JP2004157011A - Method and device for measuring slope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for measuring a slope capable of measuring a distance, position, and also coordinates, not only bearings to a subject to be measured. <P>SOLUTION: The device comprises a 1st exciting coil Ex1, a 2nd exciting coil Ex2, and a 3rd exciting coil Ex3, each center axis of which is arranged coinciding with each axis of a 3 axis coordinate system, a 1st switching circuit 13 for exciting each exciting coil sequentially with an output of a signal generating circuit, a 1st detecting coil Dx1, a 2nd detecting coil Dx2, and a 3rd detecting coil Dx3, each center axis of which is arranged coinciding with each axis of the 3-axis coordinate system at the position of the object to be measured, a 2nd switching circuit 23 for taking out an output of each detecting circuit sequentially, and a voltage taking out circuit for taking out a voltage signal. Firstly, the 1st exciting coil is excited for taking out the voltages sequentially, the 2nd exciting coil is exited, then 3rd exciting coil is excited for taking out the voltages sequentially, the 9 kinds of induced voltages totally taken out are used for calculating the bearings, a distance from a reference position to the subject, and also the coordinates of the subject. <P>COPYRIGHT: (C)2004,JPO

Description

同様にＹ軸、Ｚ軸についてのθｙ、θｚは以下の数２、数３で示される。
【００３９】
【数２】

【数３】

以上の通り、第一〜第三の検出コイルＤｘ１〜Ｄｘ３に誘起される電圧Ｅｕ１、Ｅｖ１、Ｅｗ１、Ｅｕ２、Ｅｖ２、Ｅｗ２、Ｅｕ３、Ｅｖ３、Ｅｗ３を計測すれば数１から数３の演算により、基準位置Ｐｏから測定対象位置Ｐａへの方位が求まる。
【００４０】
図４は本発明による斜面測定装置の距離測定原理を説明するための図である。図４のように基準位置Ｐｏに配置されたループ寸法が波長に比べて十分短い微小ループアンテナの測定対象位置Ｐａにおける放射電磁界は以下の一般式である数４、数５、数６で示され、ＨｒとＨθが磁界を示し、Ｅφが電界を示している。但し、ω：角周波数、Ｉ：微小ループアンテナに流れる電流、λ：波長、Ｓ：微小ループアンテナの面積、ｋ：波数（ｋ＝２π／λ）、ｒ：微小ループアンテナの中心からの距離、η_０ ：特性インピーダンス、μ：透磁率である。
【００４１】
【数４】

【数５】

【数６】

ここで、１〜１０ＫＨｚ程度の低周波で微小ループからの距離ｒを数１００ｍまでとした場合、ｋｒ＝（２πｒ／λ）＜＜１の関係が成り立つため、以下の不等式（１６）、（１７）が成立する。
【００４２】
１＋（１／ｊｋｒ）＜＜１／（ｊｋｒ）^２ （１６）
−Ｅφ＜＜Ｈθ，Ｈｒ （１７）
また、上記の数４は式（１６）の条件により以下の数７で表される。
【００４３】
【数７】

ここで、１／λ＝ｋ／２πであるから以下の数８が得られる。
【００４４】
【数８】

さらに、η_０ ＝（μ／ε）^１／２ から以下の数９が得られる。
【００４５】
【数９】

ここで、Ｃを光速とすると、以下の式が得られる。
【００４６】
（με）^１／２ ＝１／Ｃ
ω／Ｃ＝２πｆ／Ｃ＝２π／λ＝ｋ
上記の数８は、下記の数１０で表される。
【００４７】
【数１０】

同様にＨｒは下記の数１１で表される。
【００４８】
【数１１】

数１０、数１１のいずれにおいても定数、距離、減衰項、指向性の積の関数として示され、磁界の大きさは距離ｒの３乗に反比例して減衰することが示される。
【００４９】
ここで、検出コイルを励磁する磁界の強さと検出コイルに誘起される電圧は比例することから、検出コイルから得られる９種類の誘起電圧Ｅｘｕ、Ｅｘｖ、Ｅｘｗ、Ｅｙｕ、Ｅｙｖ、Ｅｙｗ、Ｅｚｕ、Ｅｚｖ、Ｅｚｗを測定し、以下の式に基づく演算を行うことで検出コイルの位置の磁界の大きさに比例した電圧Ｅを得ることができる。これらをまとめて式（２１）とする。
【００５０】
Ｅｘ^２ ＝Ｅｘｕ^２ ＋Ｅｘｖ^２ ＋Ｅｘｗ^２
Ｅｙ^２ ＝Ｅｙｕ^２ ＋Ｅｙｖ^２ ＋Ｅｙｗ^２
Ｅｚ^２ ＝Ｅｚｕ^２ ＋Ｅｚｖ^２ ＋Ｅｚｗ^２ （２１）
Ｅ^２ ＝Ｅｘ^２ ＋Ｅｙ^２ ＋Ｅｚ^２ （２２）
ここで、基準位置Ｐｏと測定対象位置Ｐａとの間の距離が既知ｒｏ の場合の電圧Ｅｏ を式（２１）、（２２）と同様な方法で予め求めておく。これにより基準位置Ｐｏと測定対象位置Ｐａの距離がｒ１の場合の電圧Ｅ１は距離の３乗に反比例することから、
ｒ１^３ ／ｒＯ ^３ ＝ＥＯ ／Ｅ１
ｒ１＝（ＥＯ ／Ｅ１）^１／３ ｒＯ
で示される。
【００５１】
したがって、検出コイルから得られる９種類の誘起電圧をそれぞれ測定することにより、基準位置Ｐｏから測定対象位置Ｐａの距離を測定することができる。基準位置Ｐｏから測定対象位置Ｐａへの方位と距離を求めることで、基準位置Ｐｏの座標から測定対象位置Ｐａの座標が特定されるので、測定対象位置Ｐａの座標に変化が生じれば斜面崩壊の前兆が捉えられることになる。
【００５２】
なお、基準位置Ｐｏの位置決めはＧＰＳや路面上の印などを用いることで容易に設定できることは言うまでもない。また、２つ以上の基準位置を決め、つまり例えば三つの励磁コイルの組み合わせを２つの位置に配置して、それぞれ測定対象位置の座標を演算し、得られた座標の平均処理を行うことで測定精度の向上を図ったり、相対変位を得ることができることは言うまでもない。勿論、三つの検出コイルの組み合わせを２組以上配置するようにしても良い。
【００５３】
さらに、図１では電圧計で計測した電圧値を用いて、上記の演算を別の装置で行うことを想定しているが、電圧計に代えてＡ／Ｄ変換機能を持つ演算処理装置を直接接続しても良い。この場合、演算処埋装置は、上記の演算処埋プログラムを内蔵しており、第二の切り替え回路２３から順に得られる９種類の電圧値を順にサンプリングして上記の演算を行うことにより、基準位置Ｐｏから測定対象位置Ｐａへの方位と、基準位置Ｐｏから測定対象位置Ｐａへの距離を求め、基準位置の座標系における測定対象位置Ｐａの座標を算出する。
【００５４】
本発明による斜面測定装置は、車両などの移動体上に設定した基準位置に対して測定対象位置を数十ｍ以上離れた位置に設定することができ、しかも測定対象位置は地表は勿論、地中、水中の別を問わない。このような斜面測定装置は、光学計測機器では測定出来ない地中内部や水中における測定が可能であり、地中内部の変位や水中での斜面の変位を測定することができるので、斜面表面の崩壊だけでなく斜面内部の土塊にひずみが発生して斜面表面が崩壊に至る前兆を検出することが可能となる。つまり、斜面内部のひずみがある値以上になっていれば警報表示を行うようにすれば良い。
【００５５】
【発明の効果】
以上説明したように、本発明の斜面測定装置によれば、基準位置を少なくとも１箇所設定することで、測定対象位置への方位と距離を求め、測定対象位置の三次元空間における座標位置を特定することができる。
【００５６】
また、発振回路の周波数を可聴帯域にすると励磁コイルから発生する電磁波は磁界成分が主となるため、電界成分が主となる高周波帯域を使用した電磁波に比べ土中、水中における減衰が少なく、地中内部や水中などの条件においても座標特定が可能となる。
【００５７】
更に、励磁電流を基準とした同期検波を用いると、検出電圧の二乗値を求めると同時に、雑音対信号特性においても有利になり、得られる効果は大である。
【図面の簡単な説明】
【図１】本発明の実施の形態による斜面測定装置の構成を示す図である。
【図２】図１の装置による測定状況を説明するための図である。
【図３】図１の装置による方位測定原理を説明するための図である。
【図４】図１の装置による距離測定原理を説明するための図である。
【符号の説明】
１１ 発振回路
１２ 増幅器
１３、２３ 第一、第二の切り替え回路
１５、２５ 第一、第二のコンピュータ
１６、２６ 第一、第二の通信回路
Ｅｘ１、Ｅｘ２、Ｅｘ３ 第一、第二、第三の励磁コイル
Ｄｘ１、Ｄｘ２、Ｄｘ３ 第一、第二、第三の検出コイル[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a slope measuring method and a measuring device for detecting early collapse of an embankment slope such as a highway.
[0002]
[Prior art]
As a measurement method for measuring the collapse of a slope such as a road shoulder, there is the following example.
[0003]
In the first example, a wire is installed between a measurement target position and a reference position, and a tension meter is installed on the wire, and the occurrence of a slope collapse is detected from the wire tension.
[0004]
In the second example, a wire is installed between the measurement target position and the reference position, and a mobile meter or the like is installed on the wire, and the occurrence of slope collapse is detected from the displacement of the wire.
[0005]
In these measurement methods, measurement is performed by bringing the measurement system into contact with the measurement target.If the measurement interval, that is, the interval between the measurement target position and the reference position, is increased, the looseness of the wire affects measurement errors. Therefore, it is limited to measurement of a relatively short distance.
[0006]
As a measuring means for solving the above problems, there is an optical measuring method. When the optical measurement method is used, a lightwave distance meter, a transit, or the like is used. By using such an optical measuring device, it is possible to determine the reference position, perform optical surveying on the measurement target position, and obtain the azimuth change of the measurement target position with respect to the reference position without contact. In addition, the measurement interval can be set to a long distance, and it is used as a method for measuring the displacement or collapse of a slope.
[0007]
However, since the optical measurement method cannot directly detect the detection target inside the ground, there is a disadvantage that the displacement of the ground surface cannot be measured even if the displacement of the ground surface can be obtained in a three-dimensional coordinate system. .
[0008]
As a method for solving this, the present applicant has proposed the following measuring method. In this measurement method, the first, second, and third excitation coils are arranged at predetermined reference positions such that the central axes coincide with respective axes of a three-axis coordinate system orthogonal to each other, and the reference position The first, second, and third detection coils are arranged such that the central axes coincide with the respective axes of the three-axis coordinate system orthogonal to each other at the measurement target position apart from the first target excitation. Exciting the coil and measuring the voltage induced in the first, second, and third detection coils in that order, and then exciting the second excitation coil, The voltage induced in the second and third detection coils is measured in order, and subsequently, the third excitation coil is excited to be induced in the first, second, and third detection coils at that time. The voltage was measured in order, and a total of 9 obtained from the first, second, and third detection coils were obtained. By performing the operation predetermined by using the induced voltage of the class, a direction measuring method for calculating the orientation of the said measuring points from the reference position (see Patent Document 1).
[0009]
[Patent Document 1]
JP-A-2002-054928 (page 1, FIG. 1)
[0010]
[Problems to be solved by the invention]
However, in the above-described measurement method, only the azimuth is measured, and there is no proposal to calculate the distance or the coordinates to the position to be measured. In addition, the first to third excitation coils must be installed at predetermined reference positions, and when measuring the collapse of a slope such as a road shoulder as described above, the first to third excitation coils are set there. Not only the third detection coil but also the first to third excitation coils must be fixedly installed. This means that as the number of measurement points increases, the number of first to third excitation coils installed also increases.
[0011]
Therefore, an object of the present invention is to provide a slope measuring method and a measuring device capable of measuring not only the azimuth to a measurement target position but also a distance, a position, and coordinates.
[0012]
Another object of the present invention is to provide a slope measuring method and a measuring apparatus which can realize the above-mentioned measurement without fixing and installing an excitation coil.
[0013]
[Means for Solving the Problems]
According to the present invention, a first coil group formed by combining first, second, and third coils is arranged at a first position on each axis of a three-axis coordinate system orthogonal to each other, and three axes orthogonal to each other are arranged. Fourth, fifth, a second coil group formed by combining the sixth coil in each axis of the axis coordinate system is arranged at a second position, first exciting the first coil, The voltage induced in the fourth, fifth, and sixth coils is measured in order, and then the second coil is excited to cause the voltage induced in the fourth, fifth, and sixth coils. Are sequentially measured, and then the third coil is excited, and at that time, the voltages induced in the fourth, fifth, and sixth coils are sequentially measured, and the fourth, fifth, and sixth voltages are measured. By performing a predetermined calculation using a total of nine types of induced voltages obtained from the coil, the first position is calculated. Calculating the azimuth to the second position, calculating the distance between the first position and the second position, the second position from the coordinates of the first position and the first position. A slope measurement method for calculating coordinates of the second position from an azimuth and a distance to a position, wherein the first coil group or the second coil group is arranged on a moving body. A slope measurement method is provided.
[0014]
According to the present invention, a signal generating circuit and a first coil which is disposed at a first position and is formed by combining first, second, and third coils on respective axes of a three-axis coordinate system orthogonal to each other. Group, a second coil group formed by combining a fourth, fifth, and sixth coils on respective axes of a three-axis coordinate system arranged at a second position and orthogonal to each other, and the first and second coils A first switching circuit for sequentially exciting a third coil with the output of the signal generating circuit, and a second switching circuit for sequentially extracting outputs from the fourth, fifth, and sixth coils, The first, fifth, and sixth control operation means for performing a predetermined operation using an output obtained from the sixth coil, and first excites the first coil, The voltages induced in the fourth, fifth and sixth coils are measured in order, and then the When the coil is excited, the voltages induced in the fourth, fifth, and sixth coils are measured in order, and then the third coil is excited, and the fourth, fifth, and fifth coils are then excited. , The voltage induced in the sixth coil is measured in order, and the first control calculation means uses the total of nine types of induced voltages obtained from the fourth, fifth, and sixth coils to calculate the voltage in advance. By performing a predetermined calculation, the azimuth from the first position to the second position is calculated, the distance between the first position and the second position is calculated, and further the A slope measurement device that calculates the coordinates of the second position from the coordinates of one position and the azimuth and distance from the first position to the second position, wherein the first coil group or the A slope measurement device is provided, wherein the second coil group is arranged on a moving body. That.
[0015]
In a preferred aspect of the present slope measurement device, the second switching circuit is connected to a second control calculation unit that collects outputs from the fourth, fifth, and sixth coils, and the second control circuit A second communication unit for transmitting and receiving information is connected to the arithmetic unit, and a first communication for transmitting and receiving information to and from the second communication unit is connected to the first control arithmetic unit. The means are connected.
[0016]
In a preferred aspect of the present slope measurement device, the first control calculation means controls switching of the first switching circuit, and switches the switching information of the second switching circuit via the first communication means. Is sent to the second control calculation means, and the second control calculation means controls switching of the second switching circuit based on the switching information received via the second communication means.
[0017]
In any of the above-described slope measurement methods and slope measurement apparatuses, improvement in measurement accuracy or relative displacement can be obtained by arranging at least two sets of the first coil group or the second coil group. it can.
[0018]
[Action]
According to the present invention, since displacement of the inside of the slope can be detected from the output of the plurality of detection coils installed in the ground under the slope, a sign is generated that the soil surface inside the slope is distorted and the slope surface collapses is detected. This makes it possible to issue an alarm not only at the slope surface collapse but also at the stage of strain generation inside the slope.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a slope measuring device according to an embodiment of the present invention.
[0020]
In FIG. 1, the slope measuring device has an oscillation circuit 11 and an amplifier 12 for amplifying the output as a signal generation circuit for outputting an alternating signal. The frequency of the oscillation circuit 11 is preferably in the audible band, but is not limited to this. In addition, the slope measuring device is integrated so that the central axes coincide with the respective axes of the three-axis coordinate system orthogonal to each other, and the first, second, and third excitation coils Ex1, Ex2 are arranged at certain specific positions. , Ex3 and a first switching circuit 13 for sequentially exciting the first to third excitation coils Ex1 to Ex3 with the output of the amplifier 12.
[0021]
The first computer 15 (first control calculation means) controls the oscillation circuit 11 and controls the first switching circuit 13 to sequentially excite the first to third excitation coils Ex1 to Ex3 in a predetermined procedure. I do. The first computer 15 also controls the second computer 25 by wireless communication using the first communication circuit 16 provided with an antenna and the second communication circuit 26.
[0022]
The slope measuring device further includes first, second, and third detection coils Dx1, Dx2, which are integrated and arranged at the measurement target position so that the central axes coincide with the respective axes of the three-axis coordinate system orthogonal to each other. Dx3, and a second switching circuit 23 for sequentially extracting the outputs of the first to third detection coils Dx1 to Dx3. A detection circuit 27 that detects the output selected by the second switching circuit 23 is connected to the second switching circuit 23. The output of the detection circuit 27 is taken out as a voltage signal by a voltmeter 28.
[0023]
The second computer 25 (second control arithmetic unit) is controlled by the first computer 15 by wireless communication using the first communication circuit 16 and the second communication circuit 26, and controls the second switching circuit 23. Control. That is, the second computer 25 receives the information on the switching procedure in the second switching circuit 23 from the first computer 15 and switches the second switching circuit 23 according to a predetermined procedure based on this information. The induced voltages of the first to third detection coils Dx1 to Dx3 obtained from the above are recorded. The induced voltages of the first to third detection coils Dx1 to Dx3 recorded in the second computer 25 are recorded in the first computer 15 by wireless communication using the first communication circuit 16 and the second communication circuit 26. Then, the first computer 15 calculates the coordinates of the position to be measured by the method described below.
[0024]
FIG. 2 is a diagram showing a measurement situation of the slope measuring device according to the present invention. The first measuring device including the first to third excitation coils Ex1 to Ex3, the oscillation circuit 11, the amplifier 12, the first switching circuit 13, the first computer 15, and the first communication circuit 16 is a movable vehicle. Mounted on top.
[0025]
On the other hand, second measurement devices such as a second switching circuit 23, a detection circuit 27, a voltmeter 28, a second computer 25, and a second communication circuit 26, and first to third devices disposed under a road surface or on a slope. , At least one set of the detection coils Dx1 to Dx3 is arranged at the position to be measured on the slope. Accordingly, if a plurality of measurement target positions are set along the road below the road surface or on the slope, the vehicle can be moved and the measurement can be sequentially performed.
[0026]
It goes without saying that there is no problem if the first measuring device is arranged on a moving body other than the vehicle or the measurement is performed after the first measuring instrument is dropped on a road surface or a slope from the moving body. Further, the second measuring device may be mounted on a moving body, and the first measuring device may be arranged at a position to be measured.
[0027]
Further, the oscillation circuit 11, the amplifier 12, the first switching circuit 13, the second switching circuit 23, and the detection circuit 27 do not use the second computer 25, the first communication circuit 16 and the second communication circuit 26. Needless to say, a similar effect can be obtained by disposing a measuring device such as a voltmeter 28 on a vehicle and connecting the measuring device and the first to third detection coils Dx1 to Dx3 using a cable. .
[0028]
FIG. 3 is a view for explaining the principle of azimuth measurement of the slope measuring device according to the present invention. The respective axes of the orthogonal three-axis coordinate system are defined as an X axis, a Y axis, and a Z axis, and a magnetic moment generated from the excitation coil at the reference position Po at which the central axis XC1 coincides with the X axis is defined as M. Here, the reference position Po is a name for explanation, and does not mean that the reference position Po is fixedly set. In this case, assuming that the magnetic field at the measurement target position Pa on the magnetic field created by the magnetic moment M is Hx, the component in the distance r direction between the reference position Po and the measurement target position Pa is Hxr, the center orthogonal to the r direction. Assuming that a component going outside the axis XC1 is Hxθ, Hxr and Hxθ are expressed by the following equations. Incidentally, [theta] x is the angle at which r direction makes with the X-axis in the following formula, mu ₀ is the permeability of the space.
[0029]
Hxr = 2M (cos θx / 4πμ ₀ r ³ )
Hxθ = M (sin θx / 4πμ ₀ r ³ )
The square of the magnetic field H is expressed by the following equations (1) and (2).
[0030]
Hx ² = Hxr ² + Hxθ ²
= Kr ² (3 cos ² θx + 1) (1)
= Kr ² {(3x ² / r ² ) +1} (2)
Here, Kr = M / 4πμ ₀ r ³ and x is a component of the distance r in the X-axis direction.
[0031]
The voltages induced on the first to third detection coils Dx1 to Dx3 arranged at the measurement target position Pa when the X-axis excitation coil is excited are defined as Eu1, Ev1, and Ew1. The voltages induced in the first to third detection coils Dx1 to Dx3 at the measurement target position Pa when the Y-axis excitation coil at the first reference position Po is excited are Eu2, Ev2, and Ew2. Further, the voltages induced on the first to third detection coils Dx1 to Dx3 at the measurement target position Pa when the Z-axis excitation coil at the first reference position Po is excited are Eu3, Ev3, and Ew3, respectively. Ex ² , Ey ² , and Ez ² are defined as a sum of squares as follows. These are collectively referred to as equation (3).
[0032]
Ex ² = Eu1 ² + Ev1 ² + Ew1 ²
Ey ² = Eu2 ² + Ev2 ² + Ew2 ^{2
Ez 2 = Eu3 2 + Ev3 2} + Ew3 2 (3)
Here, assuming that Ke is a proportional constant between the strength of the magnetic field for exciting the detection coil and the voltage induced in the coil, the square Hx ^{2 of} the magnetic field excited on the X-axis exciting coil is obtained from the equations (1) and (3). Is represented by the following equation. These are collectively referred to as equation (4).
[0033]
Hx ² = Kr ² (3 cos ² θx + 1)
^{= Ke (Eu1 2 + Ev1 2} + Ew1 2)
= KeEx ² (4)
From where (4) is solved for Ex ² (2) equation is derived the following equation. These are collectively referred to as equation (5).
[0034]
Ex ² = (Kr ² / Ke) (3 cos ² θx + 1)
^{= (Kr 2 / Ke) {} (3x 2 / r 2) +1} (5)
Similarly, output voltages when the Y-axis and Z-axis excitation coils are excited are expressed by the following equations (6) and (7). In the expressions (6) and (7), θy and θz are angles formed by the r component with the Y axis and the Z axis, respectively.
[0035]
Ey ² = (Kr ² / Ke) (3 cos ² θy + 1)
^{= (Kr 2 / Ke) {} (3y 2 / r 2) +1} (6)
Ez ² = (Kr ² / Ke) (3 cos ² θz + 1)
^{= (Kr 2 / Ke) {} (3z 2 / r 2) +1} (7)
The following equation (8) is obtained by summing the equations (5), (6) and (7).
[0036]
Ex ² + Ey ² + Ez ^{2
= (Kr 2 / Ke) [} {3 (x 2 + y 2 + z 2) / r 2} +3]
^{= 6 (Kr 2 / Ke)} (8)
By substituting equation (8) into equation (5), the following equation (9) is obtained.
[0037]
Ex ² = (Kr ² / Ke) (3 cos ² θx + 1)
= (Ex ² + Ey ² + Ez ² ) (3 cos ² θx + 1) / 6 (9)
When θx is calculated from Expression (9), it is expressed by the following Equation 1.
[0038]
(Equation 1)

Similarly, θy and θz for the Y axis and the Z axis are expressed by the following equations (2) and (3).
[0039]
(Equation 2)

[Equation 3]

As described above, if the voltages Eu1, Ev1, Ew1, Eu2, Ev2, Ew2, Eu3, Ev3, Ew3 induced in the first to third detection coils Dx1 to Dx3 are measured, the equations 1 to 3 are calculated. The azimuth from the reference position Po to the measurement target position Pa is obtained.
[0040]
FIG. 4 is a diagram for explaining the principle of distance measurement of the slope measuring device according to the present invention. As shown in FIG. 4, the radiated electromagnetic field at the measurement target position Pa of the small loop antenna whose loop size is sufficiently shorter than the wavelength disposed at the reference position Po is represented by the following general formulas 4, 5, and 6. Hr and Hθ indicate a magnetic field, and Eφ indicates an electric field. Where ω: angular frequency, I: current flowing through the small loop antenna, λ: wavelength, S: area of the small loop antenna, k: wave number (k = 2π / λ), r: distance from the center of the small loop antenna, η ₀ : characteristic impedance, μ: magnetic permeability.
[0041]
(Equation 4)

(Equation 5)

(Equation 6)

Here, when the distance r from the micro loop is set to several hundreds of meters at a low frequency of about 1 to 10 KHz, the relationship of kr = (2πr / λ) << 1 is satisfied, so the following inequalities (16) and (17) ) Holds.
[0042]
1+ (1 / jkr) << 1 / (jkr) ² (16)
−Eφ << Hθ, Hr (17)
The above equation 4 is expressed by the following equation 7 under the condition of equation (16).
[0043]
(Equation 7)

Here, since 1 / λ = k / 2π, the following Expression 8 is obtained.
[0044]
(Equation 8)

Further, the following equation 9 is obtained from η ₀ = (μ / ε) ^1/2 .
[0045]
(Equation 9)

Here, if C is the speed of light, the following equation is obtained.
[0046]
(Με) ^1/2 = 1 / C
ω / C = 2πf / C = 2π / λ = k
The above equation 8 is represented by the following equation 10.
[0047]
(Equation 10)

Similarly, Hr is represented by the following equation (11).
[0048]
[Equation 11]

In both Equations 10 and 11, this is shown as a function of the product of the constant, the distance, the attenuation term, and the directivity, and it is shown that the magnitude of the magnetic field attenuates in inverse proportion to the cube of the distance r.
[0049]
Here, since the strength of the magnetic field that excites the detection coil is proportional to the voltage induced in the detection coil, nine types of induced voltages Exu, Exv, Exw, Eyu, Eyv, Eyw, Ezu, and Ezv obtained from the detection coil are obtained. , Ezw, and performing a calculation based on the following equation, a voltage E proportional to the magnitude of the magnetic field at the position of the detection coil can be obtained. These are collectively referred to as Expression (21).
[0050]
Ex ² = Exu ² + Exv ² + Exw ²
Ey ² = Eyu ² + Eyv ² + Eyw ²
Ez ² = Ezu ² + Ezv ² + Ezw ² (21)
E ² = Ex ² + Ey ² + Ez ² (22)
Here, the voltage Eo when the distance between the reference position Po and the measurement target position Pa is known ro is obtained in advance by a method similar to the equations (21) and (22). Accordingly, when the distance between the reference position Po and the measurement target position Pa is r1, the voltage E1 is inversely proportional to the cube of the distance.
r1 ³ / rO ³ = EO / E1
r1 = (EO / E1) ^1/3 rO
Indicated by
[0051]
Therefore, the distance from the reference position Po to the measurement target position Pa can be measured by measuring each of the nine types of induced voltages obtained from the detection coil. By calculating the azimuth and the distance from the reference position Po to the measurement target position Pa, the coordinates of the measurement target position Pa are specified from the coordinates of the reference position Po. Will be captured.
[0052]
It goes without saying that the positioning of the reference position Po can be easily set by using a GPS, a mark on a road surface, or the like. In addition, two or more reference positions are determined, that is, for example, a combination of three excitation coils is arranged at two positions, coordinates of the respective measurement target positions are calculated, and averaging processing of the obtained coordinates is performed. Needless to say, accuracy can be improved and relative displacement can be obtained. Of course, two or more combinations of three detection coils may be arranged.
[0053]
Further, in FIG. 1, it is assumed that the above calculation is performed by another device using the voltage value measured by the voltmeter, but an arithmetic processing device having an A / D conversion function is directly provided instead of the voltmeter. You may connect. In this case, the arithmetic processing device incorporates the arithmetic processing program described above, and sequentially samples nine types of voltage values obtained in order from the second switching circuit 23 to perform the above arithmetic, thereby obtaining a reference value. The azimuth from the position Po to the measurement target position Pa and the distance from the reference position Po to the measurement target position Pa are obtained, and the coordinates of the measurement target position Pa in the coordinate system of the reference position are calculated.
[0054]
The slope measuring device according to the present invention can set a measurement target position at a position separated from the reference position set on a moving body such as a vehicle by several tens of meters or more. It doesn't matter whether it is medium or underwater. Such a slope measurement device is capable of measuring inside the ground or underwater, which cannot be measured by optical measuring equipment, and can measure displacement inside the ground and displacement of the slope in water, so that the slope surface can be measured. In addition to the collapse, it is possible to detect a sign of the slope surface being distorted due to the occurrence of strain in the soil mass inside the slope. That is, if the distortion inside the slope is equal to or more than a certain value, an alarm display may be performed.
[0055]
【The invention's effect】
As described above, according to the slope measuring device of the present invention, the azimuth and distance to the measurement target position are determined by setting at least one reference position, and the coordinate position of the measurement target position in the three-dimensional space is specified. can do.
[0056]
Also, when the frequency of the oscillation circuit is set to the audible band, the electromagnetic wave generated from the excitation coil mainly includes a magnetic field component. Coordinates can be specified even under conditions such as inside and underwater.
[0057]
Further, when synchronous detection based on the excitation current is used, the square value of the detected voltage is obtained, and at the same time, the noise-to-signal characteristics are advantageous, and the effect obtained is great.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a slope measuring device according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining a measurement situation by the device of FIG. 1;
FIG. 3 is a view for explaining the principle of azimuth measurement by the device of FIG. 1;
FIG. 4 is a diagram for explaining the principle of distance measurement by the device of FIG. 1;
[Explanation of symbols]
Reference Signs List 11 oscillation circuit 12 amplifier 13, 23 first and second switching circuit 15, 25 first and second computer 16, 26 first and second communication circuit Ex1, Ex2, Ex3 first, second, third Excitation coils Dx1, Dx2, Dx3 First, second and third detection coils

Claims (6)

A first coil group formed by combining the first, second, and third coils on each axis of a three-axis coordinate system orthogonal to each other is arranged at a first position,
Fourth, fifth, the second coil group formed by combining the sixth coil at each axis of the three-axis coordinate system orthogonal to each other is arranged at a second position,
First, the first coil is excited, and at that time, the fourth, fifth, and the voltage induced in the sixth coil are sequentially measured,
Next, the second coil is excited, and at that time, the fourth, fifth, and the voltage induced in the sixth coil are sequentially measured,
Next, the third coil is excited, and at that time, the fourth, fifth, and the voltages induced in the sixth coil are sequentially measured,
The direction from the first position to the second position is calculated by performing a predetermined calculation using a total of nine types of induced voltages obtained from the fourth, fifth, and sixth coils. And calculating a distance between the first position and the second position,
A slope measurement method for calculating the coordinates of the second position from the coordinates of the first position and the azimuth and distance from the first position to the second position,
A slope measuring method, wherein the first coil group or the second coil group is arranged on a moving body. The slope measuring method according to claim 1, wherein at least two sets of the first coil group or the second coil group are arranged to improve measurement accuracy or obtain relative displacement. . A signal generation circuit;
A first coil group that is arranged at the first position and combines the first, second, and third coils on respective axes of a three-axis coordinate system orthogonal to each other,
A second coil group, which is arranged at the second position and combines the fourth, fifth, and sixth coils on respective axes of a three-axis coordinate system orthogonal to each other,
A first switching circuit for sequentially exciting the first, second, and third coils with the output of the signal generation circuit;
A second switching circuit for sequentially taking output from the fourth, fifth, and sixth coils;
The fourth, fifth, including a first control calculation means for performing a predetermined calculation using the output obtained from the sixth coil,
First, the first coil is excited, and at that time, the fourth, fifth, and the voltage induced in the sixth coil are sequentially measured,
Next, the second coil is excited, and at that time, the fourth, fifth, and the voltage induced in the sixth coil are sequentially measured,
Next, the third coil is excited, and at that time, the fourth, fifth, and the voltages induced in the sixth coil are sequentially measured,
The first control calculation means performs the predetermined calculation using a total of nine types of induced voltages obtained from the fourth, fifth, and sixth coils, thereby obtaining the first control calculation means from the first position. Calculate the azimuth to the second position, calculate the distance between the first position and the second position, and further calculate the second position from the coordinates of the first position and the first position. A slope measurement device that calculates the coordinates of the second position from the azimuth and distance to the position,
A slope measuring device, wherein the first coil group or the second coil group is arranged on a moving body. 4. The slope measuring device according to claim 3, wherein the second switching circuit is connected to a second control arithmetic unit that collects outputs from the fourth, fifth, and sixth coils, and the second control circuit performs the second control. A second communication unit for transmitting and receiving information is connected to the arithmetic unit, and a first communication for transmitting and receiving information to and from the second communication unit is connected to the first control arithmetic unit. Slope measuring device, characterized in that means are connected. 5. The slope measuring device according to claim 4, wherein the first control calculation unit performs switching control of the first switching circuit, and transmits switching information of the second switching circuit via the first communication unit. 6. Sending to the second control arithmetic means, the second control arithmetic means performs switching control of the second switching circuit based on the switching information received via the second communication means, Slope measuring device. The slope measuring device according to any one of claims 3 to 5, wherein at least two sets of the first coil group or the second coil group are arranged to improve measurement accuracy or obtain relative displacement. Characteristic slope measurement device.

Images