基于Bayesian原理的低陡度光学镜面面形误差离子束修正驻留时间算法

Bayesian Principle Based Dwell Time Algorithm for Ion Beam Figuring of Low Gradient Mirrors

离子束修形是一种高效修除镜面误差的技术,驻留时间求解算法是此技术的关键问题之一。以光学镜面计算机控制成型原理为基础,建立基于Bayesian原理的平面镜面驻留时间算法,对数据边缘进行Gaussian延拓以消除边缘效应。分析驻留时间近似速度实现方式的实现误差与工艺参数的关系,通过在算法中引入附加光滑修正因子以提高驻留时间实现精度。在适当的路径规划下,将低陡度非球面修形过程近似用平面修形过程线性模型来描述,最终形成低陡度光学镜面面形误差离子束修正中驻留时间的快速近似算法。利用此算法对φ100平面镜和φ200球面镜进行修形加工,加工收敛率均可达9。研究结果表明:线性化近似模型是合理的,速度近似计算是可行的,基于Bayesian原理的低陡度非球面驻留时间求解算法是一种快速高效面形控制技术,可对镜面进行确定性精确修形。

Ion beam figuring is a technology of figuring mirrors errors of high efficiency. Dwell time algorithm is one of the key problems. Based on the Bayesian principle, an iterative dwell time algorithm for planar mirrors is deduced from the computer controlled optics shaping principle. With the Gaussian extension for the data edge, the edge effect is weakened. The rapid approximate calculation of the velocity for the realization of dwell time is presented, and then the model relation between the realization erro...