基于图像拼接的微表面三维测试系统开发

常用的干涉系统可测量较大区域但达不到足够的分辨率,干涉显微镜的测量可达较高的分辨率,但测量区域小.本文提出了一种将干涉显微技术和图像拼接结合的微表面三维测试系统.系统将Mirau显微干涉物镜与压电陶瓷传感器(PZT)结合起来实现相移干涉,从而获取被测件形貌的信息.同时采用精确定位电控平移系统精确定位,实现被测件表面的分区域扫描,并利用子区域图像的重叠区域进行拼接匹配.考虑不同重叠尺度对拼接效率以及拼接质量影响,设定不同比例的重叠区域进行对比实验.实验结果表明重叠区域在20%左右综合效果最好.

3D system for surface topography measurement based on image mosaic

In wide regional measurement,the traditional interferometry system can not achieve high-resolution easily.On the contrary,interferance microscope can get high-resolution in a limited regional.A 3D surface testing system based on phase-shifting interferometry and image mosaics technology is developed.The phase-shifting interfermetric structure is combination of Mirau interference objective and piezoelectric transducer(PZT).Surface for district scanning can be separated exactly by using stepping motor,and the sub-regional image is used for overlap region match.Considered the influence of different dimension overlapped on the mosaic quality and efficiency,comparative experiments are carried out with different percentages of overlapping regional.Experiment results show that the overlap region about 20 percent of the image has the best quality.