Research On Positioning Platform Control Method Based On Piezoelectric Actuator

Because the resolution of the micro-nano control system reaches the atomic level,the development of nanotechnology is in full swing.At present,the micro-nano control system uses piezoelectric actuators to drive positioning platform for precision positioning and tracking.However,the inherent hysteresis,vibration and other characteristics of piezoelectric actuators seriously affect the accuracy and speed of positioning.In order to improve the positioning accuracy of the piezoelectric positioning platform under working condition,firstly,the paper establishes the Prandtl-Ishlinskii(P-I)hysteresis model of piezoelectric actuators,and verifies the validity of the hysteresis model by experiment,and makes a deep analysis on the electrical and mechanical properties of the piezoelectric positioning platform,and establishes its dynamic model,and the model foundation is provided for the controller design;Secondly,the inverse model of the P-I hysteresis model is used as feedforward compensation controller to eliminate the hysteresis of the piezoelectric positioning platform,and the effectiveness of the designed controller is verified by experiments.Again,for feedforward compensation controller,it is necessary to have precise mathematical model of controlled object and to eliminate the defect of hysteresis nonlinearity completely.The self-tuning fuzzy PID feedback control method is designed,and the simulation result shows that the control method can eliminate the steady state error of the control system,but the response speed of the system is not satisfactory.Finally,combining feedforward compensation control with self-tuning fuzzy PID feedback control based on the improved P-I hysteresis model,a composite controller is designed,and the simulation results show that the compound control method not only improves the positioning accuracy of the piezoelectric positioning platform,but also the feedforward compensation control and self-tuning fuzzy PID feedback control,and the control system has the ideal response speed.