双波长数字散斑相关法表面粗糙度测量

Surface Roughness Measurement Based on Dichromatic Digital Speckle Correlation

在物面系综平均双波长散斑相关法基础上,提出了双波长数字散斑相关方法测量表面粗糙度;模拟研究了双波长散斑场空间相关参数及在两单波长散斑图像中样本子区与目标子区的位置关系;实验探讨了数字图像处理的窗口尺寸对空间相关峰值的影响;对平磨和抛喷丸表面样块的粗糙度测量实验表明,双波长散斑场空间相关参数能有效表征表面粗糙度。新的测量方法具有数据采集速度快、表征参数稳定性好的特点。

Based on the spectral-speckle correlation method with ensemble average, dichromatic digital speckle correlation method is introduced to measure the surface roughness. The properties of dichromatic speckle spatial correlation parameter are investigated through simulated speckle fields. And the location relation of sample and target areas is also studied. Window size influence in digital image process on peak value of spatial correlation is experimentally discussed. The surface roughness of blasted-shot and grinding specimen is measured. It is shown that dichromatic speckle spatial correlation parameter can describe surface roughness effectively. The new method has the virtue of fast image acquisition and good stability.