JPS6139803A - Levitating coil displacement detector - Google Patents
Levitating coil displacement detectorInfo
- Publication number
- JPS6139803A JPS6139803A JP15873184A JP15873184A JPS6139803A JP S6139803 A JPS6139803 A JP S6139803A JP 15873184 A JP15873184 A JP 15873184A JP 15873184 A JP15873184 A JP 15873184A JP S6139803 A JPS6139803 A JP S6139803A
- Authority
- JP
- Japan
- Prior art keywords
- coil
- levitation
- detection
- levitation coil
- excitation coil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- B60L13/00—Electric propulsion for monorail vehicles, suspension vehicles or rack railways; Magnetic suspension or levitation for vehicles
- B60L13/04—Magnetic suspension or levitation for vehicles
- B60L13/06—Means to sense or control vehicle position or attitude with respect to railway
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Power Engineering (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Geophysics And Detection Of Objects (AREA)
- Control Of Vehicles With Linear Motors And Vehicles That Are Magnetically Levitated (AREA)
Abstract
Description
【発明の詳細な説明】 〔発明の利用分野〕 本＠明は、浮上式鉄道の地上側浮上コイルの。[Detailed description of the invention] [Field of application of the invention] The book @Akira is about the ground-side levitation coil of a levitation railway.
在るべき位置からの変位を、電磁的に非接触で検出する
浮上コイル変位検出装置に関するもの □であ
る。□ relates to a levitation coil displacement detection device that electromagnetically detects displacement from its intended position without contact.
現在、浮上式鉄道の地上側に設置する浮上コイルや推進
コイルに対して、設置後、その実際の設置位置を厘接検
側して１本来在るべき５位置かうの変位の程直を調べる
ことは行われていたこれらのコイルを設置するとき、ア
ングル材ｔｉｋ準として、各コイルをアングル材に密着
させて設置している現状に基ｉ″′Ｃ，このアングル材
の位置を１１１Ｊ足することにより、コイル位置の間接
−ｊ定を行ってｉる。現在はコイルがＮ出しているので
、光学的な方式によって１ｗＡ歓的なコイルの位置を、
基準アングル材の位置の掬足により間接的に測定するの
ではなく、直接測定することも可能であるが、将来、こ
れらのコイルをコンクリートスラブの中に埋め込むよ５
になった場合は、光学的方式により非接触で直接測定す
ることは不可能になる。Currently, for levitation coils and propulsion coils that are installed on the ground side of levitation railways, after installation, we inspect the actual installation positions and check the displacement of the 5 positions where they should be. This was done when installing these coils.Based on the current situation where each coil is installed in close contact with the angle material, add 111J to the position of this angle material. By doing this, indirect -j determination of the coil position is performed.Currently, the coil is outputting N, so the position of the coil for 1wA can be determined using an optical method.
Although it is possible to measure directly rather than indirectly by scooping the reference angle position, in the future these coils may be embedded in the concrete slab.
When this happens, direct non-contact measurement using optical methods becomes impossible.
現在のガイドウェイ検測車は、測定車輪を前記基準アン
グル材に押し付けて測定しているが。Current guideway inspection vehicles take measurements by pressing the measurement wheels against the reference angle material.
この方法による検測走行速夏は１５〜ｓｏｈφであって
相当に遅く、実際のコイル設置位置の本来在るべき位置
からの変位を検出するのに時間がかかるという問題か′
・あ−）たＪ′〔発明の目的〕
本発明の目的は、基準アングルの位置測定から間接的に
浮上コイルの位置を測にするのではなく、非接触で浮上
コイル位置の直接測定が可能な、電磁的な浮上コイル変
位検出装置を提供することにある０ □
〔発明の１Ｉｉｔ要〕
上記目的を達成１′るために本＠明におｈては。The running speed measured by this method is 15 to sohφ, which is quite slow, and the problem is that it takes time to detect the displacement of the actual coil installation position from the original position.
・A-)TAJ′ [Object of the Invention] The object of the present invention is to enable direct measurement of the levitation coil position without contact, instead of measuring the position of the levitation coil indirectly from the measurement of the position of the reference angle. The object of the present invention is to provide an electromagnetic levitation coil displacement detection device. [1Iit Requirements of the Invention] In order to achieve the above object, the present invention has been made.
浮上式鉄道の地上側浮上コイルの在るべき位置の直上に
平行に位置するように検測車＆ｃ堰り付けられた浮上コ
イルに同等な輪郭を有する励振コイルと、励振コイルの
下に平行にＢｉＬ９付けられ取付面への励振コイルの輪
郭の正射影を前後左右離体［４等分した輪郭を有する４
＠の検出コイルとより成る検出部を備え、励振コイルを
交流で励振したとき、励振コイル磁界と、此の磁界によ
り短絡されている浮上コイル巻層に誘起された短絡電流
による浮上コイル磁界とにより、これらフィル、’Ｆｉ
’に浮上コイルと４＊出コイル夫々との一気結合度に応
じて、４個の検出コイル夫々ＩＣｅ起された起電力を側
足し、これらの測定値を処理演算して、浮上コイルの前
記検出部に対する相対位置を算出し、浮上コイルの在る
べき位置からのに位を電磁的に非接触で検出するように
したゆ
なお、浮上コイルにｍ起された短絡電流は、浮上コイル
に鎖交する磁束が無くなるように流れるから、浮上コイ
ル磁杵とは、浮上コイルと鎖交する励振コ′イル磁界Ｋ
１畳すると、浮上コイルと鎖交する磁束を丁度打ち消す
ような磁界と首５ことが出来る。An excitation coil with a contour similar to the levitation coil attached to the inspection car & c weir so as to be located directly above and parallel to where the levitation coil on the ground side of the levitation railway should be, and an excitation coil located parallel to the levitation coil below the excitation coil. The orthogonal projection of the contour of the excitation coil onto the mounting surface of BiL9 is separated from the front, rear, left and right [4 with a contour divided into four equal parts]
It is equipped with a detection section consisting of a detection coil, and when the excitation coil is excited with alternating current, the excitation coil magnetic field and the levitation coil magnetic field due to the short-circuit current induced in the levitation coil winding layer short-circuited by this magnetic field , these fills, 'Fi
According to the degree of simultaneous coupling between the levitation coil and each of the 4*output coils, the electromotive force generated by the ICe of each of the four detection coils is added up, these measured values are processed and calculated, and the above-mentioned detection of the levitation coil is performed. However, the short-circuit current generated in the levitation coil is linked to the levitation coil. Since the magnetic flux flows in such a way that the magnetic flux disappears, the levitation coil magnetic punch is called an excitation coil magnetic field K that interlinks with the levitation coil.
When it is heated to 1 tatami, a magnetic field and neck 5 can be generated that exactly cancel out the magnetic flux interlinking with the levitation coil.
語１図ＣＧ）は本発明の実施例である検出部および測定
対象浮上コイルの平面図、纂１図（りは側断面図、・ｌ
！１図Ｃｅ）は浮上コイルの変位の左右１前後の説明図
で、ＷＡ中、１〜４は検出コイル、５は励振；イ〃、６
は浮上コイルである。Figure 1 CG) is a plan view of the detection unit and the measuring object levitation coil according to an embodiment of the present invention, and Figure 1 (CG) is a side sectional view.
! Figure 1Ce) is an explanatory diagram of the displacement of the levitation coil from left to right and around 1. During WA, 1 to 4 are detection coils, 5 is excitation; A, 6
is the levitation coil.
これらの図は、浮上コイ／Ｉ／６が正しく検出部の直下
の本来在るべき位置に存在し、兜１図（すにおいては、
励振コイル５の輪郭と浮上コイル６の輪郭とは一致して
匹゛て、浮上コイル６は励振コイル５や検出コイル１〜
４の下になりて見えない。このような状態では、４個の
検出コイル１〜４夫々に誘起される起電力が全て等しい
ことは明らかである。また、検出部を形成する検出コイ
ル１〜４は励振コイル５の直ぐ近（［位置し、検出部全
体が検測車に同定取付けされているから、各検出コイル
と励振゛コイル閤の磁気結合度は互ｉに等しく、かつ一
定で変化しな一０各検出コイルにば、励振コイル磁界に
より誘起された起電力から、前記浮上コイル磁界により
誘起された起電力を差し引いた値の起電力が生ずる筈で
ある。浮上コイルが在るべき位置からずれた位置に設置
された場合には、そのずれ方に応じ℃浮上コイル６と各
検出コイル１〜４との磁気結合度が、変化し、浮上コイ
−タ磁界により各検出コイルに誘起される起電力も変化
するから、これらの起電力を励振コイルにより検出コイ
ルに誘起された起電力から差し引いた甑も、浮上コイル
と各検出コイルとの相対値ｔＩＬに応じて変化する・
浮上コイル６の検出部すなわち検出コイル１〜４ＫＷす
る相対位置が１例えは、島１図（Ｃ）に示す左方に涙位
すれは（但し１前後方向はそのままで）、検出コイル１
．３と浮上コイル６との磁気結合度は大きくなり、検出
コイルソ。These figures show that the floating carp/I/6 is located in the correct position directly below the detection part, and that
The outline of the excitation coil 5 and the outline of the levitation coil 6 are identical, and the levitation coil 6 is similar to the excitation coil 5 and the detection coils 1 to 1.
I can't see it because it's below 4. In such a state, it is clear that the electromotive forces induced in each of the four detection coils 1 to 4 are all equal. In addition, since the detection coils 1 to 4 forming the detection section are located in the immediate vicinity of the excitation coil 5, and the entire detection section is attached to the inspection vehicle, magnetic coupling between each detection coil and the excitation coil For each detection coil, the electromotive force is the value obtained by subtracting the electromotive force induced by the levitation coil magnetic field from the electromotive force induced by the excitation coil magnetic field. If the levitation coil is installed at a position shifted from its intended position, the degree of magnetic coupling between the °C levitation coil 6 and each of the detection coils 1 to 4 changes depending on the direction of the shift. Since the electromotive force induced in each detection coil by the levitation coiler magnetic field also changes, the value obtained by subtracting these electromotive forces from the electromotive force induced in the detection coil by the excitation coil is also the difference between the levitation coil and each detection coil. The relative position of the detection part of the levitation coil 6, that is, the detection coil 1 to 4KW changes according to the relative value tIL. ), detection coil 1
．． The degree of magnetic coupling between 3 and the levitation coil 6 increases, and the detection coil 6 increases.
４と浮上コイル６との磁気結合度は小さくなる。4 and the levitation coil 6 become smaller.
Ｗ１検出コイル１ 、２．、５ 、４夫々の誘起起電力
を所定倍率で増幅し、５ａｔ−て直流電圧とした出力な
■、■、■、■、とすれは、上記の如く、浮上コイル６
が左方に変位した場合には。W1 detection coil 1, 2. .
If it is displaced to the left.
出力■＋■が減少し、出力■＋■が増大する。The output ■+■ decreases and the output ■+■ increases.
また、浮上コイル６の検出コイル１〜４に対する相対位
置が、前方に変位していれは、検出コイル１，２と浮上
コイル６との磁気結合度は大きくなり、検出コイル５．
４と浮上コイル６との磁気結合度は小さくなり、出力■
十■が減少し、出力■十■が増大する。また、浮上コイ
ル６の位置か本来在るべき位置よりも上方へ、すなわち
検／１１１１１部に近寄る方向に誕位すれば、検出コイ
ル１．２，３．４と浮上コイル６との磁気結合眞は大き
くなり、出力■十■十■十■は増大する。上記ｔＭ係式
を数式で示せば。Furthermore, if the relative position of the levitation coil 6 with respect to the detection coils 1 to 4 is displaced forward, the degree of magnetic coupling between the detection coils 1 and 2 and the levitation coil 6 increases, and the degree of magnetic coupling between the detection coils 1 and 2 and the levitation coil 6 increases.
4 and the levitation coil 6 becomes smaller, and the output ■
10■ decreases and the output 10■ increases. Furthermore, if the position of the levitation coil 6 is higher than its original position, that is, in a direction approaching the detection/11111 section, the magnetic coupling between the detection coils 1.2, 3.4 and the levitation coil 6 will be reduced. becomes larger, and the output ■1■10■10 increases. The above tM coefficient formula can be expressed as a mathematical formula.
上下変位Ｘ＝−（■十■十（り十（１））となる＠ただ
し、Ｙの正負はそれぞれ右左を、Ｚの正負はそれぞれ後
前を示す。Vertical displacement X=-(■10■10 (ri1))@However, the positive and negative of Y indicate right and left, respectively, and the positive and negative of Z indicate front and rear, respectively.
第２図は１本発明冥施例システムのグロック図を示し１
図中、７は検出部、８は発振回路。Figure 2 shows a Glock diagram of the system for implementing the present invention.
In the figure, 7 is a detection section and 8 is an oscillation circuit.
９は増＠回路、１０は同期整流回路、１１は演算回路で
ある。発振回路Ｉｎｃ正弦波発振させて励振コイル５に
交流を流して磁束を発生させ、各検出コイルに起電力を
誘起させる。測定対象である浮上コイル６の変位に応じ
て、各検出コイル１〜４との磁気結合度が変化し二各検
出コイルに誘起される起電力が変化するので、それを増
幅回路９でＦｆｒ足倍率で増幅し、同期整流回路１０・
−で整流して直流電圧とした検出コイル１，２゜３．４
の出力■、■、■、■は前記のよ５１Ｃ変化する。この
各検ｔＢ：フイル出力を演″Ｘ回路１１ＪＣ演算させれ
ば、浮上コイルの変位が上記各式によって算出される。9 is an increase @ circuit, 10 is a synchronous rectifier circuit, and 11 is an arithmetic circuit. The oscillator circuit Inc causes sine wave oscillation and causes alternating current to flow through the excitation coil 5 to generate magnetic flux, thereby inducing an electromotive force in each detection coil. According to the displacement of the levitation coil 6, which is the measurement target, the degree of magnetic coupling with each detection coil 1 to 4 changes, and the electromotive force induced in each detection coil changes. Amplify by magnification, synchronous rectifier circuit 10.
Detection coils 1, 2゜3.4 rectified with - to make DC voltage
The outputs ■, ■, ■, ■ change by 51C as described above. If the output of each test tB:filter is calculated by the calculation circuit 11JC, the displacement of the levitation coil is calculated by each of the above formulas.
属５図ＣＧ）は上記各検出コイル出力が浮上コイルの左
右方向の変位に伴って変化する様子を示し％第５図（り
は各検出コイル出力が浮上コイルの前後方向の変位に伴
って変化する様子を示す図である。ただし、これらの図
で、■と■は横軸の上に；■と■は横軸の下に描いであ
るか、これらの出力値はいずれも正の数値である。Figure 5 (CG) shows how the output of each of the above-mentioned detection coils changes with the displacement of the levitation coil in the left-right direction. However, in these figures, ■ and ■ are drawn above the horizontal axis; ■ and ■ are drawn below the horizontal axis, or both of these output values are positive numbers. be.
なお、本図の縦軸の位置は、浮上コイル６の・実際の設
置位置が本来在るべき位置に丁度一致している場合に該
当する。Note that the position of the vertical axis in this figure corresponds to the case where the actual installation position of the levitation coil 6 exactly matches the position where it should be originally located.
〔発明の効果ン
以上説明したように本発明によれば、非接触で測定でき
るので横側時間を短縮することが出来、また基準アング
ルの位置を画定するのでは無く、直接、測定対象コイル
の位置を測定するのであるから測定精良が同上し、しか
も対象とするコイルかコンクリートの中に埋め込まれて
いる場合にも検出できる。[Effects of the Invention] As explained above, according to the present invention, measurement can be performed without contact, thereby shortening the lateral time. Since the position is measured, the measurement precision is the same as above, and it can also be detected even if the target coil is embedded in concrete.
兜１図（りは本発明実施例の検出部および測定対象浮上
コイルの平面図、第１図Ｃｂ）は同部分の側断面図、第
１図ＣＯ）は浮上コイルの変位の左右１前後のｉｉ［図
、纂２図は１本発明実施例システムのグーツク図、票′
！５図（りは各検出コイル出力が浮上コイルの左右方向
の変位に伴、りて変化する様子を示す図、第５図（りは
各検出コイル出力が浮上コイルの前後方向の変位に伴っ
て変化する様子を示す図である。
１＃２＊ ３＊ ４”’検出コイル
５・・・励振コイル ６・・・浮上コイル７・・・
検出部 ８・・・発振回路９・・・増幅回路
１ｏ・・・同期整流回路１１・・・演算回路Figure 1 (Fig. 1 Cb) is a side sectional view of the same part, and Figure 1 CO) is a plan view of the detection unit and the levitation coil to be measured according to the embodiment of the present invention. ii [Fig.
! Figure 5 (ri) is a diagram showing how each detection coil output changes with the displacement of the levitation coil in the left-right direction. It is a diagram showing how it changes. 1#2* 3* 4'''Detection coil 5... Excitation coil 6... Levitation coil 7...
Detection section 8...Oscillation circuit 9...Amplification circuit 1o...Synchronous rectifier circuit 11...Arithmetic circuit
Claims (1)
平行に位置するように検測車に取り付けられた浮上コイ
ルに同等な輪郭を有する励振コイルと、励振コイルの下
に平行に取り付けられ取付面への励振コイル輪郭の正射
影を前後左右対称に４等分した輪郭を有する４個の検出
コイルとより成る検出部を備え、励振コイルを交流で励
振したとき、励振コイル磁界と、この磁界により短絡さ
れている浮上コイル巻線に誘起された短絡電流による浮
上コイル磁界とにより、これらの磁界を発生させるコイ
ル、特に浮上コイルと検出コイル夫々との磁気結合度に
応じて、４個の検出コイル夫々に誘起された起電力を測
定し、これらの測定値を処理演算して、浮上コイルの前
記検出部に対する相対位置を算出し、浮上コイルの在る
べき位置からの変位を電磁的に非接触で検出するように
したことを特徴とする浮上コイル変位検出装置。An excitation coil with a contour equivalent to the levitation coil installed on the inspection vehicle so as to be located directly above and parallel to the position of the levitation coil on the ground side of the levitation railway, and an excitation coil installed parallel to the levitation coil below the excitation coil. It is equipped with a detection unit consisting of four detection coils whose contours are obtained by dividing the orthogonal projection of the excitation coil contour onto the mounting surface into four equal parts in front, rear, left and right directions, and when the excitation coil is excited with alternating current, the excitation coil magnetic field and this Due to the levitation coil magnetic field due to the short-circuit current induced in the levitation coil windings short-circuited by the magnetic field, four The electromotive force induced in each detection coil is measured, and these measured values are processed and calculated to calculate the relative position of the levitation coil with respect to the detection section, and the displacement of the levitation coil from its desired position is electromagnetically calculated. A levitation coil displacement detection device characterized by non-contact detection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59158731A JPH0789681B2 (en) | 1984-07-31 | 1984-07-31 | Levitation coil displacement detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59158731A JPH0789681B2 (en) | 1984-07-31 | 1984-07-31 | Levitation coil displacement detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6139803A true JPS6139803A (en) | 1986-02-26 |
| JPH0789681B2 JPH0789681B2 (en) | 1995-09-27 |
Family
ID=15678096
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59158731A Expired - Lifetime JPH0789681B2 (en) | 1984-07-31 | 1984-07-31 | Levitation coil displacement detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0789681B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6343859A (en) * | 1986-08-11 | 1988-02-24 | 財団法人鉄道総合技術研究所 | Position transducer |
| JP2009225495A (en) * | 2008-03-13 | 2009-10-01 | Railway Technical Res Inst | Method of measuring amount of displacement of superconductive magnet in superconducting magnetic levitated vehicle |
| US8446004B2 (en) | 2004-06-04 | 2013-05-21 | Cree, Inc. | Power light emitting die package with reflecting lens and the method of making the same |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5421375A (en) * | 1977-07-18 | 1979-02-17 | Shimadzu Corp | Magnetism searchers |
| JPS5949985U (en) * | 1982-09-27 | 1984-04-03 | 株式会社島津製作所 | metal detector |
-
1984
- 1984-07-31 JP JP59158731A patent/JPH0789681B2/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5421375A (en) * | 1977-07-18 | 1979-02-17 | Shimadzu Corp | Magnetism searchers |
| JPS5949985U (en) * | 1982-09-27 | 1984-04-03 | 株式会社島津製作所 | metal detector |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6343859A (en) * | 1986-08-11 | 1988-02-24 | 財団法人鉄道総合技術研究所 | Position transducer |
| US8446004B2 (en) | 2004-06-04 | 2013-05-21 | Cree, Inc. | Power light emitting die package with reflecting lens and the method of making the same |
| US8932886B2 (en) | 2004-06-04 | 2015-01-13 | Cree, Inc. | Power light emitting die package with reflecting lens and the method of making the same |
| JP2009225495A (en) * | 2008-03-13 | 2009-10-01 | Railway Technical Res Inst | Method of measuring amount of displacement of superconductive magnet in superconducting magnetic levitated vehicle |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0789681B2 (en) | 1995-09-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3085646A (en) | Motor vehicle control system | |
| JP2017161538A (en) | Transport rail system having weight detection means | |
| US10180361B2 (en) | Temperature estimation device and temperature estimation method for contactless power-reception device | |
| CN110395118A (en) | Method for identifying slab staggering at seam of magnetic suspension train passing track and suspension control strategy | |
| JPH10506182A (en) | Speed measuring device for rail mounted vehicles | |
| JP2526578B2 (en) | Coating film damage detection method | |
| JPS6139803A (en) | Levitating coil displacement detector | |
| KR100684465B1 (en) | Method for measuring the speed of a rail vehicle and installation therfor | |
| JPH11304405A (en) | Position detector and position detecting method using the same | |
| JPH05281063A (en) | Measuring device for tension of steel material | |
| KR101192456B1 (en) | lateral rail displacement measuring system using electromagnetic induction ,the method and the sensor thereof | |
| JPH05249127A (en) | Arithmetic unit for calculating speed and movement distance of traveling object | |
| JP6719111B2 (en) | Rail wear measuring method using eddy current sensor and its measuring device | |
| EP3330719B1 (en) | System and method for measuring the speed of a guided vehicle | |
| JPS601826B2 (en) | Linear motor stop position detection device | |
| JP2910167B2 (en) | Guide method of carrier | |
| JP5198100B2 (en) | Method and apparatus for measuring displacement of superconducting magnet position of superconducting magnetic levitation vehicle | |
| JP2590581B2 (en) | Runway judgment device for automatic guided vehicles | |
| JPH08327647A (en) | Current velocity measuring apparatus | |
| JP3546288B2 (en) | Flow velocity measuring method and device | |
| JP3644628B2 (en) | Stress measuring method and apparatus using magnetic anisotropy sensor | |
| JPH10333745A (en) | Position detection sensor for automatic traveling device | |
| JP2663767B2 (en) | Transformation rate measuring method and apparatus | |
| JP3833078B2 (en) | Method and apparatus for measuring wear on Alsas train lines | |
| JPH05281281A (en) | Device for detecting abnormality of ground coil of superconductive magnetic levitation type railroad |