计算机控制光学表面成形驻留时间算法研究

Dwell time algorithm in computer controlled optical surfacing

光学非球面的使用可以提高光学系统的性能、简化系统结构、减小系统体积，减轻系统重量，计算机控制光学表面成形（ＣＣＯＳ）方法是加工光学非球面的重要方法。介绍了ＣＣＯＳ原理，给出了ＣＣＯＳ中关键技术驻留时间计算的三种算法———基于加工仿真的算法、基于傅立叶变换的算法和基于滑动平均与傅立叶变换的算法。基于加工仿真的驻留时间算法需要做大量的卷积计算，计算时间较长，残余误差较大；基于傅立叶变换的驻留时间算法与基于滑动平均和傅立叶变换的驻留时间算法计算时间短，计算后的残余误差小。磨头单位去除函数形状与磨头大小对误差的去除也有明显的影响，小的磨头和陡峭的单位去除函数对于去除局部误差更为有利。

Performance of optical system can be improved by employing aspherical elements. Computer controlled optical surfacing (CCOS) is one of the most important methods in fabrication of optical aspheres. Rationale of CCOS is introduced, in which the dwell time algorithm is a key point. Three algorithms, algorithm based on machining simulation (AMS), algorithm based on Fourier transfer (AFT), and algorithm based on Fourier transform and moving average(AFTMA), are discussed. In AMS, because of employing convolution computation, computation needs long time with a result of large left error. In AFT and AFTMA, computation time is more shorter, with a smaller left error. The shape and size of unit removing function has a apparent effect on the removing of error. For removing local error, a shag and small unit removing function is more efficient, while process time is much longer.