JPH04268483A - Measuring method for distance of moving table by utilizing laser and feeding device for executing measurement of distance by laser - Google Patents
Measuring method for distance of moving table by utilizing laser and feeding device for executing measurement of distance by laserInfo
- Publication number
- JPH04268483A JPH04268483A JP3050569A JP5056991A JPH04268483A JP H04268483 A JPH04268483 A JP H04268483A JP 3050569 A JP3050569 A JP 3050569A JP 5056991 A JP5056991 A JP 5056991A JP H04268483 A JPH04268483 A JP H04268483A
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- Prior art keywords
- light
- mirror
- distance
- moving
- optical path
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- 238000005259 measurement Methods 0.000 title claims abstract description 73
- 238000000034 method Methods 0.000 title claims abstract description 18
- 230000003287 optical effect Effects 0.000 claims abstract description 57
- 230000010287 polarization Effects 0.000 claims abstract description 38
- 238000012545 processing Methods 0.000 claims description 6
- 230000002452 interceptive effect Effects 0.000 claims description 5
- 238000010008 shearing Methods 0.000 abstract description 14
- 230000000694 effects Effects 0.000 abstract description 6
- 238000010586 diagram Methods 0.000 description 8
- 238000000691 measurement method Methods 0.000 description 6
- 238000006073 displacement reaction Methods 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
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- Automatic Control Of Machine Tools (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】工作機械等熱変形する部分に支え
られた物体の移動距離をレーザ光を利用して測距する改
良された方法並びに工作機械等の移動する主軸台或いは
工作物または工具等を載置するテーブルの現在位置をレ
ーザ光により測距を行う送りユニットに関するものであ
る。[Industrial Application Field] An improved method of measuring the moving distance of an object supported by a thermally deformable part such as a machine tool using a laser beam, and a moving headstock or workpiece of a machine tool or a tool. This relates to a feeding unit that measures the current position of a table on which objects are placed using a laser beam.
【０００２】0002
【従来の技術】光波を利用して其の波長を基準として物
体の移動距離を測定する方法は物理学の分野で発明され
ていた光干渉計例えばマイケルソンの干渉計のように単
色光を光源とし参照光と移動物体に向けられた測定光と
の干渉を利用した方法が知られている。最近では光源に
レーザ光線を利用し基準光と測定光の位相差を検出して
移動距離を算出する方式が研究され安定した高精度の測
定が可能になった。又其の測定光路にも測定距離を二度
往復させて測定精度を２倍に向上させる研究がされてい
る。[Prior Art] A method of measuring the distance traveled by an object using light waves based on their wavelength is an optical interferometer invented in the field of physics that uses monochromatic light as a light source, such as Michelson's interferometer. A method is known that utilizes interference between reference light and measurement light directed at a moving object. Recently, research has been conducted into a method that uses a laser beam as a light source to detect the phase difference between the reference light and the measurement light to calculate the distance traveled, making it possible to perform stable and highly accurate measurements. Research is also being conducted to double the measurement accuracy by making the measurement optical path go back and forth twice.
【０００３】0003
【発明が解決しようとする課題】レーザ光利用測長方法
は充分高精度のものが得られているが、其の一部が運動
する機械にレーザ光利用測長方法を組み合わせて移動台
の移動距離を正確に測定しようとすると測長系路内のス
テージミラーと移動台との相対位置を高精度に一定にす
ることが困難または不可能で、レーザ光利用測長結果が
移動台移動距離に対応しない結果になることがある。[Problem to be solved by the invention] Although sufficiently high accuracy has been obtained with the laser beam-based length measurement method, it is difficult to combine the laser beam-based length measurement method with a machine that moves a part of it to move the movable table. When attempting to accurately measure distances, it is difficult or impossible to maintain a constant relative position between the stage mirror and the moving table in the length measurement system path, and the result of length measurement using a laser beam may not reflect the moving distance of the moving table. This may result in non-compatible results.
【０００４】例えば円筒研削盤において主軸台を載置す
るテーブルの動きを測距するのにアッベの原理に従って
工作物の中心線上にステージミラーを図１３のように配
置して中心線上の後方より測距すれば、主軸前端から反
射鏡迄が遠く工作物の位置基準である主軸台は発熱源を
有しているので熱変形をするアッベの原理による誤差は
生じないけれどもステージミラーと工作物との間の距離
が変化し誤差を生ずる。For example, in order to measure the movement of the table on which the headstock is mounted in a cylindrical grinding machine, a stage mirror is placed on the center line of the workpiece as shown in FIG. 13 according to Abbe's principle, and the distance is measured from behind on the center line. If the distance is far from the front end of the spindle to the reflector, the headstock, which is the workpiece position reference, has a heat source, so errors due to Abbe's principle of thermal deformation do not occur, but the difference between the stage mirror and the workpiece is The distance between them changes, causing an error.
【０００５】またこの熱変形の誤差を小さくするように
図１４のように主軸台を避けて工作物の中心線の側方に
反射用ミラーを配置すればアッベの原理に反しているの
でテーブルのヨーイング運動に起因する誤差が生ずる。Furthermore, if a reflection mirror is placed on the side of the center line of the workpiece, avoiding the headstock as shown in FIG. 14, in order to reduce the error due to thermal deformation, this violates Abbe's principle, so the table Errors occur due to the yawing motion.
【０００６】また熱変位を小さくし、ヨーイングの誤差
をなくするために図１５のようにテーブルの両側に測定
系を設けて平均化させると誤差が最小になるが測距装置
が高くなるという問題がある。Furthermore, in order to reduce thermal displacement and eliminate yawing errors, if measurement systems are installed on both sides of the table and averaged as shown in FIG. 15, the error will be minimized, but there is a problem that the distance measuring device will be expensive. There is.
【０００７】また旋盤，研削盤など移動する主軸台テー
ブル，刃物台テーブルの二つの位置検出を行うのに図１
６のようにすると図１３，１４の誤差の影響があらわれ
るばかりでなく、測長基準がそれぞれ干渉計設置場所で
あるのでベッド上で基準点が分散していて環境温度変化
或いは加工発熱によりベッドの熱変形により測長基準点
間隔Ｌｚ，Ｌｘの変化により直接加工精度に影響すると
いう問題がある。FIG. 1 is also used to detect the two positions of a headstock table and a turret table that move in lathes, grinders, etc.
6, not only will the effects of the errors in Figures 13 and 14 appear, but since the length measurement standards are the interferometer installation locations, the reference points are scattered on the bed, and the bed may be affected by environmental temperature changes or processing heat. There is a problem in that machining accuracy is directly affected by changes in length measurement reference point intervals Lz and Lx due to thermal deformation.
【０００８】本発明は従来の技術の有するこのような問
題点に鑑みなされたものであり、その目的とするところ
は工作機械の運動の不規則性や熱変形の影響を補償する
レーザ光波利用測距方法並びにレーザ測距を行う送りユ
ニットを提供することにある。The present invention was made in view of the above-mentioned problems of the conventional technology, and its purpose is to provide a measurement method using laser light waves that compensates for irregularities in the movement of machine tools and the effects of thermal deformation. The object of the present invention is to provide a distance method and a feeding unit that performs laser distance measurement.
【０００９】[0009]
【課題を解決するための手段】上記目的を達成するため
に本発明は移動台の移動位置をレーザを利用して測距す
る方法において、単一レーザ光源からの光線を２本の偏
光光線に分け、その内１本が移動台の移動中心に平行な
光路をとり偏光面旋回手段を介して順次移動台両側に配
置したステージミラー間を２回往復させた測長光と、他
の１本が前記偏光面旋回手段を介して順次前記移動中心
両側に対応して固定側に配置した参照光ミラー間を２回
往復させた等価な参照光とを干渉させ、光路長差により
移動台の移動距離を求める。[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for distance measuring the moving position of a moving table using a laser, in which a light beam from a single laser light source is divided into two polarized light beams. One of the beams takes an optical path parallel to the center of movement of the moving table, and the other beam is a length measuring beam that is made to travel twice between the stage mirrors placed on both sides of the moving table via a polarization plane rotation means. is caused to interfere with equivalent reference beams that have been made to go back and forth twice between reference beam mirrors placed on the fixed side corresponding to both sides of the moving center through the polarization plane rotation means, and the movement of the moving table is caused by the difference in optical path length. Find the distance.
【００１０】また単一レーザ光源の第１偏光光線を移動
台の移動方向手前側のステージミラーと前記移動方向後
側の固定部の参照光ミラーとに偏光面旋回手段を介して
導き２回往復させた第１測長光と、分離した第２偏光光
線を前記移動方向手前側の固定部の参照光ミラーと前記
移動方向後側の移動台のステージミラーとに前記偏光面
旋回手段を共用して導き２回往復させた第２測長光との
干渉をつくり、光路長差より移動台の移動距離を求める
ものである。Further, the first polarized light beam of the single laser light source is guided to the stage mirror on the front side in the moving direction of the movable table and the reference light mirror on the fixed part on the rear side in the moving direction through a polarization plane rotation means and reciprocated twice. The first length measuring light and the separated second polarized light beam are shared by the reference light mirror of the fixed part on the front side in the moving direction and the stage mirror of the moving table on the rear side in the moving direction, and the polarization plane rotation means is used in common. This method creates interference with the second length measurement light that is guided and reciprocated twice, and the moving distance of the movable table is determined from the difference in optical path length.
【００１１】また単一レーザ光源と、該単一レーザ光源
の偏光光線を移動台の移動中心の両側に配置したステー
ジミラーに偏光面旋回手段を介して順次導き移動台側か
らの測長反射光をうる測長光路変更手段と、前記単一レ
ーザ光源の分離した偏光光線を前記移動中心の両側に対
応して配置した固定台の参照光ミラーに導き前記偏光面
旋回手段を介して順次導き参照反射光をうる等価な参照
光路変更手段と、前記測長光路変更手段の測長反射光と
前記参照光路変更手段の参照反射光とから干渉光をうる
干渉手段と、光路長差より移動距離を求め送りを制御す
る制御手段とを含むものである。In addition, a single laser light source and a polarized light beam of the single laser light source are sequentially guided to stage mirrors arranged on both sides of the center of movement of the moving table via a polarization plane rotation means, and the length measurement reflected light from the moving table side. the polarized light beams separated from the single laser light source are sequentially guided through the polarization plane rotation means to guide the separated polarized light beams from the single laser light source to the reference light mirrors of the fixed base arranged on both sides of the moving center. equivalent reference optical path changing means for obtaining the reflected light; interference means for obtaining interference light from the length measurement reflected light of the length measuring optical path changing means and the reference reflected light of the reference optical path changing means; and control means for controlling the requested feed.
【００１２】また単一レーザ光源と、該単一レーザ光源
の分離した第１偏光光線を移動台の移動方向手前側のス
テージミラーと移動台の移動方向後側の固定部の参照光
ミラーとに偏光面旋回手段を介して導き２回往復させて
第１測長反射光をうる第１光路変更手段と、分離した第
２偏光光線を前記移動台の移動方向手前側の固定部の参
照光ミラーと前記移動台の移動方向後側のステージミラ
ーとに前記偏光面旋回手段を共用して導き２回往復させ
て第２測長反射光をうる第２光路変更手段と、前記第１
測長反射光と第２測長反射光と干渉させる干渉手段と、
光路長差より移動距離を求め送りを制御する制御手段と
を含むものである。Furthermore, the single laser light source and the separated first polarized light beam of the single laser light source are sent to a stage mirror on the front side in the moving direction of the moving table and a reference light mirror on the fixed part on the rear side in the moving direction of the moving table. a first optical path changing means that guides the light beam through a polarization plane rotation means and makes it reciprocate twice to obtain a first length measurement reflected light; and a reference light mirror on a fixed part on the front side of the movable base in the moving direction to direct the separated second polarized light beam. and a stage mirror on the rear side in the moving direction of the movable stage, a second optical path changing means shares the polarization plane rotation means and guides the light back and forth twice to obtain a second length measurement reflected light;
Interfering means for interfering with the length measurement reflected light and the second length measurement reflected light;
The apparatus includes a control means for determining the moving distance from the optical path length difference and controlling the feeding.
【００１３】そして同一機台上に、請求項２に記載の第
１送りユニットと、該第１送りユニットに対し移動方向
を直角方向とした請求項４に記載の第２送りユニットと
を備え、前記第１送りユニット第２送りユニットとの単
一レーザ光源を共通とするとともに測距基準となる互い
の干渉手段を隣接集中化する位置に配置した加工機であ
る。The first feeding unit according to claim 2 and the second feeding unit according to claim 4 whose movement direction is perpendicular to the first feeding unit are provided on the same machine base, This processing machine shares a single laser light source with the first feeding unit and the second feeding unit, and is arranged in a position where mutual interference means serving as a distance measurement reference are concentrated adjacent to each other.
【００１４】[0014]
【作用】請求項１、２はレーザ光線を２本の偏光光線と
し移動台の中心線方向の移動を測定する光路を移動台中
心線に平行に其の両側に中心線から等距離に形成し両光
路差を光の干渉を利用して求め移動台の移動距離とし，
送り制御する。請求項３、４は移動台の移動方向の前後
両側に達する光路を形成し第１測長反射光と第２測長反
射光との光路差を光の干渉を利用して求め移動台の移動
距離とし送り制御する。請求項５は上記二つの形の組み
合わせによって集中化して測距して送りユニットを制御
する。[Operation] According to claims 1 and 2, the laser beam is made into two polarized beams, and the optical path for measuring the movement in the direction of the center line of the moving table is formed parallel to the center line of the moving table and equidistant from the center line on both sides thereof. The difference between the two optical paths is determined using optical interference and is taken as the moving distance of the moving table.
Control the feed. Claims 3 and 4 form an optical path that reaches both front and rear sides in the moving direction of the moving table, and determine the optical path difference between the first length-measuring reflected light and the second length-measuring reflected light by using optical interference to move the moving table. Control the distance and feed. According to a fifth aspect of the present invention, the feeding unit is controlled by centrally measuring the distance by combining the above two methods.
【００１５】[0015]
【実施例】実施例第１を以下図１、図２にもとづいて構
成を説明する。移動台の中心線より離れて光路を設置し
移動台の中心線方向の移動を測定するときに光路を移動
台中心線に平行に其の両側に中心線から等距離に設置し
両光路長の和の変化を測定し移動台の移動距離とする平
均化されたレーザ測距の方式である。ベッド１案内面上
をテーブル２が移動可能に載置されており、ベッド１上
の前後のブラケット３，４に回転のみ可能に軸承された
送りねじがテーブル２のナットと連結され、テーブル２
はＮＣ制御装置２０により制御されるサーボモータ５に
よって位置決め駆動される。[Embodiment] The structure of the first embodiment will be explained below based on FIGS. 1 and 2. When measuring movement in the direction of the center line of the moving table by installing an optical path away from the center line of the moving table, set the optical path parallel to the center line of the moving table and equidistant from the center line on both sides of the moving table. This is an averaged laser distance measurement method that measures the change in the sum and uses it as the moving distance of the moving table. A table 2 is movably placed on the guide surface of the bed 1, and a feed screw rotatably supported by the front and rear brackets 3 and 4 on the bed 1 is connected to a nut on the table 2.
is positioned and driven by a servo motor 5 controlled by an NC control device 20.
【００１６】テーブル２上には例えば主軸６を回転可能
に軸承する主軸台７がテーブル移動方向中心線と同心と
なるように設置されている。またテーブル２の主軸台７
の中心線両側等距離で主軸６の前後左右位置にステージ
ミラー１１，１２が反射光の水平とするようにＤ間隔で
固設されている。ブラケット３上にはステージミラー１
１に対応してベンダミラー１３が、ステージミラー１２
に対応して干渉計１４がそれぞれ固設されている。また
ブラケット３上には右側長光に対する参照光ミラー１６
が、ベンダミラー１３に対応して左側長光に対する参照
光ミラー１５が干渉計１４に対応して固設されている。A headstock 7, which rotatably supports, for example, a main shaft 6, is installed on the table 2 so as to be concentric with the center line in the table movement direction. Also, the headstock 7 of table 2
Stage mirrors 11 and 12 are fixedly installed at the front, rear, left and right positions of the main shaft 6 at equal distances on both sides of the center line at intervals of D so that the reflected light is horizontal. Stage mirror 1 is on bracket 3
1, the bender mirror 13 and the stage mirror 12
Interferometers 14 are fixedly installed corresponding to the respective ones. Also, on the bracket 3 is a reference beam mirror 16 for the right long beam.
However, a reference beam mirror 15 for the left long beam is fixedly provided corresponding to the interferometer 14 in correspondence with the bend mirror 13 .
【００１７】干渉計１４は公知のものでビームスプリッ
タ２１のレーザ光入力側にλ／２波長板２３，偏光シア
リング板２６，側面にコーナーキューブ２２，他の２面
にλ／４波長板２４，２５が付属されている。そしてレ
ーザ光源装置１７及びレーザ光の測長光と参照光干渉光
を受光するレシーバ１８がベッド１のブラケット１９上
に設けられている。このレーザ光源装置１７は二周波ｆ
１，ｆ２ のレーザ光を出力する。The interferometer 14 is a known one, and includes a λ/2 wavelength plate 23 and a polarization shearing plate 26 on the laser light input side of the beam splitter 21, a corner cube 22 on the side, and a λ/4 wavelength plate 24 on the other two sides. 25 is attached. A laser light source device 17 and a receiver 18 that receives the length measurement light of the laser light and the interference light of the reference light are provided on the bracket 19 of the bed 1. This laser light source device 17 has a dual frequency f
Outputs a laser beam of 1, f2.
【００１８】次に図３にもとづき測距の原理を説明する
。二周波のレーザ光を光源としヘテロダイン検波を行う
測長方式を使用するものとする。光線を示す線に付した
｜印は紙面に平行な偏光面を有する直線偏光（以下Ｐ偏
光）の光線、●を付した線は紙面に垂直な偏光面を有す
る直線偏光（以下Ｓ偏光）の光線、○を付した線は円偏
光の光線を示す。Next, the principle of distance measurement will be explained based on FIG. A length measurement method using a dual-frequency laser beam as a light source and performing heterodyne detection will be used. The ｜ marks on the lines indicating light rays indicate linearly polarized light (hereinafter referred to as P-polarized light) whose plane of polarization is parallel to the plane of the paper, and the lines marked with ● indicate linearly polarized light whose plane of polarization is perpendicular to the plane of the paper (hereinafter referred to as S-polarized light). Light rays and lines marked with ○ indicate circularly polarized light rays.
【００１９】周波数ｆ１，ｆ２ のレーザ光源装置１７
よりの入力光線ｆは偏光シヤリング板２６により周波数
ｆ１ のＰ偏光の測長光線ｆａと周波数ｆ２ のＳ偏光
の参照光線ｆｂとの隣接した２本に分けられる。測長光
ｆａは干渉計１４の内部にある４５°の斜面がＰ偏光の
光線は通過させるがＳ偏光の光線は反射するところの偏
光ビームスプリッタ２１においてＰ偏光の測長光線ｆａ
は偏光ビームスプリッタ２１を通過し続いてλ／４波長
板２４を通過し偏光平面を４５°回転されて円偏光とな
りテーブル２の中心線より右側で平行に進みテーブル上
の右ステージミラー１２に到り反射される。Laser light source device 17 with frequencies f1 and f2
The input light beam f is divided by the polarization shearing plate 26 into two adjacent beams: a P-polarized measuring beam fa having a frequency f1 and an S-polarized reference beam fb having a frequency f2. The length measuring light fa is transmitted to the polarizing beam splitter 21 where a 45° slope inside the interferometer 14 allows the P polarized light to pass through but reflects the S polarized light.
passes through the polarizing beam splitter 21, then passes through the λ/4 wavelength plate 24, rotates the polarization plane by 45 degrees, becomes circularly polarized light, and travels parallel to the right side of the center line of the table 2, reaching the right stage mirror 12 on the table. reflected.
【００２０】反射光は再びλ／４波長板２４を通過し偏
光平面を４５°回転されてＳ偏光となる。従って測長光
線ｆａは偏光ビームスプリッタ２１で直角に反射されλ
／４波長板２５を通過して偏光平面を４５°回転されて
円偏光となりベンダーミラー１３で直角に反射されて再
び中心線の左側で平行となり左ステージミラー１１に到
り反射される。反射光はベンダーミラー１３を経由して
直角に曲げられλ／４波長板２５を通過して偏光平面を
４５°回転されてＰ偏光となり、偏光ビームスプリッタ
２１を通過しコーナーキューブ２２にいたる。The reflected light passes through the λ/4 wavelength plate 24 again, and the polarization plane is rotated by 45° to become S-polarized light. Therefore, the length measuring light beam fa is reflected at right angles by the polarizing beam splitter 21 and λ
The light passes through the /4 wavelength plate 25, rotates the polarization plane by 45 degrees, becomes circularly polarized light, is reflected at a right angle by the bender mirror 13, becomes parallel again to the left side of the center line, reaches the left stage mirror 11, and is reflected. The reflected light is bent at a right angle via the bender mirror 13, passes through the λ/4 wavelength plate 25, rotates the polarization plane by 45 degrees, becomes P-polarized light, passes through the polarization beam splitter 21, and reaches the corner cube 22.
【００２１】コーナーキューブ２２で１８０°曲げられ
た測長光線ｆａは偏光ビームスプリッタ２１を通過し同
様にλ／４波長板２５で円偏光、ベンダーミラー１３で
変角、左ステージミラー１１で反射、ベンダーミラー１
３が変角、λ／４波長板２５でＳ偏光、偏光ビームスプ
リッタ２１で変角、λ／４波長板２４で円偏光、右ステ
ージミラー１２で反射、λ／４波長板２４でＰ偏光とな
り、偏光ビームスプリッタ２１を経由してλ／２波長板
２３を通過し偏光面を９０°回転されＳ偏光となり、偏
光シヤリング板２６に達する。The length measurement light beam fa bent by 180° by the corner cube 22 passes through the polarizing beam splitter 21, is circularly polarized by the λ/4 wavelength plate 25, is changed in angle by the bender mirror 13, is reflected by the left stage mirror 11, and is reflected by the left stage mirror 11. vendor mirror 1
3 is angle-bending, λ/4 wavelength plate 25 turns it into S-polarized light, polarizing beam splitter 21 changes angle, λ/4-wave plate 24 turns it into circularly polarized light, right stage mirror 12 reflects it, and λ/4-wave plate 24 turns it into P-polarized light. , passes through the λ/2 wavelength plate 23 via the polarization beam splitter 21, rotates the plane of polarization by 90 degrees, becomes S-polarized light, and reaches the polarization shearing plate 26.
【００２２】一方偏光シヤリング板２６で分けられたＳ
偏光の参照光線ｆｂはλ／２波長板２３で偏光面を９０
°回転されたＰ偏光にされたあと測長光線ｆａと同様の
光路をたどるが、左右のステージミラー１１，１２に替
えてブラケット３上の参照光ミラー１５，１６で反射さ
れるものである。そして参照光線ｆｂは偏光シヤリング
板２６において測長光ｆａと合成され干渉光ｆ´がレシ
ーバ１８に受光される。On the other hand, the S separated by the polarizing shearing plate 26
The reference beam fb of polarized light is
After being turned into P-polarized light rotated by .degree., it follows the same optical path as the length measurement light beam fa, but is reflected by the reference light mirrors 15 and 16 on the bracket 3 instead of the left and right stage mirrors 11 and 12. The reference light beam fb is combined with the length measurement light fa in the polarization shearing plate 26, and the interference light f' is received by the receiver 18.
【００２３】測定に当たってはステージミラー１１，１
２はそれぞれ参照光ミラー１５及び１６と同じ位置にあ
ったと仮定して説明する。即ち図３のＡ＝Ｂ＝０の状態
からの移動量を測定するものとする。干渉計１４と右参
照光ミラー１６との距離をａ、右参照光ミラー１６と右
ステージミラー１２との距離をＡ、干渉計１４と左参照
光ミラー１５とのテーブル移動方向の距離をｂ、左参照
光ミラー１５と左ステージミラー１１との距離をＢ、右
光路と左光路の中心間距離をＤとする。[0023] During measurement, stage mirrors 11, 1
The explanation will be made assuming that 2 is at the same position as the reference light mirrors 15 and 16, respectively. That is, the amount of movement from the state of A=B=0 in FIG. 3 is measured. The distance between the interferometer 14 and the right reference beam mirror 16 is a, the distance between the right reference beam mirror 16 and the right stage mirror 12 is A, and the distance between the interferometer 14 and the left reference beam mirror 15 in the table movement direction is b. Let B be the distance between the left reference light mirror 15 and the left stage mirror 11, and D be the distance between the centers of the right optical path and the left optical path.
【００２４】測長光線ｆａの光路長は後に述べる参照光
線ｆｂの光路長と共通の部分を除くと
ビームスプリッタ２１⇔右ステージミラー１２往復
（ａ＋Ａ）＋（Ａ＋ａ）ビームスプリッタ２１⇒ベンダ
ーミラー１３ Ｄベンダーミラー１
３⇔左ステージミラー１１往復 （ｂ＋Ｂ）＋（
Ｂ＋ｂ）ベンダーミラー１３⇒コーナーキューブ２２
Ｄコーナーキューブ２２⇒ベンダー
ミラー１３ Ｄベンダーミラー１３
⇔左ステージミラー１１往復 （ｂ＋Ｂ）＋（Ｂ
＋ｂ）ベンダーミラー１３⇒ビームスプリッタ２１
Ｄビームスプリッタ２１⇔右ステージ
ミラー１２往復 （ａ＋Ａ）＋（Ａ＋ａ）の合計４（
Ａ＋Ｂ）＋４（ａ＋ｂ）＋４Ｄである。The optical path length of the measurement beam fa is the same as the optical path length of the reference beam fb, which will be described later.
(a+A)+(A+a) Beam splitter 21 ⇒ Bender mirror 13 D Bender mirror 1
3⇔Left stage mirror 11 round trips (b+B)+(
B+b) Bender mirror 13 ⇒ Corner cube 22
D Corner Cube 22 ⇒ Bender Mirror 13 D Bender Mirror 13
⇔Left stage mirror 11 round trips (b+B)+(B
+b) Bender mirror 13 ⇒ Beam splitter 21
D beam splitter 21 ⇔ right stage mirror 12 round trip (a+A)+(A+a) total 4(
A+B)+4(a+b)+4D.
【００２５】一方周波数ｆ２の参照光線ｆｂは偏光シヤ
リング板２で測長光線ｆａと分離され紙面に垂直な偏光
面を有するＳ偏光として入力されるのでλ／２波長板２
３でＰ偏光に変更させられ、ビームスプリッタ２１を通
過する。ステージミラー１１及び１２で反射されるので
はなくて参照光ミラー１５及び１６で反射される点を別
にすれば参照光線ｆｂは測長光線ｆａに準じた光路を通
過するのでその光路長は前に述べた測長光路と共通の部
分を除くとOn the other hand, the reference beam fb of frequency f2 is separated from the measurement beam fa by the polarization shearing plate 2 and is input as S-polarized light having a plane of polarization perpendicular to the plane of the paper.
3, the light is changed to P polarization and passes through the beam splitter 21. Except for the fact that it is not reflected by the stage mirrors 11 and 12 but by the reference beam mirrors 15 and 16, the reference beam fb passes through an optical path similar to that of the measurement beam fa, so its optical path length is Excluding the parts common to the length measurement optical path mentioned above,
【００２６】
ビームスプリッタ２１⇔参照光ミラー１６往復
ａ＋ａビームスプリッタ２１⇒ベンダーミラー
１３ Ｄベンダーミラー１３⇔参照
光ミラー１５往復 ｂ＋ｂベンダー
ミラー１３⇒コーナーキューブ２２
Ｄコーナーキューブ２２⇒ベンダーミラー１３
Ｄベンダーミラー１３⇔参照光ミラー１
５往復 ｂ＋ｂベンダーミラー１３
⇒ビームスプリッタ２１ Ｄビーム
スプリッタ２１⇔参照光ミラー１６往復
ａ＋ａの合計４（ａ＋ｂ）＋４Ｄである。偏光シヤリ
ング板２６で測長光線ｆａと参照光線ｆｂが合成され干
渉計ｆ´を受光したレシーバ１８の信号をＮＣ制御装置
２０の中では干渉縞をカウントして測長光線ｆａの光路
長と参照光線ｆｂの光路長との差が計算される。すなわ
ち［４（Ａ＋Ｂ）＋４（ａ＋Ｂ）＋４Ｄ］−［４（ａ＋
ｂ）＋４Ｄ］＝４（Ａ＋Ｂ）が得られる。Beam splitter 21⇔reference beam mirror 16 reciprocation
a+a beam splitter 21 ⇒ bender mirror 13 D bender mirror 13 ⇔ reference beam mirror 15 reciprocating b+b bender mirror 13 ⇒ corner cube 22
D Corner Cube 22 ⇒ Bender Mirror 13
D bender mirror 13 ⇔ Reference beam mirror 1
5 round trips b+b bender mirror 13
⇒ Beam splitter 21 D beam splitter 21 ⇔ Reference beam mirror 16 reciprocating
The total of a+a is 4(a+b)+4D. The measuring beam fa and the reference beam fb are combined by the polarizing shearing plate 26, and the signal from the receiver 18 which is received by the interferometer f' is counted in the NC control device 20 by counting the interference fringes and referring to it as the optical path length of the measuring beam fa. The difference from the optical path length of the ray fb is calculated. That is, [4(A+B)+4(a+B)+4D]-[4(a+
b)+4D]=4(A+B) is obtained.
【００２７】次いでテーブル２がサーボモータ５によっ
てΔＸ移動された場合を図４について説明する。測長光
路のＡがＡ＋ΔＸ、測長光路ＢがＢ＋ΔＸとなるので、
４（Ａ＋Ｂ）は４｛（Ａ＋ΔＸ）＋（Ｂ＋ΔＸ）｝＝４
（Ａ＋Ｂ）＋８ΔＸとなる。従ってテーブル移動ΔＸに
対して８ΔＸと８倍の距離変化となって検出されるので
レーザ測距の高分解能化が可能となる。Next, the case where the table 2 is moved by ΔX by the servo motor 5 will be described with reference to FIG. Since the length measurement optical path A is A+ΔX and the length measurement optical path B is B+ΔX,
4(A+B) is 4{(A+ΔX)+(B+ΔX)}=4
(A+B)+8ΔX. Therefore, since the distance change is detected as 8ΔX, which is eight times as large as the table movement ΔX, it is possible to improve the resolution of laser distance measurement.
【００２８】テーブル２はベッドの案内面の真直度、摩
擦係数の変化等によりヨーイング現象をさけることがで
きない。そこで図５のようにヨーイングしたとすると、
測長光路ＡはＡ＋ε、測長光路ＢがＢ−εとなる。した
がって４（Ａ＋Ｂ）は４｛（Ａ＋ε）＋（Ｂ−ε）｝＝
４（Ａ＋Ｂ）となって測長距離が平均化されヨーイング
誤差は打ち消される。The table 2 cannot avoid the yawing phenomenon due to changes in the straightness of the guide surface of the bed, changes in the coefficient of friction, etc. So, if we yaw as shown in Figure 5,
The length measurement optical path A becomes A+ε, and the length measurement optical path B becomes B−ε. Therefore, 4(A+B) is 4{(A+ε)+(B-ε)}=
4(A+B), the measured distance is averaged, and the yawing error is canceled out.
【００２９】このような機能を有するレーザ測距を行う
送りユニットはその制御装置２０内に位置決め目標値を
記憶回路３１に記憶しておき、レシーバ１８で受光した
干渉光を入力したカウンタ計算回路３２で移動量を計算
し比較回路３３で目標値と比較演算され、その差に応じ
た関数が関数発生回路３４で発生され駆動回路３５でサ
ーボモータ５を制御駆動する。テーブル２の移動量はレ
シーバ１８で干渉光を受光しフイードバックして位置制
御するものである。A feeding unit that performs laser distance measurement having such a function stores a positioning target value in a storage circuit 31 in its control device 20, and a counter calculation circuit 32 into which the interference light received by the receiver 18 is input. The amount of movement is calculated and compared with the target value in the comparison circuit 33. A function corresponding to the difference is generated in the function generation circuit 34, and the drive circuit 35 controls and drives the servo motor 5. The amount of movement of the table 2 is determined by receiving interference light with a receiver 18 and feeding it back to control the position.
【００３０】実施例第２を以下図６，図７にもとづいて
説明する。図１、図２、図３と同一部品は同符号を付し
て同等の部品に´及びサフイックスを付して説明を省略
する。移動方向手前側ステージミラー１２´はテーブル
２の移動中心のテーブル端に、移動方向後側ステージミ
ラー１１´は同中心線上のテーブル端にアッベの原理に
もとづき固設されている。ベンダーミラーは３個必要と
し第１ベンダーミラー１３ａはベッド１上のブラケット
３に第２，第３ベンダーミラー１３ｂ，１３ｃはブラケ
ット４上に固設され測長光線をそれぞれ９０°変角して
いる。また手前側ステージミラー１２´に対する手前側
参照光ミラー１６´はブラケット３上に後側ステージミ
ラー１１´に対する後側参照光ミラー１６´はブラケッ
ト４上に固定されているものである。The second embodiment will be explained below based on FIGS. 6 and 7. Components that are the same as those in FIGS. 1, 2, and 3 are designated by the same reference numerals, and equivalent components are designated with a ' and a suffix, and the description thereof will be omitted. The stage mirror 12' on the front side in the moving direction is fixed at the table end at the center of movement of the table 2, and the rear stage mirror 11' on the moving direction is fixed at the table end on the same center line based on Abbe's principle. Three bender mirrors are required, and the first bender mirror 13a is fixed on the bracket 3 on the bed 1, and the second and third bender mirrors 13b and 13c are fixed on the bracket 4, and each deflects the measuring beam by 90 degrees. . The front reference light mirror 16' for the front stage mirror 12' is fixed on the bracket 3, and the rear reference light mirror 16' for the rear stage mirror 11' is fixed on the bracket 4.
【００３１】そして周波数ｆ１，ｆ２のレーザ光源装置
１７よりの入力光線が偏光シヤリング板２６で分けられ
た周波数ｆ１のＰ偏光の第１測長光線ｆｃと周波数ｆ２
のＳ偏光の第２測長光線ｆｄとの光路について図８にも
とづいて説明する。偏光シヤリング板２６で分けられた
レーザ光線を測長光線と参照光線となした実施例第１と
異なるところは、分けられた偏光光線は第１測長光線ｆ
ｃと第２測長光線ｆｄとして使用し、それぞれステージ
ミラーと参照光ミラーで反射されることである。The input light beams from the laser light source device 17 with frequencies f1 and f2 are separated by a polarization shearing plate 26 into a first measurement light beam fc of P polarization with frequency f1 and frequency f2.
The optical path of the S-polarized light with the second measurement light beam fd will be explained based on FIG. The difference from the first embodiment is that the laser beam separated by the polarization shearing plate 26 is used as the length measurement light beam and the reference light beam.
c and second length measuring beam fd, and are reflected by the stage mirror and the reference beam mirror, respectively.
【００３２】即ちＰ偏光の第１測長光線ｆｃは偏光ビー
ムスプリッタ２１を通過、λ／４波長板２４で円偏光、
手前側ステージミラー１２´で反射、λ／４波長板２４
でＳ偏光、偏光ビームスプリッタ２１で９０°変角、λ
／４波長板２５で円偏光、ベンダーミラー１３ａ，１３
ｂ，１３ｃでそれぞれ９０°変角、後側参照光ミラー１
５´で反射、ベンダーミラー１３ｃ，１３ｂ，１３ａで
それぞれ９０°変角、λ／４波長板２５でＰ偏光、偏光
ビームスプリッタ２１を通過、コーナーキューブ２２で
１８０°変角、偏光ビームスプリッタ２１を通過、λ／
４波長板２５で円偏光、ベンダーミラー１３ａ，１３ｂ
，１３ｃでそれぞれ９０°変角、後側参照光ミラー１５
´で再度反射、ベンダーミラー１３ｃ，１３ｂ，１３ａ
でそれぞれ９０°変角、λ／４波長板２５でＳ偏光、偏
光ビームスプリッタ２１で９０°変角、λ／４波長板２
４で円偏光、手前側ステージミラー１２´で再度反射、
λ／４波長板２４でＰ偏光、偏光ビームスプリッタ２１
を通過、λ／２波長板２３でＳ偏光、偏光シヤリング板
２６に達する。That is, the P-polarized first measuring light beam fc passes through the polarizing beam splitter 21, and is circularly polarized by the λ/4 wavelength plate 24.
Reflected by front stage mirror 12', λ/4 wavelength plate 24
S polarized light, polarized beam splitter 21 changes angle by 90°, λ
/4 wavelength plate 25 circularly polarized light, bender mirrors 13a, 13
b and 13c each have a 90° angle displacement, rear reference beam mirror 1
5', deflected by 90 degrees by the bender mirrors 13c, 13b, and 13a, P-polarized by the λ/4 wavelength plate 25, passed through the polarizing beam splitter 21, deflected by 180 degrees by the corner cube 22, and polarized by the polarizing beam splitter 21. Passage, λ/
Circularly polarized light with 4 wavelength plate 25, bender mirrors 13a, 13b
, 13c each has a 90° angle displacement, and the rear reference beam mirror 15
Reflected again at ', bender mirrors 13c, 13b, 13a
90° deflection, λ/4 wavelength plate 25 for S polarization, polarization beam splitter 21 for 90° deflection, λ/4 wavelength plate 2
4, circularly polarized light, reflected again by the front stage mirror 12',
P polarized light with λ/4 wavelength plate 24, polarized beam splitter 21
The S-polarized light passes through the λ/2 wavelength plate 23 and reaches the polarized shearing plate 26.
【００３３】一方Ｓ偏光の第２測長光線ｆｄはλ／２波
長板２３でＰ偏光、偏光ビームスプリッタ２１を通過、
λ／４波長板２４で円偏光、手前側参照光ミラー１６´
で反射、λ／４波長板２４でＳ偏光、偏光ビームスプリ
ッタ２１で９０°変角、λ／４波長板２４で円偏光、ベ
ンダーミラー１３ａ，１３ｂ，１３ｃでそれぞれ９０°
変角、後側ステージミラー１１´で反射、ベンダーミラ
ー１３ｃ，１３ｂ，１３ａでそれぞれ９０°変角、λ／
４波長板２５でＰ偏光、偏光ビームスプリッタ２１を通
過、コーナーキューブ２２で１８０°変角、偏光ビーム
スプリッタ２１を通過、λ／４波長板２５で円偏光、ベ
ンダーミラー１３ａ，１３ｂ，１３ｃでそれぞれ９０°
変角、後側ステージミラー１１´で再度反射、ベンダー
ミラー１３ｃ，１３ｂ，１３ａでそれぞれ９０°変角、
λ／４波長板２５でＳ偏光、偏光ビームスプリッタ２１
で９０°変角、λ／４波長板２４で円偏光、手前側参照
光ミラー１６´で再度反射、λ／４波長板２４でＰ偏光
、偏光ビームスプリッタ２１を通過、偏光シヤリング板
２６で屈折し、第１測長光線ｆｃと合成され、干渉光が
出力されレシーバ１８に受光される。制御装置１９で検
出測距される。On the other hand, the S-polarized second measurement light beam fd passes through the λ/2 wavelength plate 23 and the P-polarized beam splitter 21.
Circularly polarized light by λ/4 wavelength plate 24, front side reference light mirror 16'
, reflected by the λ/4 wavelength plate 24, S-polarized light by the polarizing beam splitter 21, circularly polarized by the λ/4 wavelength plate 24, and 90° by each of the bender mirrors 13a, 13b, and 13c.
Shifting angle, reflection at rear stage mirror 11', 90° shifting at bender mirrors 13c, 13b, and 13a, λ/
P-polarized light is transmitted through the 4-wave plate 25, passes through the polarizing beam splitter 21, 180° angle is changed through the corner cube 22, passes through the polarized beam splitter 21, circularly polarized light is transmitted through the λ/4 wavelength plate 25, and transmitted through the bender mirrors 13a, 13b, and 13c, respectively. 90°
Shifting angle, reflecting again at rear stage mirror 11', 90° deflection at bender mirrors 13c, 13b, and 13a, respectively.
S-polarized light with λ/4 wavelength plate 25, polarized beam splitter 21
, circularly polarized by the λ/4 wavelength plate 24, reflected again by the front reference beam mirror 16', P-polarized by the λ/4 wavelength plate 24, passed through the polarizing beam splitter 21, and refracted by the polarizing shearing plate 26. Then, it is combined with the first length measurement light beam fc, and interference light is output and received by the receiver 18. The control device 19 detects and measures the distance.
【００３４】次いで光路長を図８にもとづいて検討する
。偏光ビームスプリッタ２１と前側参照光ミラー１６´
との距離をｂ、手前側参照光ミラー１６´と手前側ステ
ージミラー１２´との距離をＢ、テーブル長をｍ、後側
ステージミラー１１´と後側参照光ミラー１５´との距
離をＡ、後側参照光ミラー１５´とベンダミラー１３ｃ
との距離をａ、ベンダミラー１３ｃと１３ｂとの距離を
Ｄ、ベンダミラー１３ａと１３ｂとの距離をＬとする。Next, the optical path length will be examined based on FIG. Polarizing beam splitter 21 and front reference beam mirror 16'
The distance between the front reference light mirror 16' and the front stage mirror 12' is B, the table length is m, and the distance between the rear stage mirror 11' and the rear reference light mirror 15' is A. , rear reference light mirror 15' and bender mirror 13c.
The distance between the bender mirrors 13c and 13b is D, and the distance between the bender mirrors 13a and 13b is L.
【００３５】周波数ｆ１のＰ偏光第１測長光線ｆｃの光
路長は、
ビームスプリッタ２１⇔手前側ステージミラー１２´
（ｂ＋Ｂ）＋（Ｂ＋ｂ）ビームスプリッタ２１⇒第１
ベンダミラー１３ａ Ｄ第１ベンダミラ
ー１３ａ⇒第２ベンダミラー１３ｂ Ｌ第２
ベンダミラー１３ｂ⇒第３ベンダミラー１３ｃ
Ｄ第３ベンダミラー１３ｃ⇔後側参照光ミラー１１
´往復 ａ＋ａ第３ベンダミラー１３ｃ⇒第２ベンダ
ミラー１３ｂ Ｄ第２ベンダミラー１３ｂ⇒
第１ベンダミラー１３ａ Ｌ第１ベンダミラ
ー１３ａ⇒コーナーキューブ２２ Ｄコ
ーナーキューブ２２⇒第１ベンダミラー１３ａ
Ｄ第１ベンダミラー１３ａ⇒第２ベンダミラー
１３ｂ Ｌ第２ベンダミラー１３ｂ⇒第３ベ
ンダミラー１３ｃ Ｄ第３ベンダミラー１３
ｃ⇔後側参照光ミラー１５´往復 ａ＋ａ第３ベンダ
ミラー１３ｃ⇒第２ベンダミラー１３ｂ Ｄ
第２ベンダミラー１３ｂ⇒第１ベンダミラー１３ａ
Ｌ第１ベンダミラー１３ａ⇒ビームスプリッタ
２１ Ｄビームスプリッタ２１⇔手前側
ステージミラー１２´ （ｂ＋Ｂ）＋（Ｂ＋ｂ）の合
計４Ｂ＋４（ａ＋ｂ）＋４（Ｄ＋Ｌ＋Ｄ）である。The optical path length of the P-polarized first measuring beam fc of frequency f1 is as follows: beam splitter 21⇔front stage mirror 12'
(b+B)+(B+b) Beam splitter 21⇒1st
Bender mirror 13a D first bend mirror 13a ⇒ second bend mirror 13b L second
Bender mirror 13b⇒Third bend mirror 13c
D third bend mirror 13c ⇔ rear reference beam mirror 11
'Reciprocating a+a Third bender mirror 13c⇒Second bender mirror 13b DSecond bender mirror 13b⇒
First bender mirror 13a L first bender mirror 13a ⇒ Corner cube 22 D corner cube 22 ⇒ First bender mirror 13a
D 1st bender mirror 13a ⇒ 2nd bender mirror 13b L 2nd bender mirror 13b ⇒ 3rd bender mirror 13c D 3rd bender mirror 13
c ⇔ Rear reference light mirror 15' reciprocating a+a Third bender mirror 13c⇒Second bender mirror 13b D
2nd bender mirror 13b ⇒ 1st bender mirror 13a
L first bender mirror 13a⇒beam splitter 21 D beam splitter 21⇔front stage mirror 12' (b+B)+(B+b), totaling 4B+4(a+b)+4(D+L+D).
【００３６】同様にして周波数ｆ２の第２測長光線ｆｄ
の手前側参照光ミラー１６´及び後側ステージミラー１
１´等により形成される光路長は４Ａ＋４（ａ＋ｂ）＋
４（Ｄ＋Ｌ＋Ｄ）である。従って偏シヤリング板２６で
合成された干渉光がレシーバ１８で受光され其の両測長
光線の光路差４（Ａ−Ｂ）が計測される。Similarly, the second length measuring beam fd of frequency f2
front side reference light mirror 16' and rear side stage mirror 1
The optical path length formed by 1′ etc. is 4A+4(a+b)+
4(D+L+D). Therefore, the interference light combined by the polarized shearing plate 26 is received by the receiver 18, and the optical path difference 4 (A-B) between the two measuring beams is measured.
【００３７】いま移動体が位置ｘ＝ｘ０即ち＝Ａ０，Ｂ
＝Ｂ０の位置から図９のようにΔｘ動いてｘ＝ｘ１の位
置にきて、Ａ＝Ａ１，Ｂ＝Ｂ１になったとする。干渉計
を介して制御装置でｘ＝ｘ０の位置から計測を再開する
と、４（Ａ１−Ｂ１）−４（Ａ０−Ｂ０）＝４（Ａ０＋
Δｘ）−４（Ｂ０−Δｘ）＝８Δｘが得られ移動体の移
動量が差動化され高精度に求めることができる。[0037] The moving object is now at position x=x0, that is, =A0,B
Assume that it moves by Δx from the position =B0 to the position x=x1 as shown in FIG. 9, so that A=A1 and B=B1. When the control device restarts measurement from the position x=x0 via the interferometer, 4(A1-B1)-4(A0-B0)=4(A0+
.DELTA.x)-4(B0-.DELTA.x)=8.DELTA.x is obtained, and the movement amount of the moving object is differentiated and can be determined with high precision.
【００３８】更に又移動体が大気温度の変化等により図
１０のように２Δｍ膨張（又は収縮）しＡ、Ｂの値がそ
れぞれＡ０、Ｂ０からＡ２＝Ａ０−Δｍ、Ｂ２＝Ｂ０−
Δｍに変化したとすると干渉計を介して制御装置での計
測結果は４（Ａ２−Ｂ２）＝４｛（Ａ０−Δｍ）−（Ｂ
０−Δｍ）｝＝４（Ａ０−Ｂ０）の光路長に相当するも
のでステージミラー１１´，１２´の中間点に対する位
置情報に変化はない。Furthermore, the moving object expands (or contracts) by 2Δm as shown in FIG. 10 due to changes in atmospheric temperature, etc., and the values of A and B change from A0 and B0, respectively, to A2=A0-Δm, B2=B0-
Δm, the measurement result at the control device via the interferometer is 4(A2-B2)=4{(A0-Δm)-(B
0-Δm)}=4(A0-B0), and there is no change in the positional information with respect to the midpoint between the stage mirrors 11' and 12'.
【００３９】更に又テーブル２を載せているベッド１が
大気温度の変化等により図１１のように膨張（または収
縮）した場合にはベッド１に取り付けられている参照光
ミラー１５´，１６´間の距離Ａ＋ｍ＋Ｂが変化し誤差
を生ずる。この内ｍの変化は前述の如く誤差を生じない
。温度変化によりＡはＡ０からＡ３＝Ａ０＋Δａ、Ｂは
Ｂ０からＢ３＝Ｂ０＋Δｂとなるとすれば測定結果には
移動体が静止していても４（Ａ−Ｂ）＝４（Ａ３−Ｂ３
）＝４（Ａ０−Ｂ０）＋４（Δａ−Δｂ）に示されるよ
うに４（Δａ−Δｂ）の変化が現れ誤差を生ずる。温度
変化による変形は固定台内で一様であればΔａ／Ａ＝Δ
ｂ／ＢであるのでＡ＝Ｂ即ち移動台の移動範囲の中央で
はΔａ＝Δｂであり誤差は完全に補償されその付近では
ΔａとΔｂとの差は小さく誤差も非常に小さくなる。Further, if the bed 1 on which the table 2 is placed expands (or contracts) as shown in FIG. The distance A+m+B changes, causing an error. Among these, changes in m do not cause errors as described above. Assuming that due to temperature change, A changes from A0 to A3 = A0 + Δa, and B changes from B0 to B3 = B0 + Δb, the measurement result shows that even if the moving object is stationary, 4 (A - B) = 4 (A3 - B3
)=4(A0-B0)+4(Δa-Δb), a change of 4(Δa-Δb) appears, resulting in an error. If the deformation due to temperature change is uniform within the fixed table, Δa/A=Δ
b/B, so A=B, that is, at the center of the movement range of the moving table, Δa=Δb, and the error is completely compensated for. Near that point, the difference between Δa and Δb is small and the error is also very small.
【００４０】このような機能を有するレーザ測距を行う
送りユニットは制御装置２０内において実施例第１と同
じように干渉縞をカウントして測距値が計算され、位置
決め目標値と比較演算され、その差に対応して移動指令
がテーブル２駆動のサーボモータ５を動作させ、ボール
ねじを介してテーブル２が移動制御される。In the feed unit that performs laser distance measurement having such a function, the distance measurement value is calculated by counting interference fringes in the same way as in the first embodiment in the control device 20, and the distance value is compared with the positioning target value. , a movement command corresponding to the difference operates the servo motor 5 that drives the table 2, and the movement of the table 2 is controlled via the ball screw.
【００４１】実施例第３を図１２にもとづいて説明する
。主軸台７を載置してＮＣでＺ軸方向に移動位置決めさ
れるテーブル２ａと、刃物台又は砥石台２３を載置して
主軸台と直角方向にＮＣでＸ軸方向に移動位置決めされ
るテーブル２ｂを有する旋盤，研削盤等の２軸ＣＮＣ加
工機における送りユニットであって、本実施例は平均化
する実施例第１と、差動化する実施例第２の各測距方式
を組合わせたものである。そして実施例第１，第２と同
じ部品は同符号を付して同等部品はサフイックスを付し
て説明する。A third embodiment will be explained based on FIG. 12. A table 2a on which the headstock 7 is mounted and moved and positioned in the Z-axis direction by NC, and a table on which the tool rest or grindstone 23 is mounted and moved and positioned in the X-axis direction by NC in a direction perpendicular to the headstock. This embodiment is a feed unit for a two-axis CNC processing machine such as a lathe or grinder having a 2b, and this embodiment combines the distance measuring methods of the first embodiment, which uses averaging, and the second embodiment, which uses differential distance measurement. It is something that The same parts as in the first and second embodiments will be described with the same reference numerals, and equivalent parts will be described with a suffix.
【００４２】本実施例ではレーザ光源装置１７を１個と
し半透過ミラーを使用するベンダミラー２５によって９
０°に変角したほぼ１／２のレーザ光線は干渉計１４ａ
に送られる。またベンダミラー２５を通過したほぼ１／
２のレーザ光線はベンダミラー２６によって９０°変角
して干渉計１４ｂに送られる。そしてベンダミラー１３
及び干渉計１４ａにはそれぞれ左右参照光ミラーが、ま
たベンダミラー１３ａ，１３ｃには手前側，後側の参照
光ミラーが含まれているものである。In this embodiment, the number of laser light source devices 17 is one, and the bender mirror 25 using a semi-transparent mirror is used to
Approximately 1/2 of the laser beam with an angle angle of 0° is detected by the interferometer 14a.
sent to. Also, approximately 1/
The second laser beam is deflected by 90 degrees by the bend mirror 26 and sent to the interferometer 14b. and bender mirror 13
The interferometer 14a includes left and right reference light mirrors, and the bender mirrors 13a and 13c include front and rear reference light mirrors.
【００４３】このように構成することによって主軸台７
のＺ軸移動によるヨーイング誤差は解消され、刃物台又
は砥石台２３のＸ軸における熱変位の影響は零か非常に
小さくされる。さらに測長光路が隣接化されたのでＸ軸
，Ｚ軸の測長基準間隔は干渉計１４ａ，１４ｂのＺ軸方
向の距離Ｌ´ｚのみであるので、ベッドの熱膨張係数を
αとし環境の温度変化，加工発熱に伴うベッドの温度上
昇をΔｔとすればＺ軸方向の測長基準間隔Ｌ´ｚの変化
はα・Ｌ´ｚ・Δｔである。従来の測長基準間隔Ｌｚに
対しＬ´ｚはＬｚ≫Ｌ´ｚであるので従来の測長基準間
隔変化のα・Ｌｚ・Δｔ≫α・Ｌ´ｚ・Δｔとなり、ベ
ッドの熱変形による間隔の変化は非常に小さくできる。With this configuration, the headstock 7
The yawing error caused by the Z-axis movement of the tool head 23 is eliminated, and the influence of thermal displacement on the X-axis of the tool rest or the grindstone head 23 is reduced to zero or very small. Furthermore, since the length measurement optical paths are adjacent to each other, the length measurement reference interval on the X-axis and Z-axis is only the distance L'z in the Z-axis direction of the interferometers 14a and 14b. If the temperature rise of the bed due to temperature change and processing heat is Δt, the change in the length measurement reference interval L'z in the Z-axis direction is α·L′z·Δt. Compared to the conventional length measurement reference interval Lz, L'z is Lz≫L'z, so the conventional length measurement reference interval change is α, Lz, Δt≫α, L'z, Δt, and the interval is due to thermal deformation of the bed. The change in can be very small.
【００４４】[0044]
【発明の効果】上述のように構成したので本発明は以下
の効果を奏する。請求項１の測距方法及び請求項２の送
りユニットはレーザ光源が１個であるので、測距装置の
費用を低減でき経済的である。移動体のヨーイングによ
る誤差をなくすることができ、フイードバックされたテ
ーブル位置決め精度が向上できる。さらにアッベの原理
を用いた測長方式のように測距装置が移動方向に長くな
って多くのフロアスペースが必要となることもない。[Effects of the Invention] Since the present invention is configured as described above, the following effects can be achieved. Since the distance measuring method according to claim 1 and the feeding unit according to claim 2 include one laser light source, the cost of the distance measuring device can be reduced and it is economical. Errors due to yawing of the moving body can be eliminated, and table positioning accuracy based on feedback can be improved. Furthermore, unlike the length measuring method using Abbe's principle, the distance measuring device does not become long in the direction of movement and requires a large amount of floor space.
【００４５】請求項３の測距方法及び請求項４の送りユ
ニットはレーザ光源が１個であるので測距装置の費用を
低減でき経済的である。そして環境の温度変化，加工発
熱による熱変形に対する測距誤差を低減でき、フイード
バックコントロールされたテーブルの位置決め精度が向
上できる。Since the distance measuring method according to the third aspect and the feeding unit according to the fourth aspect include one laser light source, the cost of the distance measuring device can be reduced and it is economical. Furthermore, it is possible to reduce distance measurement errors due to environmental temperature changes and thermal deformation due to processing heat generation, and improve the positioning accuracy of the table under feedback control.
【００４６】請求項５の送りユニットは２軸の測距系路
を集約化して測長基準間隔が接近したのでベッドの熱変
形による測距誤差を低減でき、加工精度が向上できる。[0046] In the feeding unit of the fifth aspect, the two-axis distance measuring system paths are integrated and the length measurement reference intervals are brought closer, so that distance measurement errors due to thermal deformation of the bed can be reduced and machining accuracy can be improved.
【図１】本発明の実施例第１の送りユニットの説明平面
図である。FIG. 1 is an explanatory plan view of a first feeding unit according to an embodiment of the present invention.
【図２】実施例第１の側面図及び制御線図である。FIG. 2 is a side view and control diagram of a first embodiment.
【図３】実施例第１の測長光路を示す図である。FIG. 3 is a diagram showing a length measurement optical path in the first embodiment.
【図４】実施例第１のテーブル移動に伴う測距光路変化
図である。FIG. 4 is a diagram showing changes in the distance measuring optical path as the table moves in the first embodiment.
【図５】実施例第１のテーブルヨーイングによる測距光
路変化図である。FIG. 5 is a diagram showing changes in the distance measuring optical path due to table yawing in the first embodiment.
【図６】実施例第２の送りユニットの説明平面図である
。FIG. 6 is an explanatory plan view of the second feeding unit of the embodiment.
【図７】実施例第２の側面図である。FIG. 7 is a side view of a second embodiment.
【図８】実施例第２の測長光路を示す図である。FIG. 8 is a diagram showing a length measurement optical path in a second embodiment.
【図９】実施例第２のテーブル移動に伴う測距光路変化
図である。FIG. 9 is a diagram showing changes in the distance measuring optical path as the table moves in the second embodiment.
【図１０】実施例第２のテーブルの熱変形に伴う測距光
路変化図である。FIG. 10 is a diagram showing changes in the distance measuring optical path due to thermal deformation of the second table of the embodiment.
【図１１】実施例第２のベッドの熱変形に伴う測距光路
図である。FIG. 11 is a distance measurement optical path diagram due to thermal deformation of the second bed of the embodiment.
【図１２】実施例第３の送りユニットの説明平面図であ
る。FIG. 12 is an explanatory plan view of the third feeding unit of the embodiment.
【図１３】テーブルのアッベの原理に従って片側で測距
した従来の説明平面図である。FIG. 13 is an explanatory plan view of a conventional table in which distance measurement is performed on one side according to Abbe's principle.
【図１４】テーブルの移動方向中心線より離れた片側位
置で測距した従来の説明平面図である。FIG. 14 is an explanatory plan view of a conventional method in which distance measurement is performed at a position on one side away from the center line of the table in the moving direction.
【図１５】テーブルの移動方向中心線より離れた両側位
置で測距した従来の説明平面図である。FIG. 15 is an explanatory plan view of a conventional method in which distances are measured at positions on both sides apart from the center line in the moving direction of the table.
【図１６】２個のテーブルが直交２軸のＸ軸，Ｚ軸を１
個のレーザ光源で測定する従来の測距平面図である。[Figure 16] Two tables have two orthogonal axes, the X axis and the Z axis.
FIG. 2 is a plan view of a conventional distance measurement method in which measurement is performed using two laser light sources.
２，２ａ，２ｂ テーブル ３，４ ブラケット １１ 右側ステージミラー １２ 左側ステージミラー １１´ 後側ステージミラー １２´ 手前側ステージミラー １４，１４ａ，１４ｂ 干渉計 １５ 左参照光ミラー １６ 右参照光ミラー １５´ 後側参照光ミラー １６´ 手前側参照光ミラー １７ レーザ光源 １８，１８ａ，１８ｂ レシーバ 2, 2a, 2b table 3,4 Bracket 11 Right stage mirror 12 Left stage mirror 11´ Rear stage mirror 12´ Front stage mirror 14, 14a, 14b Interferometer 15 Left reference light mirror 16 Right reference light mirror 15' Rear reference light mirror 16´ Front side reference light mirror 17 Laser light source 18, 18a, 18b receiver
Claims (5)
測距する方法において、単一レーザ光源からの光線を２
本の偏光光線に分け、その内１本が移動台の移動中心に
平行な光路をとり偏光面旋回手段を介して順次移動台両
側に配置したステージミラー間を２回往復させた測長光
と、他の１本が前記偏光面旋回手段を介して順次前記移
動中心両側に対応して固定側に配置した参照光ミラー間
を２回往復させた等価な参照光とを干渉させ、光路長差
により移動台の移動距離を求める移動台のレーザ利用測
距方法。Claim 1: A method for measuring the moving position of a moving table using a laser, in which two beams from a single laser light source are
The length measurement light is divided into polarized light beams of the book, one of which takes an optical path parallel to the center of movement of the moving table, and is made to reciprocate twice between stage mirrors placed on both sides of the moving table through a polarization plane rotation means. , the other one interferes with an equivalent reference beam that has been made to go back and forth twice between the reference beam mirrors arranged on the fixed side corresponding to both sides of the moving center through the polarization plane rotation means, and the optical path length difference is A distance measuring method using a laser for a movable platform that calculates the distance traveled by the movable platform.
の偏光光線を移動台の移動中心の両側に配置したステー
ジミラーに偏光面旋回手段を介して順次導き移動台側か
らの測長反射光をうる測長光路変更手段と、前記単一レ
ーザ光源の分離した偏光光線を前記移動中心の両側に対
応して配置した固定台の参照光ミラーに導き前記偏光面
旋回手段を介して順次導き参照反射光をうる等価な参照
光路変更手段と、前記測長光路変更手段の測長反射光と
前記参照光路変更手段の参照反射光とから干渉光をうる
干渉手段と、光路長差より移動距離を求め送りを制御す
る制御手段とを含むことを特徴とするレーザ測距を行う
送りユニット。2. A single laser light source and a polarized light beam of the single laser light source are sequentially guided to stage mirrors arranged on both sides of the center of movement of the moving table via polarization plane rotation means, and are reflected for length measurement from the moving table side. a length measuring optical path changing means for receiving the light, and guiding the separated polarized light beams of the single laser light source to reference light mirrors of a fixed base arranged correspondingly on both sides of the moving center and sequentially guiding them through the polarization plane rotation means. equivalent reference optical path changing means for obtaining a reference reflected light; interference means for obtaining interference light from the length measurement reflected light of the length measuring optical path changing means and the reference reflected light of the reference optical path changing means; A feeding unit that performs laser distance measurement, characterized in that it includes a control means for determining the distance and controlling the feeding.
台の移動方向手前側のステージミラーと前記移動方向後
側の固定部の参照光ミラーとに偏光面旋回手段を介して
導き２回往復させた第１測長光と、分離した第２偏光光
線を前記移動方向手前側の固定部の参照光ミラーと前記
移動方向後側の移動台のステージミラーとに前記偏光面
旋回手段を共用して導き２回往復させた第２測長光との
干渉をつくり、光路長差より移動台の移動距離を求める
移動台のレーザ利用測距方法。3. The first polarized light beam of the single laser light source is guided twice to a stage mirror on the front side in the moving direction of the moving table and a reference light mirror on the fixed part on the rear side in the moving direction via a polarization plane rotation means. The reciprocated first length measurement light and the separated second polarized light beam are shared by the reference light mirror of the fixed part on the front side in the moving direction and the stage mirror of the movable table on the rear side in the moving direction, using the polarization plane rotation means in common. A distance measuring method using a laser for a movable table, in which interference is created with a second length measuring light that is guided and reciprocated twice, and the moving distance of the movable table is determined from the difference in optical path length.
の分離した第１偏光光線を移動台の移動方向手前側のス
テージミラーと移動台の移動方向後側の固定部の参照光
ミラーとに偏光面旋回手段を介して導き２回往復させて
第１測長反射光をうる第１光路変更手段と、分離した第
２偏光光線を前記移動台の移動方向手前側の固定部の参
照光ミラーと前記移動台の移動方向後側のステージミラ
ーとに前記偏光面旋回手段を共用して導き２回往復させ
て第２測長反射光をうる第２光路変更手段と、前記第１
測長反射光と第２測長反射光と干渉させる干渉手段と、
光路長差より移動距離を求め送りを制御する制御手段と
を含むことを特徴とするレーザ測距を行う送りユニット
。4. A single laser light source, and the separated first polarized light beam of the single laser light source is connected to a stage mirror on the front side in the moving direction of the moving table and a reference light mirror on a fixed part on the rear side in the moving direction of the moving table. a first optical path changing means that guides the beam through a polarization plane rotation means and makes it reciprocate twice to obtain a first length measurement reflected beam; a second optical path changing means for guiding the mirror and a stage mirror on the rear side in the moving direction of the movable table by sharing the polarization plane rotating means and reciprocating the light twice to obtain a second length measurement reflected light;
Interfering means for interfering with the length measurement reflected light and the second length measurement reflected light;
A feeding unit that performs laser distance measurement, characterized in that it includes a control unit that determines a moving distance from a difference in optical path length and controls feeding.
送りユニットと、該第１送りユニットに対し移動方向を
直角方向とした請求項４に記載の第２送りユニットとを
備え、前記第１送りユニット第２送りユニットとの単一
レーザ光源を共通とするとともに測距基準となる互いの
干渉手段を隣接集中化する位置に配置したことを特徴と
する加工機。[Claim 5] The first machine according to claim 2 is installed on the same machine.
A feeding unit, and a second feeding unit according to claim 4, the movement direction of which is perpendicular to the first feeding unit, wherein the first feeding unit and the second feeding unit share a single laser light source. A processing machine characterized in that interfering means, which serve as distance measurement standards, are arranged at positions where they are concentrated adjacent to each other.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3050569A JPH04268483A (en) | 1991-02-22 | 1991-02-22 | Measuring method for distance of moving table by utilizing laser and feeding device for executing measurement of distance by laser |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3050569A JPH04268483A (en) | 1991-02-22 | 1991-02-22 | Measuring method for distance of moving table by utilizing laser and feeding device for executing measurement of distance by laser |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04268483A true JPH04268483A (en) | 1992-09-24 |
Family
ID=12862637
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3050569A Pending JPH04268483A (en) | 1991-02-22 | 1991-02-22 | Measuring method for distance of moving table by utilizing laser and feeding device for executing measurement of distance by laser |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04268483A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160000052U (en) * | 2014-06-27 | 2016-01-06 | 대우조선해양 주식회사 | Measuring device for large length member |
| CN109407616A (en) * | 2018-09-29 | 2019-03-01 | 广东科杰机械自动化有限公司 | A method of real-time track compensation is realized based on measurement data |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS503654A (en) * | 1973-05-11 | 1975-01-16 | ||
| JPS62233704A (en) * | 1986-03-28 | 1987-10-14 | ジゴ− コ−ポレ−シヨン | Differential plane-mirror interferometer system |
-
1991
- 1991-02-22 JP JP3050569A patent/JPH04268483A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS503654A (en) * | 1973-05-11 | 1975-01-16 | ||
| JPS62233704A (en) * | 1986-03-28 | 1987-10-14 | ジゴ− コ−ポレ−シヨン | Differential plane-mirror interferometer system |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160000052U (en) * | 2014-06-27 | 2016-01-06 | 대우조선해양 주식회사 | Measuring device for large length member |
| CN109407616A (en) * | 2018-09-29 | 2019-03-01 | 广东科杰机械自动化有限公司 | A method of real-time track compensation is realized based on measurement data |
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