New method of improving the sensitivity of real-time measuring of the surface roughness of workpieces

摘要

Based on the principle that after illuminating the rough surface the two coherent plane waves can be coherent and this coherence has something to do with the surface roughness a split system with an adjustable incident angle is proposed in this paper - it consists of a moving reflector and a double Dove prism which can divide one beam of the plane wave into two coherent plane waves. Through an interferometer the scattered coherent optical field is produced and a correlation speckle pattern which can be received by CCD is produced. The visibility of the pattern together with the other collected signals such as incident angle and so on are put into a computer. After data processing, the result value of the roughness is exported directly by the computer. The experimental results show that because of the adjustable incident angles this new method can improve the measuring sensitivity greatly on the condition that it does not influence the measuring extent and meanwhile, because of the introduction of the CCD and the computer, it can obviously strength the real-time and aging of measuring.