CN106289089B - Test the optimization preparation method of speckle field - Google Patents
Test the optimization preparation method of speckle field Download PDFInfo
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Abstract
The invention discloses a kind of optimization preparation methods of experiment speckle field, program and speckle Quality evaluation criterion selection preferably digital speckle field are designed according to computer speckle, and the Global Information of digital speckle field is transferred to the surface of object to be measured using the indirect preparation method such as transfer (water transfer, thermal transfer etc.), laser cutting, silk-screen printing, photosensitive seal, openworking template, the speckle field that precision is high, consistency is good is provided for Digital-image correlation method.The digital speckle field that the present invention is generated by optimum choice and indirect branch computer, it solves since the unstable quality of speckle field causes Digital Image Correlation Method measurement accuracy uncertain, and due to traditional spray painting make the methods of random speckle field to technical staff's skilled operation degree there are dependences the problems such as, to ensure that reliability of the Digital Image Correlation Method in scientific research and Practical Project measure.
Description
Technical field
The invention belongs to optical measurement mechanics technical field, be related to a kind of digitlization suitable for Digital Image Correlation Method,
Controllable speckle field generates method.
Background technology
Digital Image Correlation Method is a kind of novel non-contact optical measurement method, is now applied to multiple subject necks
Domain.Its speckle to be attached to testee surface random distribution by tracking speckle, is analyzed before and after it is deformed as carrier
Probability relativity, to determine movement and the deformation behaviour of object.Therefore, the speckle for making high quality is Digital Image Correlation Method
The premise accurately measured.
And in practical applications, since there are larger differences for distinct methods or the different prepared speckle of personnel, in turn
Cause the quality of practical speckle field different, the relevant result of calculation of digital picture is made difference occur：Identical deflection is random
Inconsistent deformation field information is shown under speckle field.Existing random speckle production method, such as hand spray dumb light white paint, black
Paint, the coating such as spray gun spraying carbon dust, white powder, marking pen point etc., the random speckle that can all make cannot be controlled without repeatability, precision
The different factors such as system and manufacturing process are cumbersome, are unable to get the approval of academia and industrial quarters.
Invention content
Technical problem：Capable of solving speckle precision the present invention provides one kind, precision and consistency are poor in practical applications
Problem realizes that controllable transfer high quality tests speckle field, repeats, precision is controllable, makes simple experiment speckle field
Optimize preparation method.
Technical solution：The optimization preparation method of the experiment speckle field of the present invention, includes the following steps：
(1) as follows, the random upper limit rand of digital speckle field is optimized：
A) fixed speckle diameter d values are constant, change random upper limit rand, generate the corresponding digital speckle of different rand values
, and same rand values repeatedly generate S digital speckle field, S >=5, and calculate the average gray gradient of each digital speckle field
MIG and auto-correlation coefficient C respectively obtains S group rand-MIG curves and S group rand-C curves；
B) variances sigma of S average gray gradient MIG is calculatedMIGWith the variances sigma of S auto-correlation coefficient Cc, obtain rand-
σMIGCurve and rand- σcCurve；
C) corresponding random upper limit when average gray gradient MIG is maximized in S group rand-MIG curves is found out respectively
Rand values rand1, corresponding random upper limit rand values rand when auto-correlation coefficient C is maximized in S group rand-C curves2；Respectively
Find out rand- σMIGVariances sigma in curveMIGCorresponding random upper limit rand values rand when being minimized3, rand- σcVariance in curve
σcCorresponding random upper limit rand values rand when being minimized4, the rand values optimized are (rand1+rand2+rand3+
rand4)/4；
(2) as follows, the parameter d of digital speckle field is optimized：
A) fixed random upper limit rand is the rand values optimized in step (1), changes speckle diameter d, generates different d values pair
The digital speckle field answered, and each digital speckle field average gray gradient MIG is calculated, obtain d-MIG curves；
B) corresponding d when average gray gradient MIG is maximized in the curve d-MIG of the step a) is found out, for optimization
D values；
(3) digital speckle of optimization is generated by the middle d values optimized of the rand values and step (2) that optimize in the step (1)
；
(4) it is polar plot, the speckle physics ruler of output by the digital speckle field output of the optimization generated in the step (3)
Very little is D, wherein D is determined that W is the length of long sides in region to be measured in formula by formula D=W × d/Rs, and Rs is the camera measurement side
The resolution ratio of length direction；
(5) polar plot exported in the step (4) is fabricated into test specimen table to be measured by experimental measuring condition
Face, as experiment speckle field.
Further, in the method for the present invention, digital speckle field is generated in step (1), (2) and (3) as follows：
1) according to n=int (w2/(2π×d2)) length of side is calculated as the speckle number n of the digital speckle field of w, it counts according to the following formula
The coordinate of all speckle central points is calculated, generating heart septum in speckle isRegularly arranged speckle field：
Wherein,（x′i, y 'i) be i-th of speckle central point coordinate,WithRespectively's
Remainder and integer, d are speckle diameter；
2) coordinate of all speckle central points is calculated according to the following formula, generates digital speckle field：
Wherein, (xi, yi) be digital speckle field in i-th of speckle central point coordinate, f (0, rand) indicate section be (0,
Rand pseudo-random function), rand are the random upper limit, and rand ∈ (0,1], i-th speckle central point and the rule of digital speckle field
Then i-th of speckle central point of speckle field corresponds to.
Further, in the method for the present invention, in step (1), (2), being averaged for digital speckle field is calculated using sobel operators
Shade of gray MIG calculates the auto-correlation coefficient C of digital speckle field using cross-correlation function.
Further, in the method for the present invention, refer to by the method that polar plot is fabricated into surface of test piece to be measured in step (5)
It can will change all transfer methods of the original feature of object in pattern indirect branch to target object and not.
The method of the present invention is according to the suitable preparation method of the selections such as test specimen to be measured, experimental situation：
It is determined according to the resolution ratio of test specimen size and camera, camera lens and measures visual field, to select suitable speckle physics ruler
It is very little；Shape, the load information such as temperature for further appreciating that test specimen to be measured, in conjunction with each transfer method making precision and use ring
Border selects suitable digital speckle transfer method, consistent in order to make the experiment speckle field that transfer obtains and digital speckle field have
Speckle information.What is provided in the present invention, which can successfully complete the preparation method of speckle transfer task, includes：Transfer (water transfer,
Thermal transfer etc.), laser cutting, silk-screen printing, photosensitive seal, the speckle technology of preparing indirectly such as openworking template, that lists herein is more
The speckle field pattern that computer generates can be copied to the surface of the test specimen to be measured under different situations by kind technology.
The method of the present invention realizes the digital speckle transfer of high quality, and the experiment of high quality is provided for Digital Image Correlation Method
Speckle field：
The controllable quality digital speckle of computer is transferred directly to surface of test piece by the method for the present invention, and transfer method is not
The digital information for changing speckle field, to which preparation goes out the experiment speckle field of high quality, this method is undoubtedly digital picture correlation
It is easy in method to make the most direct reliable method of high-precision, consistency speckle.
Experiment speckle field prepared by the method for the present invention is consistent with the digital speckle field information being transferred, and can realize this purpose
Speckle preparation method has transfer (water transfer, thermal transfer etc.), laser cutting, silk-screen printing, photosensitive seal, openworking template etc., and
It is not limited to above several preparation methods；The digital speckle field of high quality makes the reality for forming high quality by speckle transfer techniques
Test speckle field so that the precision computer of Digital Image Correlation Method is controllable.
Advantageous effect：Compared with prior art, the present invention haing the following advantages：
(1) basis of the present invention using digital speckle field as making experiment speckle field.It is given birth to by computer digital speckle field
At randomness, the granular size of digital speckle can control.Traditional speckle field is that experimenter makes at random, not to dissipating
Spot randomness, granular size do quantitative control, cause to make speckle field every time all inconsistent.Therefore random relative to experimenter
The speckle field of spray, the experiment speckle field produced by digital speckle field can control in terms of randomness and granular size, make
The experiment speckle field that precision is identical, consistency is good can be obtained by obtaining experiment every time；
(2) the digital speckle field for the making experiment speckle field that the present invention uses is by optimization.Computer control generates
Digital speckle field stochastic parameter upper limit rand and speckle diameter d, calculate multigroup speckle field average gray gradient MIG and from
Related coefficient C, the rand and d of optimization enable to MIG and C to obtain stable maximum value.Traditional speckle field is due to testing people
The randomness that member makes causes it not have the characteristics of quantitative or qualitative analysis MIG and C.
(3) the digital speckle field of optimization is copied to surface of test piece by the present invention indirectly using the method for transfer, as experiment
Speckle field.Corresponding digital speckle field vector figure, obtained experiment speckle field can be exported before transfer according to measured zone size
In speckle acquired by camera after, obtain the speckle point of fixed pixel size.And traditional experiment speckle field is difficult to produce
The speckle point of fixed size.
(4) the digital speckle field of optimization is copied to surface of test piece by the present invention indirectly using the method for transfer, as experiment
Speckle field.Traditional experiment speckle field is directly to be operated in surface of test piece, it is difficult to the production quality of control experiment speckle field,
Lead to problems such as to waste test specimen, remake；And make all there is speckle field difference every time, cause to test speckle field repeatability
Difference.And digital speckle field is copied to surface of test piece to be measured by the method for using transfer indirectly, obtained experiment speckle field and number
Speckle field is consistent, and the randomness for not only eliminating experimenter's operation makes experiment speckle field effect more preferable, additionally it is possible to reach more
A test specimen can make the effect of identical experiment speckle field, more stronger than the repeatability of conventional method；Digitlization transfer process makes
It is simple, compact to test speckle making, disclosure satisfy that academic research and commercial measurement Measurement reliability demand.
Description of the drawings
The concrete operations flow chart of Fig. 1 present invention；
The optimization speckle field of Fig. 2 present invention：Fig. 2 a are regularly arranged speckle field, and Fig. 2 b are provided by the invention a kind of high
The parameter of quality speckle field, such speckle field is：Randomness upper limit rand is equal to 0.7, and speckle particle diameter d is 4 pixels
Specific implementation mode
With reference to embodiment and Figure of description, the present invention is further illustrated.
Fig. 1 is the flow chart of the present invention, which is classified largely into (1) (2) (3) three parts, can be according to following behaviour
Make the repeatable experiment speckle field that step realizes that precision is controllable, easy to operate to prepare：
(1) computer generates the digital speckle field of high quality：
A. the generation of digital speckle field：
First, to any given speckle size d, the rule row rich in parameter informations such as d, rand can be provided according to the following formula
The speckle field (such as Fig. 2 a) of row：
Wherein,（x′i, y 'i) be regularly arranged speckle field i-th of speckle center point coordinate,WithRespectivelyRemainder and integer, i.e. n speckle point is according to being ranked sequentially from left to right, from top to bottom, n
=int (w2/(2π×d2)), it is speckle total number, w is the length of side of speckle field.The regularly arranged speckle field generated by above-mentioned formula
Speckle in heart septum be
Secondly, to any given speckle size d, randomness upper limit rand, all speckle central points are calculated according to the following formula
Coordinate, generate digital speckle field, such as scheme (such as Fig. 2 b)：
Wherein, (xi, yi) be digital speckle field in i-th of speckle central point coordinate, f (0, rand) indicate section be (0,
Rand pseudo-random function), rand are the random upper limit, and rand ∈ (0,1], i-th speckle central point and the rule of digital speckle field
Then i-th of speckle central point of speckle field corresponds to.
B. the optimization of digital speckle field：
According to the average gray gradient MIG and auto-correlation coefficient C of the digital speckle field of generation, carry out overall merit speckle field matter
Amount.In calculating, the average gray gradient MIG of digital speckle field is calculated using Sobel (sobel) operator, using cross-correlation function
Calculate the auto-correlation coefficient C of digital speckle field.Optimize d and rand so that average gray gradient MIG and auto-correlation coefficient C are obtained
Stable maximum value.The specific method is as follows：
First, the random upper limit rand of digital speckle field is optimized：
A) fixed speckle diameter d values are constant, change random upper limit rand, generate the corresponding digital speckle of different rand values
, and same rand values repeatedly generate S digital speckle field, S >=5, and calculate the average gray gradient of each digital speckle field
MIG and auto-correlation coefficient C respectively obtains S group rand-MIG curves and S group rand-C curves；
B) variances sigma of S average gray gradient MIG is calculatedMIGWith the variances sigma of S auto-correlation coefficient Cc, obtain rand-
σMIGCurve and rand- σcCurve；
C) corresponding random upper limit when average gray gradient MIG is maximized in S group rand-MIG curves is found out respectively
Rand values rand1, corresponding random upper limit rand values rand when auto-correlation coefficient C is maximized in S group rand-C curves2；Respectively
Find out rand- σMIGVariances sigma in curveMIGCorresponding random upper limit rand values rand when being minimized3, rand- σcVariance in curve
σcCorresponding random upper limit rand values rand when being minimized4, the rand values optimized are (rand1+rand2+rand3+
rand4)/4；
Secondly, the parameter d of digital speckle field is optimized：
A) fixed random upper limit rand is the rand values optimized in step (1), changes speckle diameter d, generates different d values pair
The digital speckle field answered, and each digital speckle field average gray gradient MIG is calculated, obtain d-MIG curves；
B) corresponding d when average gray gradient MIG is maximized in the curve d-MIG of the step a) is found out, for optimization
D values；
C. the generation of quality digital speckle field：
By d the and rand values of optimization, following formula is substituted into, the digital speckle field of optimization is generated, is the digital speckle of high quality
：
High quality speckle field provided by the invention is according to above formula, to being equal to a randomness upper limit rand in Fig. 2 a
It is formed after 0.7, speckle size d is 4 pixels, and the high quality speckle field for meeting this feature is as shown in Figure 2 b.This figure has represent
A kind of speckle field of same characteristic features does not limit speckle field color, the minor change for not limiting randomness upper limit rand values, does not limit
Sacrifice the variation etc. for the randomness upper limit rand values that digital picture computational accuracy is brought；
(2) according to the suitable preparation method of the selections such as test specimen to be measured, experimental situation：
It is determined according to the resolution ratio of test specimen size and camera, camera lens and measures visual field, to select suitable speckle physics ruler
It is very little；Shape, the load information such as temperature for further appreciating that test specimen to be measured, in conjunction with each transfer method making precision and use ring
Border selects suitable digital speckle transfer method, consistent in order to make the experiment speckle field that transfer obtains and digital speckle field have
Speckle information.What is provided in the present invention, which can successfully complete the preparation method of speckle transfer task, includes：Transfer (water transfer,
Thermal transfer etc.), laser cutting, silk-screen printing, photosensitive seal, the speckle technology of preparing indirectly such as openworking template, that lists herein is more
The speckle field pattern that computer generates can be copied to the surface of the test specimen to be measured under different situations by kind technology.
(3) the digital speckle transfer for realizing high quality, the experiment speckle field of high quality is provided for Digital Image Correlation Method：
A. it is polar plot by the output of the digital speckle field of optimization, the speckle physical size of output is D, wherein D is by formula D
=W × d/Rs determines that W is the length of long sides in region to be measured in formula, and Rs is the resolution ratio in the camera measurement length of side direction；
B. using the method for transfer, the polar plot of above-mentioned output is fabricated into surface of test piece to be measured, most as the present invention
Whole high quality tests speckle field.
A kind of optimization preparation method of experiment speckle field optimization proposed by the present invention, can solve the speckle because making at random
Without repeatability, precision cannot control and the factors such as manufacturing process is cumbersome caused by Digital Image Correlation Method measurement accuracy and
The problems such as consistency is poor.Compared with traditional speckle manufacturing technology, the production method for the digital speckle field that the present invention provides has
The features such as repeatability, precision be controllable, process simple and compact, can make digital picture is related preferably to obtain academia and industry
Approve on boundary.
Above-described embodiment is only the preferred embodiment of the present invention, it should be pointed out that：For the ordinary skill of the art
For personnel, without departing from the principle of the present invention, several improvement and equivalent replacement can also be made, these are to the present invention
Claim be improved with the technical solution after equivalent replacement, each fall within protection scope of the present invention.
Claims (4)
1. a kind of optimization preparation method of experiment speckle field, is characterized in that, this approach includes the following steps：
(1) as follows, the random upper limit rand of digital speckle field is optimized：
A) fixed speckle diameter d values are constant, change random upper limit rand, generate the corresponding digital speckle field of different rand values, and
Same rand values repeatedly generate S digital speckle field, S >=5, and calculate each digital speckle field average gray gradient MIG and
Auto-correlation coefficient C respectively obtains S group rand-MIG curves and S group rand-C curves；
B) variances sigma of S average gray gradient MIG is calculatedMIGWith the variances sigma of S auto-correlation coefficient Cc, obtain rand- σMIGCurve
With rand- σcCurve；
C) corresponding random upper limit rand values when average gray gradient MIG is maximized in S group rand-MIG curves are found out respectively
rand1, corresponding random upper limit rand values rand when auto-correlation coefficient C is maximized in S group rand-C curves2；It finds out respectively
rand-σMIGVariances sigma in curveMIGCorresponding random upper limit rand values rand when being minimized3, rand- σcVariances sigma in curvecIt takes
Corresponding random upper limit rand values rand when minimum value4, the rand values optimized are (rand1+rand2+rand3+rand4)/
4；
(2) as follows, the parameter d of digital speckle field is optimized：
A) fixed random upper limit rand is the rand values optimized in step (1), changes speckle diameter d, it is corresponding to generate different d values
Digital speckle field, and each digital speckle field average gray gradient MIG is calculated, obtain d-MIG curves；
B) corresponding d when average gray gradient MIG is maximized in the curve d-MIG of the step a) is found out, for the d of optimization
Value；
(3) the digital speckle field of optimization is generated by the middle d values optimized of the rand values and step (2) that optimize in the step (1)；
(4) it is polar plot by the digital speckle field output of the optimization generated in the step (3), the speckle physical size of output is
D, wherein D is determined that w is the length of long sides in region to be measured in formula by formula D=W × d/Rs, and Rs is the camera measurement length of side side
To resolution ratio；
(5) polar plot exported in the step (4) is fabricated into surface of test piece to be measured, made by experimental measuring condition
To test speckle field.
2. the optimization preparation method of experiment speckle field described in accordance with the claim 1, it is characterised in that：The step (1), (2)
(3) digital speckle field is generated in as follows：
1) according to n=int (w2/(2π×d2)) length of side is calculated as the speckle number n of the digital speckle field of w, institute is calculated according to the following formula
There is the coordinate of speckle central point, generating heart septum in speckle isRegularly arranged speckle field：
Wherein, (x 'i, y 'i) be i-th of speckle central point coordinate,WithRespectivelyIt is remaining
Number and integer；
2) coordinate of all speckle central points is calculated according to the following formula, generates digital speckle field：
Wherein, (xi, yi) be digital speckle field in i-th of speckle central point coordinate, f (0, rand) indicate section be (0,
Rand pseudo-random function), and random upper limit rand ∈ (0,1], i-th of speckle central point of digital speckle field and regular speckle field
I-th of speckle central point correspond to.
3. the optimization preparation method of experiment speckle field described in accordance with the claim 1, it is characterised in that：The step (1), (2)
In, the average gray gradient MIG of digital speckle field is calculated using sobel operators, and digital speckle field is calculated using cross-correlation function
Auto-correlation coefficient C.
4. according to the optimization preparation method of experiment speckle field as claimed in claim 1,2 or 3, it is characterised in that：The step (5)
The middle method that polar plot is fabricated into surface of test piece to be measured is that refer to will be in pattern indirect branch to target object and not
Change all transfer methods of the original feature of object.
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| CN110618538A (en) * | 2018-12-27 | 2019-12-27 | 武汉大学 | Manufacturing method of micro-nano-scale speckles |
| CN110238531A (en) * | 2019-04-15 | 2019-09-17 | 清华大学 | Femtosecond laser makes the method and system of microcosmic speckle in Digital Image Correlation Method |
| CN110793453B (en) * | 2019-10-10 | 2021-02-26 | 北京科技大学 | Simple and rapid manual speckle preparation method suitable for three-dimensional curved surface special-shaped structure |
| CN110986811B (en) * | 2019-11-01 | 2021-05-25 | 武汉科技大学 | Speckle preparation method for deformation test of shaped refractory material |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103808440A (en) * | 2014-02-18 | 2014-05-21 | 清华大学 | Preparation method and system for micro-nano speckle |
| CN104864819A (en) * | 2015-01-19 | 2015-08-26 | 华中科技大学 | Digital speckle-based high-speed three-dimensional strain measurement method |
| CN105043543A (en) * | 2015-08-27 | 2015-11-11 | 河南科技大学 | Apparatus for generating controllable super-Rayleigh speckle field and method for generating the same |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9671218B2 (en) * | 2014-12-22 | 2017-06-06 | National Chung Shan Institute Of Science And Technology | Device and method of quick subpixel absolute positioning |
-
2016
- 2016-07-29 CN CN201610615850.1A patent/CN106289089B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103808440A (en) * | 2014-02-18 | 2014-05-21 | 清华大学 | Preparation method and system for micro-nano speckle |
| CN104864819A (en) * | 2015-01-19 | 2015-08-26 | 华中科技大学 | Digital speckle-based high-speed three-dimensional strain measurement method |
| CN105043543A (en) * | 2015-08-27 | 2015-11-11 | 河南科技大学 | Apparatus for generating controllable super-Rayleigh speckle field and method for generating the same |
Non-Patent Citations (4)
| Title |
|---|
| 散斑全息存储中的散斑尺寸优化;张培琨等;《光子学报》;20010925;第30卷(第09期);1128-1131 * |
| 数字散斑时间序列相关三维面形测量中提高精度的方法;代红军等;《激光杂志》;20010215;第22卷(第01期);46-51 * |
| 数字散斑相关方法的数学模型及研究;洪宝宁等;《南京建筑工程学院学报(自然科学版)》;19960330(第01期);1-4 * |
| 频率域数字散斑相关方法的研究;亓东平等;《光学学报》;20000405;第20卷(第04期);489-493 * |
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