为了解决大口径凸球面镜高精度检测问题,建立了子孔径拼接检测数学模型,模型以全局优化算法及最小二乘拟合算法为基础,优化得出被检测镜面全口径面形,并基于该数学模型对一口径φ120 mm凸球面镜完成了拼接检测,检测中共测量5个子孔径。由检测结果可以看出,拼接面形表面光滑连续,无拼接痕迹。为了验证拼接精度,在子孔径检测中另取一用于评价拼接精度的自检验子孔径,完成了对应子孔径的检测,并将拼接结果与自检验子孔径检测结果进行了点对点相减,从而获得残差图,实验结果表明:残差图PV值为0.014λ,RMS值为0.003λ,表明拼接结果的可信性,验证了算法的可靠性与准确性。
In order to solve the problem of large optical convex spherical mirror testing, a stitching model was established, which was based on global optimization algorithm and least-square method. The full aperture map can be achieved with this relative algorithm. At the same time, based on our model, aφ120 mm convex spherical mirror was tested. In the testing, five subapertures were tested. It can be seen that the stitching map is smooth and continuous, with no stitching mark. To evaluate the stitching accuracy, a subaperture called self-calibration subaperture was tested. Comparing the stitching map with the self-calibration map point by point, the residual map can be got. It can be seen from the residual map that the PV value is 0.014λ and the RMS value is 0.003λ, proving the reliability and accuracy of the stitching algorithm.