快轴伺服系统的设计与性能测试

研制了用于加工非回转对称光学元件的快轴伺服系统(FAS)的整体结构及其控制系统,系统具备较大行程和高工作频率,最大的行程可达到30mm。系统采用了音圈电机驱动的气体静压轴承技术、线性电流放大器、高分辨率编码器以及高速控制系统。对不同截面形状气浮导轨的静、动态特性进行了有限元分析。系统采用PID反馈和速度/加速度前馈控制方法来改善系统的动态性能。FAS系统0.1mm阶跃响应的上升时间为2ms,最大超调量为0.4%,稳态时间为4ms,对铝件进行超精密切削实验,表面粗糙度可达Ra24nm,实验结果表明系统具有较好的动态和切削特性。

Design and performance testing of fast axis servo for diamond turning

This paper briefly describes the configuration and control system of a linear long stroke and high frequency fast axis servo (FAS) for the production of asymmetric optics. The maximum stroke of the FAS is 30mm. The proposed Fast Axis Servo (FAS) utilizes the aerostatic bearings driven by a voice coil actuator, a custom linear current amplifier, a high-resolution encoder and a high-speed control system. The static and dynamic characteristic of air slide with different cross-sectional shapes was studied by the finite element method. A control strategy consists of a proportional, integral and derivative (PID) feedback controller and velocity/acceleration feedforward controller was implemented to accommodate the changed system dynamics. The 0.1mm step response was applied on the FAS, the rise time is 2ms, the over shoot is 0.4%, the settling time is 4ms.An aluminium part with theSsuper precision cutting had a surface finish value 24nm Ra. The experiment results indicate that the FAS has a better dynamic and cutting performance.