调制度测量轮廓术在复杂面形测量中的应用

Application of Modulation Measurement Profilometry in Complex Object Shape Measurement

调制度测量轮廓术(MMP)是将物体的高度信息编码在投影到待测物面上的正弦条纹的调制度信息中,可以实现对物体的垂直测量,特别适合测量表面有高度剧烈变化或不连续区域的物体。探讨了基于傅里叶变换的调制度测量轮廓术在复杂面形测量中的应用,提出了调制度焦深的概念并详细分析了调制度焦深对测量的影响,以调制度焦深为基础从测量系统设计的角度提出了提高测量精度的具体措施,给出了实验系统设计方案,讨论了影响测量精度的几个实际问题及解决方案。对复杂面形和深孔物体的实测结果表明,基于傅里叶变换的调制度测量轮廓术测量复杂面形物体可以达到较高的测量精度。

Modulation measurement profilometry (MMP), which encode the height information into the modulation information of sinusoidal grating on the measuring surface, is a vertical measurement technique. It is suitbed for measuring those objects with discontinuous height steps and/or spatially isolated surfaces. The application of MMP based on Fourier-transform is discussed in measuring complex surface, with presenting the concept of the depth-of-modulation and anlyzing its influence on measurement. Based on the depth-of-modulation, the detailed method and projects of designing measurement system are proposed to improve accuracy of measurement, and several practical questions influencing accuracy and solutions are discussed. The measured results show that the MMP based on Fourier transform measuring surface of complex objects can improve the accuracy of measurement greatly.