Research On Improved Duhem Hysteresis Modeling And Control Of Piezoelectric Actuator

As a kind of micro-displacement smart material,piezoelectric ceramics have the advantages of high resolution,high energy density,low energy consumption,and fast response.The designed actuators are widely used in the positioning of scanning tunneling microscopes,micromanipulators,precision machining machine tools and computer component systems.However,the piezoelectric ceramic material itself has hysteresis and nonlinearity.This characteristic limits the actuators on the application side and reduces the positioning accuracy,resulting in system instability.In practical applications,the hysteresis and nonlinear characteristics of piezoelectric ceramic actuators will become more serious as the frequency of the input signal increases.Therefore,this article takes the piezoelectric ceramic actuator system as the research object,and mainly conducts research work from the following aspects:1?Aiming at the hysteresis and nonlinear characteristics of piezoelectric ceramic actuators,an improved Duhem model is proposed.According to the collected input and output data of the actuator,a modeling experiment is carried out based on the differential evolution algorithm.Compared with the classic Duhem modeling method,the proposed improved Duhem method has a simple structure,is convenient for the design of the control system,and improves the hysteresis and nonlinear characteristics of the piezoelectric ceramic actuator under high-frequency signal excitation.2?An inverse model is constructed based on the improved Duhem model,and an internal model control method is designed to track the piezoelectric ceramic actuator system.At the same time,in order to improve the stability of the closed-loop system,a feedback filter can be used to enhance the robustness when the model is not accurate.For the real-time tracking of the piezoelectric ceramic actuator system,the relative error between the actual output displacement of the actuator and the expected displacement is less than 10%,which proves that the proposed control method can effectively eliminate the effect of hysteresis and nonlinear characteristics on the positioning accuracy of the actuator.influences.3?Aiming at the problem of filter parameter tuning in internal model control,a fuzzy internal model control scheme is designed.Fuzzy thinking is introduced into the internal model control,and the parameters of the feedback filter are constantly adjusted through the fuzzy controller to enhance the adaptiveness of the control system.Through the tracking control simulation of the piezoelectric ceramic actuator,the feasibility of the designed fuzzy internal model control method is verified.