JPH07111322B2 - Control method of non-contact displacement gauge - Google Patents
Control method of non-contact displacement gaugeInfo
- Publication number
- JPH07111322B2 JPH07111322B2 JP3151076A JP15107691A JPH07111322B2 JP H07111322 B2 JPH07111322 B2 JP H07111322B2 JP 3151076 A JP3151076 A JP 3151076A JP 15107691 A JP15107691 A JP 15107691A JP H07111322 B2 JPH07111322 B2 JP H07111322B2
- Authority
- JP
- Japan
- Prior art keywords
- displacement meter
- contact
- meter
- micro
- displacement
- 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.)
- Expired - Lifetime
Links
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- Numerical Control (AREA)
- Control Of Position Or Direction (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Length Measuring Devices With Unspecified Measuring Means (AREA)
- Measurement Of Optical Distance (AREA)
Description
【０００１】[0001]
【産業上の利用分野】この発明は超精密加工や超精密計
測において使用する非接触変位計に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact displacement meter used in ultra-precision machining and ultra-precision measurement.
【０００２】[0002]
【従来の技術】超精密鏡面板の加工等の超精密加工や物
体部表面の粗さ測定等の超精密計測において、測定装置
の動作距離範囲を大きく保ちながら、物体表面までの距
離を高分解能、非接触かつ物体表面に何等の特別な処理
をすることなく測定できる変位計が必要とされる。2. Description of the Related Art In ultra-precision machining such as machining of ultra-precision mirror surface plates and ultra-precision measurement such as roughness measurement of the surface of an object part, the distance to the object surface is highly resolved while keeping the operating distance range of the measuring device large. There is a need for a displacement gauge that is non-contact and that can measure the surface of the object without any special treatment.
【０００３】超精密加工や超精密計測に使用可能な測長
装置としてはレーザ干渉計、静電容量式、渦電流式など
の電気式検出器、非点収差式や臨界角式等の光学式微小
変位計、プランジャ型の変位測定器等がある。Laser interferometers, electrical detectors such as capacitance type and eddy current type, and optical types such as astigmatism type and critical angle type are available as length measuring devices that can be used for ultra-precision machining and ultra-precision measurement. There are micro-displacement meters and plunger-type displacement measuring instruments.
【０００４】[0004]
【発明が解決しようとする課題】しかるに、レーザ干渉
計は物体表面に精密な鏡面またはプリズムを設置しなけ
ればならない。また、電気式検出器や光学式微小変位計
は高い分解能を有し、検出物体表面に特別の処理を必要
としないが、動作距離範囲が大幅に制限される。また、
プランジャ型の変位測定器には高分解能かつ大動作距離
のものがあるが、物体表面に測定子を接触させる必要が
ある。このようなことから、測定装置の動作距離範囲を
大きく保ちながら、物体表面までの距離を高分解能、非
接触かつ物体表面に何等の特別な処理をすることなく測
定できる変位計の開発が望まれている。However, the laser interferometer must be provided with a precise mirror surface or prism on the surface of the object. Further, the electric detector and the optical micro-displacement meter have high resolution and do not require any special treatment on the surface of the detected object, but the working distance range is significantly limited. Also,
Some plunger type displacement measuring instruments have high resolution and a large working distance, but it is necessary to bring the probe into contact with the surface of the object. Therefore, it is desirable to develop a displacement gauge that can measure the distance to the object surface with high resolution, non-contact, and without any special treatment on the object surface while keeping the operating distance range of the measuring device large. ing.
【０００５】この発明は上記のごとき事情に鑑みてなさ
れたものであって、測定装置の動作距離範囲を大きく保
ちながら、物体表面までの距離を高分解能、非接触かつ
物体表面に何等の特別な処理のをすることなく測定でき
る非接触変位計の制御方法を提供することを目的とする
ものである。The present invention has been made in view of the circumstances as described above, and while keeping the operating distance range of the measuring device large, the distance to the object surface is high resolution, non-contact, and no special matter is applied to the object surface. It is an object of the present invention to provide a control method of a non-contact displacement meter that can perform measurement without performing any processing.
【０００６】[0006]
【課題を解決するための手段】この目的に対応して、こ
の発明の非接触変位計の制御方法は、物体表面までの距
離を非接触で計測可能な微小変位計と、前記微小変位計
を直線状に移動させる直線運動機構と、前記直線運動機
構の移動量を測定するレーザ干渉計と、前記微小変位計
の出力から前記微小変位計と前記物体表面との距離が一
定となる前記直線運動機構の移動速度を求めて移動速度
指令として前記直線運動機構に与える制御装置とを備え
る非接触変位計における前記変位計を前記物体表面から
十分遠い位置から前記微小変位計の動作距離まで移動さ
せる方法であって、前記微小変位計を出力特性に単調性
を有しない変位計で構成し、前記微小変位計の出力が予
め定められた２つの信号レベルを定められた順番で通過
したことを検出してフリップフロップに記憶させ、前記
フリップフロップの記憶内容によって前記直線運動機構
に与える移動速度指令値をある一定値から前記微小変位
計の出力から求められた値へ切り替えることを特徴とし
ている。To solve this problem, a control method for a non-contact displacement meter according to the present invention is a micro displacement meter capable of measuring a distance to an object surface in a non-contact manner, and the micro displacement meter. A linear movement mechanism that moves linearly, a laser interferometer that measures the amount of movement of the linear movement mechanism, and the linear movement that makes the distance between the micro displacement meter and the object surface constant from the output of the micro displacement meter. A method for moving the displacement gauge in a non-contact displacement gauge from a position sufficiently far from the object surface to a working distance of the minute displacement gauge, which comprises a controller for determining the movement speed of the mechanism and giving it to the linear movement mechanism as a movement speed command. The micro displacement meter is constituted by a displacement meter having no monotonic output characteristic, and it is detected that the output of the micro displacement meter passes through two predetermined signal levels in a predetermined order. Is stored in the flip-flop, it is characterized in that switching to the value obtained from the output of the micro-displacement gauge from a certain value of the moving speed command value to be given to the linear motion mechanism by the storage contents of the flip-flop.
【０００７】またこの発明の非接触変位計の制御方法
は、物体表面までの距離を非接触で計測可能な微小変位
計と、前記微小変位計を直線状に移動させる直線運動機
構と、前記直線運動機構の移動量を測定するレーザ干渉
計と、前記微小変位計の出力から前記微小変位計と前記
物体表面との距離が一定となる前記直線運動機構の移動
速度を求めて移動速度指令として前記直線運動機構に与
える制御装置とを備える非接触変位計における前記変位
計を前記物体表面から十分遠い位置から前記微小変位計
の動作距離まで移動させる方法であって、前記微小変位
計を非点収差式光学微小変位計で構成し、前記微小変位
計の受光素子に入射する全光量がしきい値Ｓを越えると
きに前記直線移動機構の移動速度をある大きな一定値か
らある小さな一定値へ切り替えることを特徴としてい
る。Further, the control method of the non-contact displacement meter according to the present invention comprises a minute displacement meter capable of measuring the distance to an object surface in a non-contact manner, a linear movement mechanism for linearly moving the minute displacement meter, and the straight line. A laser interferometer that measures the amount of movement of the movement mechanism, and the movement speed command to obtain the movement speed of the linear movement mechanism in which the distance between the minute displacement gauge and the object surface is constant from the output of the minute displacement gauge. A method for moving the displacement gauge in a non-contact displacement gauge provided with a controller for giving a linear movement mechanism to a working distance of the minute displacement gauge from a position sufficiently distant from the object surface, wherein the minute displacement gauge is used for astigmatism. When the total amount of light incident on the light receiving element of the micro displacement meter exceeds a threshold value S, the moving speed of the linear moving mechanism is changed from a certain large constant value to a certain small constant value. It is characterized in that switch.
【０００８】[0008]
【作用】物体表面までの距離を非接触で微小変位計が測
定し、かつその微小変位計の出力に基づいてその微小変
位計と物体表面が一定の距離を保つように直線運動機構
の移動速度を制御する。直線運動機構の移動量をレーザ
干渉計が測定し、結局物体表面までの距離が測定され
る。微小変位計の位置が動作距離範囲から外れたとき
は、そのことを微小変位計の出力との比較によって検出
して、微小変位計の位置を動作距離範囲内の基準位置に
もどす。[Function] The distance to the object surface is measured by a non-contact microdisplacement meter, and based on the output of the microdisplacement meter, the moving speed of the linear motion mechanism is set so that the microdisplacement meter and the object surface maintain a constant distance. To control. A laser interferometer measures the amount of movement of the linear motion mechanism, and eventually the distance to the object surface is measured. When the position of the micro displacement meter is out of the working distance range, the fact is detected by comparison with the output of the micro displacement meter, and the position of the micro displacement meter is returned to the reference position within the working distance range.
【０００９】[0009]
【実施例】以下、この発明の詳細を一実施例を示す図面
について説明する。図１において、１は非接触変位計で
あり、非接触変位計１は非接触型微小変位計２を直線運
動機構３の移動台４に、軸の方向を直線運動機構の軸と
一致させて設置している。非接触型微小変位計２の後端
には平面鏡又は反射プリズム５が取付けられている。非
接触型微小変位計２の後方にはレーザ干渉計６が位置す
る。レーザ干渉計６としては既存のものを使用すること
ができる。レーザ干渉計６は直線運動機構の固定部７に
設置され、平面鏡又は反射プリズム５と対向して位置し
ている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings showing an embodiment. In FIG. 1, reference numeral 1 is a non-contact displacement gauge, and the non-contact displacement gauge 1 has a non-contact micro-displacement gauge 2 aligned with a moving base 4 of a linear motion mechanism 3 and an axial direction aligned with the axis of the linear motion mechanism. It is installed. A plane mirror or a reflecting prism 5 is attached to the rear end of the non-contact type micro displacement meter 2. A laser interferometer 6 is located behind the non-contact type micro displacement meter 2. An existing one can be used as the laser interferometer 6. The laser interferometer 6 is installed on the fixed portion 7 of the linear movement mechanism, and is positioned so as to face the plane mirror or the reflection prism 5.
【００１０】また、非接触変位計１は制御装置８を有す
る。制御装置８は非接触型微小変位計２の出力信号を受
け、それに位相補正、ゲイン補正等適当な補償を施した
後、その信号を直線運動機構３に移動速度指令値として
与えるものである。The non-contact displacement meter 1 also has a control device 8. The control device 8 receives the output signal of the non-contact type micro displacement meter 2 and performs appropriate compensation such as phase correction and gain correction, and then gives the signal to the linear motion mechanism 3 as a moving speed command value.
【００１１】非接触型微小変位計２としては、測定分解
能は高いが動作距離範囲が小さいものを使用し、例えば
公知の静電容量式、渦電流式等の電気式変位計、非点収
差法、臨界角法、フーコー法等の各種光ディスク用ヘッ
ド、または物体面からの反射光量を測定する光ファイバ
ー式変位計等が使用できる。As the non-contact type micro displacement meter 2, one having a high measurement resolution but a small working distance range is used. For example, a known capacitance type or eddy current type electric displacement meter or an astigmatism method is used. Various optical disk heads such as the critical angle method and the Foucault method, or an optical fiber type displacement meter for measuring the amount of light reflected from the object surface can be used.
【００１２】図２には非接触型微小変位計２として使用
可能な一例としての非点収差法光学式微小変位計１１を
示している。非点収差法光学式微小変位計１１は光源で
あるレーザダイオード１２からの光をコリメータレンズ
１３で平行光としたのち、偏光ビームスプリッタ１４で
光路を９０°曲げてλ／４板１５及び対物レンズ１６を
通して物体表面１７に照明し、その反射光を収束レンズ
１９及び円筒レンズ１８を通して４分割フォトダイオー
ド２１の４分割フォトダイオード受光セル２２に入射す
る。物体表面１７の位置により４分割フォトダイオード
２１上のビーム形状が変化する。FIG. 2 shows an astigmatic optical micro-displacement meter 11 as an example which can be used as the non-contact micro-displacement meter 2. In the astigmatism method optical micro-displacement meter 11, the light from the laser diode 12 which is the light source is collimated by the collimator lens 13 and then the polarization beam splitter 14 bends the optical path by 90 ° to form the λ / 4 plate 15 and the objective lens. The object surface 17 is illuminated through 16 and the reflected light is made incident on the 4-division photodiode light receiving cell 22 of the 4-division photodiode 21 through the converging lens 19 and the cylindrical lens 18. The beam shape on the quadrant photodiode 21 changes depending on the position of the object surface 17.
【００１３】図３に示すように、４分割フォトダイオー
ド受光セル２２の各受光セルＡ，Ｂ，Ｃ，Ｄに入射する
ビーム形状２０の分割型である光の強さをａ，ｂ，ｃ，
ｄとすると（ａ＋ｃ）−（ｂ＋ｄ）を演算すれば、物体
表面１７の位置に関係した出力が得られる。図３におい
て（ｉ）は物体表面が焦点位置より遠い場合を示す。
（ｉｉ）は物体表面が焦点位置にある場合を示す。（ｉ
ｉｉ）は物体表面が焦点位置より近い場合を示す。As shown in FIG. 3, the light intensity of the split type of the beam shape 20 incident on each of the light receiving cells A, B, C and D of the four-division photodiode light receiving cell 22 is represented by a, b, c, and
If d is calculated, (a + c)-(b + d) can be calculated to obtain an output related to the position of the object surface 17. In FIG. 3, (i) shows the case where the object surface is far from the focal position.
(Ii) shows the case where the object surface is at the focal position. (I
ii) shows the case where the object surface is closer than the focus position.
【００１４】この場合の運動に使用する演算回路の一例
を図４に示す。直線運動機構３としては、転がり案内、
静圧案内または滑り案内とねじ送り機構、電磁力による
送り機構などとの組合せからなる一般的なものが使用で
きる。FIG. 4 shows an example of an arithmetic circuit used for exercise in this case. The linear motion mechanism 3 includes rolling guides,
A general one composed of a combination of a static pressure guide or a slide guide and a screw feed mechanism, a feed mechanism by electromagnetic force, etc. can be used.
【００１５】レーザ干渉計６は一例として図５に原理を
示す。すなわち、図５に示すレーザ干渉計は偏光ビーム
スプリッタ２３、キューブコーナープリズム２４、キュ
ーブコーナープリズム２５、受光器２８を有する。キュ
ーブコーナープリズム２５は平面鏡または反射プリズム
５の一例として使用されるもので、従って、キューブコ
ーナープリズム２５は非接触型微小変位計２の背面に取
付けられて使用するものである。レーザ光源からのレー
ザ光は偏光ビームスプリッタ２３によって２分割され、
一方のレーザ光２６はキューブコーナープリズム２４で
反射されて再び偏光ビームスプリッタ２３に入る。他方
のレーザ光２７は移動するキューブコーナープリズム２
５で反射されて再び偏光ビームスプリッタ２３に入り、
２つのレーザ光２６，２７は干渉して受光器２８上に干
渉縞を形成するので、この干渉縞を観測することによっ
て、キューブコーナープリズム２５の位置、すなわち非
接触型微小変位計２の位置を検出することができる。The principle of the laser interferometer 6 is shown in FIG. 5 as an example. That is, the laser interferometer shown in FIG. 5 has a polarization beam splitter 23, a cube corner prism 24, a cube corner prism 25, and a light receiver 28. The cube corner prism 25 is used as an example of the plane mirror or the reflecting prism 5, and therefore, the cube corner prism 25 is used by being attached to the back surface of the non-contact type micro displacement meter 2. The laser light from the laser light source is split into two by the polarization beam splitter 23,
One of the laser beams 26 is reflected by the cube corner prism 24 and enters the polarization beam splitter 23 again. The other laser light 27 moves the cube corner prism 2
Is reflected by 5 and enters the polarization beam splitter 23 again,
Since the two laser beams 26 and 27 interfere with each other to form an interference fringe on the light receiver 28, by observing the interference fringe, the position of the cube corner prism 25, that is, the position of the non-contact type micro displacement meter 2 is determined. Can be detected.
【００１６】次に、このように構成された非接触変位計
によって物体表面１７を計測する操作について説明す
る。非接触型微小変位計２を物体表面１７に対向させて
直線運動機構３の移動台４に、軸の方向を直線運動機構
３の軸の方向と一致させて設置している。直線運動機構
３は移動指令によって移動台４を前後に移動し、非接触
型微小変位計２の測定対象である物体表面１７までの距
離を調節する。レーザ干渉計６は直線運動機構の固定部
７に設置され、移動台またはその上に設置された非接触
型微小変位計に取付けられた平面鏡または反射プリズム
５と自身との間の距離を計測する。制御装置８は非接触
型微小変位計の出力信号３１を受け、それに位相補正、
ゲイン補正等の適当な補償を施した後、その信号を直線
運動機構３に移動速度指令値３２として与える。その信
号の符号は、非接触型微小変位計２が基準の動作距離よ
り大きい出力を与えたときには非接触型微小変位計２が
近づくように、小さい出力を与えたときは遠ざかるよう
に選ぶ。Next, the operation of measuring the object surface 17 with the non-contact displacement meter constructed as described above will be described. The non-contact type micro-displacement meter 2 is placed on the moving table 4 of the linear motion mechanism 3 so as to face the object surface 17 so that the axis direction matches the axial direction of the linear motion mechanism 3. The linear movement mechanism 3 moves the movable table 4 back and forth according to a movement command, and adjusts the distance to the object surface 17 which is the measurement target of the non-contact type micro displacement meter 2. The laser interferometer 6 is installed on the fixed part 7 of the linear motion mechanism, and measures the distance between itself and the plane mirror or the reflection prism 5 attached to the movable table or the non-contact type micro displacement meter installed on it. . The control device 8 receives the output signal 31 of the non-contact type micro displacement meter, and phase-corrects it,
After performing appropriate compensation such as gain correction, the signal is given to the linear movement mechanism 3 as the moving speed command value 32. The sign of the signal is selected so that the non-contact type micro displacement meter 2 approaches when the non-contact type micro displacement meter 2 gives an output larger than the reference working distance, and moves away when the small output is given.
【００１７】物体表面１７が直線運動機構３の固定部７
に対して近づき、または遠ざかっても非接触型微小変位
計２は物体表面１７までの距離が常に基準値になるよう
に、直線運動機構３によってその位置が調節される。レ
ーザ干渉計６は直線運動機構３の移動量を正確に計測す
るから、その計測値がすなわち直線運動機構３の固定部
７から物体表面１７までの距離の変動値に等しい。この
ようにして、レーザ干渉計６の計測分解能をもち、物体
表面を直接非接触で測定でき、直線運動機構３の移動範
囲によってのみ測定距離範囲が制限される変位計が実現
できる。The object surface 17 is the fixed portion 7 of the linear motion mechanism 3.
The position of the non-contact type micro displacement meter 2 is adjusted by the linear motion mechanism 3 so that the distance to the object surface 17 always becomes a reference value, even if the non-contact type micro displacement meter 2 approaches or moves away. Since the laser interferometer 6 accurately measures the amount of movement of the linear motion mechanism 3, the measured value is equal to the variation value of the distance from the fixed portion 7 of the linear motion mechanism 3 to the object surface 17. In this way, it is possible to realize a displacement meter having the measurement resolution of the laser interferometer 6, capable of directly measuring the surface of an object without contact, and limiting the measurement distance range only by the moving range of the linear motion mechanism 3.
【００１８】次に非接触微小変位計の物体表面１７に対
する自動接近制御の一例について説明する。非接触型微
小変位計２として、出力特性に単調性を有さないものを
用いるときは、何等かの方法で非接触型微小変位計２と
物体表面１７との間の距離が適性動作距離範囲内になる
ように非接触型微小変位計２を移動した後、正規サーボ
動作モードに切り替える必要がある。さもなくば物体表
面１７と非接触型微小変位計２の間の距離の変動に対し
て直線運動機構３が望ましい運動と逆に運動し、正規の
動作ができないか、または非接触型微小変位計の物体表
面１７への衝突を招く可能性がある。Next, an example of automatic approach control for the object surface 17 of the non-contact micro displacement meter will be described. When the non-contact type micro displacement meter 2 which does not have monotonicity in output characteristics is used, the distance between the non-contact type micro displacement meter 2 and the object surface 17 is set in an appropriate operating distance range by some method. After moving the non-contact type micro displacement meter 2 so as to be inside, it is necessary to switch to the normal servo operation mode. Otherwise, the linear motion mechanism 3 moves in the opposite direction to the desired motion with respect to the variation in the distance between the object surface 17 and the non-contact type micro displacement meter 2, or the normal operation cannot be performed, or the non-contact type micro displacement meter. May collide with the object surface 17.
【００１９】従って、この発明では非接触型微小変位計
２が物体表面１７から十分に離れた位置から適性動作距
離範囲まで非接触型微小変位計２を自動的に接近させる
制御方式を採用している。すなわち、出力特性に単調性
を有さない非接触型微小変位計の出力特性の例を図６に
模式的に示す。３３は臨界角法光学式検出器の出力特
性、３４は非点収差法光学式検出器の出力特性、３５は
反射光量を検出するファイバー型光学式検出器の出力特
性の例である。これらの例では、適性動作距離範囲３６
より離れた位置に、適性動作距離範囲と勾配が逆でレベ
ルが同様の部分３７が存在する。この部分３７でサーボ
動作モードに移行させようとすると非接触型微小変位計
は更に接近することなく、反対に遠ざかってしまう。そ
こで、非接触型微小変位計が十分遠くの位置にある場
合、一定速度で接近させるように直線運動機構３に指令
し、非接触型微小変位計の出力が特性曲線上の最大値付
近に設けた２つのしきい値４１及び４２を４１，４２の
順に上から下へ横切ったことを比較器（図示せず）によ
って検出したならば直線運動機構３に非接触型微小変位
計２の出力信号を供給することによって、安全かつ確実
に正規のサーボ動作モードに移行することが可能にな
る。Therefore, in the present invention, a control system is adopted in which the non-contact type micro displacement meter 2 is automatically approached from a position sufficiently distant from the object surface 17 to an appropriate operating distance range. There is. That is, FIG. 6 schematically shows an example of the output characteristic of the non-contact type micro displacement meter which does not have monotonicity in the output characteristic. Reference numeral 33 is an output characteristic of the critical angle method optical detector, 34 is an output characteristic of the astigmatism method optical detector, and 35 is an example of the output characteristic of a fiber type optical detector for detecting the amount of reflected light. In these examples, the appropriate working distance range 36
At a position farther away, there is a portion 37 having a gradient opposite to that of the appropriate operating distance range and a similar level. If an attempt is made to shift to the servo operation mode at this portion 37, the non-contact type micro displacement meter does not approach further but moves away from it. Therefore, when the non-contact type micro displacement meter is located at a position sufficiently far away, the linear motion mechanism 3 is instructed to approach it at a constant speed, and the output of the non-contact type micro displacement meter is set near the maximum value on the characteristic curve. If it is detected by a comparator (not shown) that the two threshold values 41 and 42 are traversed in the order of 41 and 42 from top to bottom, the linear motion mechanism 3 outputs the output signal of the non-contact type micro displacement meter 2. Is supplied, it becomes possible to safely and surely shift to the regular servo operation mode.
【００２０】次に非接触型微小変位計の物体表面１７に
対する自動接近制御の他の例について説明する。上記第
１の例の自動接近制御においては、非接触型微小変位計
の特性曲線の如何によって接近動作モードからサーボ動
作モードに切り替えた後、適性動作距離範囲を越えて非
接触型微小変位計が物体表面１７に接近し、安定な動作
が得られないことがある。接近速度を下げればこれを避
けることができるが、接近に長時間かかることになる。
そこでこの第２の例の自動接近制御は高速かつ安定にサ
ーボ動作モードに引き込むことを可能にする制御方法で
ある。Next, another example of automatic approach control for the object surface 17 of the non-contact type micro displacement meter will be described. In the automatic approach control of the first example described above, after switching from the approach operation mode to the servo operation mode depending on the characteristic curve of the non-contact type micro displacement meter, the non-contact type micro displacement meter exceeds the appropriate operating distance range. It may approach the object surface 17 and stable operation may not be obtained. This can be avoided by reducing the approach speed, but it will take a long time to approach.
Therefore, the automatic approach control of the second example is a control method that enables the servo operation mode to be pulled in quickly and stably.
【００２１】すなわち、非接触型微小変位計として非点
収差光学式変位計を用いる場合、受光セルに入射する光
量の和（全光量）は一般的に図７に示すように、適性動
作距離範囲の近傍では大きくそれ以外では小さい。そこ
で、全光量があるレベルを上回る場合は非接触型微小変
位計の接近速度を小さく、下回る場合は接近速度を大き
くするように直線運動機構３への速度指令を切り替え
る。これによって高速かつ安定にサーボ動作モードに移
行することが可能になる。That is, when an astigmatic optical displacement meter is used as the non-contact type minute displacement meter, the sum of the light amounts incident on the light receiving cells (total light amount) is generally in the proper operating distance range as shown in FIG. It is large in the vicinity of and small otherwise. Therefore, when the total amount of light exceeds a certain level, the speed command to the linear motion mechanism 3 is switched so that the approach speed of the non-contact type micro displacement meter is decreased, and when it is below a certain level, the approach speed is increased. This enables a fast and stable transition to the servo operation mode.
【００２２】次に非接触型微小変位計２の物体表面１７
への近づき過ぎ又は離れ過ぎの位置からの自動退避制御
について説明する。上記サーボ動作モードにおいて、物
体表面１７の変位が急速かつ大振幅で、直線運動機構３
の動きがそれに十分追従できなくなると、非接触型微小
変位計と物体表面１７の距離が適性動作距離範囲を越
え、サーボ動作が有効に働かなくなり、場合によっては
非接触型微小変位計の物体表面１７への衝突を招く。こ
れを避けるため、この発明では自動退避制御を採用して
いる。Next, the object surface 17 of the non-contact type micro displacement meter 2
The automatic withdrawal control from a position that is too close to or too far from will be described. In the servo operation mode, the displacement of the object surface 17 is rapid and has a large amplitude, and the linear motion mechanism 3
When the movement of the object cannot sufficiently follow it, the distance between the non-contact type micro displacement meter and the object surface 17 exceeds the appropriate operating distance range, the servo operation does not work effectively, and in some cases the object surface of the non-contact type micro displacement meter. It causes a collision to 17. In order to avoid this, the present invention employs automatic evacuation control.
【００２３】非接触型微小変位計の出力が、図８に示す
ように適性距離範囲４３の両端に対応する２つのしきい
値４４，４５のいずれかを横切ったことを検出する図９
に示す回路の比較器４６と、その出力を記憶するフリッ
プフロップ４７とを設け、上記フリップフロップ４７に
上記事象の検出がセットされたときにスイッチ４８によ
って直線運動機構３への指令を非接触型微小変位計の出
力から退避速度を与える一定値に切換えることにより、
サーボ動作を止め、非接触型微小変位計を物体表面１７
から遠ざける退避動作を直線運動機構３に指令する。こ
れにより、サーボ動作の不完全から非接触型微小変位計
２と物体表面１７との衝突を回避する。フリップフロッ
プ４７は退避動作が完了したときにリセットする。It is detected that the output of the non-contact type micro displacement meter crosses either of two threshold values 44 and 45 corresponding to both ends of the appropriate distance range 43 as shown in FIG.
A comparator 46 of the circuit shown in FIG. 4 and a flip-flop 47 for storing the output thereof are provided, and when the detection of the event is set in the flip-flop 47, the switch 48 issues a command to the linear motion mechanism 3 in a non-contact type. By switching from the output of the micro displacement meter to a constant value that gives the evacuation speed,
Stop the servo operation and attach the non-contact type micro displacement meter to the object surface 17
The linear movement mechanism 3 is instructed to move away from This avoids the collision between the non-contact type micro displacement meter 2 and the object surface 17 due to the imperfect servo operation. The flip-flop 47 is reset when the saving operation is completed.
【００２４】[0024]
【発明の効果】この発明の非接触変位計では測定装置の
動作距離の大きいレーザ干渉計と分解能の高い非接触型
微小変位計のそれぞれの適性範囲での協働により測定装
置の動作距離範囲を大きく保ちながら、物体表面までの
距離を高分解能、非接触かつ物体表面に何等の特別な処
理をすることなく測定することが可能になる。According to the non-contact displacement meter of the present invention, the working distance range of the measuring device is increased by the cooperation of the laser interferometer having a long working distance of the measuring device and the non-contact type micro displacement meter having a high resolution. It becomes possible to measure the distance to the object surface with high resolution, non-contact, and without any special treatment on the object surface while keeping it large.
【図１】この発明の一実施例に係わる非接触型変位計を
示す構成説明図。FIG. 1 is a structural explanatory view showing a non-contact type displacement meter according to an embodiment of the present invention.
【図２】非点収差法光学式微小変位計を示す構成説明
図。FIG. 2 is a structural explanatory view showing an astigmatism method optical micro displacement meter.
【図３】４分割フォトダイオード受光セル上のビーム形
状を示す説明図。FIG. 3 is an explanatory view showing a beam shape on a 4-division photodiode light receiving cell.
【図４】演算回路を示す回路図。FIG. 4 is a circuit diagram showing an arithmetic circuit.
【図５】レーザ干渉計を示す構成説明図。FIG. 5 is a structural explanatory view showing a laser interferometer.
【図６】非接触型微小変位計の出力特性を示すグラフ。FIG. 6 is a graph showing the output characteristics of a non-contact type micro displacement meter.
【図７】非接触型微小変位計の出力と物体表面からの距
離を示すグラフ。FIG. 7 is a graph showing the output of the non-contact type micro displacement meter and the distance from the object surface.
【図８】非接触型微小変位計の出力特性を示すグラフ。FIG. 8 is a graph showing output characteristics of a non-contact type micro displacement meter.
【図９】退避制御装置の回路図。FIG. 9 is a circuit diagram of an evacuation control device.
１ 非接触変位計 ２ 非接触型微小変位計 ３ 直線運動機構 ４ 移動台 ５ 平面鏡または反射プリズム ６ レーザ干渉計 ７ 固定部 ８ 制御装置 １１ 非点収差法光学式微小変位計 １２ レーザダイオード １３ コリメータレンズ １４ 偏光ビームスプリッタ １５ λ／４板 １６ 対物レンズ １７ 物体表面 １８ 円筒レンズ １９ 収束レンズ ２０ ビーム形状 ２１ ４分割フォトダイオード ２２ ４分割フォトダイオード受光セル ２３ 偏光ビームスプリッタ ２４ キューブコーナープリズム ２５ キューブコーナープリズム ２６ 一方のレーザ光 ２７ 他方のレーザ光 ２８ 受光器 ３１ 出力信号 ３２ 移動速度指令値 ３３ 出力特性 ３４ 出力特性 ３５ 出力特性 ３６ 適性動作距離範囲 ３７ 部分 ４１ しきい値 ４２ しきい値 ４３ 適性距離範囲 ４４ しきい値 ４５ しきい値 ４６ 比較器 ４７ フリップフロップ ４８ スイッチ 1 Non-contact displacement meter 2 Non-contact type micro displacement meter 3 Linear motion mechanism 4 Moving table 5 Plane mirror or reflection prism 6 Laser interferometer 7 Fixed part 8 Control device 11 Astigmatic optical micro displacement meter 12 Laser diode 13 Collimator lens 14 Polarizing Beam Splitter 15 λ / 4 Plate 16 Objective Lens 17 Object Surface 18 Cylindrical Lens 19 Converging Lens 20 Beam Shape 21 4-Division Photodiode 22 4-Division Photodiode Photoreceptive Cell 23 Polarization Beam Splitter 24 Cube Corner Prism 25 Cube Corner Prism 26 Laser light 27 Other laser light 28 Receiver 31 Output signal 32 Moving speed command value 33 Output characteristic 34 Output characteristic 35 Output characteristic 36 Appropriate operating distance range 37 Part 41 Threshold 42 Threshold 43 Appropriate distance range 44 Threshold 45 threshold 46 comparator 47 flip-flop 48 switches
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｇ０５Ｄ 3/00 Ｘ (56)参考文献 特開 昭64−26106（ＪＰ，Ａ) 特開 昭51−108187（ＪＰ，Ａ) 実開 昭52−23065（ＪＰ，Ｕ)─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI Technical indication location G05D 3/00 X (56) References JP-A-64-26106 (JP, A) JP-A-51 -108187 (JP, A) Actually open Sho 52-23065 (JP, U)
Claims (2)
な微小変位計 と、前記微小変位計を直線状に移動させる
直線運動機構と、前記直線運動 機構の移動量を測定する
レーザ干渉計と、前記微小変位計の出力から前記 微小変
位計と前記物体表面との距離が一定となる前記直線運動
機構の移動 速度を求めて移動速度指令として前記直線運
動機構に与える制御装置とを 備える非接触変位計におけ
る前記変位計を前記物体表面から十分遠い位置 から前記
微小変位計の動作距離まで移動させる方法であって、前
記微小変 位計を出力特性に単調性を有しない変位計で構
成し、前記微小変位計の出 力が予め定められた２つの信
号レベルを定められた順番で通過したことを 検出してフ
リップフロップに記憶させ、前記フリップフロップの記
憶内容 によって前記直線運動機構に与える移動速度指令
値をある一定値から前記 微小変位計の出力から求められ
た値へ切り替えることを特徴とする非接触 変位計の制御
方法。 1. The distance to the surface of an object can be measured without contact.
Minute displacement meter and move the minute displacement meter in a straight line
A linear movement mechanism and the amount of movement of the linear movement mechanism are measured.
A laser interferometer, the minute variable from the output of the micro displacement meter
The linear motion in which the distance between the position gauge and the surface of the object is constant
The moving speed of the mechanism is obtained and the moving speed command is used for the linear operation.
In a non-contact displacement gage provided with a control device for a dynamic mechanism
That the said displacement gauge from a sufficiently distant position from the object surface
It is a method of moving to the working distance of a micro displacement meter,
Up of no displacement meter monotonic output characteristics the serial minute strange position meter
Form, 2 output of said small displacement meter predetermined Tsunoshin
Off by detecting that has passed in the order defined a No. Level
It is stored in the lip flop,
Movement speed command given to the linear motion mechanism according to the stored contents
The value is calculated from the output of the micro displacement meter from a certain value.
Of non-contact displacement gauge characterized by switching to different values
Method.
な微小変位計 と、前記微小変位計を直線状に移動させる
直線運動機構と、前記直線運動 機構の移動量を測定する
レーザ干渉計と、前記微小変位計の出力から前記 微小変
位計と前記物体表面との距離が一定となる前記直線運動
機構の移動 速度を求めて移動速度指令として前記直線運
動機構に与える制御装置とを 備える非接触変位計におけ
る前記変位計を前記物体表面から十分遠い位置 から前記
微小変位計の動作距離まで移動させる方法であって、前
記微小変 位計を非点収差式光学微小変位計で構成し、前
記微小変位計の受光素子に 入射する全光量がしきい値Ｓ
を越えるときに前記直線移動機構の移動速度 をある大き
な一定値からある小さな一定値へ切り替えることを特徴
とする 非接触変位計の制御方法。 2. The distance to the object surface can be measured without contact.
Minute displacement meter and move the minute displacement meter in a straight line
A linear movement mechanism and the amount of movement of the linear movement mechanism are measured.
A laser interferometer, the minute variable from the output of the micro displacement meter
The linear motion in which the distance between the position gauge and the surface of the object is constant
The moving speed of the mechanism is obtained and the moving speed command is used for the linear operation.
In a non-contact displacement gage provided with a control device for a dynamic mechanism
That the said displacement gauge from a sufficiently distant position from the object surface
It is a method of moving to the working distance of a micro displacement meter,
The serial micro-displacement of meter configured with astigmatism type optical micro-displacement meter, before
The total amount of light incident on the light receiving element of the micro displacement meter is the threshold value S
The moving speed of the linear moving mechanism above a certain level
Characterized by switching from a fixed value to a small fixed value
Control method for non-contact displacement meter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3151076A JPH07111322B2 (en) | 1991-05-27 | 1991-05-27 | Control method of non-contact displacement gauge |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3151076A JPH07111322B2 (en) | 1991-05-27 | 1991-05-27 | Control method of non-contact displacement gauge |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04350505A JPH04350505A (en) | 1992-12-04 |
| JPH07111322B2 true JPH07111322B2 (en) | 1995-11-29 |
Family
ID=15510791
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3151076A Expired - Lifetime JPH07111322B2 (en) | 1991-05-27 | 1991-05-27 | Control method of non-contact displacement gauge |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07111322B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5438988B2 (en) * | 2009-02-17 | 2014-03-12 | 株式会社ミツトヨ | Measurement system and interferometer |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51108187A (en) * | 1975-03-19 | 1976-09-25 | Mitsubishi Electric Corp | IDOTAINOKUDOSOCHI |
| JPS5825441Y2 (en) * | 1975-08-06 | 1983-06-01 | 株式会社神戸製鋼所 | Kogiyouyourobottsutonoanzenouchi |
| JP2575128B2 (en) * | 1987-03-13 | 1997-01-22 | キヤノン株式会社 | Surface shape measuring device |
-
1991
- 1991-05-27 JP JP3151076A patent/JPH07111322B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04350505A (en) | 1992-12-04 |
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