Error Modeling and Simulation of Serial-Parallel Mechanism Based on Screw Theory

Abstract

Focus on the problems of calculation complexity and abstractness in the traditional analysis methods of serial-parallel mechanism, the complete kinematic product of exponentials formula of serial-parallel mechanism was established in the paper based on the screw representation of spatial rigid motion. The errors of 4 D-H parameters were equivalent to error screw and the practical screw coordinate containing error screw of every joint axis was established. After the practical kinematic product of exponentials formula of serial-parallel mechanism being derived, the pose error model of tool coordinate system was established. According to the above screw method, numerical calculation of cutting machine about kinematic and error analysis was performed with MATLAB and the calculation results were compared with the simulation results of ADAMS. The comparison results show that relative error of the two groups of calculation results is within the 0.001 orders of magnitude and the correctness of screw methods application in the analysis of serial-parallel mechanism.