自适应控制在纳米加工微驱动器中的应用研究

Application Research of Self-adaptive Control in Nanofabrication Actuator

为提高扫描隧道显微镜微驱动器的响应速度和定位精度,提出了一种基于自适应理论的控制方法。微驱动器采用压电陶瓷驱动,在分析其结构的基础上,建立了驱动器的简化运动模型,利用最小二乘法对驱动器参数进行了在线辨识。把自适应控制理论引入到微驱动器的控制中,在参数自校正PID控制律的作用下,实现了PID控制器参数的自动整定。采用专用的压电陶瓷驱动电源,进行了位移的测试实验。结果表明,参考位移量为12.39μm时,相对于传统PID控制,动态响应时间由3 s缩短到1.4 s,稳态位移误差由3.2%减小到2.7%。

In order to improve the response rate and positioning accuracy of micro actuator of scanning tunneling microscope, a new control scheme which is based on the self-adaptive is proposed. The piezoelectric ceramics is used as the actuator. The structure of the actuator is analyzed and the simplified moving model is set up. Parameters of the actuator are identified on-line by Least Square Method. The self-adaptive theory is introduced into the control system and parameters of the PID controller are adjusted automatically under the self-tuning PID control law. Experiments of micro displacement using the special electronic ceramics power are conducted. Results show that the dynamic response time for a micro displacement of 12.39 μm is shortened from 3 s to 1.4 s and the stable error is reduced from 3.2 % to 2.7 % compared with the traditional PID control.