Hysteresis Modeling And Control Compensation Of Piezoelectric Ceramics

Piezoelectric ceramic is being applied to medical apparatus and instruments.Whether as drivers or sensors,piezoelectric ceramics can meet the requirements of medical apparatus and instruments,such like the precision of precision positioning device operating table,the micro pump used for the carriage of drugs in the human body and the ultrasonic sensor for in vitro detection of human internal lesions.However,the inherent hysteresis nonlinearity of piezoelectric ceramics makes it difficult to improve the positioning accuracy and restricts the development of piezoelectric ceramics in the field of ultra-precise positioning.In view of the traditional Prandtl-Ishlinskii model's low accuracy in modeling piezoelectric hysteresis and the difficulty in parameter identification,this paper firstly takes PZT-5H as an example to propose an(MPI)Modified Prandtl-Ishlinskii model.The MPI model proposed in this paper can improve the defects of traditional PI model.In order to further verify the MPI model,hysteresis compensation and control were studied on P11,and good results were achieved.The main work and achievements of this paper are as follows:1)Taking PZT-5H(one of typical piezoelectric ceramics)as an example,the hysteresis curve was tested.According to the "bump" and slope characteristics of the hysteresis curve and its "return zero",a unilateral multi-slope MPI hysteresis modeling method was proposed.Compared with the PI model,the MPI model uses the multi-slope curve instead of the single-slope curve in the traditional PI model to fit the hysteresis curve,which can greatly improve the fitting accuracy of the hysteresis curve and reduce the number of parameters to be identified.2)The model parameter identification algorithm for piezoelectric hysteresis modeling is studied,and the quadratic programming algorithm and PSO algorithm are compared.Using the optimized model identification parameters,the PZT-5H hysteresis curve PI model and MPI model were simulated and analyzed.The results showed that the MPI model reduced the average absolute error by 78.6%and the mean square error by 74.6%compared with the classical PI model.3)In order to verify the effectiveness of the MPI model,a PZT-5H hysteresis compensation control experimental bench was built,and the MPI inverse model was used for feedforward control compensation.The experimental results showed that the mean square error was controlled within 0.8%of the total travel of the piezoelectric ceramics.4)In order to further verify the MPI modeling method,the necessary simple correction of MPI was made on the two-dimensional piezoelectric platform P11.The simulation and experiments show that the MPI model has good adaptabilities to different piezoelectric platforms and can also achieve high positioning control accuracy.