JPH03274404A - Instrument for measuring cubic configuration - Google Patents

Abstract

PURPOSE:To measure the configurations of the front, side and back of a solid by picking up the image after shifting a phase by shift means and providing means for calculating the surface configuration of an object to be measured from a plurality of sensed images stored in memory means. CONSTITUTION:Light beams emitted from irradiating devices 1 are irradiated on the whole surface of an object 10 to be measured via grids 5, imaging lenses 6 and parallel lenses 7 to be scattered. Scattered light is picked up by a television camera 11. Then, a picked-up zero'th image is stored in an image memory 13 in an image processor 12. Then, when the pickup of the zero'th image is terminated, pulse motors 9 are driven in synchronism with each other by a grid controller 14 in the image processor 12. The grids 5 of the devices 1 are uniformly shifted by a phase pi/2. Thereafter, a first image is picked up by the camera 11 and stored in the memory 13. Thereafter, similarly, the phases of the grids 5 of the devices 5 are shifted by pi and 3pi/2 and second and third images are stored.After picking up all the four images is terminated, a phase distribution phi is calculated by the image processor 12 and displayed on a monitor 15 as a phase picture.

Description

【発明の詳細な説明】 ［産業上の利用分野］ この発明は立体形状の計測装置に関し、特に対象物の複
数面を同時に且つ短時間に計測することができる計測装
置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a measuring device for three-dimensional shapes, and more particularly to a measuring device that can measure multiple surfaces of an object simultaneously and in a short time.

［従来の技術及び発明が解決１．ようどする課題］立体
形状を計測する技術として　例えば特開昭５８−３３８
９０号公報や特開昭５８−１１５３１２号公報に開示さ
れたものがある。これらは理論上厚みのない平面光を対
象物の一面、例えば正面に投影し、平面光と対象物の正
面との交線を計測して、対象物の立体形状を認識する技
術であり、したかって第１に、計測精度上必要な程度に
厚みの薄い平面光を用意する必要があり、すなわち厚み
が厚いと計測精度か劣化するという開題点があった７第
２に、平面光を該平面と直交する方向に５計測端度上ゼ
・要な程度に細かな間隔をもって移動させつつ撮像しな
ければ５対象物の正面形状のすべてを計測することはで
きず２すなわち時間がかかるという間匣点があった。第
３に　平面光が透過できずに影どなる側面や背面の形状
については、−度には計測できないという問題点があっ
た。[Prior art and inventions solve the problem 1. Issues to be addressed] As a technology for measuring three-dimensional shapes, for example, JP-A-58-338
Some of them are disclosed in Japanese Patent Publication No. 90 and Japanese Patent Application Laid-open No. 115312/1983. These are techniques that theoretically project flat light with no thickness onto one side of the object, such as the front of the object, and measure the intersection line between the plane light and the front of the object to recognize the three-dimensional shape of the object. First, it was necessary to prepare a flat light beam as thin as necessary for measurement accuracy.In other words, the problem was that the thicker the thickness, the worse the measurement accuracy. Unless the image is captured while moving in the direction perpendicular to the 5 measurement angle and at the necessary intervals, it will not be possible to measure the entire frontal shape of the object, which means that it will take time. There was a point. Thirdly, there was a problem in that the shape of the side and back surfaces, which could not be penetrated by plane light and would cast shadows, could not be measured in -degrees.

これらの問題点に鑑み本出願人は、理論上厚みのない平
面光を、対象物の正面のほか側面や背面にも投影して、
側面や背面をも同時に計測し、したがって例えば平面光
が対象物を切断して作る閉曲線を計測することも可箭な
技術を提唱したが（特願平１−２６７３６５号）、この
技術においても、上記第１及び第２の問題点が残ってい
た。In view of these problems, the present applicant theoretically projects flat light with no thickness onto the front side and back of the object, and
We have proposed a technique that can simultaneously measure the side and back surfaces of an object, and thus measure, for example, a closed curve created by cutting an object with flat light (Japanese Patent Application No. 1-267365); The first and second problems mentioned above remained.

他方、精密工学会誌５５／ｌ／１９８９、ｐｐ１４１〜
１４５や、同誌５５／１０／１９８９、ｐｐ１〜６には
、照射方向に直交するＸ−Ｙ直交軸のうち、Ｘ軸方向に
は一様でありＹ軸方向には正弦状であり、且つ照射方向
に拡大する光束を対象物の一面、例えば正面に照射し、
Ｙ軸方向の正弦状強度分布の位相をシフトさせて、対象
物の正面形状を計測する技術が開示されている。この技
術によれば、位相をシフトさせた少数回（通常４回）の
撮像のみで、対象物の正面形状を計測することができ、
したがって上記第１及び第２の問題点は解決されるが、
側面や背面の形状については、同時には計測できないと
いう問題点が残っていた。On the other hand, Journal of the Japan Society for Precision Engineering 55/l/1989, pp141~
145 and the same magazine 55/10/1989, pp1-6, it is stated that among the X-Y orthogonal axes orthogonal to the irradiation direction, it is uniform in the X-axis direction and sinusoidal in the Y-axis direction, and A beam of light that expands in the direction is irradiated onto one side of the object, for example, the front,
A technique has been disclosed for measuring the front shape of an object by shifting the phase of a sinusoidal intensity distribution in the Y-axis direction. According to this technology, the front shape of the object can be measured by only a small number of phase-shifted images (usually 4 times).
Therefore, the first and second problems above are solved, but
The problem remained that the shapes of the sides and back could not be measured at the same time.

したがって本発明は、少数回の撮像のもとに、対象物の
正面のほか側面や背面の形状をも同時に計測することが
できる計測装置を提供することを目的とする。Therefore, it is an object of the present invention to provide a measuring device that can simultaneously measure the shape of the front side and the back side of an object as well as the shape of the object by taking images a small number of times.

［課題を解決するための手段］ 本発明は、先ず平面光ではなく、照射方向に直交するＸ
−Ｙ直交軸のうち、Ｘ軸方向には一様でありＹ軸方向に
は正弦状である光束を用い、該光束を複数用いて複数方
向より対象物に照射し、その際各光束の正弦状の強度分
布が互いに合致するように各光束の照射方向を定め、し
たがって各光束は照射方向に拡大しないものを用い、更
に各光束の正弦状の強度分布の位相を一律に同位相だけ
シフトすることによって、上記目的を達成したものであ
る。[Means for Solving the Problems] The present invention firstly uses not plane light but X light that is orthogonal to the irradiation direction.
- Among the Y-orthogonal axes, a light beam that is uniform in the X-axis direction and sinusoidal in the Y-axis direction is used, and a plurality of these light beams are used to irradiate the object from multiple directions, and in this case, the sine of each light beam is The irradiation direction of each light beam is determined so that the shaped intensity distributions match each other, so each light beam is used so that it does not expand in the irradiation direction, and the phase of the sinusoidal intensity distribution of each light beam is uniformly shifted by the same phase. By doing so, the above objectives were achieved.

［作用］ 対象物の表面に照射される光は正弦状に分布しているか
ら、撮像装置で撮像した強度分布も、Ｉ−ａ十Ａ　Ｃ０
８（φ） 但し、Ｉ＝Ｉ　＜ｓ＞　・光の強度分布ａ＝ａ（ｓ）・
定数 Ａ＝Ａ（ｓ）：定数 φ−φ（ｓ）　位相分布 Ｓ：対象物の表面位置 で与えられる。しかるに対象物の表面Ｓに凹凸（湾曲な
どや稜線による形状変化も含む）があるときには、該凹
凸に従って、撮像装置で見た位相φはずれる６したがっ
て位相分布φを求めれば、対象物の表面の凹凸の分布を
知ることができるが、位相分布φを直接撮像することは
できず、撮像できるのはφのずれに起因してゆがんだ光
の強度分布Ｉだけである。[Operation] Since the light irradiated onto the surface of the object is distributed sinusoidally, the intensity distribution captured by the imaging device is also I-a + A C0
8(φ) However, I=I <s> ・Light intensity distribution a=a(s)・
Constant A=A(s): Constant φ−φ(s) Phase distribution S: Given by the surface position of the object. However, if the surface S of the object has irregularities (including changes in shape due to curvature and ridge lines), the phase φ as seen by the imaging device will shift according to the irregularities6. Therefore, if the phase distribution φ is determined, However, it is not possible to directly image the phase distribution φ, and only the intensity distribution I of the light that is distorted due to the deviation of φ can be imaged.

そこで照射光束の位相を人為的に一律にδだけずらすと
、撮像装置で見た強度分布■は５１＝ａ＋Ａ・ｃｏｓ　
（φ＋δ） 但し、Ｉ＝Ｉ　（ｓ、δ）・光の強度分布δ・位相のシ
フト量 となる、したがって未知数はφの他にａとＡがあるから
、最低３回δを変化させて■を撮像すれば、各点Ｓの位
相分布φを求めることができる６また４回以上δを変化
させて■を計測したときには、最小二乗法によってもつ
とも確からしいφを求めることができる。一般にはδは
、 δｏ−０．δ１−π／２ δ２＝π、δ、＝３π／２ とし、このときの強度分布■。、Ｉｌ、Ｉ２及びＩ３を
観測し、 より位相分布φ、すなわち対象物表面の凹凸分布を求め
る。Therefore, if the phase of the irradiation light beam is artificially shifted uniformly by δ, the intensity distribution ■ seen by the imaging device becomes 51=a+A・cos
(φ+δ) However, I = I (s, δ), light intensity distribution δ, and phase shift amount.Therefore, the unknowns include a and A in addition to φ, so change δ at least three times and By taking an image of , the phase distribution φ at each point S can be determined. When δ is measured by changing δ more than 6 times or 4 times, the most probable φ can be determined by the method of least squares. In general, δ is δo−0. Let δ1−π/2 δ2=π, δ, =3π/2, and the intensity distribution at this time is ■. , Il, I2, and I3, and determine the phase distribution φ, that is, the unevenness distribution on the surface of the object.

いま対象物として直方体を想定し、−の頂点に接する３
面が水平面に対して等角度となるように直方体を配置し
、水平面上反対方向より２個の光束によって直方体を照
射して、上方より撮像すれば、通常４回の撮像のみて−
の頂点に接する３面の形状のすべてを求めることができ
る６したがって直方体を上下反転させて他の３面を撮像
すれは、合わせて８回の撮像によって直方体の全面の形
状を計測することができるし、また撮像装置を上下に設
ければ、撮像時間を半減することもできる。Now assuming a rectangular parallelepiped as the object, 3 touching the vertex of -
If you arrange a rectangular parallelepiped so that its surfaces are at equal angles to the horizontal plane, illuminate the rectangular parallelepiped with two light beams from opposite directions on the horizontal plane, and take an image from above, it usually takes only four images to -
6 Therefore, by flipping the rectangular parallelepiped upside down and imaging the other three surfaces, the shape of the entire surface of the rectangular parallelepiped can be measured by taking images a total of 8 times. However, if the imaging devices are provided above and below, the imaging time can be halved.

［実施例］ 本発明を図面によって説明する。第１図は本発明の一実
施例を示す模式図であり、この計測装置は、各々同一に
形成された２個の照射装置１．１を有１１、各照射装置
１は第２図に示すように、光源２の光を結像レンズ３と
平行レンズ４によってコリメートし、グリッド５によっ
て多段の平行光どし、結像レンズ６と平行Ｉ／ンズ７に
よって、進行方向には平行であり横方向には一様であり
一縦方向すなわち一様面と直交する方向には正弦状の光
束８を発射するように形成されている。グリッド５には
パルスモータ９が接続されており、該パルスモータ９に
よってグリッド５は前記縦方向に移動できるように構成
されている、また各々の照射装Ｗ１，１は、その平行光
が合致するように配置されている。[Example] The present invention will be explained with reference to the drawings. FIG. 1 is a schematic diagram showing an embodiment of the present invention, and this measuring device has two irradiation devices 1.1, each of which is formed identically. Each irradiation device 1 is shown in FIG. The light from the light source 2 is collimated by the imaging lens 3 and the parallel lens 4, and the grid 5 collimates the light into multiple stages of parallel light, and the imaging lens 6 and the parallel I/lens 7 collimate the light from the light source 2, which is parallel to the traveling direction and transversely. It is formed so as to emit a sinusoidal light beam 8 that is uniform in direction and in one longitudinal direction, that is, a direction perpendicular to the uniform surface. A pulse motor 9 is connected to the grid 5, and the grid 5 is configured to be able to move in the vertical direction by the pulse motor 9, and the parallel beams of the respective irradiation devices W1, 1 coincide with each other. It is arranged like this.

照射装Ｗ１．１から発せられた光束は対象物１０の全面
に照射されて散乱し、該散乱光はテＩ／ビカメラ１１に
よって撮像される。対象物１０表面の凹凸を観察するた
めには、テレビカメラ〕１の撮像軸は上記−裸面と交差
していなければならない、一般にはテＩ／ビカメラ１１
の撮像軸を上記−機軸と直交するように５すなわち上記
縦方向より撮像することが好ましく、このとき同一の縞
に属する対象物の表面は、テＩ／ビカメラからの距離が
等しいこととなって都合がよいし５また対象物を最も均
等に撮ｆ象することができる、 こう１．て撮像された第０画面２０（第３図）は、画像
処理装置１２内の画像メモリ１３に記憶される。The light flux emitted from the irradiation device W1.1 is irradiated onto the entire surface of the object 10 and scattered, and the scattered light is imaged by the TV camera 11. In order to observe the irregularities on the surface of the object 10, the imaging axis of the television camera 1 must intersect with the bare surface.
It is preferable to take images from 5, that is, from the above-mentioned vertical direction so that the imaging axis of This is convenient and allows you to photograph the object most evenly.1. The 0th screen 20 (FIG. 3) captured by the above-described process is stored in the image memory 13 within the image processing device 12.

第０画面２０の撮像が終了したときには、画像処理装置
１２内のグリッド制御装置１４によって両パルスモータ
９，９を同期して駆動し、両照射装置１１のグリッド５
，５を一律に位相π／２だけシフトし、しかる後テレビ
カメラ１１によって第１画面２１を撮像して画像メモリ
１３に記憶する。以降同様にグリッド５．５の位相をπ
及び３π／２だけシフトして、第２及び第３画面２２　
、２３を記憶する。When the imaging of the 0th screen 20 is completed, the grid control device 14 in the image processing device 12 drives both pulse motors 9, 9 synchronously, and the grid 5 of both irradiation devices 11 is driven.
, 5 are uniformly shifted by a phase of π/2, and then the first screen 21 is imaged by the television camera 11 and stored in the image memory 13. Similarly, the phase of grid 5.5 is set to π
and shifted by 3π/2, the second and third screens 22
, 23.

全４画面の撮像が終了した後には５画像処理装置　１２
によって前記０式に従って位相分布φを算出して位相面
２４としてモニタ］５に表示する。第３図から明らかな
ように、対象物ＩＯの表面が一様な勾配をもっている部
分ａ、ｃではφも一様な勾配となり、対象物１．０の表
面が異なる勾配をもっている部分すではφも異なる勾配
どなり、したがって対象物１０の表面の凹凸を位相分布
φによって知ることができる６ なお０式で求めたφは５当初の光束の周期の半分の周期
となるほか、ｊａｎ−’が−π／２からπ／２までの値
しか持たないことから、−π／２とπ／２において不連
続どなる。したがって画像を走査したときに、走査方向
に対してφが−π／２からπ／２に飛び移ったどきには
πだけ減じ、π／２から−π／２に飛び移ったときには
πだけ加算する等の手段によって、連続しなφを得るこ
とができる。After the imaging of all 4 screens is completed, 5 image processing devices 12
The phase distribution φ is calculated according to the above equation 0 and displayed on the monitor 5 as a phase plane 24. As is clear from FIG. 3, φ also has a uniform slope in parts a and c where the surface of the object 1.0 has a uniform slope, and φ in parts where the surface of the object 1.0 has a different slope. Therefore, the unevenness of the surface of the object 10 can be known from the phase distribution φ. 6 Note that φ determined by the formula 0 is half the period of the original luminous flux, and jan-' is − Since it only has values from π/2 to π/2, there is a discontinuity between -π/2 and π/2. Therefore, when scanning an image, when φ jumps from -π/2 to π/2 in the scanning direction, π is subtracted, and when φ jumps from π/2 to -π/2, π is added. Continuous φ can be obtained by means such as

また連続し六：φを得た後に、テレビカメラ１）の撮像
系から対象物１０の座標系に変換してモニタ１５に表示
することは容易である、したがって対象物の寸法等を計
測することもできるし、また予め良品の表面形状を記憶
しておいて、その画像と対象物の画像とを比較すること
によって、対象物の表面の欠陥を検査することもできる
。Furthermore, after obtaining 6:φ continuously, it is easy to convert from the imaging system of the television camera 1) to the coordinate system of the object 10 and display it on the monitor 15. Therefore, it is possible to measure the dimensions of the object. Alternatively, defects on the surface of the object can be inspected by storing the surface shape of a non-defective item in advance and comparing that image with an image of the object.

［発明の効果］ 本発明による計測装置によれば、少数回の撮像のもとに
、立体の正面のほか側面や背面の形状をも同時に計測す
ることができる７[Effects of the Invention] According to the measuring device according to the present invention, it is possible to simultaneously measure the shape of the front side and the back side of a three-dimensional object by performing imaging a small number of times7.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の一実施例を示す模式図、第２図は照射
装置の一例を示す模式図、第３図は撮像装置で得た光の
強度分布と該強度分布より求めた位相分布との一例を示
す模式図である。 １　照射装置　５・　クリッド　９・・パルスモータ１
０・対象物］１・・テレビカメラFig. 1 is a schematic diagram showing an embodiment of the present invention, Fig. 2 is a schematic diagram showing an example of an irradiation device, and Fig. 3 is an intensity distribution of light obtained by an imaging device and a phase distribution obtained from the intensity distribution. It is a schematic diagram showing an example. 1 Irradiation device 5. Clid 9... Pulse motor 1
0. Object] 1. TV camera

Claims (1)

【特許請求の範囲】 同一平面内にあって互いに異なる方向をそれぞれの照射
方向とし、前記同一平面と平行な方向にはそれぞれ実質
的に一様な強度分布を有し、前記同一平面と直交する方
向にはそれぞれ実質的に正弦状の且つ実質的に同一位相
の強度分布を有する複数の光束を、対象物に照射する手
段と、 前記正弦状強度分布の位相を、各光束について同位相だ
けシフトする手段と、 前記照射装置によって照射された対象物の表面形状を、
前記同一平面と交差する方向より撮像する手段と、 該撮像手段によって得た撮像を記憶する手段と、前記シ
フト手段によって前記位相をシフトさせて撮像し前記記
憶手段によって記憶した複数の撮像から、対象物の表面
形状を算出する手段とを有する立体形状の計測装置。[Claims] The irradiation directions are different directions within the same plane, each having a substantially uniform intensity distribution in directions parallel to the same plane, and each direction being orthogonal to the same plane. means for irradiating a target object with a plurality of light beams each having a substantially sinusoidal intensity distribution in a direction and substantially the same phase; and shifting the phase of the sinusoidal intensity distribution by the same phase for each light beam. means for determining the surface shape of the object irradiated by the irradiation device;
means for capturing an image from a direction intersecting the same plane; a means for storing images obtained by the image capturing means; A three-dimensional shape measuring device having means for calculating the surface shape of an object.