Rate-dependent Modeling And Inverse Control Of Piezoelectric Actuators

PEA(Piezoceramic actuator)is a new type of actuator with the advantage of fast response speed and high energy density.It has a broad prospect of application in aerospace,precision machining areas.For rate-dependent hysteresis nonlinearity of PEAs,the modeling,tracking control and experiments are studied.The main work are listed as follows:First of all,the rate-dependent hysteresis nonlinearity model of PEAs is established on the Hammerstein.The model consists of two parts: static nonlinear part and dynamic linear part.The static nonlinear part is composed of MPI model,which is presented by Play and Deadzone operators.And the dynamic linear part is characterized by an ARX model,which is a two order rational transfer function to represent the impact of frequency.In order to compare the model precision and frequency generalization ability,the multi-frequency experiments in the frequency range of 1-100 Hz are designed.The results show that the model can effectively characterize the PEA.Secondly,inverse control methods based on inverse Hammerstein model are established.The direct inverse compensation strategy and feed-forward inverse compensation+PID strategy are achieved as static compensation methods.The adaptive inverse control adaptively regulates the weight coefficients of Play operators by LMS algorithm,and make inverse model constantly approaching the inverse of the real model.The design techniques and principles of the three control strategies are given.Finally,The Hardware-in-the-loop Simulation System based on dSPACE platform is built.The hardware,S-function and the process of the control experiments are respectively introduced.The direct inverse compensation,feed-forward inverse compensation+PID and adaptive inverse control strategies are applied to real-time tracking respectively.Validity of the three strategies are proven effectively by experimental results.