基于FTS的非轴对称微结构表面超精密切削系统研究

摘要

A precision diamond turning system for fabrication of non-symmetric micro-structured surfaces based on fast tool servo (FTS) system is proposed. The fast tool servo is driven by a piezoelectric actuator along with a capacitive displacement sensor. To overcome the inherent non-linearity of the piezoelectric actuator, an inverse model of FTS is constructed using neural network and expended input space. Besides, PID feedback control is also implemented to achieve better tracking performance. Actual testing data show that the following error is less than 150 nm. The fabrication of a sinusoidal grid surface has indicated the effectiveness of the fabrication system.%介绍了基于快速伺服刀架(FTS)的微结构表面超精密金刚石车削加工系统，并利用该系统成功实现了典型非轴对称结构正弦网格表面的加工。作为FTS的驱动元部件，压电陶瓷微位移驱动器的迟滞、蠕变非线性特性大大影响了系统的动态性能与加工精度。因此，建立了基于拓展输入空间法的FTS神经网络逆模型，并结合PID反馈控制，实现了FTS的闭环控制。实验结果表明，该控制策略可以有效提高FTS的动态性能，其跟踪误差小于150 nm，为微结构表面的加工提供了可靠的保证。