Related Technical Research On Integer-pixel Displacement Measurement Of Digital Speckle Image

Digital speckle correlation method because of its simple optical path, the advantages of the non-contact measurement, after nearly 30 years of development, has been widely used in materials such as tensile strength test, deformation and many areas. It has its important value of research.Because of the problems of the traditional digital speckle correlation method such as data computation, low efficiency, easy to fall into local optimum, not being uesd in real time measurement, therefore this article revolves around a few questions.In this paper, research work mainly include the following aspects:(1)This paper expounds research background, significance and development history of the digital speckle measurement technology.The stage of development of the digital speckle correlation method is seriously studied.(2)Related technologies involved with digital speckle correlation method including algorithm principle, the principle of computer simulation of speckle figure, several classical integer pixel search algorithms and sub-pixel search algorithms are seriously studied.(3)Fruit fly optimization algorithm of simple principle and less parameters is seriously studied.Aiming at the problems of low convergence precision and easily relapsing into local extremum caused by olfaction searching random blind and only learning from the optimal fruit fly in basic Fruit fly Optimization Algorithm(FOA), an improved FOA called Fruit fly Optimization Algorithm based on Non-uniform mutation and Adaptive escape(NAFOA) was proposed.Non-uniform mutation operator is introduced into olfaction searching phase to adjust dynamically searching step of each iteration.The proposed algorithm divided states of population into premature state and normal state by setting thresh old.If population is in normal state,basic FOA was adopted to evolve;otherwise,it falls into “premature”, dimensionby dimension perturbations to the global optimal fruit was adopted to generate the new solution.It enhances the ability to escape from local optimum and deals well with the balance between exploring and developing.Test of six classic function was designed and the experimental results showed that the algorithm in terms of accuracy and robustness were better than FOA and other several improved algorithms.NAFOA was applied to measurement of digital speckle correlation method and the experimental results show that the method is feasible.(4)Aiming at the existence of the traditional digital speckle correlation method in data processing, calculation problem of onerous redundancy and low calculation efficiency, from another aspect, namely the characteristics of digital speckle, extremum displacement Method with multi-level crossing algorithm also called MLCA-EDM is proposed.The method is based on the extreme displacement measurement method, combination of multilayer truncation algorithm.Under the condition of experiment in the absence of noise and noise, the results show that MLCA- EDM algorithm improves efficiency a lot.The error of the mean and standard deviation of these two kinds of algorithm are analyzed.MLCA- EDM algorithm is applied to locate the laser mouse and the experimental results show that the method has achieved better results.