Three Dimensional Deformation Measurement Research By Electronic Speckle Pattern Interferometry (ESPI)

Electronic speckle pattern interferometry is an optical measurement which evolves immediately after the advent of the laser.The technique is used for the measurement of the deformation of the object through the pattern analysis and makes the non-destructive measurement come true.As it has the merits of whole-field,non-contact and high-accuracy,it has been an important method in the deformation measurement in the recent 20 years and used in different domains.With the development of the industry and production and the improvement of the accuracy of the measurement device,the electronic speckle pattern interferometry(ESPI) is gradually developing toward the three-dimension and high accuracy.So how to make the three-dimensional deformation measurement of the high-accuracy of the object by ESPI come true is an important task.Three-dimensional modulation deformation measurement by ESPI is an important way in measuring the deformation of the object.It includes all the merits of the electronic speckle interferometry and particularly it has the merits of the simple-set,easy-operation ,the low requiration to the condition and low-cost etc.This paper presents the principle and operation method of the 3D modulation deformation measurement by ESPI.The main content is given below.1. introduce the principle of the speckle,the method of the speckle production and correlative concepts;review the origin and development of the speckle pattern interferometry;give the actuality and evolution direction of the 3D measurement by the electronic speckle pattern interferometry.2. Review the evolution of the electronic speckle pattern interferometry ,introduce some kinds of the methods and principles of the electronic speckle pattern interferometry and the technique of image processing;illuminate the origin and development vista of the carry frequency modulation through ESPI.3. Discuss the method,principle and the way of the image processing,introduce the deformation measurement by ESPI with the Wollaston prism and the working principle of the new type of the square prism;introduce the principle,method and application prospect of the 3D deformation measurement by ESPI.4. Make a deformation measurement to the three-point bending beam based on the new type of the square prism by 3D deformation modulation measurement through ESPI and separate the in-plane displacement from out-of-plane displacement with the Fourier transform .obtain the image through one time modulation and deformation.This method has the merits of the simple optical setup,easy operation,low requiration to the condition and low cost and has the prospect of the scene check in the project.Analyse the polarization characteristic of the new type of the square prism and Wollaston prism.