压电陶瓷执行器迟滞的滑模逆补偿控制

摘要

In order to reduce the nonlinear hysteresis of piezoceramic actuators, a sliding mode control scheme based on Preisach inverse compensation was proposed in this paper. Firstly, an inverse Preisa-ch model of the hysteresis was built by using the sorting &- taxis realization method. Then the inverse model was connected in series with the hysteresis of the system to reduce the impact of the nonlinear hysteresis. In consideration of that the hysteresis can't be entirely offseted by the inverse model and there are also many uncertainties in the system, a sliding mode controller with a sub-boundary layer was designed. Finally, to verify the feasibility of the sliding mode controller, a PI controller was presented to compare with the proposed scheme. The experiment results show that the control scheme improves the tracking accuracy of the system,and the average absolute error is 0. 020 6μm when tracking is on sinusoidal input. Compared with the PI controller based on the inverse Preisach model, the proposed control scheme has a better adaptability and can offer a good tracking accuracy.%为了降低迟滞特性对压电陶瓷执行器的影响,研究了基于Preisach逆补偿的滑模控制策略.首先,利用分类排序方法在控制平台上实现了迟滞的Preisach逆模型；然后,将其串联到压电陶瓷执行器前用于抵消迟滞非线性.考虑到迟滞逆补偿的非完全抵消、模型参数的不确定性以及扰动等问题,设计了一种分段边界层滑模控制律.最后,为了验证所设计的控制策略的有效性,设计并实现了逆补偿+PI控制器.实验结果表明,逆补偿+滑模控制提高了基于压电陶瓷执行器驱动的纳米定位系统的跟踪精度,其跟踪正弦输入的平均绝对误差为0.020 6μm.与逆补偿+PI控制策略相比,逆补偿+滑模控制对不同的输入信号有很好的适应性,保证了纳米定位平台的定位精度.