Research On A Two-dimensional Motion Stage Driving By Piezoelectric Actuator

Precision driving technology has wide applications and requirments in the ultra-presion manufacturing,micro-nano operation,micro-nano assembly,microelectronics and other fields.As a new type of presion actuator,piezoelectric actuator has the advantages of high positioning accuracy,short response time,etc.So it has been studied deeply.Moreover,the piezoelectric stepper actuator has the advantages of high s tep resolution and large stroke.The traditional piezoelectric stepper actuator is complex to be assembled and processed.and it can only accomplish linar driving in one dimension.This paper has designed a two-dimensional piezoelectric stepper actuator with cantilever beam structure.Firstly,the driving principle of the driver in two dimension was analyzed.The piezoelectric actuator is composed of two longitudinal bending compound piezoelectric vibrators.The driving foot is located at the end of the beam,the up and down movement of driving foot is caused by actuator 's vertical bending,the driving of foot in one dimension is caused by hori zontal bending of actuator,the driving of foot in other dimension is caused by lengthwise telescopic deformation.The driving process of actuator in the two directions is analyzed,a cycle of six sub-steps is determined,and the voltage timing signal is designed according to the analysis.By being simplified as a cantilever beam,the relationship between voltage and displacement of driving foot is deduced using the piezoelectric equation.The stiffness of actuator at the loacation of driving foot is calculated using the Carnival theorem.In order to study the static and performance of the actuator,FEM simulations were carried out.The basic structure of actuator was designed according to the driving principle,parametric fem simulative model was established using the software ANSYS.The influence of the polarization partition of piezoelectric on the displacement of the driving foot wad analyzed,the arrangement of piezoelectric ceramics was determined.The influence of the flange on the displacement of the driving foot was studied,the effect of the bending deformation of the actuator on the piezoelectric stack was avoided.The influence of the ceramic outer diameter on the displacement of the driving foot and the stiffness at the location of driving foot were analyzed,and the theoretical model was compared with analyzed result.The range of operating frequency of the actuator was determined by modal analysis.Using the method of transient analysis,the transient displacement response of the driving foot in different directions was obtained when the different excitation signal was applied to each part.On the basis of planned timing signal,the excitation signal of more than one cycle was applied to each phase of the actuator,the space movement trajectory was obtained.On the basis of basic structure and parameters determined by theoretical and simulation analysis,the experimental prototype and platform have been manufactured and assembled.And the corresponding experimental system has been built.Firstly,the stiffness of the actuator was tested,the stiffness in the clamping direction is 8.3N/?m.By applying different excitation voltages to the vertical bending ceramic,horizontal bending ceramic and piezoelectric stack of actuator respectively,the dynamic response performence of the actuator has been obtained.Besides,the output performence of the actuator has been tested.By changing the amplitude of the vertical clamping voltage,the output displacement of the platform in two directions has been obtained.And the clamping voltage velocity curve has been obtained.By changing the horizontal bending voltage and the longitudinal stack voltage,the displacement in two directions in different excitation voltages has been obtained.And the minimum driving step in two directions are 0.1?m and 0.2?m respectively.And the driving voltage velocity curve has been obtained.By changing the driving frequency,the frequency velocity curves in two directions have been obtained.And the maximum driving speeds in two directions are 1010?m/s and 274.1?m/s respectively.Besides,the maximum driving speed in one direction has been improved to 382.6?m/s by perfecting the signal.By changing the driving load,the load velocity curve s in two directions has been obtained.When the platform was driven in one direction,the coupling effect of the platform in the other direction was tested.