CN102788558A - Three-dimensional deformation measuring system and three-dimensional deformation measuring method combining speckle correlation and speckle interference - Google Patents

Abstract

The invention relates to a three-dimensional deformation measuring system and a three-dimensional deformation measuring method combining speckle correlation and speckle interference. The system comprises a laser, wherein laser light emitted by the laser passes through a semi-permeable and semi-reflective mirror after being expanded for illuminating a tested object and a reference object surface respectively; the tested object surface and the reference object surface are imaged simultaneously on the target surface of a CCD (Charge Coupled Device) camera through an imaging lens by means of the semi-permeable and semi-reflective mirror; the semi-permeable and semi-reflective mirror is arranged obliquely at an angle of 45 degrees relative to incident rays; and when a reference path exists, object surface speckles and reference surface speckles are interfered with mutually on the target surface of the CCD camera to form an interference speckle image for measuring an off-plane displacement component. A reference substance light path is removed, a speckle image on the object surface is acquired, and two components of in-plane displacement are calculated by using two speckle images acquired before and after deformation. A typical digital speckle light path which is sensitive to the off-plane displacement is utilized, so that the in-plane displacement and speckle interference off-plane displacement of a speckle relevance measuring object are realized, and three-dimensional displacement measurement is realized; and and the system and the method have the advantages of simple light path, and easiness and rapidness for operating and processing data.

Description

Relevant measurement system for three-dimensional deformation and the method that combines with speckle interference of speckle

Technical field

The present invention relates to a kind of measurement system for three-dimensional deformation and method, relate in particular to relevant measurement system for three-dimensional deformation and the method that combines with speckle interference of a kind of speckle.

Background technology

(Digital Speckle Correlation Method DSCM) has showed its applicability and superiority in the mechanics of materials, fracturing mechanics, biomechanics, on-site real-time measurement, the measurement of microscale deformation field, Electronic Packaging and numerous applications such as dynamic displacement and deformation test by digital speckle image correlation method that people such as I Yamaguchi, W.H.Peters and W.F.Ranson propose.Digital speckle image correlation technique is through image and displacement and the distortion of using certain image relevant search algorithm draw object of record before and after the deformation of body, have that principle is simple, light path simple, noncontact, to advantages such as requirement on measurement environment are low.In recent years, mathematical theory that some are modern and mathematical method are introduced in this method gradually, and the raising progressively of its measuring accuracy for example uses the sub-pix searching algorithm can obtain the sub-pix displacement.The sub-pix algorithm has a variety of, mainly contains related coefficient fitting process, Newton.Raphson (N-R) process of iteration, based on method of gradient etc.With data by MoM and MEI, gradient method has that anti-noise ability is higher, calculated amount is little, precision is than advantages such as height, and is hour more stable in displacement.At present, the DSCM field of using just gradually from the test of conventional material to some new materials tests, from macroscopic field gradually to trickle sight yardstick, from conventional environment to rugged environment relatively, progressively use, develop to dynamic accurate dynamic dispatching aspect from static quasistatic to engineering site from lab investigation.

Because the limitation that method itself is had, the speckle correlation technique of single beam illumination can only be measured in-plane displacement.The scientific research personnel is just through combining DSCM or measuring three-D displacement through the relevant method of three-dimensional speckle with other measuring techniques.DSCM is combined with stereoscopic photograph technology or binocular measuring technique, can measure the three-D displacement field.For example the stereoscopic photography of professor Yao Xuefeng of Tsing-Hua University proposition combines with the digital speckle correlation technique and is used to study the 3 D deformation field; Binocular 3-dimensional digital speckle measurement of correlation 3 D deformation that Xie Hui people professor proposes and 3 d shape technology.DSCM is combined with the pin hole camera technique, and professor He Xiaoyuan of Southeast China University has proposed relevant the combining with the pinhole camera imaging model of digital picture and has measured the three-dimensional body displacement method.Through the relevant method of three-dimensional speckle, the 5 little flat academicians of Chinese University of Science and Technology, professor Hu Xiaofang etc. utilize simulated experiment to obtain interior of articles three-D displacement field.

Utilize the three-D displacement that ESPI (ESPI) method can Measuring Object, have noncontact, measurement of full field, advantage of high precision.The ESPI technology is based on reference light and thing light and produces on the CCD target surface that speckle interference measures.Therefore, three-dimensional speckle is interfered often light path more complicated.Complicated light path has increased the measuring system instability, has reduced measuring accuracy.

DSCM is combined with speckle interference, also can measure the three-D displacement field.Professor Zhang Qingchuan adopts two cover light paths, to the positive speckle measurement of correlation that adopts of test specimen, the reverse side employing speckle interference of test specimen is measured, and has realized the three-D displacement field measurement.This method is that the different surfaces of test specimen is measured, and is not the 3 D deformation on same surface.Professors Zhou Canlin etc. measure distortion to relevant combining with ESPI of speckle; What adopt is typical speckle relevant light paths; The speckle interference image of at first speckle interference four step phase shifts being gathered is handled; Then processed images is carried out the speckle correlation computations, thereby obtain the 3 D deformation field.Used principle is then very complicated; Image processing process is also very complicated; Not directly to obtain required speckle pattern when utilizing speckle correlation computations in-plane displacement, but obtain through handling, be difficult to obtain the numerical value of 3 D deformation field in the practical operation by the phase shifted images of gathering before and after the distortion.

Summary of the invention

The object of the invention is exactly in order to address the above problem; Provide a kind of speckle relevant measurement system for three-dimensional deformation and the method that combines with speckle interference; It utilizes typically responsive to acoplanarity displacement Michelson speckle light path, and through the reference light in the control light path, acoplanarity displacement is measured in the in-plane displacement and the speckle interference of realization speckle measurement of correlation object; Realized the three-D displacement measurement, this method has that light path is simple, the advantage of operation and data processing simple and fast.

To achieve these goals, the present invention adopts following technical scheme:

The relevant measurement system for three-dimensional deformation that combines with speckle interference of a kind of speckle, the laser that laser instrument sends is sent into beam expanding lens; The beam expanding lens rear is provided with incident ray and becomes the tilted-putted semi-transparent semi-reflecting lens of 45, and the reflected light of semi-transparent semi-reflecting lens shines measured object, and transmitted light then shines with reference to object plane, connects and composes the reference phase shift light path with reference to object plane and PZT phase-shifter; The speckle image of measured object is imaged on the ccd video camera by imaging len through semi-transparent semi-reflecting lens, utilizes two width of cloth speckle patterns of measured object distortion front and back, calculates two components of in-plane displacement; The speckle image on measured object surface is interfered speckle image with the speckle image formation with reference to object plane when reference path is worked, and is imaged on the ccd video camera Measuring Object acoplanarity displacement component by imaging len.

A kind of measuring method that adopts the relevant measurement system for three-dimensional deformation that combines with speckle interference of speckle, it is through the control reference path, combines the 3 D deformation of Measuring Object with speckle interference with digital speckle is relevant; Detailed process is: at first when the reference laser of no reference path, gather the preceding speckle pattern of width of cloth measured object distortion; The reference laser that adds reference path is then realized speckle interference; Loading makes the measured object distortion, measures the measured object acoplanarity displacement in conjunction with phase-shifting technique; Remove the speckle pattern after reference laser is gathered width of cloth measured object distortion more at last; Speckle pattern before and after the measured object distortion is carried out the speckle related operation, obtain two-dimensional surface intrinsic displacement component, thereby realize the 3 D deformation measurement.

Concrete steps of the present invention are:

Step 1: the reflected light with reference to object plane constitutes reference light; When no reference light, utilize the speckle pattern before CCD gathers the measured object distortion;

Step 2: add the reference light of reference path, realize digital speckle interference;

Step 3: load and make the measured object distortion, measure measured object acoplanarity displacement w field in conjunction with four step phase-shifting techniques;

Step 4: remove reference light; Utilize the speckle pattern after CCD gathers the measured object distortion;

Step 5: the speckle pattern after the speckle pattern before the measured object distortion of integrating step one and the measured object distortion of step 4, speckle pattern before and after the measured object distortion is carried out the speckle related operation, obtain two-dimensional surface intrinsic displacement component u, v field.

Acoplanarity displacement is the displacement w field perpendicular to the body surface direction in the said step 3, and concrete measuring process is:

According to phase of light wave change and deformation of body between relation:

Wherein, λ is used Wavelength of Laser, and θ is the angle of illumination light and body surface normal, and w is the acoplanarity displacement of deformation of body, and u is the interior horizontal direction displacement of the face of deformation of body; Know when illumination light incident angle θ=0, have by formula (4):

Adopt existing phase-shifting technique, computing object is out of shape phase place

and then is drawn acoplanarity displacement w field.

The concrete steps of said step 5 are: said two-dimensional surface intrinsic displacement component is horizontal direction displacement component u and vertical direction displacement component v, and the speckle correlation computations is utilized formula (1),

$C(u,v)=\frac{\underset{i}{\overset{m}{\mathrm{\Σ}}}\underset{j}{\overset{m}{\mathrm{\Σ}}}[f(x_i,y_i)-\stackrel{\‾}{f}][g(x_i+u,y_j+v)-\stackrel{\‾}{g}]}{\sqrt{\underset{i}{\overset{m}{\mathrm{\Σ}}}\underset{j}{\overset{m}{\mathrm{\Σ}}}{[f(x_i,y_j)-\stackrel{\‾}{f}]}^2}\sqrt{\underset{i}{\overset{m}{\mathrm{\Σ}}}\underset{j}{\overset{m}{\mathrm{\Σ}}}{[g(x_i+u,y_j+v)-\stackrel{\‾}{g}]}^2}}---\left(1\right)$

Wherein, (x y) is the image before the distortion, (x to f _i, y _j) being any displacement point in the image before the distortion, g (x ', y ') is the image after the distortion, u, v be (x, y) the whole pixel displacement of corresponding point in the image after distortion (x ', y '), (x of displacement point in the corresponding original image respectively _i+ u, y _j+ v) be displacement point (x _i, y _j) in x _iU and y have been moved _jMoved the displacement point in the image after the distortion that v obtains,

With

Be the image subsection average gray;

In order to improve measuring accuracy, on the basis of formula (1), utilize gradient algorithm further to carry out the sub-pix calculation of displacement and find the solution, the selected related coefficient computing formula of gradient method be formula (1) square, i.e. formula (2);

$C(u,v)=\frac{{\left\{\underset{i}{\overset{m}{\mathrm{\Σ}}}\underset{j}{\overset{m}{\mathrm{\Σ}}}\right[f(x_i,y_j)-\stackrel{\‾}{f}\left]\right[g(x_i+u+\mathrm{\Δu},y_j+v+\mathrm{\Δv})-\stackrel{\‾}{g}\left]\right\}}^2}{\underset{i}{\overset{m}{\mathrm{\Σ}}}\underset{j}{\overset{m}{\mathrm{\Σ}}}{[f(x_i,y_j)-\stackrel{\‾}{f}]}^2\underset{i}{\overset{m}{\mathrm{\Σ}}}\underset{j}{\overset{m}{\mathrm{\Σ}}}{[g(x_i+u+\mathrm{\Δu},y_j+v+\mathrm{\Δv})-\stackrel{\‾}{g}]}^2}---\left(2\right)$

Wherein, Δ u, Δ v are the sub-pix displacement corresponding to whole pixel displacement result, (x _i+ u+ Δ u, y _j+ v+ Δ v) is displacement point (x _i, y _j) in x _iU+ Δ u and y have been moved _jMoved the displacement point in the image after the distortion that v+ Δ v obtains;

With

Taylor expansion; Get first approximation, and make

through deriving:

$\left[\begin{array}{c}\mathrm{\Δu}\\ \mathrm{\Δv}\end{array}\right]={\left[\begin{array}{cc}B& C\\ E& H\end{array}\right]}^{-1}\left[\begin{array}{c}A\\ D\end{array}\right]---\left(3\right)$

Wherein

$A=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{\mathrm{<figure-callout\; id="2"\; label="m\; G"\; filenames="HDA00001949709200011.png"\; state="\{\{state\}\}">m</figure-callout>}}{\mathrm{\&Sigma;}}}{G}^{}{}^2,$

$B=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G_x}^2\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$C=2\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G}_x{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$D=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{\mathrm{<figure-callout\; id="2"\; label="m\; G"\; filenames="HDA00001949709200011.png"\; state="\{\{state\}\}">m</figure-callout>}}{\mathrm{\&Sigma;}}}{G}^{}{}^2,$

$E=2\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G}_x{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$H=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{\mathrm{<figure-callout\; id="2"\; label="m\; G\; y"\; filenames="HDA00001949709200011.png"\; state="\{\{state\}\}">m</figure-callout>}}{\mathrm{\&Sigma;}}}{G}_y^{}{}_2^{}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$G=g(x_i+u,y_j+v)-\stackrel{\&OverBar;}{g},$

$G_x=g_x-{\stackrel{\&OverBar;}{g}}_x,G_y=g_y-{\stackrel{\&OverBar;}{g}}_y,$

$F=f(x_i,y_j)-\stackrel{\&OverBar;}{f},$

In the formula, G _xG is to x in expression _iAsk local derviation, G _yG is to y in expression _jAsk local derviation, g _xExpression g (x _i+ u, y _j+ v) to x _iAsk local derviation, g _yExpression g (x _i+ u, y _j+ v) to y _jAsk local derviation,

Expression

To x _iAsk local derviation,

Expression

To y _jAsk local derviation, m is an iterations.

Beneficial effect of the present invention: utilize typically responsive digital speckle interference light path,, realized the in-plane displacement and the speckle interference measurement acoplanarity displacement of speckle measurement of correlation object, realized the three-D displacement measurement through the reference light in the control light path to acoplanarity displacement.This method has that light path is simple, the advantage of operation and data processing simple and fast.

Description of drawings

Fig. 1 is optical measuring system figure;

The speckle image of Fig. 2 when not being out of shape;

Fig. 3 interferes bar for the face that leaves after being out of shape;

Fig. 4 is the speckle image after being out of shape;

Fig. 5 is the three-D displacement component behind the deformation of body, horizontal direction u field pattern;

Fig. 6 is the three-D displacement component behind the deformation of body, vertical direction v field pattern;

Fig. 7 is the three-D displacement component behind the deformation of body, acoplanarity displacement w field pattern;

Fig. 8 is a process flow diagram of the present invention.

Wherein, 1. laser instrument, 2. beam expanding lens, 3. semi-transparent semi-reflecting lens, 4. measured object, 5. with reference to object plane, 6.PZT phase-shifter, 7. imaging len, 8.CCD video camera.

Embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is described further.

Among Fig. 1, the relevant measurement system for three-dimensional deformation that combines with speckle interference of a kind of speckle, it comprises the speckle relevant light paths and the speckle interference phase shift light path of measuring the acoplanarity displacement component of measurement object dignity internal strain component; Behind the laser beam expanding that laser instrument 1 sends through throw light on respectively tested object plane 4 and of semi-transparent semi-reflecting lens 3 with reference to object plane 5.Semi-transparent semi-reflecting lens 3 becomes 45 to tilt to place with incident light.The reflected light of object plane 4 sees through semi-transparent semi-reflecting lens 3, reflect on semi-transparent semi-reflecting lens 3 with reference to the reflected light of object plane 5, and two bundle light pass through imaging lens 7 post-concentrations on ccd video camera 8.

The experiment light path is as shown in Figure 1, and test specimen is the organic glass free beam, long 150.0mm, high 19.5mm, thick 18.5mm.With water paint, to strengthen its reflectivity, whole experiment device is placed on the shockproof platform carries out in the free beam surfaces coated.As light source, light beam is radiated on the free beam surface after beam expanding lens 2 expands bundle with He-Ne laser instrument 1.Another Shu Guang that is told by semi-transparent semi-reflecting lens 3 (BS) is light as a reference.During experiment, process flow diagram as shown in Figure 8, the speckle image when at first blocking reference light and gathering a width of cloth free beam and be not out of shape, as shown in Figure 2; Add reference light then, realize ESPI; Gather object speckle interference image and subtract each other in real time, during free beam is loaded, can observe object acoplanarity displacement striped, as shown in Figure 3; Use phase shifts such as PZT phase-shifter 6 realizations and gather speckle interference fringe pattern; At last, block reference light, gather the speckle image after free beam is out of shape once more, as shown in Figure 4.

Said two-dimensional surface intrinsic displacement component is: utilize formula (1)

$C(u,v)=\frac{\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}[f(x_i,y_i)-\stackrel{\&OverBar;}{f}][g(x_i+u,y_j+v)-\stackrel{\&OverBar;}{g}]}{\sqrt{\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}{[f(x_i,y_j)-\stackrel{\&OverBar;}{f}]}^2}\sqrt{\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}{[g(x_i+u,y_j+v)-\stackrel{\&OverBar;}{g}]}^2}}---\left(1\right)$

Wherein, (x y) is the image before the distortion, (x to f _i, y _j) being any displacement point in the image before the distortion, g (x ', y ') is the image after the distortion, u, v be (x, y) the whole pixel displacement of corresponding point in the image after distortion (x ', y '), (x of displacement point in the corresponding original image respectively _i+ u, y _j+ v) be displacement point (x _i, y _j) in x _iU and y have been moved _jMoved the displacement point in the image after the distortion that v obtains,

With Be the image subsection average gray;

In order to improve measuring accuracy, on the basis of formula (1), utilize existing gradient method further to carry out the sub-pix calculation of displacement, the selected related coefficient computing formula of gradient method be formula (1) square, i.e. formula (2)

$C(u,v)=\frac{{\left\{\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}\right[f(x_i,y_j)-\stackrel{\&OverBar;}{f}\left]\right[g(x_i+u+\mathrm{\&Delta;u},y_j+v+\mathrm{\&Delta;v})-\stackrel{\&OverBar;}{g}\left]\right\}}^2}{\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}{[f(x_i,y_j)-\stackrel{\&OverBar;}{f}]}^2\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}{[g(x_i+u+\mathrm{\&Delta;u},y_j+v+\mathrm{\&Delta;v})-\stackrel{\&OverBar;}{g}]}^2}---\left(2\right)$

Wherein, Δ u, Δ v are the sub-pix displacement corresponding to whole pixel displacement result;

With Taylor expansion; Get first approximation, and make

through deriving:

$\left[\begin{array}{c}\mathrm{\&Delta;u}\\ \mathrm{\&Delta;v}\end{array}\right]={\left[\begin{array}{cc}B& C\\ E& H\end{array}\right]}^{-1}\left[\begin{array}{c}A\\ D\end{array}\right]---\left(3\right)$

Wherein

$A=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{<figure-callout\; id="2"\; label="G"\; filenames="HDA00001949709200011.png"\; state="\{\{state\}\}">G</figure-callout>}}^2,$

$B=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G_x}^2\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$C=2\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G}_x{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$D=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{<figure-callout\; id="2"\; label="G"\; filenames="HDA00001949709200011.png"\; state="\{\{state\}\}">G</figure-callout>}}^2,$

$E=2\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G}_x{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$H=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{<figure-callout\; id="2"\; label="G\; y"\; filenames="HDA00001949709200011.png"\; state="\{\{state\}\}">G</figure-callout>}}_y^{}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG}.$

$G(x_i,y_j)=g(x_i+u,y_j+v)-\stackrel{\&OverBar;}{g},$

$G_x=g_x-{\stackrel{\&OverBar;}{g}}_x,G_y=g_y-{\stackrel{\&OverBar;}{g}}_y,$

$F(x_i,y_i)=f(x_i,y_j)-\stackrel{\&OverBar;}{f},$

In the formula, G _xG is to x in expression _iAsk local derviation, G _yG is to y in expression _jAsk local derviation, g _xExpression g (x _i+ u, y _j+ v) to x _iAsk local derviation, g _yExpression g (x _i+ u, y _j+ v) to y _jAsk local derviation,

Expression To x _iAsk local derviation,

Expression

To y _jAsk local derviation, m is an iterations.

Said off-surface displacement measurement process is:

Phase of light wave changes and the phase relation of deformation of body is:

Wherein, λ is used Wavelength of Laser, and θ is the angle of illumination light and body surface normal, and w is the acoplanarity displacement of deformation of body, and u is the interior horizontal direction displacement of the face of deformation of body; Know that by formula (4) to regard change in optical path length as only relevant with acoplanarity displacement w when illumination light incident angle θ is approximate during less than 5 °, by formula (4):

Adopt phase-shifting technique computing object distortion phase place

and then draw the w field.

Speckle image (Fig. 2 and Fig. 4) is used for speckle correlation computations in-plane displacement u field and v field (unit: pixel) before and after the distortion.Adopt existing phase-shifting technique that speckle interference fringe pattern is handled, can obtain acoplanarity displacement w field (unit: micron).Variable shaped beam 3 D deformation component experimental result such as Fig. 5, Fig. 6, shown in Figure 7.

Experimental result shows, utilizes the relevant method that combines with speckle interference of speckle Measuring Object 3 D deformation fast and effectively, has that light path is simple to operation, the simple advantage of data processing.Experimental result v, w field and document [Sun Ping, Fan Xiangju, Wang Xinghai. based on the three-dimensional carrier frequency electronic speckle interference technique [J] of large-misplacement square glass prism. optics journal, 2011,31 (4): 0412012] in the result coincide better, the u field is identical basically.

Though the above-mentioned accompanying drawing specific embodiments of the invention that combines is described; But be not restriction to protection domain of the present invention; One of ordinary skill in the art should be understood that; On the basis of technical scheme of the present invention, those skilled in the art need not pay various modifications that creative work can make or distortion still in protection scope of the present invention.

Claims (5)

1. the relevant measurement system for three-dimensional deformation that combines with speckle interference of speckle is characterized in that the laser that laser instrument sends is sent into beam expanding lens; The beam expanding lens rear is provided with incident ray and becomes the tilted-putted semi-transparent semi-reflecting lens of 45, and the reflected light of semi-transparent semi-reflecting lens shines measured object, and transmitted light then shines with reference to object plane, connects and composes reference path with reference to object plane and PZT phase-shifter; The speckle image of measured object is imaged on the ccd video camera by imaging len through semi-transparent semi-reflecting lens, utilizes two width of cloth speckle patterns of measured object distortion front and back, calculates two components of in-plane displacement; The speckle image on measured object surface is interfered speckle image with the speckle image formation with reference to object plane when reference path is worked, and is imaged on the ccd video camera Measuring Object acoplanarity displacement component by imaging len.

2. a measuring method that adopts the relevant measurement system for three-dimensional deformation that combines with speckle interference of the described speckle of claim 1 is characterized in that, it is through the control reference path, combines the 3 D deformation of Measuring Object with speckle interference with digital speckle is relevant; Detailed process is: at first when the reference laser of no reference path, gather the preceding speckle pattern of width of cloth measured object distortion; The reference laser that adds reference path is then realized speckle interference; Loading makes the measured object distortion, measures the acoplanarity displacement of measured object in conjunction with phase-shifting technique; Remove the speckle pattern after reference laser is gathered width of cloth measured object distortion more at last; Speckle pattern before and after the measured object distortion is carried out the speckle related operation, obtain two-dimensional surface intrinsic displacement component, thereby realize the 3 D deformation measurement.

3. speckle as claimed in claim 2 is correlated with and the measuring method of the measurement system for three-dimensional deformation that speckle interference combines, and it is characterized in that concrete steps are:

Step 1: the reflected light with reference to object plane constitutes reference light; When no reference light, utilize the speckle pattern before CCD gathers the measured object distortion;

Step 2: add the reference light of reference path, realize digital speckle interference;

Step 3: load and make the measured object distortion, measure measured object acoplanarity displacement w field in conjunction with four step phase-shifting techniques;

Step 4: remove reference light; Utilize the speckle pattern after CCD gathers the measured object distortion;

Step 5: the speckle pattern after the speckle pattern before the measured object distortion of integrating step one and the measured object distortion of step 4, speckle pattern before and after the measured object distortion is carried out the speckle related operation, obtain two-dimensional surface intrinsic displacement component u, v field.

4. speckle as claimed in claim 3 is correlated with and the measuring method of the measurement system for three-dimensional deformation that speckle interference combines, and it is characterized in that, acoplanarity displacement for the concrete measuring process in displacement w field perpendicular to the body surface direction is in the said step 3:

Phase relation according to phase of light wave variation and deformation of body:

Wherein, λ is used Wavelength of Laser, and θ is the angle of illumination light and body surface normal, and w is the acoplanarity displacement of deformation of body, and u is the interior horizontal direction displacement of the face of deformation of body; Know when illumination light incident angle θ=0, have by formula (4):

Adopt existing phase-shifting technique, computing object is out of shape phase place

and then is drawn the w field.

5. speckle as claimed in claim 3 is correlated with and the measuring method of the measurement system for three-dimensional deformation that speckle interference combines; It is characterized in that; The concrete steps of said step 5 are: said two-dimensional surface intrinsic displacement component is horizontal direction displacement component u and vertical direction displacement component v; The speckle correlation computations is utilized formula (1)

$C(u,v)=\frac{\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}[f(x_i,y_i)-\stackrel{\&OverBar;}{f}][g(x_i+u,y_j+v)-\stackrel{\&OverBar;}{g}]}{\sqrt{\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}{[f(x_i,y_j)-\stackrel{\&OverBar;}{f}]}^2}\sqrt{\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}{[g(x_i+u,y_j+v)-\stackrel{\&OverBar;}{g}]}^2}}---\left(1\right)$

Wherein, (x y) is the image before the distortion, (x to f _i, y _j) being any displacement point in the image before the distortion, g (x ', y ') is the image after the distortion, u, v be (x, y) the whole pixel displacement of corresponding point in the image after distortion (x ', y '), (x of displacement point in the corresponding original image respectively _i+ u, y _j+ v) be displacement point (x _i, y _j) in x _iU and y have been moved _jMoved the displacement point in the image after the distortion that v obtains,

With

Be the image subsection average gray;

In order to improve measuring accuracy, on the basis of formula (1), utilize existing gradient algorithm to carry out the sub-pix calculation of displacement and find the solution, the selected related coefficient computing formula of gradient method be formula (1) square, i.e. formula (2);

$C(u,v)=\frac{{\left\{\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}\right[f(x_i,y_j)-\stackrel{\&OverBar;}{f}\left]\right[g(x_i+u+\mathrm{\&Delta;u},y_j+v+\mathrm{\&Delta;v})-\stackrel{\&OverBar;}{g}\left]\right\}}^2}{\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}{[f(x_i,y_j)-\stackrel{\&OverBar;}{f}]}^2\underset{i}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j}{\overset{m}{\mathrm{\&Sigma;}}}{[g(x_i+u+\mathrm{\&Delta;u},y_j+v+\mathrm{\&Delta;v})-\stackrel{\&OverBar;}{g}]}^2}---\left(2\right)$

Wherein, Δ u, Δ v are the sub-pix displacement corresponding to whole pixel displacement result;

With

Taylor expansion; Get first approximation, and make

through deriving:

$\left[\begin{array}{c}\mathrm{\&Delta;u}\\ \mathrm{\&Delta;v}\end{array}\right]={\left[\begin{array}{cc}B& C\\ E& H\end{array}\right]}^{-1}\left[\begin{array}{c}A\\ D\end{array}\right]---\left(3\right)$

Wherein

$A=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G}^2,$

$B=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G_x}^2\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$C=2\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G}_x{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$D=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G}^2,$

$E=2\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_x-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G}_x{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$H=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}F{G}_y\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}G{G}_y-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{G}_y^2\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\mathrm{FG},$

$G(x_i,y_j)=g(x_i+u,y_j+v)-\stackrel{\&OverBar;}{g},$

$G_x=g_x-{\stackrel{\&OverBar;}{g}}_x,G_y=g_y-{\stackrel{\&OverBar;}{g}}_y,$

$F(x_i,y_j)=f(x_i,y_j)-\stackrel{\&OverBar;}{f},$

In the formula, G _xG is to x in expression _iAsk local derviation, G _yG is to y in expression _jAsk local derviation, g _xExpression g (x _i+ u, y _j+ v) to x _iAsk local derviation, g _yExpression g (x _i+ u, y _j+ v) yj is asked local derviation,

Expression

To x _iAsk local derviation,

Expression

To y _jAsk local derviation, m is an iterations.

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