JPH07208950A - Three-dimensional measuring method of surface shape - Google Patents

Three-dimensional measuring method of surface shape

Info

Publication number
JPH07208950A
JPH07208950A JP459694A JP459694A JPH07208950A JP H07208950 A JPH07208950 A JP H07208950A JP 459694 A JP459694 A JP 459694A JP 459694 A JP459694 A JP 459694A JP H07208950 A JPH07208950 A JP H07208950A
Authority
JP
Japan
Prior art keywords
image
shape
measured
surface shape
data
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP459694A
Other languages
Japanese (ja)
Other versions
JP2985635B2 (en
Inventor
Noriaki Fujiwara
憲明 藤原
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Electric Works Co Ltd
Original Assignee
Matsushita Electric Works Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Works Ltd filed Critical Matsushita Electric Works Ltd
Priority to JP6004596A priority Critical patent/JP2985635B2/en
Publication of JPH07208950A publication Critical patent/JPH07208950A/en
Application granted granted Critical
Publication of JP2985635B2 publication Critical patent/JP2985635B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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  • Length Measuring Devices By Optical Means (AREA)
  • Image Analysis (AREA)

Abstract

PURPOSE:To provide a three-dimensional measuring method, of a surface shape, in which an error in the judgment of a shape is hard to generate. CONSTITUTION:By a deformed-lattice projection method in which a lattice 2 projected from a light source 1 in a direction with reference to the face of an object 4 to be measured is observed by using a CCD camera 7 from another angle, a plurality of fringe images in which the lattice is deviated little by little in its pitch direction are obtained. Shape data is obtained by a fringe scanning method on the basis of the fringe images. In addition, image data is found by an image processing operation on the basis of the fringe images. The shape data and the image data are arithmetic-processed. Thereby, the surface shape of the object 4 to be measured is found.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、非接触で計測対象物体
の表面形状を求める表面形状3次元計測方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional surface shape measuring method for non-contactly obtaining the surface shape of an object to be measured.

【0002】[0002]

【従来の技術】従来、機械部品や接点等の電気部品の表
面を非接触で高精度に計測する方法として、三角測量の
原理を応用した光触針を計測ヘッドとし、XYテーブル
の上に計測対象物体を設置して、このXYテーブルを駆
動することにより表面形状を計測するものや、走査型電
子顕微鏡を用いて電子ビームを計測対象物体面にあて、
反射したビームを複数のセンサーで捕らえて演算により
形状に直す方法がある。
2. Description of the Related Art Conventionally, as a method of highly accurately measuring the surfaces of electrical parts such as mechanical parts and contacts in a non-contact manner, an optical contact probe applying the principle of triangulation is used as a measuring head and measured on an XY table. A target object is installed and the surface shape is measured by driving this XY table, or an electron beam is applied to the measurement target object surface using a scanning electron microscope.
There is a method in which the reflected beam is captured by multiple sensors and the shape is calculated by calculation.

【0003】また、特開平4−278406に示すよう
に、計測対象物体面に対し斜め方向より照明の照度分布
が正弦状態の格子を投影し、物体面にできた縞画像の明
度を格子の投影方向とは別の角度から計測して演算する
ことにより、物体の3次元の表面形状を求める縞走査法
がある。
Further, as shown in Japanese Patent Application Laid-Open No. 4-278406, a grid in which the illuminance distribution of illumination is sinusoidal is projected obliquely to the object surface to be measured, and the brightness of the striped image formed on the object surface is projected onto the grid. There is a fringe scanning method for obtaining a three-dimensional surface shape of an object by measuring and calculating from an angle different from the direction.

【0004】[0004]

【発明が解決しようとする課題】前述した表面形状3次
元計測方法は、次のような問題がある。
The above-mentioned three-dimensional surface shape measuring method has the following problems.

【0005】三角測量の原理を応用したものは、XYテ
ーブルのスキャニングに時間を要するため実用にならな
い場合があり、走査型電子顕微鏡を用いたものは、計測
対象物体の前処理として蒸着が必要なため、厳密には非
接触とは言えず、計測対象物体が使用できなくなること
がある。
An application of the principle of triangulation may not be practical because it takes time to scan an XY table, and an application of a scanning electron microscope requires vapor deposition as a pretreatment of an object to be measured. Therefore, it is not strictly non-contact, and the measurement target object may not be usable.

【0006】また、縞走査法は、通常画像入力に使用す
るCCDカメラの濃淡分解能は8ビット、つまり256
階調であり、ノイズの影響などにより階調は1/3 程度に
まで低下するため、表面形状データの信頼性が低下し、
影響が大きい場合は凹凸判断を間違える場合がある。さ
らに、同じく階調の影響により、位相計算を実行する場
合の位相飛び現象のため、特に傾斜部での誤差が大きく
なり、傾斜部での形状判断を間違えることがある。この
ような問題を解消するために、格子を取り除いて、濃淡
画像を別に入力することも考えられるが、格子を取り除
くためには物理的な移動作業を必要とし、手間と時間が
必要である。
In the fringe scanning method, the gradation resolution of the CCD camera normally used for image input is 8 bits, that is, 256.
Since it is a gradation and the gradation is reduced to about 1/3 due to the influence of noise, etc., the reliability of the surface shape data decreases,
When the influence is large, the unevenness judgment may be wrong. Further, similarly, due to the influence of the gray scale, a phase jump phenomenon in the case of executing the phase calculation causes an error particularly in the inclined portion to be large, and the shape determination in the inclined portion may be erroneous. In order to solve such a problem, it is conceivable to remove the grid and input the grayscale image separately. However, removing the grid requires physical movement work, which requires time and effort.

【0007】本発明は、かかる事由に鑑みてなしたもの
で、その目的とするところは、形状判断の誤差が生じに
くい表面形状3次元計測方法を提供するにある。
The present invention has been made in view of the above circumstances, and an object thereof is to provide a three-dimensional surface shape measuring method in which an error in shape determination is less likely to occur.

【0008】[0008]

【課題を解決するための手段】かかる課題を解決するた
めに、請求項1記載の表面形状3次元計測方法は、計測
対象物体面に対してある方向から投影した格子を別の角
度から観察する変形格子投影法により複数の縞画像を
得、該縞画像から縞走査法により形状データを求め、
又、該縞画像から画像処理により画像データを求め、形
状データと画像データとを演算処理することにより計測
対象物体の表面形状を求める方法としている。
In order to solve such a problem, the surface shape three-dimensional measuring method according to claim 1 observes a grid projected from a certain direction with respect to the object surface to be measured from another angle. Obtain a plurality of stripe images by the modified grid projection method, and obtain shape data from the stripe images by the stripe scanning method,
Further, the method is such that image data is obtained from the striped image by image processing, and the surface shape of the measurement target object is obtained by arithmetically processing the shape data and the image data.

【0009】[0009]

【作用】請求項1記載の方法によれば、変形格子投影法
により得られた縞画像により、計測対象物体面の形状デ
ータと画像データが同時に得られ、それらを演算処理す
ることができる。
According to the method of the first aspect, the striped image obtained by the modified grid projection method can simultaneously obtain the shape data and the image data of the object surface to be measured, and can process them.

【0010】[0010]

【実施例】以下、本発明の一実施例を図1及び図2に基
づいて説明する。図1は本発明のシステム構成図であ
り、表面形状3次元計測方法は、センサー部A と制御部
B を主要構成部材として計測対象物体の表面形状を計測
する。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a system configuration diagram of the present invention. The surface shape three-dimensional measuring method is based on a sensor unit A and a control unit.
The surface shape of the object to be measured is measured with B as the main component.

【0011】1 は光源であり、ランプ1a、レンズ1b、反
射板1cを有して光を放出するものである。光は後述する
格子、投影レンズを通って、計測対象物体の法線に対し
て一定角度をもって当てられる。
Reference numeral 1 denotes a light source, which has a lamp 1a, a lens 1b, and a reflector 1c, and emits light. The light passes through a grating and a projection lens, which will be described later, and is applied at a constant angle with respect to the normal line of the object to be measured.

【0012】2 は格子であり、一定間隔のピッチからな
る隙間を光が通過するよう構成されている。なお、この
格子は、光が通過する所としない所の2パターンだけで
なく、徐々に光の通過量が変化するような、例えば正弦
波形状の濃淡画像の液晶パターンで構成してもよい。
Reference numeral 2 denotes a grating, which is configured to allow light to pass through a gap having a constant pitch. The grid may be formed not only in two patterns, that is, a place where light passes and a place where light does not pass, but may also be configured by a liquid crystal pattern of a gray-scale image of, for example, a sine wave in which the amount of passing light gradually changes.

【0013】3 は投影レンズであり、格子2 を通過した
光を計測対象物体4 の表面に投影し、縞画像を形成する
ものである。投影レンズ3 の光軸は格子2 に対して垂直
になっており、計測対象物体4 の法線に対して一定角度
を有している。5 は計測台である。
Reference numeral 3 is a projection lens, which projects the light passing through the grating 2 onto the surface of the object 4 to be measured to form a fringe image. The optical axis of the projection lens 3 is perpendicular to the grating 2 and has a constant angle with respect to the normal line of the measurement target object 4. 5 is a measuring stand.

【0014】6 は撮影レンズであり、計測対象物体4 の
表面の縞画像を撮影するものであって、計測対象物体4
の真上に設けられている。撮影レンズ6 で撮影した縞画
像は、CCDカメラ7 に入力される。以上がセンサー部
の構造である。
Reference numeral 6 denotes a photographing lens for photographing a striped image of the surface of the measurement target object 4 and
It is located right above. The striped image taken by the taking lens 6 is input to the CCD camera 7. The above is the structure of the sensor unit.

【0015】制御部では、CCDカメラ7 に入力された
縞画像を、カメラコントローラ8 、画像入力ボード9 を
介してコンピュータ10に入力する。
In the control unit, the stripe image input to the CCD camera 7 is input to the computer 10 via the camera controller 8 and the image input board 9.

【0016】11はテーブルコントローラであり、格子2
の位置をピッチ方向に移動させるものであり、コンピュ
ータ10に接続されている。
Reference numeral 11 is a table controller, which is a grid 2
Is moved in the pitch direction, and is connected to the computer 10.

【0017】次に、以上の構成を用いた表面形状3次元
計測方法について説明する。光源1を点灯することで、
格子2 、投影レンズ3 を通過した光は、計測対象物体4
の表面に投影レンズ3 から見て等間隔のピッチの格子か
らなる縞画像を形成する。それを別の角度に設けた撮影
レンズ6 で観察することにより、表面の凹凸に応じた変
形格子からなる縞画像を撮影することができる。その縞
画像の画素データを、CCDカメラ7 、カメラコントロ
ーラ8 、画像入力ボード9 を経て、コンピュータ10に入
力したあとで、テーブルコントローラ11により格子2 を
格子の1/4ピッチだけピッチ方向に移動させる。そし
て上記と同様に縞画像を撮影する。これを4回繰り返
し、4種類の縞画像(縞画像1、縞画像2、縞画像3、
縞画像4)を画素データとしてコンピュータ10に入力す
る。
Next, a three-dimensional surface shape measuring method using the above configuration will be described. By turning on the light source 1,
The light that has passed through the grating 2 and the projection lens 3 is
A fringe image is formed on the surface of the grid, which is composed of a grid of pitches at equal intervals when viewed from the projection lens 3. By observing it with the taking lens 6 provided at another angle, it is possible to take a fringe image composed of a deformed lattice corresponding to the unevenness of the surface. After inputting the pixel data of the striped image to the computer 10 via the CCD camera 7, the camera controller 8 and the image input board 9, the table controller 11 moves the grid 2 in the pitch direction by 1/4 pitch of the grid. . Then, a striped image is captured in the same manner as above. This is repeated four times, and four types of striped images (striped image 1, striped image 2, striped image 3,
The striped image 4) is input to the computer 10 as pixel data.

【0018】計測対象物体の任意の位置での各縞画像の
画素の光強度をI1,I2,I3,I4とすると、任意
の位置の位相φは、次の式で求められる。
Assuming that the light intensities of the pixels of each fringe image at arbitrary positions on the object to be measured are I1, I2, I3, and I4, the phase φ at the arbitrary positions can be obtained by the following equation.

【0019】 φ=tan-1((I2−I4)/(I1−I3)) このデータを計測対象物体の表面全体にわたってつなぎ
合わせることで、全体の形状データが得られる。なお、
以上のような演算をすることを縞走査法と呼ぶ。また、
4画面利用の縞走査法について説明したが、特に4画面
に限定されるものではなく、3画面以上で利用すること
が可能である。
Φ = tan −1 ((I 2 −I 4) / (I 1 −I 3)) By connecting this data over the entire surface of the measurement target object, the entire shape data can be obtained. In addition,
Performing the above calculation is called a stripe scanning method. Also,
Although the fringe scanning method using four screens has been described, the present invention is not particularly limited to four screens, and three or more screens can be used.

【0020】次に、計測対象物体の任意の位置の濃淡値
gは、次の式で求められる。 g=(I1+I2+I3+I4)/4 このデータを計測対象物体の表面全体にわたってつなぎ
合わせることで、濃淡で表せられる全体の画像データが
得られる。従って、新規に濃淡画像を入力する必要はな
い。
Next, the grayscale value g at an arbitrary position of the object to be measured is obtained by the following equation. g = (I1 + I2 + I3 + I4) / 4 By connecting this data over the entire surface of the object to be measured, the entire image data represented by shading can be obtained. Therefore, it is not necessary to newly input a grayscale image.

【0021】以上により求められた形状データ、画像デ
ータより、両者を合わせて演算することにより正確な3
次元の表面形状が求められ、また、図2に示すように各
しきい値を用いて形状データ、画像データを判定するこ
とにより、表面のキズ、付着などの欠陥が簡単に求める
ことができる。
The shape data and the image data obtained as described above are combined to calculate an accurate 3
By determining the three-dimensional surface shape and determining the shape data and the image data by using the respective threshold values as shown in FIG. 2, it is possible to easily find defects such as scratches and adhesion on the surface.

【0022】次に、本発明の変形例を図3及び図4に示
す。図3は第1変形例であり、光源1 、格子2 、投影レ
ンズ3 からなる投影系を計測対象物体4 の真上に設け、
撮影レンズ6 、CCDカメラ7 からなる撮影系を計測対
象物体4 の法線に対して一定の角度を有するようにした
ものである。また、図4は第2変形例であり、投影系、
撮影系とも計測対象物体4 の法線に対して一定の角度を
有するようにしたものである。図4の場合は、図1及び
図3と比較して撮影する格子のピッチが拡大される。
Next, a modified example of the present invention is shown in FIGS. FIG. 3 shows a first modified example, in which a projection system including a light source 1, a grating 2, and a projection lens 3 is provided directly above a measurement target object 4,
An image pickup system including an image pickup lens 6 and a CCD camera 7 is arranged so as to have a constant angle with respect to a normal line of the object 4 to be measured. Further, FIG. 4 shows a second modification, in which the projection system,
Both the imaging system and the imaging system have a constant angle with respect to the normal line of the object to be measured 4. In the case of FIG. 4, the pitch of the grating to be photographed is enlarged as compared with FIGS. 1 and 3.

【0023】[0023]

【発明の効果】請求項1記載の表面形状3次元計測方法
は、変形格子投影法により得られた縞画像により、計測
対象物体面の形状データと画像データが同時に得られ、
それらを演算処理することができるので、短時間で、正
確な計測対象物体面の形状判断ができる。
According to the three-dimensional surface shape measuring method of the first aspect, the shape data and the image data of the object surface to be measured are obtained at the same time by the stripe image obtained by the modified grid projection method.
Since they can be arithmetically processed, the shape of the measurement target object surface can be accurately determined in a short time.

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

【図1】本発明の一実施例を示すシステム構成図であ
る。
FIG. 1 is a system configuration diagram showing an embodiment of the present invention.

【図2】その処理アルゴリズムである。FIG. 2 shows the processing algorithm.

【図3】その第1変形例を示すシステム構成図である。FIG. 3 is a system configuration diagram showing a first modified example thereof.

【図4】その第2変形例を示すシステム構成図である。FIG. 4 is a system configuration diagram showing a second modification thereof.

【符号の説明】[Explanation of symbols]

1 光源 2 格子 3 投影レンズ 4 計測対象物体 5 計測台 6 撮影レンズ 7 CCDカメラ 8 カメラコントロール 9 画像入力ボード 10 コンピュータ 11 テーブルコントローラ 1 Light source 2 Lattice 3 Projection lens 4 Object to be measured 5 Measuring stand 6 Shooting lens 7 CCD camera 8 Camera control 9 Image input board 10 Computer 11 Table controller

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 計測対象物体面に対してある方向から
投影した格子を別の角度から観察する変形格子投影法に
より複数の縞画像を得、該縞画像から縞走査法により形
状データを求め、又、該縞画像から画像処理により画像
データを求め、形状データと画像データとを演算処理す
ることにより計測対象物体の表面形状を求めることを特
徴とする表面形状3次元計測方法。
1. A plurality of striped images are obtained by a modified lattice projection method of observing a lattice projected from a certain direction with respect to an object surface to be measured from different angles, and shape data is obtained from the striped images by a striped scanning method, Also, a three-dimensional surface shape measuring method is characterized in that image data is obtained from the striped image by image processing, and the surface shape of the measurement target object is obtained by arithmetically processing the shape data and the image data.
JP6004596A 1994-01-20 1994-01-20 Surface shape 3D measurement method Expired - Lifetime JP2985635B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6004596A JP2985635B2 (en) 1994-01-20 1994-01-20 Surface shape 3D measurement method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6004596A JP2985635B2 (en) 1994-01-20 1994-01-20 Surface shape 3D measurement method

Publications (2)

Publication Number Publication Date
JPH07208950A true JPH07208950A (en) 1995-08-11
JP2985635B2 JP2985635B2 (en) 1999-12-06

Family

ID=11588431

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6004596A Expired - Lifetime JP2985635B2 (en) 1994-01-20 1994-01-20 Surface shape 3D measurement method

Country Status (1)

Country Link
JP (1) JP2985635B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008516245A (en) * 2004-10-13 2008-05-15 ソルビジョン インコーポレイティド Method and system for measuring height profile of reflective object
JP2010082689A (en) * 2008-10-02 2010-04-15 Kurosaki Harima Corp Apparatus and method for deciding replacement of plate brick

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008516245A (en) * 2004-10-13 2008-05-15 ソルビジョン インコーポレイティド Method and system for measuring height profile of reflective object
JP2010082689A (en) * 2008-10-02 2010-04-15 Kurosaki Harima Corp Apparatus and method for deciding replacement of plate brick

Also Published As

Publication number Publication date
JP2985635B2 (en) 1999-12-06

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