The Three-Stage Identification Method of the Sandwich Model With Hysteresis

This paper investigates the identification of sandwich systems exhibiting hysteresis behavior. To address the problem that the filtering effect of the previous-stage subsystem on the input signal results in the filtered excitation input causing insufficient excitation of the subsequent-stage subsystems, thus reducing the identification accuracy, a new robust three-stage identification method is proposed to ensure the sufficient excitation of the entire system and enhance the identification accuracy. The key to this method lies in the staged estimation of subsystem parameters. In each stage, parameter estimation is carried out using the key-item separation principle combined with an iterative process. Then, based on the previously estimated submodel parameters, an inverse model is developed to filter the input excitation signal. Therefore, the insufficient excitation of the subsequent-stage subsystem caused by the filtering effect of the previous-stage subsystem on the input signal is counteracted, enhancing parameter estimation accuracy. Finally, this method is applied to the parameter identification of an electromagnetic micromirror.