压电作动器的动态迟滞建模与H∞鲁棒控制

压电作动器具有率相关动态迟滞非线性特性,给传统建模和控制技术提出了挑战.本文针对压电作动器,提出了一种基于Bouc-Wen的Hammerstein率相关迟滞非线性模型,其中Bouc-Wen模型和线性动态模块分别用于描述系统的静态迟滞非线性特性和率相关特性.同时,构造了一个基于Bouc-Wen模型的迟滞补偿器,将迟滞补偿器与被控对象串联使系统线性化;并建立了不确定性系统模型,提出了一种H∞鲁棒跟踪控制方案,可以实现给定频率范围内单频率和复合频率参考信号的良好跟踪.实验结果表明,所建动态模型具有良好的泛化能力,跟踪控制相对误差小于8%,证明了所提出方法的有效性.

Dynamic hysteresis modeling and H-infinity robust control of piezoelectric actuators

Piezoelectric actuators (PEAs) have rate-dependent hysteretic nonlinearities, which pose challenges to the traditional modeling and control techniques. A Hammerstein-based rate-dependent hysteresis model with a Bouc-Wen nonlinearity is proposed in this paper for the piezoelectric actuators. The Bouc-Wen model and a linear dynamic block are used to describe the static hysteresis nonlinearity and rate-dependent properties, respectively. Further, a hysteretic compensator based on the Bouc-Wen model is constructed and connected in cascade with the plant to linearize the system. Next, an uncertainty system model is built and a H-infinity robust control scheme is proposed to track the reference signals with either single frequencies or compound frequencies in the given frequency range. Experimental results show that the dynamic model proposed has good generalization ability and the encouraging tracking performances have been achieved with the relative error less than 8%.