Analysis of the Curved Surface on Surface Roughness Measurement Using Dichromatic Speckle Pattens

This paper focuses on the influence of curved surface on surface roughness measurement, the method of dichromatic speckle autocorrelation was used in measuring surface roughness, and curvature radius of surface is introduced. The rough surface and the dichromatic speckle patterns are simulated, and the effects of different radius of curved surface on speckle patterns and speckle elongation ratio are discussed. The results show that the factor of surface radius is valid in dichromatic speckle autocorrelation measurement. When the curvature radius is large, the speckle elongation is greater, the deviation of measured surface roughness is smaller. The curvature of rough surface will affect on measurement precision when we measure the roughness by the method of dichromatic speckle autocorrelation.