超磁致伸缩致动器的等效电路模型研究及实验分析

Research and Experimental Analysis on Equivalent Circuit Models for Giant Magnetostrictive Actuators

针对现有等效电路模型不能准确描述致动器稳态和瞬态特性,以致于无法精确计算致动器电流的问题,设计了一种新的致动器等效电路模型。与现有两种等效电路模型在致动器阻抗方面进行对比,以相对误差作为评价标准,通过参数辨识及理论计算与实验结果对比,验证了设计的等效电路模型优于其余两种,能够较准确地描述致动器的稳态特性。理论分析了设计的等效电路模型的输出电流表达式,得到了不同频率方波输入下电流的输出曲线;计算了高电平持续时间不同的情况下,输入为单个波形情况下电流的输出曲线;同时通过实验系统测量了电流的实际曲线,与理论计算曲线进行对比,验证了设计的等效电路模型能够较精确地描述致动器的瞬态特性,为设计合理驱动方案以提升致动器响应速度奠定了良好基础。

The state-of-art equivalent circuit models for giant magnetostrictive actuators usually fail to account for its static and transient performances, which lead to a poor description Of its driving currents. This paper faced up this issue by coming up with a novel equivalent circuit modeling method for giant magnetostrictive actuators. Different from the existing algorithm, this model calculated the impendence by using the relative error as the evaluation criterion. Through the theoretical calculation and parameter identification using test data, it ,proves that the equivalent circuit model performs better in description of the static characteristics. The output current expression of the equivalent circuit model was theoretically studied. Different output current curves were obtained using different fi＇equency square waves. Different single-wave response curves were obtained when the high level duration for the driving current was varied. A series of experiments were conducted accordingly in comparison with the theoretical study, it proves that the proposed equivalent circuit model can describe the actuator transient characteristic more accurately. The results of this paper set a comer stone for subsequent research of its driving strategy and response enhancements.