Research On Precise On-line Surface Measurement By Synchronism Phase-shifting Shearing Interference

Following the rapid development of Microelectronic, MEMS, Optoelectronic information technology and airspace technology, the demand of high surface quality for high accuracy information base and other accessories of precise equipment increases stably, for example, optical element surface, silicon crystal surface, disc. The problem with surface on-line measurement and quality control becomes more prominent. In the paper, a synchronism phase-shifting shearing interference system is proposed to resovle this problem about precise on-line surface measurement, the main contents and results of thesis are as follows:(1)Based on the principle of synchronism phase-shifting shearing interference, accomplish the system integrated design;(2)Design a shearing unit with complete common path, simple, compact, steady structure, and convenient adjusting for shearing displacement. Explore sychronism phase-shifting technique, design CCD cameras connecting scheme in sychronism. Based on these principle buit sychronism phase-shifting shearing interference experimental facility;(3)Realize phase recovery algorithm of the shearing interference image, including phase-shifting algorithm, phase unwrapped, wave rebuilding, shearing displacement calculating;(4)Fulfill openGL three-dimensional display technique, based on VC++ platform build a software system which consists of image capturing, image processing and measuring result displaying of shearing interference, and do some experiment to test the measurement system;(5)Analyze the anti-vibration characteristic of the whole measurement system, especially analyze the mechanism for synchronism phase-shifting to decrease phase shifting interference measurement error in theory, and build some experiments to verify the anti-vibration characteristic of sychronism phase-shifting.Last, the research and experiment result indicate the designed sychronism phase-shifting shearing interference system provide high degree of accuracy, high reliability and stability, good anti-vibration charateristic, adapted to precise on-line surface measurement.