Structural Optimization Design And Experimental Study Of Piezoelectric Driven Two-dimensional Micro-motion Platform

With the rapid development of science and technology,cutting-edge industrial production is gradually moving toward the micro-nano level.Among them,in the field of micro-machining and research,precision positioning technology has become one of the core technologies.At present,all countries are conducting research on precision positioning technology,especially in military and aerospace.Among them,the micro-motion platform technology is the most widely used one.With regard to the problem of low positioning accuracy,low stiffness and low resolution for the current micro-motion platform,a two-dimensional micro-motion platform was designed.It realizes X and Y direction uncoupled nano-scale displacement output.The specific research contents are as follows:Considering the scheme of the piezoelectric ceramic actuator as the drive and the double parallel four-bar flexible hinge structure as the transmission,a new two-dimensional micro-motion platform structure was designed,which has the advantages of frictionless wear,high positioning accuracy and fast response.Taking the critical dimension of the structure as the design variable,the mathematical model of the objective function and the constraint condition was established for the micro-motion platform.The sequence quadratic programming algorithm was used to optimize the structure size of the micro-motion platform,so that the designed micro-motion platform could meet the requirement of displacement output.Under the condition,a large stiffness could be obtained,thereby an optimal structural size could be obtained,and the theoretical maximum displacement value and structural stiffness value could be calculated.The ANSYS software was used to model the three-dimensional solids of the micro-motion platform,and the fixed constraints were applied to the model.The static characteristics,dynamic characteristics and coupling characteristics were numerically simulated and analyzed.The maximum displacement,structural stiffness,maximum stress and the natural frequency of the micro-motion platform in the X and Y directions were obtained,and the bearing capacity in the Z direction was obtained.The conclusion of independent and uncoupled motion in X and Y directions was obtained.The experimental research on the micro-motion platform system was carried out.The output displacement of the micro-motion platform in the X and Y directions has good linearity.There is no hysteresis and creep phenomenon in the closed-loop state.The positioning accuracy,repeat positioning accuracy and resolution in both directions are nanometer level,the step response time is millisecond level,and there is no oscillation and overshoot phenomenon;according to the experimental data,the maximum displacement of the X and Y directions is satisfied,and the structural stiffness is high.The experimental results prove the correctness of theoretical calculation and simulation and the usability of the micro-motion platform,which can meet the requirements of nano-scale precision positioning.