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JP2010230523A - Phase connection method and device therefor - Google Patents

Phase connection method and device therefor Download PDF

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JP2010230523A
JP2010230523A JP2009078874A JP2009078874A JP2010230523A JP 2010230523 A JP2010230523 A JP 2010230523A JP 2009078874 A JP2009078874 A JP 2009078874A JP 2009078874 A JP2009078874 A JP 2009078874A JP 2010230523 A JP2010230523 A JP 2010230523A
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wave pattern
sine wave
phase
measurement
phase connection
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Tomohito Masuda
智仁 増田
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Toppan Inc
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Toppan Printing Co Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for performing accurate phase connection, in a three-dimensional measuring system for measuring a surface shape by observing an image obtained by irradiating a measuring object with sine-wave pattern light. <P>SOLUTION: This method has a constitution including: a phase value data calculation means for calculating phase value data for measurement from an observation image group obtained by an observation means by changing in a plurality of times, an initial phase of the sine-wave pattern light A for measurement, and calculating phase value data for phase connection reference from the observation image group obtained by the observation means by changing in a plurality of times, an initial phase of sine-wave pattern light B for phase connection reference; and a sine-wave pattern period determination means for phase connection reference for determining a period of the sine-wave pattern light A for phase connection reference so that the least common multiple between pixel width equivalent to one period of the sine-wave pattern light A for measurement and pixel width equivalent to one period of the sine-wave pattern light B for phase connection reference becomes equal to or larger than the number effective pixels on a projection surface of the measuring object 1. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

本発明は、位相シフト法により対象物を三次元計測するための位相接続方法及びその装置に関するものである。   The present invention relates to a phase connection method and an apparatus for three-dimensionally measuring an object by a phase shift method.

正弦波格子位相シフト法による三次元計測システムとは、正弦波パターンの対象物への投影手段(プロジェクタ)と対象物上のパターンの観察手段(カメラやビデオ)からなる、対象物の表面形状を計測するシステムである。
投影手段と観察手段の間の相対的な位置姿勢が既知(幾何学的キャリブレーション済み)であり、投影手段のどの方向から対象物表面上の各点に光が投影されるか、また、観察手段のどの方向からそれらの反射光が観察されるかが分かれば、三角測量法の原理に基づき対象物の表面形状が求まる。
以下では、対象物表面上を各点において投影手段のどの方向から光が投影されているか、つまり、投影手段平面上のどのピクセルが物体表面を照射しているかを求める方法について示す。
A three-dimensional measurement system based on the sine wave grating phase shift method is a method for measuring the surface shape of an object consisting of means for projecting a sine wave pattern onto the object (projector) and means for observing the pattern on the object (camera or video). This is a measurement system.
The relative position and orientation between the projection means and the observation means are known (geometrically calibrated), from which direction of the projection means the light is projected onto each point on the object surface, and the observation If the direction from which the reflected light is observed is known, the surface shape of the object can be determined based on the principle of triangulation.
In the following, a method for determining from which direction of the projection means the light is projected at each point on the object surface, that is, which pixel on the projection means plane irradiates the object surface will be described.

投影手段からは図3の(1)式で表される平行縞が照射される。
ここで、L(x,y)は投影手段の最小入力輝度、L(x,y)は最大入力輝度と最小入力輝度のオフセット、I(x,y)は投影手段平面上の(x,y)上における入力輝度である。Φ(x,y)は投影手段平面上の画素位置に対応する位相であり、投影手段平面上のy軸に平行な正弦波パターンであれば、図3の(2)式で表わされる。
但し、xは正弦波パターンの1周期に相当するピクセル幅)と表される。δは初期位相であり、この値を変化させることにより正弦波パターンがシフトする。
The projection means emits parallel stripes represented by the expression (1) in FIG.
Here, L g (x, y) is the minimum input luminance of the projection means, L d (x, y) is the offset between the maximum input luminance and the minimum input luminance, and I i (x, y) is ( x, y) is the input luminance. [Phi] (x, y) is a phase corresponding to the pixel position on the projection means plane, and if it is a sine wave pattern parallel to the y-axis on the projection means plane, it is expressed by equation (2) in FIG.
However, xf is expressed as a pixel width corresponding to one cycle of the sine wave pattern. δ i is an initial phase, and changing this value shifts the sine wave pattern.

初期位相δで投影された各ピクセルの輝度値I(x,y)が対象物表面で観察手段により観察されると、式(1)上での未知数はΦ(x,y)、L(x,y)、L(x,y)となり、異なる初期位相でI(x,y)を複数回(理論上三回以上)観察することで連立方程式をたてることができ、これらの未知数を計算することが可能となる。初期位相を離散的に変化させた場合は、図3の(1)式より以下に示す図3の(3)式及び図3の(4)式の関係が得られる。
図3の(3)式及び図3の(4)式共に左辺は既知の値であり、この2つの式より、図3の(5)式が得られる。
この図3の(5)式を再び図3の(3)式、図3の(4)式に代入することによりΦ(x,y)が0から2πの範囲で得られる。これが計測用位相値データである。
When the luminance value I i (x, y) of each pixel projected at the initial phase δ i is observed by the observation means on the surface of the object, the unknowns in the equation (1) are Φ (x, y), L d (x, y), L g (x, y), and simultaneous equations can be established by observing I i (x, y) multiple times (theoretically three times or more) at different initial phases. These unknowns can be calculated. When the initial phase is changed discretely, the relationship between the following expression (3) in FIG. 3 and expression (4) in FIG. 3 is obtained from the expression (1) in FIG.
The left side of both equations (3) and (4) in FIG. 3 is a known value, and equation (5) in FIG. 3 is obtained from these two equations.
By substituting Equation (5) in FIG. 3 into Equation (3) in FIG. 3 and Equation (4) in FIG. 3, Φ (x, y) is obtained in the range of 0 to 2π. This is the phase value data for measurement.

但し、もともとΦ(x,y)は図3の(2)式で表される位相である。一方、観察手段上で得られたΦ(x,y)は0から2πに畳み込まれた不連続な位相になっているので、2πの周期の曖昧性を解決する必要がある。これを解決する方法を位相接続法と呼ぶ。   However, Φ (x, y) is originally a phase represented by equation (2) in FIG. On the other hand, since Φ (x, y) obtained on the observation means has a discontinuous phase convoluted from 0 to 2π, it is necessary to resolve the ambiguity of the 2π period. A method for solving this is called a phase connection method.

ところで、特許文献1,2では、計測用位相値データのみを用い、隣接画素間の位相が滑らかに変化すると仮定し、2πに畳み込まれる不連続な境界(2π=0)が発生する箇所について位相接続の可能性を判断している。しかし、この仮定は対象物の表面が不連続面を含まないという仮定と同義であるので、複雑な形状をもつ対象物表面の三次元形状を求めることは不可能である。
また、特許文献4では振幅値L(x,y)で画像をマスキングして領域分割することで、位相接続の可能性判定を行っている。これは、奥行きが異なれば振幅値も異なるという仮定に基づくが、この仮定は実世界では厳密には正しい仮定とは言えないため、あらゆる対象物に適用可能とは言えない。
また、特許文献5では、有効画素の全領域で基準平面に投影されるパターンの位相を求め、その後計測物体上のパターンの位相との差を高さ情報に変換する方法が実現されているが、基準平面となるものが必要な上、基準平面上と計測物体上のパターンの位相差が2π以上になるような勾配をもつ物体表面の三次元形状を求めることはできない。
By the way, in Patent Documents 1 and 2, it is assumed that a discontinuous boundary (2π = 0) generated by 2π is generated on the assumption that only the phase value data for measurement is used and the phase between adjacent pixels changes smoothly. The possibility of phase connection is judged. However, since this assumption is synonymous with the assumption that the surface of the object does not include a discontinuous surface, it is impossible to obtain the three-dimensional shape of the object surface having a complicated shape.
In Patent Document 4, the possibility of phase connection is determined by masking an image with the amplitude value L d (x, y) and dividing the region. This is based on the assumption that the amplitude value is different for different depths, but this assumption is not strictly correct in the real world and is not applicable to all objects.
Further, in Patent Document 5, a method is obtained in which the phase of a pattern projected on the reference plane is obtained in the entire effective pixel region, and then the difference from the phase of the pattern on the measurement object is converted into height information. In addition, a reference plane is required, and a three-dimensional shape of the object surface having a gradient such that the phase difference between the pattern on the reference plane and the measurement object is 2π or more cannot be obtained.

一方、計測用正弦波パターン光とは周期の異なる一種類以上の位相接続参照用正弦波パターン光を用い、計測用正弦波パターン光と同様に初期位相を変化させて位相接続参照用位相データを算出し、これを基に計測用位相データの位相接続を行う方法がある。特許文献3や非特許文献1では計測用正弦波パターン光における輝度振幅に対して、位相接続参照用正弦波パターンの周期に関する必要条件を開示している。   On the other hand, the phase connection reference phase data is obtained by changing the initial phase in the same way as the measurement sine wave pattern light, using one or more types of phase connection reference sine wave pattern light having a different period from the measurement sine wave pattern light. There is a method of calculating and connecting the phase data for measurement based on this. Patent Document 3 and Non-Patent Document 1 disclose necessary conditions regarding the period of the phase connection reference sine wave pattern with respect to the luminance amplitude in the measurement sine wave pattern light.

特許第3178436号公報Japanese Patent No. 3178436 特開2008−082869号公報JP 2008-082869 A 特開2006−003212号公報JP 2006-003212 A 特開2006−079275号公報JP 2006-079275 A 特開2006−084286号公報JP 2006-084286 A

「位相シフト法を用いた高速な3次元計測手法の提案」、電子情報通信学会技術研究報告、PRMUパターン認識・メディア理解、vol. 99、No. 515、pp. 43-50、1999"Proposal of high-speed 3D measurement method using phase shift method", IEICE technical report, PRMU pattern recognition / media understanding, vol. 99, No. 515, pp. 43-50, 1999

上述の特許文献3や非特許文献1では、計測用正弦波パターン光の輝度振幅における分解能を加味し、位相接続参照用正弦波パターンの周期に関する必要条件を示している。
そこで、本発明では、上記の必要条件の中でさらに、一種類の位相接続参照用正弦波パターンのみで位相接続が可能な周期を算出し、かつ複数の算出値における理論上の位相接続誤差を評価してその誤差を最小化する周期を探索する。
これにより、本発明は、位相接続時に参照する位相接続参照用正弦波パターンを一種類のみ使うことにより効率性が向上し、位相接続計算を高精度に行うことができる位相接続方法及びその装置を提供することを目的とする。
The above-mentioned Patent Document 3 and Non-Patent Document 1 show the necessary conditions related to the period of the phase connection reference sine wave pattern, taking into account the resolution in the luminance amplitude of the measurement sine wave pattern light.
Therefore, in the present invention, in addition to the above-mentioned necessary conditions, a cycle in which phase connection can be performed with only one type of phase connection reference sine wave pattern is calculated, and a theoretical phase connection error in a plurality of calculated values is calculated. Evaluate and search for a period that minimizes the error.
Thus, the present invention improves the efficiency by using only one type of phase connection reference sine wave pattern to be referred to at the time of phase connection, and a phase connection method and apparatus capable of performing phase connection calculation with high accuracy. The purpose is to provide.

上記の目的を達成するために請求項1の発明は、計測用正弦波パターン光を計測対象物に投影し、前記計測用正弦波パターン光の初期位相値を複数回変化させて前記計測対象物上で相対的にシフトさせることにより観察される観察画像群から計測用位相値データを算出し、前記計測用正弦波パターン光と周期の異なる位相接続参照用正弦波パターン光を前記計測対象物に投影し、前記位相接続参照用正弦波パターン光の初期位相を複数回変化させて前記計測対象物上で相対的にシフトさせることにより観察される観測画像群から位相接続参照用位相値データを算出し、前記計測用位相値データと前記位相接続参照用位相値データを用いて位相接続する方法であって、前記計測用正弦波パターン光の一周期に相当するピクセル幅と前記位相接続参照用正弦波パターン光の一周期に相当するピクセル幅との最小公倍数が、前記計測対象物の投影面の有効画素数以上になるように前記位相接続参照用正弦波パターン光の周期を決定することを特徴とする。   In order to achieve the above object, the invention according to claim 1 is characterized in that the measurement sine wave pattern light is projected onto the measurement object, and the initial phase value of the measurement sine wave pattern light is changed a plurality of times to thereby measure the measurement object. The phase value data for measurement is calculated from the observation image group observed by relatively shifting the above, and the phase connection reference sine wave pattern light having a different period from the measurement sine wave pattern light is applied to the measurement object. The phase connection reference phase value data is calculated from the observed image group by projecting and changing the initial phase of the phase connection reference sine wave pattern light a plurality of times and relatively shifting on the measurement object. And a phase connection using the phase value data for measurement and the phase value data for phase connection reference, the pixel width corresponding to one cycle of the sine wave pattern light for measurement and the phase connection The period of the phase connection reference sine wave pattern light is determined so that the least common multiple of the pixel width corresponding to one period of the illumination sine wave pattern light is equal to or greater than the number of effective pixels on the projection surface of the measurement object. It is characterized by that.

請求項2の発明は、請求項1記載の位相接続法において、算出された前記計測用位相値データ中で同じ位相を示す各々の箇所において、前記位相接続参照用正弦波パターンにおける位相値の任意二つの値の差の絶対値のうちの最小の値が、前記位相接続参照用正弦波パターンの周期を変化させることより最大となる周期を決定することを特徴とする。   According to a second aspect of the present invention, in the phase connection method according to the first aspect, an arbitrary phase value in the phase connection reference sine wave pattern is obtained at each location showing the same phase in the calculated phase value data for measurement. The minimum value of the absolute values of the differences between the two values determines the maximum period by changing the period of the phase connection reference sine wave pattern.

請求項3の発明は、位相接続装置であって、計測用正弦波パターン光及び前記計測用正弦波パターン光と周期の異なる位相接続参照用正弦波パターン光を計測対象物に投影する投影手段と、前記計測対象物に投影された前記計測用正弦波パターン光及び前記計測用正弦波パターン光を観察する観察手段と、前記計測用正弦波パターン光の初期位相値を複数回変化させることより前記観察手段で得られる観察画像群から計測用位相値データを算出し、かつ前記位相接続参照用正弦波パターン光の初期位相を複数回変化させることより前記観察手段で得られる観察画像群から位相接続参照用位相値データを算出する位相値データ算出手段と、前記計測用正弦波パターン光の一周期に相当するピクセル幅と前記位相接続参照用正弦波パターン光の一周期に相当するピクセル幅との最小公倍数が、前記計測対象物の投影面の有効画素数以上になるように前記位相接続参照用正弦波パターン光の周期を決定する位相接続参照用正弦波パターン周期決定手段とを備えることを特徴とする。   Invention of Claim 3 is a phase connection apparatus, Comprising: The projection means which projects the measurement sine wave pattern light and the phase connection reference sine wave pattern light having a different period from the measurement sine wave pattern light onto the measurement object The observation means for observing the measurement sine wave pattern light and the measurement sine wave pattern light projected on the measurement object, and changing the initial phase value of the measurement sine wave pattern light a plurality of times Phase connection from the observation image group obtained by the observation unit by calculating phase value data for measurement from the observation image group obtained by the observation unit and changing the initial phase of the phase connection reference sine wave pattern light a plurality of times Phase value data calculating means for calculating reference phase value data; a pixel width corresponding to one cycle of the measurement sine wave pattern light; and one of the phase connection reference sine wave pattern light. A phase connection reference sine wave pattern period for determining a period of the phase connection reference sine wave pattern light so that a least common multiple with a pixel width corresponding to a period is equal to or greater than the effective pixel number of the projection surface of the measurement object And a determining means.

請求項4の発明は、請求項3記載の位相接続装置において、前記位相接続参照用正弦波パターン周期決定手段は、算出された前記計測用位相値データ中で同じ位相を示す各々の箇所において、前記位相接続参照用正弦波パターンにおける位相値の任意二つの値の差の絶対値のうちの最小の値が、前記位相接続参照用正弦波パターンの周期を変化させることより最大となる周期を決定することを特徴とする。   According to a fourth aspect of the present invention, in the phase connection device according to the third aspect, the phase connection reference sine wave pattern cycle determining means is provided at each location indicating the same phase in the calculated phase value data for measurement. The minimum value of the absolute value of the difference between any two values of the phase value in the phase connection reference sine wave pattern is determined by changing the period of the phase connection reference sine wave pattern. It is characterized by doing.

本発明の位相接続法及び移送接続装置によれば、位相接続時に参照する位相接続参照用正弦波パターンを一種類のみ使うことにより効率性が向上し、また位相接続計算を高精度に行うことができる。   According to the phase connection method and the transfer connection device of the present invention, the efficiency is improved by using only one type of phase connection reference sine wave pattern to be referred to at the time of phase connection, and the phase connection calculation can be performed with high accuracy. it can.

本発明の位相接続方法を用いた三次元形状計測装置の一例を示す構成図である。It is a block diagram which shows an example of the three-dimensional shape measuring apparatus using the phase connection method of this invention. 本発明の位相接続方法により投影手段に入力する計測用と位相接続参照用の二つの正弦波パターン及び各々の正弦波パターンから位相値データと整数値データが算出される過程を示す図である。It is a figure which shows the process in which phase value data and integer value data are calculated from two sine wave patterns for a measurement and a phase connection reference input into a projection means by the phase connection method of this invention, and each sine wave pattern. 従来及び本発明に使用される数式を示す図である。It is a figure which shows the numerical formula used conventionally and this invention.

(実施の形態1)
以下、本発明の実施の形態について、図1及び図2を参照して詳細に説明する。
三次元形状計測装置は、図1に示すように、計測対象物1の表面に対して上方から斜め下方に向けて配置された、観察光学系2及び観察記録装置3からなる観察手段20、観察記録装置3と逆に計測対象物1の表面に対して上方から斜め下方に向けて配置された、投影光学系4及び投影光源5からなる投影手段50、及び正弦波パターン観察部6、正弦波パターン入力部7、位相値データ算出部8、位相接続処理部9、三次元形状算出部10、位相接続参照用正弦波パターン周期決定部11、計測用正弦波パターン周期入力部12を含んで構成される。
(Embodiment 1)
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2.
As shown in FIG. 1, the three-dimensional shape measuring apparatus includes an observation optical system 2 and an observation recording apparatus 3, which are arranged obliquely downward from above with respect to the surface of the measurement object 1, Contrary to the recording apparatus 3, the projection unit 50 including the projection optical system 4 and the projection light source 5, the sine wave pattern observation unit 6, and the sine wave, which are disposed obliquely downward from above with respect to the surface of the measurement object 1. A pattern input unit 7, a phase value data calculation unit 8, a phase connection processing unit 9, a three-dimensional shape calculation unit 10, a phase connection reference sine wave pattern cycle determination unit 11, and a measurement sine wave pattern cycle input unit 12 are configured. Is done.

このように構成された三次元形状計測装置において、正弦波パターン入力部7から入力された正弦波パターン信号により投影光源5を動作させ、その正弦波パターン光を投影光学系4を通して計測対象物1の表面に投影する。そして、計測対象物1の表面に投影された正弦波パターン光の画像を観察手段20の観察光学系2を通して観察記録装置3で記録し、正弦波パターン観察部6に出力する。正弦波パターン観察部6では、計測対象物1の表面に投影された正弦波パターンを観察し、その観察画像を正弦波パターン観察部6により位相値データ算出部8に送出する。また、この時、位相値データ算出部8は、投影された正弦波パターンの初期位相値を正弦波パターン入力部7から取得する。初期位相値を複数回変化させて得られた観察画像群から、位相値データ算出部8によって計測用位相値データを取得する。また、位相接続処理部9では、位相値データ算出部8で算出された位相値データと、後述する位相接続参照用正弦波パターン光を基に算出された位相値データとに基づいて位相接続処理を行い、その処理結果を三次元形状算出部10に出力し、三次元形状算出部10で計測対象物1の表面の三次元形状を算出する。   In the three-dimensional shape measuring apparatus configured as described above, the projection light source 5 is operated by the sine wave pattern signal input from the sine wave pattern input unit 7, and the sine wave pattern light passes through the projection optical system 4 to be measured 1 Project onto the surface of the. Then, the image of the sine wave pattern light projected on the surface of the measurement object 1 is recorded by the observation recording device 3 through the observation optical system 2 of the observation means 20 and output to the sine wave pattern observation unit 6. The sine wave pattern observation unit 6 observes the sine wave pattern projected on the surface of the measurement object 1, and sends the observation image to the phase value data calculation unit 8 by the sine wave pattern observation unit 6. At this time, the phase value data calculation unit 8 acquires the initial phase value of the projected sine wave pattern from the sine wave pattern input unit 7. Phase value data for measurement is acquired by the phase value data calculation unit 8 from the observation image group obtained by changing the initial phase value a plurality of times. Further, the phase connection processing unit 9 performs phase connection processing based on the phase value data calculated by the phase value data calculation unit 8 and phase value data calculated based on phase connection reference sine wave pattern light described later. The processing result is output to the three-dimensional shape calculation unit 10, and the three-dimensional shape calculation unit 10 calculates the three-dimensional shape of the surface of the measurement object 1.

図2は、照射された正弦波パターン光と、それを観察することにより得られる位相値を図式化したものである。計測用位相値データの取得時には、計測用正弦波パターン周期入力部12によって入力される周期を持つ計測用正弦波パターン光を投影して位相値データを取得する。
計測用正弦波パターン周期入力部12により入力された周期の値は、位相接続参照用正弦波パターン周期決定部11に入力され、位相値の計算誤差に対して強靱な位相接続が可能な位相接続参照用正弦波パターンの周期を算出し決定する。
FIG. 2 is a diagram schematically showing the irradiated sine wave pattern light and the phase value obtained by observing it. At the time of acquisition of measurement phase value data, phase value data is acquired by projecting measurement sine wave pattern light having a period input by the measurement sine wave pattern period input unit 12.
The period value input by the measurement sine wave pattern period input unit 12 is input to the phase connection reference sine wave pattern period determination unit 11, which enables phase connection that is robust against phase value calculation errors. The period of the reference sine wave pattern is calculated and determined.

図2は二組の正弦波パターン、すなわち三次元計測用の正弦波パターン光Aと位相接続用の正弦波パターン光Bによって投影手段平面上の画素位置を特定する仕組みを表している。投影手段平面が縦方向に24ピクセル有しており、三次元計測用の正弦波パターン光Aと位相接続参照用正弦波パターン光Bはそれぞれ8ピクセル、6ピクセルを一周期としているとする。観測装置20は対象物体1の表面上でこれら各正弦波パターン光を観察し、それぞれの位相値データを算出する。求められた各々の位相値データをそれぞれ、1ピクセルに対応する周期で割った値の整数値データM(x,y)に変換する。
また、図2では、計測用正弦波パターン光Aと位相接続参照用正弦波パターン光Bにおける各々の1ピクセルに対応する周期は、π/4(=2π/8)とπ/3(=2π/6)である。これにより、投影手段平面上におけるピクセル番号0〜23の24ピクセルの画素位置は、これら二つの整数値の組で一意に特定できる。例えば、対象物1の表面上のある点で整数値(7、1)の組が得られた場合、これはピクセル番号7である8番目のピクセルから光を投影されていることが分かる。
FIG. 2 shows a mechanism for specifying a pixel position on the plane of the projection means by two sets of sine wave patterns, that is, a sine wave pattern light A for three-dimensional measurement and a sine wave pattern light B for phase connection. It is assumed that the projection unit plane has 24 pixels in the vertical direction, and the sine wave pattern light A for three-dimensional measurement and the sine wave pattern light B for phase connection reference each have 8 pixels and 6 pixels as one cycle. The observation device 20 observes each sine wave pattern light on the surface of the target object 1 and calculates each phase value data. Each obtained phase value data is converted into integer value data M (x, y) obtained by dividing the phase value data by a period corresponding to one pixel.
In FIG. 2, the periods corresponding to each pixel in the measurement sine wave pattern light A and the phase connection reference sine wave pattern light B are π / 4 (= 2π / 8) and π / 3 (= 2π). / 6). Thereby, the pixel positions of the 24 pixels having pixel numbers 0 to 23 on the projection means plane can be uniquely specified by a set of these two integer values. For example, when a set of integer values (7, 1) is obtained at a certain point on the surface of the object 1, it can be seen that light is projected from the eighth pixel having the pixel number 7.

一般的に計測用正弦波パターン光Aと位相接続参照用正弦波パターン光Bの一周期に相当するピクセル幅をそれぞれxf1、xf2とすると、観測装置の平面上における任意の画素上で二つの正弦波パターン光A,Bにより割り当てられる位相値の組は、xf1とxf2の最小公倍数lcm(xf1、xf2)のピクセル幅の整数倍の位置で再び割り当てられる。投影手段における平面上の有効画素がlcm(xf1、xf2)以下であれば、位相接続参照用正弦波パターン光はこの1種類のみで投影手段における平面上の有効画素を一意に表現できるが、有効画素数がlcm(xf1、xf2)より多いと、全ての有効画素を一意に表現できるまで、新たに上述の2つの正弦波パターン光とは異なる周期を持つ正弦波パターン光を複数用意する必要がある。投影する正弦波パターン光の数が増えると処理する観察画像も増大するので望ましくない。このため、位相接続参照用正弦波パターン光の周期は、入力された計測用正弦波パターン光の周期に対し、lcm(xf1、xf2)が投影手段における平面上の有効画素以上になるようにすれば、ただ1種類の位相接続参照用正弦波パターン光を用いるだけで位相接続が可能となる。 In general, assuming that the pixel widths corresponding to one period of the sine wave pattern light A for measurement and the sine wave pattern light B for phase connection reference are x f1 and x f2 respectively, One of the sinusoidal pattern light a, the set of phase values assigned by B is assigned again an integer multiple of the position of the pixel width of the least common multiple lcm of x f1 and x f2 (x f1, x f2 ). If the effective pixels on the plane in the projection means are 1 cm (x f1 , x f2 ) or less, the phase connection reference sine wave pattern light can uniquely represent the effective pixels on the plane in the projection means with only this one type. If the number of effective pixels is greater than 1 cm (x f1 , x f2 ), a plurality of new sine wave pattern lights having a different period from the above two sine wave pattern lights until all the effective pixels can be uniquely expressed. It is necessary to prepare. As the number of sinusoidal pattern lights to be projected increases, the number of observation images to be processed also increases, which is not desirable. For this reason, the period of the phase connection reference sine wave pattern light is such that lcm (x f1 , x f2 ) is greater than or equal to the effective pixel on the plane of the projection unit with respect to the period of the input measurement sine wave pattern light. Then, phase connection can be achieved by using only one type of phase connection reference sine wave pattern light.

また、計測用と位相接続参照用の正弦波パターン光の1ピクセルに対応する位相をそれぞれθLf1、θLf2(図2中ではπ/4とπ/3)とし、各々の位相値データをθLf1、θLf2で割った整数値データMf1(x,y)、Mf2(x,y)のうち、Mf1(x,y)が等しい箇所におけるMf2(x,y)の整数値データを全て求める(図2中でMf1(x,y)=3である箇所のMf2(x,y)は{3、5、1})。
この数の任意のニ整数の差のうち最小の値をMf2minとすると、位相値の計算誤差がεの時、図3の(6)式を満たすことが正確な位相接続を保証する条件となる。この条件は、Mf1(x,y)の全ての値に対して同様に式(6)を満たすことが必要条件となる。
Further, the phases corresponding to one pixel of the sine wave pattern light for measurement and phase connection reference are respectively θ Lf1 and θ Lf2 (π / 4 and π / 3 in FIG. 2), and the respective phase value data are θ Lf1, theta integer divided by Lf2 data M f1 (x, y), M f2 (x, y) of, M f1 (x, y) integer data M f2 at the location equals (x, y) (M f2 (x, y) at a location where M f1 (x, y) = 3 in FIG. 2 is {3, 5, 1}).
Assuming that the minimum value of the difference between any two integers in this number is M f2min , when the phase value calculation error is ε, satisfying the expression (6) in FIG. Become. This condition is a necessary condition that all the values of M f1 (x, y) satisfy the same expression (6).

位相値の計算誤差に最も強靱な位相接続参照用正弦波パターンの周期は、lcm(xf1、xf2)が投影平面上の有効画素数より大きくなる周期の中で、Mf1(x,y)の全ての値に対して計算されるMf2minの最小値が最大になる周期を選択すればよい。Mf2minの最小値が最大を示す値を求める計算は、候補となる全ての周期に対して計算を行うことにより可能である。 The period of the phase connection reference sine wave pattern most robust to the phase value calculation error is M f1 (x, y) in a period in which lcm (x f1 , x f2 ) is larger than the number of effective pixels on the projection plane. It is sufficient to select a period in which the minimum value of M f2min calculated for all the values of) is maximized. The calculation for obtaining a value indicating that the minimum value of M f2min is the maximum can be performed by performing the calculation for all candidate cycles.

一方、上述の方法で対象物表面状に投影される計測用と位相接続参照用の正弦波パターン光から各々の位相値データに変換され、この二つのデータにより位相接続処理部8で位相接続が行われる。投影手段50と観察手段20の相対的な位置姿勢が分かっていれば(図1中Bが既知であれば)、対象物表面状(図1中p)に光を投影している画素位置が分かり(図1中の方向ベクトルdが分かり)、かつ観察手段平面上のどの画素位置で観察されているかが分かる(図1中の方向ベクトルdが分かる)ので、三角測量法の原理に基づき対象物1表面状(図1中p)の三次元位置を三次元形状算出部10において算出することができる。 On the other hand, the phase connection data is converted into phase value data from the sine wave pattern light for measurement and phase connection reference projected onto the surface of the object by the above-described method. Done. If the relative position and orientation of the projection means 50 and the observation means 20 are known (if B in FIG. 1 is known), the pixel position at which light is projected onto the surface of the object (p in FIG. 1) find (see direction vector d p in FIG. 1), and since either has been observed at any pixel location on the viewing means plane seen (seen direction vector d c in FIG. 1), the principle of the triangulation method Based on this, the three-dimensional position of the surface of the object 1 (p in FIG. 1) can be calculated by the three-dimensional shape calculation unit 10.

1……計測対象物、2……観察光学系、3……観察記録装置、4……投影光学系、5……投影光源、6……正弦波パターン観察部、7……正弦波パターン入力部、8……位相値データ算出部、9……位相接続処理部、10……三次元形状算出部、11……位相接続参照用正弦波パターン周期決定部、12……計測用正弦波パターン周期入力部、20……観察手段、50……投影手段。   DESCRIPTION OF SYMBOLS 1 ... Measurement object, 2 ... Observation optical system, 3 ... Observation recording device, 4 ... Projection optical system, 5 ... Projection light source, 6 ... Sine wave pattern observation part, 7 ... Sine wave pattern input , 8... Phase value data calculation unit, 9... Phase connection processing unit, 10... Three-dimensional shape calculation unit, 11... Phase connection reference sine wave pattern period determination unit, 12. Period input unit, 20 ... observation means, 50 ... projection means.

Claims (4)

計測用正弦波パターン光を計測対象物に投影し、
前記計測用正弦波パターン光の初期位相値を複数回変化させて前記計測対象物上で相対的にシフトさせることにより観察される観察画像群から計測用位相値データを算出し、
前記計測用正弦波パターン光と周期の異なる位相接続参照用正弦波パターン光を前記計測対象物に投影し、
前記位相接続参照用正弦波パターン光の初期位相を複数回変化させて前記計測対象物上で相対的にシフトさせることにより観察される観測画像群から位相接続参照用位相値データを算出し、
前記計測用位相値データと前記位相接続参照用位相値データを用いて位相接続する方法であって、
前記計測用正弦波パターン光の一周期に相当するピクセル幅と前記位相接続参照用正弦波パターン光の一周期に相当するピクセル幅との最小公倍数が、前記計測対象物の投影面の有効画素数以上になるように前記位相接続参照用正弦波パターン光の周期を決定する、
ことを特徴とする位相接続方法。
Project sine wave pattern light for measurement onto the object to be measured,
Calculating the phase value data for measurement from the observation image group observed by changing the initial phase value of the sine wave pattern light for measurement a plurality of times and relatively shifting on the measurement object;
Projecting the phase connection reference sine wave pattern light having a different period from the measurement sine wave pattern light onto the measurement object,
Calculating phase connection reference phase value data from an observation image group observed by changing the initial phase of the phase connection reference sine wave pattern light a plurality of times and relatively shifting on the measurement object;
A phase connection method using the phase value data for measurement and the phase value data for phase connection reference,
The least common multiple of the pixel width corresponding to one period of the sine wave pattern light for measurement and the pixel width corresponding to one period of the sine wave pattern light for phase connection reference is the number of effective pixels on the projection surface of the measurement object. Determine the period of the phase connection reference sine wave pattern light so as to be above,
A phase connection method characterized by that.
算出された前記計測用位相値データ中で同じ位相を示す各々の箇所において、前記位相接続参照用正弦波パターンにおける位相値の任意二つの値の差の絶対値のうちの最小の値が、前記位相接続参照用正弦波パターンの周期を変化させることより最大となる周期を決定することを特徴とする請求項1記載の位相接続法。   At each location showing the same phase in the calculated phase value data for measurement, the minimum value of the absolute values of the difference between any two values of the phase values in the phase connection reference sine wave pattern is 2. The phase connection method according to claim 1, wherein the maximum period is determined by changing the period of the phase connection reference sine wave pattern. 計測用正弦波パターン光及び前記計測用正弦波パターン光と周期の異なる位相接続参照用正弦波パターン光を計測対象物に投影する投影手段と、
前記計測対象物に投影された前記計測用正弦波パターン光及び前記計測用正弦波パターン光を観察する観察手段と、
前記計測用正弦波パターン光の初期位相値を複数回変化させることより前記観察手段で得られる観察画像群から計測用位相値データを算出し、かつ前記位相接続参照用正弦波パターン光の初期位相を複数回変化させることより前記観察手段で得られる観察画像群から位相接続参照用位相値データを算出する位相値データ算出手段と、
前記計測用正弦波パターン光の一周期に相当するピクセル幅と前記位相接続参照用正弦波パターン光の一周期に相当するピクセル幅との最小公倍数が、前記計測対象物の投影面の有効画素数以上になるように前記位相接続参照用正弦波パターン光の周期を決定する位相接続参照用正弦波パターン周期決定手段と、
を備えることを特徴とする位相接続装置。
Projection means for projecting measurement sine wave pattern light and phase connection reference sine wave pattern light having a period different from that of the measurement sine wave pattern light onto a measurement object;
Observation means for observing the measurement sine wave pattern light and the measurement sine wave pattern light projected on the measurement object;
Calculate phase value data for measurement from an observation image group obtained by the observation means by changing the initial phase value of the sine wave pattern light for measurement a plurality of times, and the initial phase of the sine wave pattern light for phase connection reference Phase value data calculation means for calculating phase connection reference phase value data from the observation image group obtained by the observation means by changing the multiple times,
The least common multiple of the pixel width corresponding to one period of the sine wave pattern light for measurement and the pixel width corresponding to one period of the sine wave pattern light for phase connection reference is the number of effective pixels on the projection surface of the measurement object. The phase connection reference sine wave pattern period determining means for determining the period of the phase connection reference sine wave pattern light as described above,
A phase connection device comprising:
前記位相接続参照用正弦波パターン周期決定手段は、算出された前記計測用位相値データ中で同じ位相を示す各々の箇所において、前記位相接続参照用正弦波パターンにおける位相値の任意二つの値の差の絶対値のうちの最小の値が、前記位相接続参照用正弦波パターンの周期を変化させることより最大となる周期を決定することを特徴とする請求項3記載の位相接続装置。   The phase connection reference sine wave pattern cycle determining means is configured to calculate two arbitrary values of the phase values in the phase connection reference sine wave pattern at each position indicating the same phase in the calculated phase value data for measurement. 4. The phase connection device according to claim 3, wherein the minimum value of the absolute values of the differences determines the maximum period by changing the period of the phase connection reference sine wave pattern.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10302422B2 (en) 2015-12-16 2019-05-28 Seiko Epson Corporation Measurement system, measurement method, robot control method, robot, robot system, and picking apparatus

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0666527A (en) * 1992-08-20 1994-03-08 Sharp Corp Three-dimensional measurement method
JP2001159510A (en) * 1999-12-01 2001-06-12 Matsushita Electric Ind Co Ltd Three-dimensional shape measuring method and its device
JP2006003212A (en) * 2004-06-17 2006-01-05 Konica Minolta Sensing Inc Phase measurement system
JP2006322949A (en) * 2006-07-24 2006-11-30 Wakayama Univ Phase analysis method of projection grid utilizing aliasing
JP2008145209A (en) * 2006-12-08 2008-06-26 Nec Engineering Ltd Device for measuring three-dimensional shape, and method for measuring three-dimensional shape

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0666527A (en) * 1992-08-20 1994-03-08 Sharp Corp Three-dimensional measurement method
JP2001159510A (en) * 1999-12-01 2001-06-12 Matsushita Electric Ind Co Ltd Three-dimensional shape measuring method and its device
JP2006003212A (en) * 2004-06-17 2006-01-05 Konica Minolta Sensing Inc Phase measurement system
JP2006322949A (en) * 2006-07-24 2006-11-30 Wakayama Univ Phase analysis method of projection grid utilizing aliasing
JP2008145209A (en) * 2006-12-08 2008-06-26 Nec Engineering Ltd Device for measuring three-dimensional shape, and method for measuring three-dimensional shape

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10302422B2 (en) 2015-12-16 2019-05-28 Seiko Epson Corporation Measurement system, measurement method, robot control method, robot, robot system, and picking apparatus

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