考虑高精度子孔径拼接干涉测量技术对自动化拼接的要求, 提出了一种子孔径零条纹自动快速调节方法。分析了干涉条纹数量对拼接误差的影响, 分析显示: 当子孔径干涉条纹数量少于5条时, 干涉仪回程误差小于λ/50(PV值)。对子孔径拼接测量装置进行了结构优化, 提出了拼接位移台角位移偏差自动补偿方法, 实现了各个子孔径的零条纹测量, 进而控制了子孔径拼接的累积误差。对450 mm×60 mm长条镜进行了子孔径拼接干涉测量, 结果表明: 自动测量结果与手动调整零条纹测量结果在面形分布上更为一致; 但前者测量速度及测量效率都有所提高, 测量时间平均减少5 min。提出的方法不仅能完成干涉拼接测量装置的自动定位及自动快速调整, 还提高了测量重复性与检测效率。

An automatic and quick adjustment method for zero interference fringes was proposed to meet the requirement of high precision subaperture stitching interferometry . The influence of interference fringe numbers on stitching errors was analyzed, and the analyzed results show that the interferometer return error is less than λ/50(PV value) when the interference fringe numbers of subaperture are less than 5. A subaperture stitching measurement apparatus was optimized, and an auto-compensation method of angular displacement deviation for the motion stage was proposed. By which, zero fringe of each subaperture was realized, and the cumulative error of subaperture stitching was controlled finally. A 450mm×60mm flat mirror was measured by subaperture stitching interferometry, the experiment result shows that the surface distributions of automatic stitching measurement results are more consistent with that of the zero fringe measurement by manual adjustment , the measuring speed and measuring efficiency are improved and the measuring time is reduced by 5 min on average. As compared with zero fringe measurement by manual adjustment. The proposed method not only completes the automatic positioning and automatic adjustment of the interference stitching measurement apparatus, but also improves the measuring repeatability and detection efficiency.