Dai Yifan, Hu Hao, Peng Xiaoqiang, Wang Jianmin, Shi Feng
National University of Defense Technology, DeYa, Changsha, Hunan Province 410073 China.
Appl Opt. 2011 Jul 1;50(19):3321-9. doi: 10.1364/AO.50.003321.
Although magnetorheological finishing (MRF) is a deterministic finishing technology, the machining results always fall short of simulation precision in the actual process, and it cannot meet the precision requirements just through a single treatment but after several iterations. We investigate the reasons for this problem through simulations and experiments. Through controlling and compensating the chief errors in the manufacturing procedure, such as removal function calculation error, positioning error of the removal function, and dynamic performance limitation of the CNC machine, the residual error convergence ratio (ratio of figure error before and after processing) in a single process is obviously increased, and higher figure precision is achieved. Finally, an improved technical process is presented based on these researches, and the verification experiment is accomplished on the experimental device we developed. The part is a circular plane mirror of fused silica material, and the surface figure error is improved from the initial λ/5 [peak-to-valley (PV) λ=632.8 nm], λ/30 [root-mean-square (rms)] to the final λ/40 (PV), λ/330 (rms) just through one iteration in 4.4 min. Results show that a higher convergence ratio and processing precision can be obtained by adopting error control and compensation techniques in MRF.
尽管磁流变抛光（MRF）是一种确定性的抛光技术，但在实际加工过程中，加工结果总是达不到模拟精度，仅通过一次处理无法满足精度要求，而是需要经过多次迭代。我们通过模拟和实验研究了这个问题的原因。通过控制和补偿制造过程中的主要误差，如去除函数计算误差、去除函数定位误差以及数控机床的动态性能限制，单次加工中的残余误差收敛比（加工前后图形误差之比）明显提高，从而实现了更高的图形精度。最后，基于这些研究提出了一种改进的工艺流程，并在我们开发的实验装置上完成了验证实验。加工部件为熔融石英材料的圆形平面镜，通过在4.4分钟内仅一次迭代，表面图形误差从初始的λ/5[峰谷值（PV），λ=632.8nm]、λ/30[均方根（rms）]提高到最终的λ/40（PV）、λ/330（rms）。结果表明，在磁流变抛光中采用误差控制和补偿技术可以获得更高的收敛比和加工精度。
