压电陶瓷驱动平台自适应输出反馈控制

Adaptive Output Feedback Control for Piezoactuator-driven Stage

压电陶瓷驱动平台的精度和动态特性主要取决于所设计的控制器是否可以有效地补偿压电陶瓷固有的迟滞特性.针对这一问题,提出了一种基于神经网络(Neural network,NN)的自适应输出反馈控制策略.为了避免压电陶瓷速度测量噪声的影响,采用高增益观测器对压电陶瓷平台的速度状态进行估计;为了克服压电陶瓷的迟滞非线性特征,采用神经网络动态补偿策略;针对神经网络逼近误差和观测器估计误差,控制器设计中增加了鲁棒控制项.最后应用Lyapunov稳定性理论证明了所提出的控制器的收敛性问题.仿真实验表明了所提控制方法的有效性.

The accuracy and dynamic characteristics of piezoactuator-driven stage mainly depend on whether the con- troller can effectively compensate the inherent hysteresis of piezoactuator. For this problem, a neural network （NN） based adaptive output feedback control scheme is proposed. In or- der to avoid the impact of the velocity measurement noise of the piezoactuator, a high-gain observer is used to estimate un- measured velocity of the system, and a neural network dynamic compensation strategy is proposed. A robust controller is used to compensate the neural network approximation error and the observer estimation error. Finally, the stability analysis is given by Lyapunov stability theory. Simulation results show the effec- tiveness of the proposed method.