Analysis And Design Of 3-DOF Micro Positioning Stage Based On Multi Notch Flexure Hinges

Precision positioning technology has been widely used in many fields,such as high-end equipment manufacturing(such as photolithography,scanning electron microscope,etc.),aerospace,nano operation and medical treatment.Due to the advantages of high accuracy,high rigidity and compact structure,the precision positioning technology based on the compliant mechanism is the focus of current research.As a key part of compliant mechanism bearing deformation,the performance of flexure hinge directly determines the overall performance of the mechanism.The main research object of this paper is a new type of hinge: multi notch flexure hinge,which is applied to planar 3-RRR mechanism and spatial XYZ three degree of freedom(3-DOF)mechanism.The main research contents are as follows:(1)Firstly,the multi notch flexure hinge is modeled and analyzed,and compared with the right circular flexure hinge which is widely used in compliant mechanism.The compliance,rotation accuracy and maximum stress of the two kinds of flexure hinges under the same size are studied,and the theoretical model is verified and analyzed by finite element simulation(FEM).(2)The multi notch flexure hinges are applied to the planar 3-RRR parallel compliant mechanism.First,the inverse kinematics of planar 3RRR mechanism is solved by closed-loop vector method.Second,the workspace,input coupling,maximum stress,input stiffiness and natural frequency of the 3-RRR micro positioning stage are simulated by ANSYS finite element analysis(FEA),and compared with the 3-RRR micro positioning stage based on the right circular flexure hinges.Finally,the experimental prototype is processed by 3D printing,and the transfer matrix and input coupling of the stage are analyzed by micro vision measurement.(3)The multi notch flexure hinges are applied to the spatial XYZ three degree of freedom compliant mechanism.First,the input displacement of piezoelectric ceramics is amplified by a compound bridge type displacement amplification mechanism.Based on the elastic beam model and the Castigliano's second theorem,the displacement amplifier ratio,natural frequency and maximum stress of the design mechanism are analyzed considering the influence of external stiffness.Second,the displacement amplifier ratio and natural frequency of XY micro positioning stage are optimized by the multi-objective optimization algorithm,and the optimized results are compared with those of the micro positioning stage based on the right circular hinges.Then,XYZ three degree of freedom micro positioning stage is processed by machining XY fretting stage by slow wire cutting and installing piezoelectric ceramics and displacement guiding mechanism in Z direction.The working space,cross coupling and natural frequencies in three directions of XYZ micro positioning stage are measured by capacitance sensor.Finally,by planning the theoretical trajectory,the trajectory tracking of the threedimensional curve of the space at the end of the micro-motion stage is realized.