A Study On The Accuracy Of The Stewart Platform With Hook Hinges On Both Sides

The Stewart platform has been studied and refined since it was developed in 1965.From the initial simulation platform to the current precision platform,from the single structure,to the current structure diversification,people in the mechanical structure,forward and inverse kinematics algorithm,dynamic algorithm,precision compensation and other aspects of continuous improvement,so that its application is more extensive.In this paper,kinematics algorithm analysis,theoretical research and kinematic calibration analysis will be carried out mainly on the Stewart platform with hooker hinge at both ends.In the introduction,the research significance and background of parallel mechanism are introduced.In this paper,the development and application of parallel mechanism and related modern mechanism theory are simply understood.In this chapter,the current situation of kinematics and kinematics calibration are described.The research degree of Stewart platform at home and abroad in recent years is understood.Taking the 6-UHU Stewart platform as the research object,this paper first introduces the mechanical structure,especially the pendulum Angle amplitude of hooker hinge.In this paper,Solidworks simulation is used to analyze the motion characteristics,rigidity and load capacity of parallel mechanism,and G-K correction method is used to analyze the freedom of the platform.Secondly,the Stewart platform is modeled and basic theories such as Euler Angle,spiral theory,D-H parameter method,exponential product formula and Jacobi are briefly introduced in this paper.On the basis of theory,this chapter analyzes the rotation Angle of the electric cylinder spiral adjoint.In the inverse kinematics algorithm,the D-H method is used to analyze the single chain,and the Angle transformation matrix is used to figure out the spiral Angle and compensate the electric cylinder to improve the accuracy of the platform.When analyzing forward kinematics algorithm,this chapter uses GAUSS-Newton iterative method to obtain the optimal solution,and uses inverse kinematics algorithm to verify.Finally,in this paper,the laser tracker is used to measure the coordinates of the end pose positions of multiple groups of 6-UHU Stewart platform,and the end pose errors are analyzed by the matrix singular value decomposition method.The above error is analyzed by the identification algorithm,and the error value is calculated.Then the accuracy and reliability of the method are verified by the orthogonal experiment of 8 level and 6 factors.This design combines kinematics algorithm and kinematics calibration to double improve the accuracy of Stewart platform.After a large number of experimental data testing,the accuracy of thisalgorithm is up to 0.001 mm in multi-group pose data.In the error calibration,the calculated error is in perfect agreement with the assumed error data.Therefore,this design verifies the reliability of this method.