Modeling And Control For Nonlinear Systems With Dynamical Hysteresis Based On MPI Model

Intelligent material structure is causing more and more attentions for its appearance,it has been became a study focus in recent years.Giant magnetostrictive actuator(GMA)produced by the intelligent material structure has great potential in sonar,robots,aerospace,lingenierie marine and other fields of engineering.GMA is a kind of potential new intelligent micro displacement actuator and bring about high speed development and widespread applications.The rate-dependent hysteresis and stress-dependent hysteresis in giant magnetostrictive actuators is a major impediment to the engineering application.The main drawback of the GMA is the hysteresis nonlinearity,which can cause the positioning inaccuracy and even lead to the instability of the closed-loop system.In this paper,In consideration of the drawback,the dynamic modeling and control methods for GMA which performs stress-dependent hysteresis nonlinearity and rate dependent hysteresis nonlinearity are proposed based on Modified Prandtl-Ishlinskii(MPI)model.The main works are as follows:1?The new model is based on the MPI model combined with the dynamic weight and dynamic threshold.Simulation results show that the proposed model effectively represents the characterization of the GMA's rate-dependent hysteresis nonlinearity within a range of frequency.In order to verify the performance of the proposed model in the real-time control,a direct feedforward inverse compensation control scheme is applied in this dissertation to the tracking control of the GMA under varying input frequency based on the proposed rate-dependent hysteresis model.Both the simulation and experiment results show that the output signal can thoroughly track the desired signal well,and also resultantly present the rate-dependent hysteresis nonlinear model can describe rightly the rate-dependent hysteresis characteristics of the actuators,The validity is so proven well.2?A stress-dependent Hammerstein model is proposed to characterize the stressdependent hysteresis nonlinearity of GMA.The new model is based on the MPI model combined with the ARX model.Simulation results show that the proposed model effectively represents the characterization of the GMA's stress-dependent hysteresis nonlinearity within a range of frequency.In order to verify the performance of the proposed model in the real-time control,a PID feedback controller scheme combined with a feed-forward compensation is applied in this dissertation to the tracking control of the GMA under varying stress based on the proposed stress-dependent hysteresis model.Both the simulation and experiment results show that the output signal can thoroughly track the desired signal well,and also resultantly present the stressdependent Hammerstein model can describe rightly the stress-dependent hysteresis characteristics of the actuators,the validity is so proven well.