Yu Jun, Shen Zhengxiang, Wang Xiaoqiang, Sheng Pengfeng, Wang Zhanshan
Opt Express. 2018 Nov 12;26(23):30724-30739. doi: 10.1364/OE.26.030724.
Ultra-precision diamond machining is a promising technique for non-rotationally symmetrical surfaces with sub-micrometer form accuracy. The measurement and compensation processes in the fabrication process must be conducted carefully to achieve high form accuracy. However, significant challenges remain to improve the measurement accuracy and machining efficiency. Because of the remounting process, the off-machine measurements would reduce the efficiency. On the other hand, contact-type measurements can cause physical damage to some soft materials. To overcome these problems, a noncontact on-machine measurement (OMM) system is developed using two optical probes, and a two-step compensation strategy is proposed to generate a modified tool path. To verify the accuracy of the proposed measurement system, OMMs were performed on a spherical mirror using this system and were later compared with off-machine measurements. To evaluate the compensation strategy, an off-axis paraboloid mirror was diamond-machined and compensated using the proposed method. The results show that the OMM system and compensation strategy are effective for improving the form accuracy while simultaneously enhancing the machining efficiency.
超精密金刚石加工是一种用于加工具有亚微米形状精度的非旋转对称表面的很有前景的技术。在制造过程中，测量和补偿过程必须谨慎进行，以实现高形状精度。然而，在提高测量精度和加工效率方面仍存在重大挑战。由于重新安装过程，离线测量会降低效率。另一方面，接触式测量可能会对一些软材料造成物理损坏。为了克服这些问题，利用两个光学探头开发了一种非接触式在位测量（OMM）系统，并提出了一种两步补偿策略来生成修正的刀具路径。为了验证所提出测量系统的精度，使用该系统在球面镜上进行了在位测量，随后与离线测量进行了比较。为了评估补偿策略，使用所提出的方法对离轴抛物面镜进行了金刚石加工和补偿。结果表明，在位测量系统和补偿策略对于提高形状精度同时提高加工效率是有效的。
