大口径非球面的组合加工

Multi-mode optimization for large optical aspheric mirror

为提高大口径非球面光学反射镜研磨与抛光阶段的加工效率,提出了一种采用多磨头组合方式同时提高材料去除效率和面形收敛率的加工方法。该方法基于矩阵运算,在一次优化过程中同时优化多个加工循环,并对传统的单去除函数驻留时间求解过程进行扩展,以实现多去除函数的综合优化求解。由于扩展了驻留时间求解范围,使大磨头和小磨头在加工过程中优势互补,实现了多个磨头多个加工循环的全局优化。最后,采用计算机虚拟加工的方法对等厚和实际加工中的面形误差进行加工模拟。结果表明:与传统的驻留时间求解算法相比,提出的方法使加工效率提高了50%,RMS收敛率与小磨头相当。实际面形仿真加工结果显示,RMS由0.011 5变为0.004 4,收敛率为0.621 2,满足实际加工要求。该技术有效缩短了加工周期,具有很强的实用性。

To manufacture a large aspheric mirror in higher efficiency and higher precision, a new method by using multi-mode optimization is proposed to improve material removal efficiency and sur- face convergence rates. On the basis of matrix calculation, this method optimizes multi-processing cy- cle in one optimizing processing simultaneously and extends the calculating process of the dwell time for traditional Tool Influence Functions（TIF）to complete the integrating optimizing solution of multi TIF . As the solution area of dwell time is extended, the bigger grinding head and the small one have complementary advantages and obtain a global optimization for multi grinding heads and multi-pro- cessing cycles. In the end, an error map is simulated with actual parameters by using computer virtual multi-mode method. The simulation result shows that the multi-mode technique can improve the pro- cessing efficiency by 50% as compared with traditional method and its convergence rate（ RMS value） is the same as that of the smaller grinding head. When the simulation is on the real surface, the RMS changes from 0. 011 5 to 0. 004 4 and the convergence rate is 0.62l 2, whic of real manufacture. The multi-mode technique improves polishing efficien cision and is an attractive solution for the large optical aspheric mirror iab h satisfies cy in main rlcatlon the requirements taining good precision and is an attractive solution for the large optical aspheric mirror Iabrication.