gravitational acceleration direction detector). It can be obtained by correcting the horizontal position and the depth position of the first magnetic field detector or the second magnetic field detector. If the first magnetic field detector is sufficiently close to the tip of the propulsion head, the first
The horizontal position and the depth position of the magnetic field detector may be used as the tip position of the propulsion head.

In the following description, for the sake of simplicity, the case where the position of the first magnetic field detector is set as the position of the propulsion head will be described. However, the position of the propulsion head is not limited to the position of the first magnetic field detector. Absent.

First and second magnetic field detectors 101 and 102
A semiconductor-type high-sensitivity magnetic field detector was used. The first and second magnetic field detectors 101 and 102 generate magnetic fields in three directions of a horizontal direction (Y ′ axis) and a vertical direction (X ′ axis) on a plane perpendicular to the propulsion direction (Z ′ axis) and the propulsion direction. A magnetic field is detected in directions of three axes orthogonal to each other in intensity (H _{x ′} , H _{y ′} , H _{z ′} ).

The three-axis gravity direction detector 12 detects gravity in the horizontal direction (Y 'axis) and the vertical direction (X' axis) in a propulsion direction (Z 'axis) and a plane perpendicular to the propulsion direction. The magnitude of the acceleration (g _{x ′} , g _{y ′} , g _{z ′} ) is detected, and the gravitational acceleration with respect to the attitude of the propulsion head is measured. As the three-axis accelerometer 5, a servo type accelerometer was used. These detectors are provided inside a rigid propulsion head casing made of a non-magnetic SUS material.

In this device, the first and second magnetic field detectors 1
After detecting the magnetic field at 01 and 102, each time the propulsion head is propelled by the predetermined distance L, the second magnetic field detector 102 detects the terrestrial magnetism 140. Then, a change in the propulsion direction of the propulsion head is measured by comparing the azimuth angles of the terrestrial magnetism 140 detected by the two magnetic field detectors. Further, the horizontal position of the propulsion head is obtained by converting the change in the propulsion direction and the propulsion distance into a horizontal displacement amount. Also,
The depth of the propulsion head is obtained by converting the inclination angle and the propulsion distance obtained from the gravitational acceleration direction detector 110 into a displacement amount in the depth direction and integrating the displacement amount.

In this embodiment, the first magnetic field detector 101 provided on the underground propulsion head in the non-cutting method,
A second magnetic field detector 1 provided at a position away from the first magnetic field detector 101 by a predetermined distance L in the same propulsion head.
02, a gravitational acceleration direction detector provided on the same propulsion head, a propulsion distance measuring means 9, and a processor 130 for calculating the horizontal position and the depth position of the propulsion head from information from these detectors. Used.

In the present invention, as described below, a distance L between the two magnetic field detectors 101 and 102 and a single propulsion distance L ′.
Even if these do not necessarily match, the true change in the horizontal direction of the propulsion head can be obtained while correcting the disturbance of the geomagnetism.

[0027] from the first magnetic field detector 101 detects the first magnetic field azimuthal angle phi _alpha, the second magnetic field detector 102 detects the second magnetic field azimuth phi _beta, the first magnetic field azimuth angle phi _α and the second
From the magnetic field azimuth angle φ _β of the first magnetic field detector 101, the magnetic field azimuth angle at the virtual position P in front of the first magnetic field detector 101 is estimated. At this time, the distance between the virtual position P and the second magnetic field detector 102 is L ′.

The method of estimating the magnetic field azimuth angle φ _{p at} the virtual position P includes a first magnetic field azimuth angle φ _α and a second magnetic field azimuth angle φ _β
Then, a method of linear approximation was applied as in the following equation.

[0029]

(Equation 1)

The propulsion head 100 is propelled by a constant interval L '.
The virtual position P estimated in the previous measurement
Magnetic field azimuth φ_pAnd the second magnetic field direction in this measurement
Angle φ _βChange of the propulsion direction of the propulsion head 100 while comparing
And the change in the horizontal direction along with the excavation distance L '
To the horizontal position of the propulsion head 100,
Obtained from the gravitational acceleration direction detector 110.
Angle of inclination along with the propulsion distance changes to the amount of displacement in the depth direction.
After that, the depth of the propulsion head is obtained by integration.

A detection method using the apparatus shown in FIG. 1 will be described with reference to FIGS. 2 and 3 show the geomagnetism 14
FIG. 2 is a plan view showing how the propulsion is performed while the position of the propulsion head is measured by the measuring method of the present invention in a state where the lines of magnetic force are not parallel because 0 is distorted by the influence of a nearby magnetic material.

First, FIG. 2 shows a case where a straight section is propelled. When the propulsion head is at the position shown in FIG. 2A, the first magnetic field detector 101 measures the azimuth of geomagnetism (azimuth of geomagnetism with respect to the direction of the propulsion head) φ _α and the second magnetic field azimuth φ _β. From these, the magnetic field azimuth φ _p at the virtual position located near and in front of the first magnetic field detector is estimated.

Next, when reaching the position shown in FIG. 2B by propulsion by the distance L 'between the virtual position and the second magnetic field detector, the azimuth angle φ _β of the geomagnetism is measured by the second magnetic field detector 102. I do. When φ _β -φ _p is calculated, in this case, the drilling is performed in a straight line. Therefore, φ _β -φ _p = 0, and the horizontal displacement calculated from the difference in the angle and the drilling distance becomes zero. Is measured. Therefore, by repeating this operation, the tip position of the propulsion head accompanying the propulsion can be continuously measured.

On the other hand, FIG. 3 shows a case where the propulsion head excavates a curved portion. The propulsion head 100 is shown in FIG.
When the position of (a), the first magnetic field detector 101 geomagnetic azimuth phi _alpha and second magnetic field azimuth phi _beta in measuring, near and located in front of the first magnetic field detector 101 from these The magnetic field azimuth angle φ _p at the virtual position to be estimated is estimated. Next, when the vehicle is propelled by the distance L ′ between the virtual position P and the second magnetic field detector 102 and reaches the position shown in FIG. 3B, the azimuth φ _β of the geomagnetism is measured by the second magnetic field detector 102. . φ _β −φ
_{When p} is calculated, in this case, the excavation is performed in a curved line, so that _{β β} −φ _p ≒ φ, and the horizontal displacement calculated from the difference φ of this angle and the excavation distance is the horizontal position when the curve is propelled. It is a displacement and it is measured that a curve is propelled.
Therefore, by repeating this operation, the position of the propulsion head accompanying the propulsion can be continuously measured.

In both the case of straight propulsion (FIG. 2) and the case of curved propulsion (FIG. 3), the correct horizontal position of the propulsion pipe can be measured irrespective of the distortion of geomagnetism due to the nearby magnetic material. As for the position in the depth direction, the depth displacement can be calculated from the inclination angle measured by the inclination angle meter and the propulsion distance.

Next, a method of measuring the position and direction of the propulsion head of the present apparatus will be described with reference to a block diagram (FIG. 4) showing the configuration of the present apparatus in more detail. FIG. 4 is a block diagram showing the configuration of the propulsion head position / direction measuring device according to the first embodiment of the present invention.

In this apparatus, the propulsion distance of the propulsion head 100 is managed by the propulsion distance measuring device 120, and the propulsion head 10 is controlled.
Each time 0 is propelled by 1 m, the following measurement and signal processing are performed.

Here, a description will be given of a method of obtaining a change in the horizontal position and a change in the depth direction of the excavated pipe between the i-th excavation and the (i + 1) -th excavation.

Measurement of geomagnetism measured by a first magnetic field detector 101 provided on the propulsion head 100 and a second magnetic field detector 102 provided on the same propulsion head as the magnetic field detector 101 and separated by 0.8 m The values φ _α and φ _β are respectively stored in the first magnetic field measurement value storage unit 201 and the second magnetic field measurement value storage unit 20.
Store it in 2. The measured value of the gravitational acceleration direction detector 110 at that time is stored in the measured acceleration value storage unit 203.

The first and second magnetic field measurement value storage units 201,
The azimuth angles φ _{α, i} and φ _{β, i} of the geomagnetism are calculated from the geomagnetic measurement value stored in the storage unit 202 and the acceleration measurement value stored in the acceleration measurement storage unit 203, and the first and second azimuths are calculated.
Are stored in the geomagnetic azimuth storage units 221 and 222, respectively.

The calculation of the azimuth angle of the geomagnetism here will be described more specifically. The inclination / rotation angle calculation unit 213 uses the gravity propulsion direction component g _{Z ′} and the vertical direction component g _{x ′} stored in the acceleration measurement value storage unit 203 to perform propulsion on a plane orthogonal to the propulsion plan line. Angle of inclination θ to the planning line
_{y, i,} and calculates a rotation angle θ _{r, i} about the propulsion plan direction from the vertical direction component g _{x ′} and the horizontal direction component g _{y ′,} and calculates the tilt angle / rotation angle calculation unit. 223.

Then, the first and second geomagnetic azimuth calculating units 211 and 212 measure the magnetic field measured values φ _α and φ _β stored in the first and second magnetic field measured value storage units 201 and 202, respectively. , The rotation angle θ _{r, i} and the inclination angle θ of the propulsion head 100 stored in the inclination / rotation angle calculation unit 223.
By performing coordinate conversion using _{y and i} , the azimuth angles φ _{α, i} and φ _{β, i} of the geomagnetism are calculated. Then, the calculation results φ _{α, i} , φ of the geomagnetic azimuth calculation units 211, 212 respectively
_{β, i} are stored in first and second geomagnetic azimuth storage units 221 and 22
Store it in 2.

Next, the magnetic field azimuth estimating unit 224 calculates
The azimuth angle φ _{p, i} of the geomagnetism at the virtual point P _i where the second magnetic field detector 102 is located is estimated by the first excavation.
Note that the azimuth angle of the geomagnetic phi _alpha, from _i, phi _{beta, i} excavation distance L ', and the magnetic field detector installation interval L, the azimuth angle phi _{p, i} geomagnetic in the virtual point P _i is calculated using the formula: .

[0044]

(Equation 2)

Next, the propulsion head 100 is propelled by a constant interval L '= 1 m by the (i + 1) -th excavation. Since the distance between the second magnetic field detector 102 and the virtual point P _i is set to one excavation distance of the propulsion head, the propulsion head is excavated by 1 m, so that the second magnetic field detector 10 is excavated.
No. 2 advances to near the virtual position P _i .

After the propulsion head 100 is excavated, the first and second magnetic field detectors 101 and 102 detect geomagnetism in three axial directions, and the gravitational acceleration direction detector 110 detects acceleration in three axial directions. Then, similarly to the above, the rotation angles θ _{r, i + 1} and the inclination angles θ of the propulsion head 100 are calculated from the accelerations in the three axial directions.
_{y, i + 1} , the obtained rotation angle θ _{r, i + 1} and the inclination angle θ
_y, the _{i +1} performing coordinate conversion of the three axial components of geomagnetism, the azimuth angle of the geomagnetic _{φ α, i + 1, φ} β, seeking _{i +1,} the first and second geomagnetic azimuth storage unit 221 , 222.

The horizontal position direction calculation section 230 performs the following calculation. That is, the azimuth angle φ _{p, i} of the geomagnetism obtained at the previous i-th measurement point is subtracted from the azimuth angle φ _{β, i + 1 of} the geomagnetism obtained at the _{(i + 1} ) -th measurement point, and i
Azimuth angle change of propulsion head due to _{+ 1st} excavation φ _{i + 1}
= Φβ _{, i + 1} − φp _{, i} .

Total excavation at the end of the j-th excavation
Head azimuth θ with respect to image direction _jIs θ_j= Φ₀+ Φ₁+ Φ_Two+ ... + φ_j-1+ Φ_j Becomes

The horizontal position change X _j of the head tip with respect to the j-th excavation distance L [m] is X _j = L · ta
n (θ _j ). Therefore, the tip position X in the horizontal direction for the number of excavation times m so far can be obtained by integrating X _i , that is, using the following equation, with X ₀ as the initial value.

X = X ₀ + X ₁ +... + X _j +... + X _m The horizontal position of the tip position of the propulsion head thus determined is displayed on the horizontal position display section 240.

On the other hand, the depth direction position calculation section 250 performs the following calculation to determine the position Y in the depth direction. The position change Y _j of the head tip in the depth direction with respect to the excavation distance [m] at the i-th position is calculated by using the inclination angle θ _{y, j} stored in the inclination / rotation angle storage unit, and Y _j = L · tan (θ _{y, j} ). Therefore, the position Y in the depth direction at the number of excavation times m so far
Is obtained by using the integral of Y _j , that is, using the following equation, with Y ₀ as the initial value.

Y = Y ₀ + Y ₁ +... + Y _j +... + Y _{m In} this manner, the depth direction position of the propulsion head position obtained by the depth direction position calculation section 250 is displayed on the depth direction position display 260. Is displayed.

As described above, the first in the propulsion head
And a second magnetic field detector, and the second azimuth angle φα _{, i} , φβ _{, i obtained} from the two magnetic field detectors
Of the geomagnetic azimuth φ _{p, i} at a virtual position P _i one excavation distance L [m] away from the magnetic field detector of the second embodiment, and the second at the position where the propulsion head is excavated L [m] The azimuth angle φ _{β, i + 1} of the geomagnetism is obtained by using the magnetic field detected by the magnetic field detector, and from the difference between the obtained φ _{β, i +1} and φ _{p, i} , the propulsion head by the (i + 1) th excavation The horizontal displacement of the propulsion head can be known by obtaining the azimuth angle change φ _{i + 1} of. In addition, by integrating the horizontal displacement of the propulsion head for each excavation, the horizontal position of the propulsion head can be accurately known.

In addition, there are fewer restrictions on the position where the magnetic field detector is mounted in the propulsion head, and the excavation distance and the distance between the two magnetic field detectors can be determined independently of each other, which is effective in designing the propulsion head.

Since the change in the direction of the tip of the propulsion head can be accurately measured, effective information contributing to the work of correcting the propulsion direction that occurs in actual propulsion work can be measured. As described above, the present invention enables practical construction even in a situation where a geomagnetic field is distorted due to the presence of a steel-framed building or other buried piping, especially in an urban area.

Further, by measuring the inclination angle of the propulsion head every time the propulsion head advances a predetermined distance, the displacement of the propulsion head in the depth direction can be known from the product of the inclination angle and the predetermined distance. By integrating the displacement in the direction,
The position of the propulsion head in the depth direction can be accurately known.

In this embodiment, the installation interval L between the two magnetic field detectors is smaller than one excavation distance L '. However, the installation interval L between the two magnetic field detectors is one excavation distance L'. If it is larger than ', the same operation can be performed if the virtual point P is provided between the two magnetic field detectors.

(Second Embodiment) This embodiment shows an example in which the number of magnetic field detectors is set to three to further improve the accuracy. FIG. 5 is a diagram showing a schematic configuration of a propulsion head position / direction measuring device according to a second embodiment of the present invention. The distance between the magnetic field detector 301 and the magnetic field detector 302 is L1 = 0.
3 m, and the distance between the magnetic field detector 302 and the magnetic field detector 303 is set in the propulsion head 100 at a distance of L2 = 0.5 m. The virtual position P is 1 m in front of the magnetic field detector 303 (=
L ′) The position is distant. That is, this is an embodiment in which a single propulsion distance is set to 1 m.

First, at a certain excavation position i, the magnetic field detector 301, the magnetic field detector 302, and the magnetic field detector 303 measure the terrestrial magnetism to determine the azimuth of each terrestrial magnetism. At the virtual position P, the azimuth angle φ _{p, i} of the geomagnetism is determined by the azimuth angle φ _{α, i of} the magnetic field detector 301 and the magnetic field detector 30.
2 of the geomagnetic azimuth φ _{β, i,} geomagnetic azimuth phi _gamma of the magnetic field detectors _{303, i,} by using the estimated by the following equation.

[0060]

(Equation 3)

Next, digging is performed by 1 [m] (= L '), and the magnetic field detector 301, the magnetic field detector 302, and the magnetic field detector 303
The terrestrial magnetism is measured in each of the above, and the azimuth angle of each terrestrial magnetism is obtained. At this time, the azimuth of the geomagnetism is φ _{p, i + 1} , the azimuth of the magnetic field detector 301 is φ _{α, i + 1} , the azimuth of the magnetic field detector 302 is φ _{β, i + 1} , The geomagnetic azimuth of 303 is φγ _{, i + 1} . From these azimuths,
The change in the azimuth angle of the propulsion head is φ _{i + 1} = φ _{γ, i + 1} −φ _{p, i}
Is obtained as If the change in the azimuth angle of the propulsion head for each propulsion can be measured, the horizontal position of the propulsion head can be obtained by sequentially accumulating the changes according to the propulsion distance.

In this embodiment, the case where the number of magnetic field detectors is three has been described. However, even when the number of magnetic field detectors is generally four or more, the embodiment can be implemented in the same manner as this embodiment. it can.

(Third Embodiment) FIG. 6 shows a third embodiment of the present invention.
It is a figure showing the schematic structure of the propulsion head position direction measuring device concerning an embodiment. 6, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. The device shown in FIG. 6 differs from the device described in the first embodiment in that an artificial magnetic field generating means 601 is further provided. As the artificial magnetic field generating means 601, a circular coil having a radius of 2 m and a magnetomotive force of 100 AT was used.

Since the measuring method of this apparatus is the same as that of the first embodiment, the description is omitted. However, when an artificial magnetic field is used, the direction of the artificial magnetic field near the center of the coil is only the vertical direction. In the vicinity of the artificial magnetic field measurement place of the propulsion head, a place where the horizontal component of the artificial magnetic field exists is applied.

It should be noted that the present invention is not limited to the above-described embodiment, but can be implemented in various modifications without departing from the scope of the invention.

[0066]

As described above, according to the present invention, the azimuth of the magnetic field with respect to the propulsion direction of the propulsion head is determined from the respective magnetic fields detected using the plurality of magnetic field detectors including the main magnetic field detector. It determined, from a plurality of magnetic field azimuth obtained, wherein the main magnetic field detector virtual place P propulsion set in the forward a distance L 'away the estimates the magnetic azimuth angle phi _p with respect to the propulsion direction, When the propulsion distance of the propulsion head becomes the distance L ′, the main magnetic field detector is used to detect the magnetic field azimuth φ _{β with} respect to the propulsion direction of the propulsion head.
The calculated, by comparing the magnetic field azimuth angle phi _p and magnetic azimuth phi _beta, by calculating the horizontal direction of the change of the propulsion head, even if there is geomagnetic disturbances by magnetic structure in the vicinity , The true azimuth angle of the propulsion head can be obtained regardless of the spatial disturbance. Further, the azimuth angle is converted into a displacement in accordance with the excavation distance and integrated, whereby the position of the propulsion head can be accurately measured.

In particular, even when the distance L between the two magnetic field detectors and the one-time propulsion distance L 'do not always coincide with each other, it is necessary to obtain a true change in the horizontal direction of the propulsion head while correcting the disturbance of the geomagnetism. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a propulsion head position / direction measuring device according to a first embodiment.

FIG. 2 is a diagram used for explaining the measurement method of the present invention.

FIG. 3 is a diagram used for describing the measurement method of the present invention.

FIG. 4 is a block diagram showing the propulsion head position / direction measuring device shown in FIG. 1 in more detail;

FIG. 5 is a diagram showing a schematic configuration of a propulsion head position / direction measuring device according to a second embodiment.

FIG. 6 is a diagram showing a schematic configuration of a propulsion head position / direction measuring device according to a third embodiment.

FIG. 7 is a diagram showing a schematic configuration of a conventional propulsion head position / direction measuring device.

FIG. 8 is a diagram showing a schematic configuration of a conventional propulsion head position / direction measuring device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 propulsion head 101 first magnetic field detector 102 second magnetic field detector 103 propulsion pipe 110 gravitational acceleration direction detector 120 propulsion distance measuring device 130 arithmetic processing unit 140 geomagnetic 201 first Magnetic field measurement value storage unit 202: second magnetic field measurement value storage unit 203: acceleration measurement value storage unit 213: tilt angle / rotation angle calculation unit 221: first geomagnetic azimuth angle storage unit. 222 ... second geomagnetic azimuth storage unit 223 ... tilt angle / rotation angle calculation unit 224 ... magnetic field azimuth angle estimation unit 230 ... horizontal position direction calculation unit 240 ... horizontal position display unit 250 ... direction position calculation unit 260 ... direction position Display 303: Magnetic field detector

 ────────────────────────────────────────────────── ─── Continued on front page (72) Inventor Osamu Araki 1-2-1 Marunouchi, Chiyoda-ku, Tokyo F-term in Nihon Kokan Co., Ltd. (reference) 2D054 AC18 GA17 GA25 GA42 GA62 GA65 GA85 GA92

Claims (11)

[Claims] A step of obtaining a magnetic field azimuth angle with respect to the propulsion direction at a position where each magnetic field detector is installed, using a plurality of magnetic field detectors provided in the propulsion head along the propulsion direction; using a plurality of magnetic field azimuth obtained, at a distance L 'away virtual position P in the propulsion direction forward from the selected magnetic field detector from a plurality of magnetic field detectors, the magnetic field azimuth angle phi _p with respect to the propulsion direction Estimating, measuring the propulsion distance of the propulsion head, and, when the measured propulsion distance becomes the distance L ′, using the selected magnetic field detector to determine the propulsion direction of the propulsion head. promotion determining a magnetic field azimuth angle phi _beta, by comparing the magnetic field azimuth angle phi _p and magnetic azimuth phi _beta, characterized in that it comprises a step of computing a horizontal change of the propulsion head Head position direction measuring method. 2. A step of determining a first magnetic field azimuth angle using a first magnetic field detector provided on a propulsion head, wherein the first magnetic field azimuth is located behind the first magnetic field detector provided on the propulsion head. Determining a second magnetic field azimuth using a second magnetic field detector; and detecting a first magnetic field at a distance L ′ from the second magnetic field detector using the first and second magnetic field azimuths Estimating a third magnetic field azimuth at a virtual position near the vessel, measuring the propulsion distance of the propulsion head, and determining the first and second magnetic field azimuths. A step of obtaining a fourth magnetic field azimuth from the magnetic field detected by using the second magnetic field detector at the time when the distance L ′ has been reached; and calculating the third magnetic field azimuth and the fourth magnetic field azimuth. Calculating the change in the horizontal direction of the propulsion head. A method for measuring the position and direction of a propulsion head. 3. When the measured propulsion distance reaches the distance L ', the inclination angle of the propulsion head is measured, and a change in the depth direction of the propulsion head is measured based on the measured inclination angle. The propulsion head position / direction measuring method according to claim 1 or 2, wherein 4. The horizontal position of the propulsion head is measured by measuring the horizontal change of the propulsion head a plurality of times, and integrating the changes measured a plurality of times to measure the horizontal position of the propulsion head. 3. The method for measuring the position and direction of a propulsion head according to any one of 3. 5. A method for measuring the position of the propulsion head by measuring changes in the depth direction and the horizontal direction of the propulsion head a plurality of times, and integrating the changes measured in the horizontal direction and the depth direction a plurality of times, respectively. The method for measuring the position and direction of a propulsion head according to claim 4. 6. A magnetic field detector is fixed to the propulsion head, detects a magnetic field with the magnetic field detector, measures a rotation angle and an inclination angle of the propulsion head, and measures the measured magnetic field, rotation angle, and inclination angle. 6. The method for measuring the position and direction of a propulsion head according to claim 1, wherein the azimuth angle of the magnetic field is determined based on the following formula. 7. The propulsion head position / direction measurement method according to claim 1, wherein an azimuth angle of geomagnetism is detected as the magnetic field azimuth angle. 8. The propulsion head position according to claim 1, wherein an artificial magnetic field is generated by a magnetic field generator installed on the ground, and the azimuth of the artificial magnetic field is detected as a magnetic field azimuth. Direction measurement method. 9. A plurality of magnetic field detectors provided on the same propulsion head along a propulsion direction, a propulsion distance detector for measuring a propulsion distance of the propulsion head, and a magnetic field direction measured by the magnetic field detector, respectively. A magnetic field azimuth estimating unit for estimating a magnetic field azimuth at a virtual point ahead of the propulsion direction from the angle; a magnetic field azimuth estimated by the magnetic field azimuth estimating unit;
A propulsion head position / direction measuring device, comprising: a processor for calculating a change in the horizontal direction of the propulsion head based on the magnetic field azimuth angle obtained by the magnetic field detector. 10. A magnetic field detector fixed to the propulsion head, a posture detector for detecting at least one of a rotation angle and an inclination angle of the propulsion head; a magnetic field measured by the magnetic field detector; 10. The propulsion head position / direction measuring apparatus according to claim 9, further comprising an arithmetic processing unit for obtaining a magnetic field azimuth angle based on the rotation angle and the inclination angle detected by the device. 11. The propulsion head position / direction measuring apparatus according to claim 9, further comprising artificial magnetic field generating means provided on the ground surface.