Design On Three Sections Of The Removable Type Inchworm Piezoelectric Actuator

Among the new types of intelligent materials, piezoelectric ceramics with high frequency response, high displacement precision, no noise etc, take people’s more and more attention. Inchworm-type actuators reduce the influence of hysteresis effects by the way of stepping, at the same time,it produces a lot of displacements,which are more and more applicated to the field of high precision control. This article puts forward a three-section removable inchworm piezo drive design and conducts the study.First of all, the piezoelectric stack HPST150/20-15/12 is selected for the purpose of design, which is based on piezoelectric parameters and equations. The piezoelectric vibrator’s electromechanical coupling mathematical model is established. The modal analysis are done in ANSYS. The resonant frequency is obtained. The sine excitation response analysis is also carried out for the purpose of its time- displacement curve.And the experiment of single pile is also done to verify the validity of the mathematical model and ANSYS simulation model.Secondly, the clamping mechanism and the middle driving mechanism do such a great impact on the performance of driver, so that the holding arm and the intermediate cylinder will be analyzed and optimized by mean of ANSYS. Based on the optimization of overall strain energy of the holding arm, the displacement amplification factor and the clamping force reach their optimal value; based on the optimization of the intermediate cylinder’s wall thickness, the equivalent elasticity coefficient meets the requirements of driving force; combining the hysteretic loop of piezoelectric stack and the driving experiments of the intermediate cylinder, the optimization of the intermediate cylinder’s wall thickness is proved to be reasonable.Next, much work has been done, such as the design of adjustment nut, the selection of preloaded spring and the overall driving simulation by means of ANSYS. At last,the overall physical design is determined and the processing and assembling of sample is also completed.Based on the analysis of the piezoelectric actuator characteristics and the experiment curve, the sequential programming is completed on the S-Function model. Open loop and closed loop drive controller designs are realized by the MATLAB/Simulink. And the sequential simulation is conducted in order to adjust the procedure with the oscilloscope. The function of the piezoelectric actuator is realized theoretically.