3D deformation measurement based on colorful electronic speckle pattern interferometry

Abstract

In this paper, we proposed a transient three-dimensional deformation and profile measurement method based on colorful electronic speckle pattern interferometry (ESPI) and wavelet transform. The method employs a color CCD to capture the speckle pattern from three deformation directions (vertical in-plane, horizontal in-plane and out-of-plane) by taking three different colorful lasers as light sources, respectively. The colorful speckle pattern is separated into three images according to different colors. Each separated speckle interferogram is processed with wavelet transform algorithm to demodulate the deformation phase in the corresponding direction and then to get the 3D deformation of the tested object. It can also measure the profile of an object with the out-of-plane speckle pattern. Computer simulation and experimental results are presented to verify that the system can achieve 3D transient deformation and shape measurement using a plate and a cylindrical object as the samples.