Tool path generation and optimization for freeform surface diamond turning based on an independently controlled fast tool servo
Tool path generation and optimization for freeform surface diamond turning based on an independently controlled fast tool servo
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DOI：
10.1088/2631-7990/ac5f12
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发表时间：
2022-06-01
影响因子：
14.7
通讯作者：
Yan, Jiwang
中科院分区：
文献类型：
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作者：
Sato, Yusuke;Yan, Jiwang
基于快速刀具伺服系统的金刚石车削技术具有加工精度高、加工效率高等优点，在自由曲面光学加工中得到了广泛的应用。作为一种新的趋势，最近开发的高频和长行程FTS单元由独立于机床控制器的控制系统独立驱动。然而，独立控制的FTS的刀具轨迹生成策略还远未完成。本研究旨在建立独立控制FTS的刀具路径优化方法，以减少单一加工步骤中的形状误差。不同于传统的集成FTS控制系统，其中控制点分布在一个螺旋图案，在这项研究中，独立FTS控制器的刀具路径生成的环形方法和网格方法，分别。加工表面轮廓预测模拟和控制点生成的参数进行了优化，通过最大限度地减少预测和设计的表面之间的偏差。为了验证所提出的刀具轨迹生成策略的可行性，进行了二维正弦波和微透镜阵列的切削试验，并对结果进行了比较。结果表明，优化后的加工路径使二维正弦波加工的峰谷形状误差从429 nm减小到56 nm，微透镜阵列加工的峰谷形状误差从191 nm减小到103 nm。
Diamond turning based on a fast tool servo (FTS) is widely used in freeform optics fabrication due to its high accuracy and machining efficiency. As a new trend, recently developed high-frequency and long-stroke FTS units are independently driven by a separate control system from the machine tool controller. However, the tool path generation strategy for the independently controlled FTS is far from complete. This study aims to establish methods for optimizing tool path for the independent control FTS to reduce form errors in a single step of machining. Different from the conventional integrated FTS control system, where control points are distributed in a spiral pattern, in this study, the tool path for the independent FTS controller is generated by the ring method and the mesh method, respectively. The machined surface profile is predicted by simulation and the parameters for the control point generation are optimized by minimizing the deviation between the predicted and the designed surfaces. To demonstrate the feasibility of the proposed tool path generation strategies, cutting tests of a two-dimensional sinewave and a micro-lens array were conducted and the results were compared. As a result, after tool path optimization, the peak-to-valley form error of the machined surface was reduced from 429 nm to 56 nm for the two-dimensional sinewave by using the ring method, and from 191 nm to 103 nm for the micro-lens array by using the mesh method, respectively.