Research On The Dynamic-Static Characteristics And Kinematic Accuracy Of Miero Positioning Platform

With the development of science and technology,the requirement of processing and manufacturing precision is increasing.The scale used in the field of manufacturing goes ahead from micron level to the nanometer level.Therefore,in order to meet the requirements of high precision,large stroke micro positioning has become research hotspot.Large parallel micro positioning platform is majored in this paper.Researches on the stiffness method of basic unit,leverage amplification ratio solving was done in this paper.Configuration design,integral rigidity,kinematics,motion space,natural frequency and was also done in our research.The specific research results and innovation points are as follows:(1)The method of solving the transfer matrix,the transitivity of transfer matrix has been discussed in this paper.The relationship between the transfer matrix and element stiffness matrix was also researched in this paper.Coordinate transformation method was solved to transform unit coordinate system to structural coordinate system.(2)Transfer matrix method was proposed with the combination of the characteristics of transfer matrix,force balance equation and deformation coordination equation.Transformation of deformation coordination equation and global coordinate system was avoided with the use of this method.Simple solution,with recursive and conducive to programming is the characteristics of this method.Because of considering the deformation of each subunit,results more accurate.The deformation of each subunit was also taken into consideration in order to exact he results.The solution process of stiffness and optimization of structural parameters was inferred with the example flexible lever enlarging mechanism.(3)The relationship between the transfer matrix and the stiffness matrix was used to solve the stiffness of the flexible hinge element.Shear force and non-uniformity coefficient were taken into consideration to ensure the result more accurate than other papers.(4)Parallel micro positioning platform with large stroke was designed.Lever magnifying mechanism with folding beam was used to reduce the resistance and increase the magnification.Flexible parallel four-bar mechanism was used as redundant branch to improve the carrying capacity and stiffness of the platform.Parallel structure with two branches of orthogonal arrangement was used to ensure the isotropy of the platform.Two translational free degrees were decoupled.The platform possesses a large trip,good rigidity,high sensitivity with these mechanisms.It is easily to control the platform with the help of these mechanisms.(5)The characteristics of the parallel stroke micro-positioning platform are analyzed,providing a theoretical basis to the design of resolution and stroke range of the micro positioning platform.Transfer matrix method was used to solve its stiffness and kinematics.MATLAB was used to draw the movement space.Workbench was used to perform modal analysis to solve the natural frequency and vibration mode.The reason of the error of the transfer matrix method is analyzed.A modified method is proposed to consider the association of cell interfaces.The accuracy of result has been significantly improved after taking these measures.The accuracy of the transfer matrix method is proved through the FEA analysis results and it is in line with the reality.These researches have practical value in micro-platform configuration,size optimization and error analysis.They also provide a theoretical basis for the design of large-stroke parallel micro-positioning platform control system.