压电陶瓷叠层作动器迟滞蠕变非线性自适应混合补偿控制方法

压电陶瓷叠层作动器的迟滞蠕变非线性特性严重影响了控制系统的稳定性及动态跟踪精度。针对其迟滞蠕变非线性补偿控制问题，提出了一种高精度动态补偿压电陶瓷叠层作动器非线性特性的自适应混合补偿控制方法，即迟滞蠕变前馈补偿与自适应滤波反馈补偿结合的前馈-反馈混合控制方法。采用改进的Prandtl-Ishlinskii（Modified Prandtl-Ishlinskii，MPI）模型对压电陶瓷叠层作动器迟滞蠕变非线性特性进行精细化建模，并得到其逆补偿模型进行前馈补偿。根据前馈补偿误差，采用自适应滤波反馈控制对输入信号进行实时调控，实现对压电陶瓷叠层作动器的迟滞非线性及lg（t）型蠕变特性的实时精确补偿控制。数值仿真与实验结果表明，相比于常规前馈迟滞蠕变补偿，所提出的自适应混合补偿控制方法可以有效降低压电陶瓷叠层作动器的迟滞补偿误差，极大提高了迟滞蠕变非线性动态跟踪精度以及自适应性。

Hysteresis and creep nonlinearities modeling and adaptive hybrid compensation control of piezoelectric stack actuators

The hysteresis and creep nonlinear characteristics of piezoelectric actuators seriously affect the stability of the control system and the accuracy of dynamic tracking. To mitigate hysteresis and creep effects, this paper presents an adaptive hybrid compensation control method that is a feedforward-feedback control method combining hysteresis-creep feedforward compensator with adaptive filter feedback control. Based on the Modified Prandtl-Ishlinskii (MPI) model, the hysteresis and creep nonlinear characteristics of piezoelectric actuators are refined and the inverse hysteresis-creep compensator is established for feedforward compensation. Based on the errors of the feedforward compensation, an adaptive filter feedback controller is adopted to adjust the input signal in real time to achieve an accurate compensation control of hysteresis nonlinearity and lg(t)-type creep characteristics of the piezoelectric ceramic actuator. The numerical simulation and experimental results show that the error of the adaptive hybrid compensation control of piezoelectric actuators is reduced effectively compared with the traditional feedforward compensation. It is shown that the proposed adaptive feedforward-feedback control scheme can largely improve the accuracy and adaptation of hysteretic compensation dynamic tracking.