压电驱动器记忆特性迟滞非线性建模

考虑压电驱动器固有的迟滞特性对驱动器定位精度的影响,提出了一种精确描述压电驱动器迟滞非线性特性的建模方法.根据迟滞曲线的运动规律,并且考虑迟滞曲线的记忆更新特性,新的迟滞数学模型修正了单纯采用抛物线拟合时的建模误差.为了验证模型的有效性,以PST150/7/40VS12型压电陶瓷驱动器为例进行了试验研究.研究显示,采用抛物线迟滞模型对一阶反转输入信号进行预测时,最大误差为0.141 3 μm,均方误差为0.060 4 μm,对复杂信号模型预测的最大误差为1.396 0 μm,均方误差为0.856 6 μm;采用修正后的模型对文中复杂信号建模时,最大误差为0.237 0 μm,均方误差为0.09 μm.实验结果表明,修正后的模型不仅能够满足迟滞曲线的运动规律,还能够满足迟滞非线性的记忆更新特性,可以比较精确地描述复杂输人信号下的迟滞非线性特性.

Modeling of nonlocal memory hysteresis in piezoelectric actuators

As piezoelectric actuators have poor position accuracy caused by their inherent hysteresis nonlinearities,this paper proposed a new modeling method to precisely describe their hysteresis phenomena.Based on the motion rules of hysteresis curves and the nonlocal memory property of the hysteresis nonlinearity,proposed model modified the modeling errors fitted by parabolic model.To verify the feasibility of the model,an experiment was performed by the PST150/7/40VS12 piezoelectric actuator.Experimental results indicate that for the first order reversal signal,the maximum error is 0.141 3 μm and the mean-squared error(MSE) is 0.060 4 μm by using the parabolic model.However,for a more complex signal,those of the parabolic model are 1.396 0 μm and 0.856 6 μm,respectively.When using the amended model to predict the actuator response under the above-mentioned complex signal,the maximum prediction error and the mean-squared error are 0.237 0 μm and 0.09 μm,respectively.These data demonstrate that the proposed model not only provides a minor-loop identical property,but also offers the nonlocal property and it can precisely predict the hysteresis path for assigned complex input profiles.