Design And Hysteresis Control Of Piezoelectric Driven Micro Platform

With the continuous progress of modern technology,the microelectronics industry has become a strategic industry that measures a country’s comprehensive national strength,and is an important development area in the national science and technology development plan.With the continuous development of the microelectronics manufacturing industry,the precision requirements for its manufacturing are becoming increasingly high,and micro nano precision positioning technology has played a crucial role in precision equipment manufacturing.At present,the most widely studied micro nano precision positioning technology is the precision positioning platform,which is mainly composed of compliant mechanisms and piezoelectric actuators.It has the characteristics of frictionless,small volume,low cost,no gap,easy to achieve miniaturization,and easy to achieve high positioning accuracy.It has been widely applied in the field of ultra precision and has become one of the key technologies in the forefront of science and engineering technology.This article designs a micro positioning platform based on piezoelectric drive,and the layout of the platform’s flexible hinges adopts a dual parallel series parallel four bar mechanism.By using the Cartesian theorem to analyze the displacement generated by the force on the micro moving platform,the stiffness formula of the chamfered elastic plate flexible hinge is derived.The equivalent stiffness of the micro platform was derived based on Hooke’s law and the law of energy conservation.The effectiveness of the theoretical model was verified by comparing the theoretical calculations,experimental measurements,and finite element simulation results.Aiming at the shortcomings of traditional P-I hysteresis model in describing the nonlinearity of piezoelectric ceramics,an improved hysteresis model based on the P-I model was established by introducing a first order polynomial.Then,the fitting error is used to correct the error.The experimental results show that the fitting accuracy of the hysteresis model is higher and the effect of describing the hysteresis characteristics is stronger.In order to reduce the impact of piezoelectric hysteresis characteristics on the micro positioning platform,a method combining hysteresis models and control strategies is used to reduce the adverse results caused by piezoelectric nonlinearity.The hysteresis inverse model is constructed using the improved hysteresis model established in the previous article,and a composite control strategy is constructed using PID control algorithms.To further improve the control effect,a fuzzy adaptive PID sliding mode controller is designed to suppress the hysteresis problem of piezoelectric ceramics(PZT),and the stability of the control is analyzed using Lyapunov function;The results show that the control effect of the sliding mode control and PID control is significantly better than PID control in comparison experiments.