A Driving Power With Dynamic Hysteresis Model For Piezoelectric Ceramics

Piezoelectric ceramic actuator is a kind of micro actuator which is based on the converse piezoelectric effect of the piezoelectric ceramics.Due to the advantages of small size,high resolution,fast response,it has been widely applied in precision manufacturing,aerospace,micro-positioning and ultrasonic motors.Piezoelectric ceramic actuator inherits the hysteresis nonlinearity,which degrades the positioning accuracy and even may causes the system instable.With analysis the nonlinear characteristics of piezoelectric actuators,a piezoelectric ceramics driving power with nonlinear compensation is an effective method to improve the positioning accuracy.It is also one of the research focuses in the field of piezoelectric ceramics driving power.To analyze the dynamic hysteresis nonlinearity of the piezoelectric ceramic actuator,the response of the piezoelectric ceramic actuator was measured at different frequencies.Based on the static Prandtl-Ishlinskii model and automatic control theory,a dynamic Prandtl-Ishlinskii model and its inverse model were developed to describe the dynamic hysteresis nonlinear of piezoelectric ceramic actuator.After identified the parameters of classical and dynamic Prandtl-Ishlinskii model,a simulation was performed to test dynamic Prandtl-Ishlinskii model.Comparing the simulation results and measured data,it indicates that the dynamic Prandtl-Ishlinskii model can describe the hysteresis nonlinearity of piezoelectric actuators more accurately in the wide frequency band.A topological structure of switching mode power supply was proposed for the hardware circuit of piezoelectric ceramics driving power,which is composed of a front DC/DC boost circuit and a back stage DC/AC inverter circuit.The boost circuit which step up the voltage was developed with TL494,and inverter circuit designed with a single phase full bridge.Both circuits were simulated with MATLAB/Simulink software,and the results show that the performance is better than the design requirements.with simulation results,the parameters of circuit devices with calculated in the hardware design.Using the CompactRIO Platform,the software of proposed drive power was designed with the dynamic Prandtl-Ishlinskii model which parameters have been identified.With this design,the proposed piezoelectric ceramics driving power can compensate for the dynamic hysteresis nonlinearity of piezoelectric ceramic actuator.To verify the proposed piezoelectric ceramics driving power,an experiment was setup with a piezoelectric bimorph actuator(60mm×10mm×0.8mm).The performance of the proposed driving power was tested respectively with static and dynamic Prandtl-Ishlinskii model at different frequencies.Experimental results show that the maximum relative errors in the experiments with static Prandtl-Ishlinskii model are 0.0158,0.0290 and 0.0347 at 5Hz,10Hz,20Hz,respectively.With the dynamic Prandtl-Ishlinskii model,the errors are 0.0141,0.0129 and 0.0105.The proposed piezoelectric ceramics driving power with dynamic Prandtl-Ishlinskii model can compensate for the dynamic hysteresis nonlinearity of piezoelectric actuator and improve positioning accuracy in the wide frequency band.