Modern optoelectronic methods for non-contact deformation measurement in industry

Abstract

Two different types of optoelectronic method for non-contact deformation measurement are described: the ray method and the interferometric method. The ray method is based on the law of reflection and can be used for large continuous reflective surfaces, which behave approximately as deformable mirrors of a general type. The work is focused on several theoretical and experimental aspects of evaluation of the deformations with the ray method, especially on problems of measuring extended objects in engineering practice and automatic processes for evaluation of deformations. We also propose a technique for the smoothing of continuous optically rough surfaces to allow successful application of the ray method for deformation measurement. The interferometric measurement methods are based on the principle of interference of two coherent wave fields and subsequent evaluation of the interference pattern. In this work we describe a proposed optical method for measuring static deformations based on the interference of coherent wave fields and a phase shifting procedure. Detailed analysis of the measurement and evaluation process with respect to the most important measurement factors is performed.