JP4815859B2 - Magnetic model calculation method - Google Patents

Magnetic model calculation method Download PDF

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JP4815859B2
JP4815859B2 JP2005130776A JP2005130776A JP4815859B2 JP 4815859 B2 JP4815859 B2 JP 4815859B2 JP 2005130776 A JP2005130776 A JP 2005130776A JP 2005130776 A JP2005130776 A JP 2005130776A JP 4815859 B2 JP4815859 B2 JP 4815859B2
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光博 高畑
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Shimadzu Corp
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Description

この発明は,磁性構造体の外部磁界測定を行い、その実測値をもとに、磁性構造体の磁気モデルを計算する磁気モデル計算方法に関する。   The present invention relates to a magnetic model calculation method for measuring an external magnetic field of a magnetic structure and calculating a magnetic model of the magnetic structure based on the actually measured value.

船舶の磁性体からなる船体のX,Y,Z方向の外部磁界を打ち消すために、船体内に複数個の消磁コイルを設けると共にその船体内に複数個の磁気検知器からなる磁気監視部を設置し、各磁気検知器から測定された船内磁界に基づいて算出した船外磁気モーメントと、予め測定算出した各消滅コイル効果による船外磁気モーメントとから、外部磁界を最小にする消磁電流を決定して、各消磁コイルに通電して、消磁する方法が開示されている(例えば特許文献1参照)。   In order to cancel the external magnetic field in the X, Y, and Z directions of the ship's magnetic body, a plurality of degaussing coils are installed inside the ship and a magnetic monitoring unit consisting of a plurality of magnetic detectors is installed in the ship's body. The demagnetizing current that minimizes the external magnetic field is determined from the outboard magnetic moment calculated based on the inboard magnetic field measured from each magnetic detector and the outboard magnetic moment due to each extinction coil effect measured and calculated in advance. Thus, a method of demagnetizing each demagnetizing coil by energizing each demagnetizing coil is disclosed (for example, see Patent Document 1).

従来、この種の艦艇などの消磁を行うために、実測した外部磁界から、任意の位置の磁界を推定する方法として、(1)磁界が距離比率のべき乗に比例して減衰・増大するという理論を用いた「べき乗計算方式」、(2)外部磁界から逆計算で磁気源を求め任意の点の磁界を再計算する方式(「マルチダイポール方式」、「長球調和関数方式」)などがある。
一例として、マルチダイポール方式について説明する。今磁気構造体である艦艇が、図6に示すように位置n=1〜6に配置される6個のダイポールモーメントM1、M2、・・・、M6で表せる磁気源であるとする。このうちの1つのダイポールモーメントMにつき図7に示すようにr離れた点P(x,y,z)の磁界は次式で表せる。
Conventionally, in order to demagnetize this type of ship, etc., as a method of estimating the magnetic field at an arbitrary position from the actually measured external magnetic field, (1) The theory that the magnetic field attenuates and increases in proportion to the power of the distance ratio (2) A method of calculating a magnetic source by inverse calculation from an external magnetic field and recalculating a magnetic field at an arbitrary point (“multi-dipole method”, “long spherical harmonic function method”), etc. .
As an example, a multi-dipole system will be described. Assume that the ship, which is a magnetic structure, is a magnetic source represented by six dipole moments M1, M2,..., M6 arranged at positions n = 1 to 6 as shown in FIG. As shown in FIG. 7, the magnetic field at a point P (x, y, z) separated by r per one dipole moment M can be expressed by the following equation.

Hx=100×〔(3x‐r)・Mx+3xy・My+3xz・Mz〕/r〔nT〕
Hy=100×〔3xy・Mx+(3y‐r)・My+3yz・Mz〕/r〔nT〕
Hz=100×〔3xz・Mx+3yz・My+(3z‐r)・Mz〕/r〔nT〕

Mx:ダイポールモーメントのX成分
My:ダイポールモーメントのY成分
Mz:ダイポールモーメントのZ成分
r:ダイポールモーメントと観測点Pとの距離 r=(x+y+z0.5

ダイポールモーメントM及び、その各成文Mx、My、Mzと観測点Pとの関係を図7に示す。
Hx = 100 × [(3x 2 −r 2 ) · Mx + 3xy · My + 3xz · Mz] / r 5 [nT]
Hy = 100 × [3xy · Mx + (3y 2 −r 2 ) · My + 3yz · Mz] / r 5 [nT]
Hz = 100 × [3xz · Mx + 3yz · My + (3z 2 −r 2 ) · Mz] / r 5 [nT]

Mx: X component of dipole moment My: Y component of dipole moment Mz: Z component of dipole moment r: Distance between dipole moment and observation point P r = (x 2 + y 2 + z 2 ) 0.5

FIG. 7 shows the relationship between the dipole moment M and its respective sentences Mx, My, Mz and the observation point P.

マルチダイポール方式とは、ダイポールモーメントが艦艇内に複数個分布していると仮定し、それぞれのダイポールモーメントからの磁界の積算で磁界を近似するという考え方である。例えば、図6のようにダイポールの個数がn=6個の場合、その磁界は次の式で与えられる。
Hx(全体)=100×〔(3x ‐r )・Mx+3x・My+3x・Mz〕/r
+100×〔(3x ‐r )・Mx+3x・My+3x・Mz〕/r
+・・・・・・・
+100×〔(3x ‐r )・Mx+3x・My+3x・Mz〕/r 〔nT〕

Hy(全体)=100×〔3x・Mx+(3y ‐r )・My+3y・Mz〕/r
+100×〔3x・Mx+(3y ‐r )・My+3y・Mz〕/r
+・・・・・・・
+100×〔3x・Mx+(3y ‐r )・My+3y・Mz〕/r 〔nT〕

Hz(全体)=100×〔3x・Mx+3y・My+(3z ‐r )・Mz〕/r
+100×〔3x・Mx+3y・My+(3z ‐r )・Mz〕/r
+・・・・・・・
+100×〔3x・Mx+3y・My+(3z ‐r )・Mz〕/r 〔nT〕
各ダイポールモーメントの3軸成分を各配置した複数の磁気センサの実測磁界から最小自乗法等で逆算して求め、求められた各ダイポールモーメントから、任意の水深の磁界を逆計算する。
特開平8−78234号公報
The multi-dipole method is an idea that a plurality of dipole moments are distributed in a ship and the magnetic field is approximated by integrating the magnetic fields from the respective dipole moments. For example, when the number of dipoles is n = 6 as shown in FIG. 6, the magnetic field is given by the following equation.
Hx (whole) = 100 × [(3x 1 2 −r 1 2 ) · Mx 1 + 3x 1 y 1 · My 1 + 3x 1 z 1 · Mz 1 ] / r 1 5
+ 100 × [(3x 2 2 -r 2 2 ) · Mx 2 + 3x 2 y 2 · My 2 + 3x 2 z 2 · Mz 2 ] / r 2 5
+ ...
+ 100 × [(3x 6 2 -r 6 2 ) · Mx 6 + 3x 6 y 6 · My 6 + 3x 6 z 6 · Mz 6 ] / r 6 5 [nT]

Hy (whole) = 100 × [3x 1 y 1 · Mx 1 + (3y 1 2 −r 1 2 ) · My 1 + 3y 1 z 1 · Mz 1 ] / r 1 5
+ 100 × [3x 2 y 2 · Mx 2 + (3y 2 2 -r 2 2 ) · My 2 + 3y 2 z 2 · Mz 2 ] / r 2 5
+ ...
+ 100 × [3x 6 y 6 · Mx 6 + (3y 6 2 -r 6 2 ) · My 6 + 3y 6 z 6 · Mz 6 ] / r 6 5 [nT]

Hz (overall) = 100 × [3x 1 z 1 · Mx 1 + 3y 1 z 1 · My 1 + (3z 1 2 −r 1 2 ) · Mz 1 ] / r 1 5
+ 100 × [3x 2 z 2 · Mx 2 + 3y 2 z 2 · My 2 + (3z 2 2 -r 2 2 ) · Mz 2 ] / r 2 5
+ ...
+ 100 × [3x 6 z 6 · Mx 6 + 3y 6 z 6 · My 6 + (3z 6 2 -r 6 2 ) · Mz 6 ] / r 6 5 [nT]
A triaxial component of each dipole moment is obtained by back-calculating from the measured magnetic fields of a plurality of magnetic sensors arranged by the least square method or the like, and a magnetic field at an arbitrary water depth is back-calculated from each obtained dipole moment.
JP-A-8-78234

上記した従来の実測した外部磁界から、任意の位置の磁界を推定する方法において、磁気源を求めた後に実測データ位置(磁気センサの配置位置)の磁界を再計算(あてはめ計算という)を行う際、実測データの存在する位置については、実測データとほぼ同等の計算値が得られるが、実測データのない位置(磁気センサの配置されない位置)についての計算値は異常な値を計算結果として得ることがある。これは最小自乗法において実測データだけとの誤差を最小としてしまうような磁気源の計算をしてしまうため磁気モーメント自体が角度、大きさにおいて異常な値が計算されることによる。この現象は「発散」あるいは「食いつぶし現象」と呼ばれるものであり、特に位置測定方式では、船底下の磁気センサ数がコスト面などから限られるため、実測データのない位置では、等磁界曲線で実際にはありえない磁界が計算されることがある。   In the above-described conventional method for estimating the magnetic field at an arbitrary position from the actually measured external magnetic field, the magnetic field at the measured data position (positioning position of the magnetic sensor) is recalculated (referred to as fitting calculation) after obtaining the magnetic source. For the position where the actual measurement data exists, a calculated value almost equivalent to the actual measurement data can be obtained, but the calculated value for the position without the actual measurement data (position where the magnetic sensor is not arranged) should be obtained as an abnormal result. There is. This is because, in the least square method, the magnetic source is calculated so as to minimize the error with only the actually measured data, and therefore the magnetic moment itself is calculated as an abnormal value in angle and size. This phenomenon is called “divergence” or “crushing phenomenon”. In particular, in the position measurement method, the number of magnetic sensors under the ship bottom is limited in terms of cost and so on. A magnetic field that is not possible is calculated.

この発明は上記問題点に着目してなされたものであって、最小自乗法で得られた正規
方程式の解、すなわち磁気源の発散を抑えることができ、より精度の良い近傍磁界計算値や等磁界曲線を得ることができる磁気モデル計算方法を提供することを目的とする。
The present invention has been made paying attention to the above problems, and can solve the normal equation obtained by the method of least squares, that is, suppress the divergence of the magnetic source, and can calculate a near magnetic field calculation value with higher accuracy, etc. It is an object to provide a magnetic model calculation method capable of obtaining a magnetic field curve.

この発明は、磁性構造体に対して複数の外部磁界を実測し、この複数の実測データに基づいて磁性構造体における仮想的な磁気源を計算し、実測データを測定した実測位置以外の任意の位置の磁界を計算する磁気測定システムにおける磁気モデル計算方法において、前記実測位置に対して実測データのない仮想位置を設定し、この仮想位置における仮想データを、仮想位置の設定に係る複数の実測位置における複数の実測データに基づく補間により求め、前記実測位置の計算上のデータが当該実測位置の実測データと同じになるように前記実測データ及び前記仮想データを正規方程式に代入し、最小自乗法による前記磁気源の計算を行うものである。 According to the present invention , a plurality of external magnetic fields are actually measured for a magnetic structure, a virtual magnetic source in the magnetic structure is calculated based on the plurality of measured data, and an arbitrary position other than the actually measured position where the measured data is measured is calculated . In a magnetic model calculation method in a magnetic measurement system for calculating a magnetic field at a position, a virtual position without actual measurement data is set for the actual measurement position, and the virtual data at the virtual position is used as a plurality of actual measurement positions related to the setting of the virtual position. Substituting the actual measurement data and the virtual data into a normal equation so that the calculation data of the actual measurement position is the same as the actual measurement data of the actual measurement position, and by the least square method The calculation of the magnetic source is performed.

仮想データを得る具体例としては、例えば、キール下の磁界を実測データ、左右舷遠方磁界を零とし、その間のデータをスプライン関数等で近似し、仮定する方法を採用する。   As a specific example of obtaining the virtual data, for example, a method of assuming that the magnetic field under the keel is actually measured data, the left and right far field is zero, and the data between them is approximated by a spline function or the like is used.

また、実測データに重みつけするために、仮想データは、実測データの数より少ない個数の値に設定する。   Further, in order to weight the actually measured data, the virtual data is set to a number of values smaller than the number of actually measured data.

また、この発明において、磁気源の計算がマルチダイポール方式である場合、前記磁性構造体の磁性体量から想定され得る最大磁気量を規定値として設定し、前記磁気源の磁気モーメントの磁気量が前記規定値以下となるまで、規定値の再設定、前記実測データ及び前記仮想データの正規方程式への代入並びに最小自乗法による前記磁気源の計算を繰り返すと良い。 In the present invention , when the calculation of the magnetic source is a multi-dipole method, the maximum magnetic amount that can be assumed from the amount of magnetic material of the magnetic structure is set as a specified value, and the magnetic amount of the magnetic moment of the magnetic source is It is preferable to repeat the resetting of the specified value, the substitution of the actual measurement data and the virtual data into the normal equation, and the calculation of the magnetic source by the method of least squares until the value becomes the specified value or less .

請求項1に係る発明によれば、実測位置の他に仮想位置を設定し、この仮想位置の仮想データを仮想位置の設定に係る複数の実測位置における複数の実測データに基づく補間により求め、実測データと仮想データにより磁気モデル計算を行うので、磁気源の発散を抑えることができる。従ってより精度の高い近傍磁界計算値や等磁界曲線を得ることができる。
また、請求項2に係る発明によれば、計算される磁気源の磁気モーメントが均一化し、磁気源の発散を防ぐことができる。
According to the first aspect of the present invention, a virtual position is set in addition to the actually measured position, and virtual data of this virtual position is obtained by interpolation based on a plurality of actually measured data at a plurality of actually measured positions related to the setting of the virtual position. Since magnetic model calculation is performed using data and virtual data , the divergence of the magnetic source can be suppressed. Accordingly, it is possible to obtain a near magnetic field calculation value and an isomagnetic field curve with higher accuracy.
Moreover, according to the invention which concerns on Claim 2, the magnetic moment of the magnetic source calculated can be equalize | homogenized, and the divergence of a magnetic source can be prevented.

以下、実施の形態により、この発明をさらに詳細に説明する。図1の(a)は、艦艇1の発生磁界を計測し、磁気モデルを計算し、磁気モデルを計算するための、磁気計測システムの設置例を示す概略図である。図1の(a)において海底下に直線上に複数個の磁気センサMD1、MD2、・・・、MD16が固定的に設置されている。この磁気センサMD1、MD2、・・・、MD16の設置された領域の海面に、被測定艦艇1が係留されている。   Hereinafter, the present invention will be described in more detail with reference to embodiments. FIG. 1A is a schematic diagram illustrating an installation example of a magnetic measurement system for measuring a magnetic field generated by a ship 1, calculating a magnetic model, and calculating a magnetic model. In FIG. 1A, a plurality of magnetic sensors MD1, MD2,..., MD16 are fixedly installed on a straight line below the seabed. The to-be-measured ship 1 is moored on the sea surface in the area where the magnetic sensors MD1, MD2,.

図2は、この実施形態磁気計測システムの構成を示すブロック図である。図2において、磁気計測装置11は、制御、演算の種々の処理を実行するCPU12と、実測データ、仮想データ、設定値等を記憶する各記憶部を存するメモリ13と、磁気センサMD1、MD2、・・・、MDN(N=16)に接続するための入力ポート14とを備えている。磁気計測装置11は、艦艇1の係留地点に近い港湾の施設に設置されるが、係留された艦艇1上に搭載してもよい。   FIG. 2 is a block diagram showing the configuration of the magnetic measurement system of this embodiment. In FIG. 2, a magnetic measurement device 11 includes a CPU 12 that executes various processes of control and calculation, a memory 13 that stores storage units for storing actual measurement data, virtual data, setting values, and the like, magnetic sensors MD1, MD2, ..., an input port 14 for connecting to MDN (N = 16). The magnetic measuring device 11 is installed at a port facility near the mooring point of the ship 1, but may be mounted on the moored ship 1.

次に、この実施形態磁気測定システムにおいて、各磁気センサMD1、・・・MD16による実測データに基づき、磁気モデル計算を行う場合の処理を、図3に示すフロー図を参照して説明する。   Next, in the magnetic measurement system of this embodiment, the processing in the case of performing a magnetic model calculation based on the measured data by each magnetic sensor MD1,... MD16 will be described with reference to the flowchart shown in FIG.

この処理動作が開始されると、ステップST1において各磁気センサMD1、・・・MD16から各点におけるX、Y、Zの各成分磁界が検知され。つまり、外部磁界が測定され、各X、Y、Zの成分磁界がメモリ13の実測データ記憶部に記憶される。 When this process operation is started, the magnetic sensors MD1 at step ST1, X from · · · MD16 at each point, Y, each component magnetic field Z is Ru is detected. That is, the external magnetic field is measured, and the component magnetic fields of X, Y, and Z are stored in the actual measurement data storage unit of the memory 13.

この場合、各磁気センサMD1,・・・MD16には、それぞれ図1の(b)に示す対応位置の各成分が検知される。ここでX成分は艦艇1の船首尾方向の磁界成分であり、船首方向が+である。Z成分は艦艇1の垂直方向の磁界成分であり、海底方向が+である。Y成分は左右方向の磁界成分であり、左舷方向が+である。図1で艦艇1のキール中央下に近い磁気センサMD8は、Z成分が最大値となり、X成分は、0に近い値となる。続いてステップST2へ移行する。   In this case, each magnetic sensor MD1,... MD16 detects each component at the corresponding position shown in FIG. Here, the X component is a magnetic field component in the bow-stern direction of the ship 1, and the bow direction is +. The Z component is a magnetic field component in the vertical direction of the ship 1, and the sea bottom direction is +. The Y component is a magnetic field component in the left-right direction, and the port direction is +. In the magnetic sensor MD8 near the lower center of the keel of the ship 1 in FIG. 1, the Z component has a maximum value and the X component has a value close to zero. Subsequently, the process proceeds to step ST2.

ステップST2においては、実測データのない位置の仮想データの設定を行う。図1の磁気センサは、実際に1直線上に、16個の磁気センサMD1、・・・MD16が配置されている。ここでは仮想データを設定する位置として、磁気センサMD8,MD6、MD10の左右方向に一定距離離れた位置P8a、P8b、P6a、P6b、P10a、P10bとする。   In step ST2, virtual data at a position without actual measurement data is set. In the magnetic sensor shown in FIG. 1, 16 magnetic sensors MD1,... MD16 are actually arranged on one straight line. Here, the positions where virtual data are set are positions P8a, P8b, P6a, P6b, P10a, and P10b that are a fixed distance apart in the left-right direction of the magnetic sensors MD8, MD6, and MD10.

これらの位置における仮想データの設定方法を、磁気センサMD8の左右に設ける位置P8a、P8bを例にして説明する。図4の矢印Aが艦艇1の船首方向とし、P8が磁気センサMD8の位置、P8aが左側の仮想データを設定する位置、P8bが右側の仮想データを設定する位置である。曲線mは艦艇1のキール下における磁界の強さのZ成分を示す波形であり、磁気センサMD8の位置P8でZ成分磁界が最大値である。これに対し、左右舷方向の遠方は、指数関数的に磁界が減衰するので、零に収束する。   A method for setting virtual data at these positions will be described using positions P8a and P8b provided on the left and right of the magnetic sensor MD8 as an example. 4 is the bow direction of the ship 1, P8 is the position of the magnetic sensor MD8, P8a is the position where the left virtual data is set, and P8b is the position where the right virtual data is set. A curve m is a waveform indicating the Z component of the strength of the magnetic field under the keel of the ship 1, and the Z component magnetic field is the maximum value at the position P8 of the magnetic sensor MD8. On the other hand, the far field in the left-right direction converges to zero because the magnetic field attenuates exponentially.

そこで、位置P8の磁界(X成分、Y成分、Z成分)を最大とし左右舷方向の遠方の磁界が零になるように例えばスプライン関数を用いて近似計算し、仮想位置P8a、P8bのデータを求める。図4においてaは仮想位置P8aにおけるZ成分波形、bは仮想位置P8bにおけるZ成分波形である。なおここで、使用するスプライン補間式は次式で与えられる。   Therefore, an approximate calculation is performed using, for example, a spline function so that the magnetic field at the position P8 (X component, Y component, Z component) is maximized, and the far magnetic field in the left-right direction becomes zero, and the data at the virtual positions P8a and P8b are obtained. Ask. In FIG. 4, a is a Z component waveform at the virtual position P8a, and b is a Z component waveform at the virtual position P8b. Here, the spline interpolation formula to be used is given by the following formula.

Sj(x)=aj(x-xj)2+bj(x-xj)+cj
jは1〜3{センサ位置(1.3は遠方)}
この仮想データはあくまでも「発散」防止の手段であるため、実測データより少なく個数を設定する。これにより、個数の上から実測データに重みがかかる解が計算される。重み付けについては、ここでは個数による重み付けを使用しているが、他の重み付け方法を用いてもよい。仮想データの設定が終了すると次にステップST3に移行する。
Sj (x) = aj (x-xj) 2 + bj (x-xj) + cj
j is 1 to 3 {sensor position (1.3 is far away)}
Since this virtual data is only a means for preventing “divergence”, the number is set smaller than the actual measurement data. Thereby, a solution in which the actually measured data is weighted is calculated from the number. For weighting, weighting by number is used here, but other weighting methods may be used. When the virtual data setting is completed, the process proceeds to step ST3.

ステップST3においては、最大磁気量の計算を行い、規定値の設定を行う。この最大磁気量は、被測定艦艇の磁性体量から想定する。この規定値の設定の具体例を説明する。図5に示すように、艦艇1を6つのブロックに分け、その各部分に、それぞれ磁気モーメントM1、M2、・・・M6があると仮定する。今、キール下直近の磁気センサMD8で検出したキール下磁界Z成分を例えば2μ・Tとすると艦艇1から、磁気センサMD8までの距離を20mとして磁気モーメントM4の垂直方向磁気量は、約800μ・T^と推定されるが、余裕をみて、その1.5倍の1200μ・T^とする。これを最大磁気量の規定値として設定し、メモリ13の設定値記憶部に記憶する。次にステップST4に移行する。 In step ST3, the maximum magnetic quantity is calculated, and a prescribed value is set. This maximum magnetic quantity is assumed from the magnetic substance quantity of the ship to be measured. A specific example of setting the specified value will be described. As shown in FIG. 5, it is assumed that the warship 1 is divided into six blocks, and each portion has magnetic moments M1, M2,. If the magnetic field Z component under the keel detected by the magnetic sensor MD8 immediately below the keel is 2 μ · T, for example, the distance from the ship 1 to the magnetic sensor MD8 is 20 m, and the vertical magnetic amount of the magnetic moment M4 is about 800 μ · T ^ 3 is estimated, but with a margin, it is set to 1,200 μ · T ^ 3 , which is 1.5 times that. This is set as a prescribed value of the maximum magnetic quantity and stored in the set value storage unit of the memory 13. Next, the process proceeds to step ST4.

ステップST4においては、繰り返し計算回数を設定し、メモリ13の設定値記憶部に記憶する。続いてステップST5へ移行する。   In step ST4, the number of repeated calculations is set and stored in the set value storage unit of the memory 13. Subsequently, the process proceeds to step ST5.

ステップST5においては最小自乗法による正規方程式の演算及び磁気源の計算を行う。この計算は、実測データ及び仮想データを併せて行う。   In step ST5, a normal equation is calculated by a least square method and a magnetic source is calculated. This calculation is performed by combining the actual measurement data and the virtual data.

ここで上記例のように、ダイポールの個数を6個とすると、未知数は、6個×3(Mx、My、Mz)で18個であり、仮に、実測点以外の仮想位置も含めた、位置pの点数が100個であるとすれば、未知数18個を含む1次結合式が100個できる。これを行列式で表すと次のとおりとなる。   Here, if the number of dipoles is 6 as in the above example, the number of unknowns is 18 by 6 × 3 (Mx, My, Mz), and the position including the virtual position other than the actual measurement point is assumed. If the number of points of p is 100, 100 linear coupling equations including 18 unknowns can be made. This is expressed as a determinant as follows.

Figure 0004815859
Figure 0004815859

これらから、Mm(m=1〜18)の18元連立方程式が次のように決まる。   From these, the 18-way simultaneous equations of Mm (m = 1 to 18) are determined as follows.

Figure 0004815859
Figure 0004815859

続いてステップST6へ移行する。ステップST6においては全ての磁気源が規定値以下か否かを判定する。規定値を超える磁気源が1個でもあると、ステップST7へ移行する。一方、計算で得た全ての磁気源が規定値以下の場合は処理を終了する。   Subsequently, the process proceeds to step ST6. In step ST6, it is determined whether or not all the magnetic sources are below a specified value. If there is even one magnetic source exceeding the specified value, the process proceeds to step ST7. On the other hand, if all the magnetic sources obtained by the calculation are below the specified value, the process is terminated.

ステップST7においては、全ての磁気源の計算回数(繰り返し回数)が設定値以上になったか否かを判定する。計算の繰り返し回数が設定値よりも小さい場合は、ステップST8へ移行する。一方繰り返し回数が設定値以上の場合は、ここで処理を終了する。 In step ST7, it is determined whether or not the number of calculations (the number of repetitions) of all magnetic sources has reached a set value or more. When the number of repetitions of calculation is smaller than the set value, the process proceeds to step ST8. On the other hand , if the number of repetitions is equal to or greater than the set value, the process ends here.

ステップST8においては、それまで設定していた最大磁気量の規定値よりも大きな磁気源を新たな規定値として設定する。例えばそれまで最大磁気量を800μ・T^の1.5倍の1200μ・T^としていた場合に更に800μ・T^の1.6倍の1280μ・T^とする。そして、ステップST5へ戻り、再び磁気源の計算を行い、その後、全ての磁気源が規定値以下となるか、繰り返し回数が規定値以上となるまで、ステップST6〜ステップST8の処理を繰り返す。 In step ST8, a magnetic source that is larger than the specified value of the maximum magnetic amount that has been set up to that point is set as a new specified value. For example, when the maximum magnetic amount has been set to 1200 μ · T 3 , 1.5 times 800 μ · T 3 , it is further set to 1280 μ · T 3 , 1.6 times 800 μ · T 3 . Then, returning to step ST5, the calculation of the magnetic source is performed again, and thereafter, the processing of step ST6 to step ST8 is repeated until all the magnetic sources become the specified value or less or the number of repetitions becomes the specified value or more.

艦艇の発生磁界を計測し磁気モデルを計算するための磁気計測システムの設置例を示す概略図(a)、及び艦艇のキール下の磁気成分を示す図(b)である。It is the schematic (a) which shows the example of installation of the magnetic measurement system for measuring the magnetic field generated of a ship, and calculating a magnetic model, and the figure (b) which shows the magnetic component under the keel of a ship. 同実施形態磁気計測システムの構成を示すブロック図である。It is a block diagram which shows the structure of the magnetic measurement system of the embodiment. 同実施形態磁気計測システムにおいて、磁気モデル計算を行う場合の処理を説明するフロー図である。It is a flowchart explaining the process in the case of performing a magnetic model calculation in the magnetic measurement system of the embodiment. 同実施形態磁気計測システムにおいて、仮想データの設定を説明するための図である。It is a figure for demonstrating the setting of virtual data in the magnetic measurement system of the embodiment. 同実施形態磁気計測システムにおいて、艦艇を複数のブロックに分けて、各磁気モーメントを考慮した場合の最大磁気量の設定を説明する図である。In the magnetic measurement system of the same embodiment, a ship is divided into a plurality of blocks, and the setting of the maximum magnetic quantity when each magnetic moment is taken into account is described. マルチダイポール方式を説明するための艦艇のマルチダイポールの配置例を示す図である。It is a figure which shows the example of arrangement | positioning of the multi-dipole of the ship for demonstrating a multi-dipole system. 同マルチダイポールの1つのダイポールモーメントは及びその成分値を示す図である。It is a figure which shows the one dipole moment of the multi dipole, and its component value.

符号の説明Explanation of symbols

1、 艦艇
MD1、・・、MDN 磁気センサ
11、 磁気計測装置
12、 CPU
13、 メモリ
14、 入力ポート
1. Ship MD1, .., MDN Magnetic sensor 11, Magnetic measuring device 12, CPU
13, Memory 14, Input port

Claims (2)

磁性構造体に対して複数の外部磁界を実測し、この複数の実測データに基づいて磁性構造体における仮想的な磁気源を計算し、実測データを測定した実測位置以外の任意の位置の磁界を計算する磁気測定システムにおける磁気モデル計算方法において、
前記実測位置に対して実測データのない仮想位置を設定し、この仮想位置における仮想データを、仮想位置の設定に係る複数の実測位置における複数の実測データに基づく補間により求め、前記実測位置の計算上のデータが当該実測位置の実測データと同じになるように前記実測データ及び前記仮想データを正規方程式に代入し、最小自乗法による前記磁気源の計算を行うことを特徴とする磁気モデル計算方法。
A plurality of external magnetic fields are measured for the magnetic structure, a virtual magnetic source in the magnetic structure is calculated based on the plurality of measured data, and a magnetic field at an arbitrary position other than the actually measured position where the measured data is measured is calculated. In the magnetic model calculation method in the magnetic measurement system to calculate,
A virtual position without actual measurement data is set for the actual measurement position, and virtual data at the virtual position is obtained by interpolation based on a plurality of actual measurement data at a plurality of actual measurement positions related to the setting of the virtual position, and calculation of the actual measurement position is performed. A magnetic model calculation method characterized by substituting the actual measurement data and the virtual data into a normal equation so that the above data becomes the same as the actual measurement data of the actual measurement position, and calculating the magnetic source by the method of least squares .
前記磁気源の計算は、マルチダイポール方式であり、前記磁性構造体の磁性体量から想定され得る最大磁気量を規定値として設定し、前記磁気源の磁気モーメントの磁気量が前記規定値以下となるまで、規定値の再設定、前記実測データ及び前記仮想データの正規方程式への代入並びに最小自乗法による前記磁気源の計算を繰り返すことを特徴とする請求項1記載の磁気モデル計算方法。 The calculation of the magnetic source is a multi-dipole method, the maximum magnetic amount that can be assumed from the amount of magnetic material of the magnetic structure is set as a specified value, and the amount of magnetic moment of the magnetic source is equal to or less than the specified value. The magnetic model calculation method according to claim 1 , wherein resetting of a prescribed value, substitution of the actual measurement data and the virtual data into a normal equation, and calculation of the magnetic source by the method of least squares are repeated until it becomes .
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