微细加工用两轴联动压电平台控制系统研究

Coordinated control system of two-axis piezo platform for micro machining

根据微细加工的实时性、精度要求,提出压电器件的分段控制方法及其两轴联动的嵌入式控制系统结构。根据误差将压电器件控制分为恒电压控制与误差控制两个阶段,恒电压控制段采用迟滞特性主环的平均曲线估算恒值控制电压,误差控制段利用积分控制,研制了基于ARM Cortex处理器的两轴联动微细加工用压电平台控制系统。测试表明:阶跃响应稳态误差<0.1μm,调节时间约1.2ms,超调量约5.6%;正弦响应误差-0.343～0.245μm;轮廓稳态误差-0.084～0.079μm,考虑系统超调,轮廓误差-0.41～0.131μm,能满足微细加工领域的实时精确控制要求。

To meet the demands on real time performance and accuracy of micro machining, a sectional control method and the coordinated controller by embedded microcontroller for two-axis piezo platform is pro- posed. According to the displacement error, the control procedure was divided into two sections, con- stant voltage control and error eliminating control. With constant voltage control, the control voltage is calculated using the average curve of the main loop of the hysteresis, and an integration control unit is used in error eliminating control. Then, the controller for micro machining with above method was a- chieved with an ARM Cortex microcontroller, STM32F103. System tests indicated that about the step re- sponse, the steady state error is less than 0.1 μm, the settling time is about 1.2 ms and the overshoot is about 5.6%; About the sinusoidal response, the error is ranged from-0. 343 μm to 0. 245 μm; the steady contour error is ranged from -0. 084 μm to 0. 079 μm, and the contour error is ranged from - 0.41 μm to 0. 131 μm include system overshoot. It is indicated that with the controller built, the pre- cise, real-time control for micro machining can be achieved.