Modeling And Control Of Piezoelectric Ceramic Actuators With Hysteresis Nonlinearity

Piezoelectric ceramic actuators has the characteristic of high resolution,fast response and low cost.It has been widely used in the fields of precision instruments,precision control,precision positioning,and so on.Hysteresis nonlinearity is hard nonlinearity which result in significant challenges in controlling piezoelectric ceramic actuators,and thus limits application of piezoelectric ceramic actuators.This thesis mainly study the tracking control of piezoelectric ceramic actuators based on the model of Hammerstein.The main works are present as follows.We choose the Hammerstein model to modeling the piezoelectric ceramic actuators.By conducting experiments and collecting input and output data of the real piezoelectric ceramic actuators.We use the system identification work out the parameters of Hammerstein model.By comparing the input and output data of real piezoelectric ceramic actuators with the Hammerstein model,we find that the model of Hammerstein performs very well.For controller design,we first tried a PID controller,and found the simulation result not satisfactory,we then use the neural network to tune the PID controller parameters,but the result is not satisfactory neither.So we add an inverse model to cancel the hysteresis nonlinearity.That is the so called feedforward inverse compensation +PID controller and it performs very well.By modeling piezoelectric ceramic actuators as a second order system an Active Disturbance Rejection Control(ADRC)controller is designed.The ADRC controller mainly uses the linear expansion state observer to observe the disturbance of the system,then eliminates the system disturbance.The simulation and experimental results show that the ADRC controller perform very well.