Adaptive tool servo diamond turning for enhancing machining efficiency and surface quality of freeform optics
Adaptive tool servo diamond turning for enhancing machining efficiency and surface quality of freeform optics
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DOI：
10.1364/oe.23.020234
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发表时间：
2015-08-10
期刊：
影响因子：
3.8
通讯作者：
To, Suet
中科院分区：
文献类型：
--
作者：
Zhu, Zhiwei;To, Suet
快刀伺服/慢刀伺服 (FTS/STS) 金刚石车削是一种非常有前景的自由曲面光学生成技术。然而，目前采用的方位采样和侧向进给运动的恒定方案不适应表面形状变化，导致表面质量不均匀和加工效率低。为了克服这一缺陷，本文报告了一种新型自适应刀具伺服（ATS）金刚石车削技术，该技术本质上基于新型二自由度（2-DOF）FTS/STS。在ATS中，在任何切削点主动控制采样间隔和侧进给运动，以使加工过程适应所需表面的形状变化，使采样引起的插补误差和侧向进给引起的残留刀痕都在所需的公差范围内。所需切削运动的特性表明，除了传统的 z 轴伺服运动之外，还需要由 c 轴合成的沿 x 轴的另一个伺服运动来实现 ATS。从理论上和实验上对FTS/STS和ATS中典型微结构表面的表面生成进行了深入的比较研究。结果表明，ATS 优于 FTS/STS，表面质量得到改善，同时加工效率也得到提高。 (C) 2015年美国光学学会
Fast tool servo/slow tool servo (FTS/STS) diamond turning is a very promising technique for the generation of freeform optics. However, the currently adopted constant scheme for azimuth sampling and side-feeding motion possesses no adaptation to surface shape variation, leading to the non-uniform surface quality and low machining efficiency. To overcome this defect, this paper reports on a novel adaptive tool servo (ATS) diamond turning technique which is essentially based on the novel two-degree-of-freedom (2-DOF) FTS/STS. In the ATS, the sampling interval and the side-feeding motion are actively controlled at any cutting point to adapt the machining process to shape variation of the desired surface, making both the sampling induced interpolation error and the side-feeding induced residual tool mark be within the desired tolerances. Characteristic of the required cutting motion suggests that besides the conventional z-axis servo motion, another servo motion along the x-axis synthesizing by the c-axis is mandatory for implementing the ATS. Comparative studies of surface generation of typical micro-structured surfaces in FTS/STS and ATS are thoroughly conducted both theoretically and experimentally. The result demonstrates that the ATS outperforms the FTS/STS with improved surface quality while simultaneously enhanced machining efficiency. (C) 2015 Optical Society of America