迟滞特性具有非光滑、多值映射等复杂特性,如果迟滞环节的末端还存在一个线性子系统,导致其输出信号不可测,常规的方法难以进行有效的辨识和控制。提出一种基于退化激励信号的分步辨识法。设计一个退化激励信号将迟滞退化为一条光滑的、一一映射的曲线,并由广义递推最小二乘法(RGIA)辨识线性环节;根据已辨识的线性子模型,采用"扩展输入空间法"辨识迟滞环节;根据辨识所得的Hammerstein模型设计一个PID前馈控制器,实现对PEA的精确运动控制。
Due to its non-smoothness and multi-value mapping,it is difficult to apply the conventional identification methods to identifying the hysteresis model. Moreover,if the hysteresis subsystem follows with a linear subsystem,it is more challenging to identify the Hammerstein model because the output of the hysteresis model cannot be measured directly. This paper proposes a two-stage method. Firstly,the degeneration input,which is a special exciting signal,is designed to degenerate the hysteresis into a static smooth curve with one-to-one mapping. Thus, the non-smoothness and multi-value mapping of hysteresis are avoided so that the parameters of the linear subsystem can be estimated by the recursive general identification algorithm( RGIA). Secondly,with the identified linear submodel,the hysteresis subsystem is modeled with the expanded input space method. Finally,a PID feedforward controller for controlling the motion of the PEA is proposed. The experimental results on the PEA are presented to show the effects of the identification and control method.