具有Hammerstein结构的非对称PI模型的超磁致作动器数学建模

Mathematical modeling of a giant magnetostrictive actuator by using an asymmetric PI model with Hammerstein structure

超磁致作动器(giant magnetostrictive actuator,GMA)作为一种以磁致伸缩材料为核心的智能驱动器,由于其优良的性能而广泛应用于诸多领域中,但是其本身固有的回滞非线性的存在限制了其进一步地发展,因而针对回滞非线性的建模研究一直是该领域的重点。基于Hammerstein结构,应用非对称Prandtl-Ishlinskii(PI)模型来表示Hammerstein结构中的非线性环节,用受控自回归(auto-regressive with exogenous,ARX)模型来表示Hammerstein结构的动态环节(尤其是针对高频信号),并且基于AIC准则的判定过程辨识出了动态系统传递函数的阶次和具体形式,建立了超磁致作动器的一种具有Hammerstein结构的非对称PI模型,并有效地减少了模型辨识参数的数量。试验结果表明,具有Hammerstein结构的非对称PI模型比单一非对称PI模型拥有更高的精度,尤其是针对较大频率的激励信号。

A giant magnetostrictive actuator(GMA),which is one of intelligent drivers made of one kind of smart materials,magnetostrictive material,is widely used in many fields due to its excellent performance,but its inherent hysteresis nonlinearity limits its further development,so the modeling of its hysteresis nonlinearity has been the focus of the field.Based on the Hammerstein structure,an asymmetric Prandtl-Ishlinskii(PI)model was applied to represent the non-linear link of the Hammerstein structure,and an auto-regressive with exogenous(ARX)model was used to represent the dynamic links of the Hammerstein structure(especially for high-frequency signals),and the order and specific form of the transfer function of the dynamic system were identified by virtue of the judgment process according to the AIC criterion.Then,the asymmetric PI model with Hammerstein structure for the GMA was developed,which effectively reduces the number of identified parameters.The experimental results show that the asymmetric PI model with Hammerstein structure has higher accuracy than the single asymmetric PI model,especially for higher frequency excitation signals.