Forward Position Analysis and Error Modeling of the 2UPS-RPU Parallel Manipulator

Abstract

The forward kinematics of manipulator was studied to analyze the positive position of the novel 2UPS-RPU parallel mechanism with series connection inputs. With the restrict condition of the lengths of three actuated limbs as constraint conditions, the constrained equations were established, and the four nonlinear equations were obtained to solve forward positional problems of the mechanism. Based on the elimination method, a two-dimensional equation is obtained by eliminating the four-dimensional equation. The search method based on the least square method of the MATLAB software was utilized to analyze forward position of 2UPS-RPU parallel mechanism. The results of numerical verification showed that through this method all forward solutions can be found which are basically coincident with the inverse ones, and the little error was caused by the accumulating calculation error. An error model was established based on differential theory and kinematics equations .This model simplified the installation error as the manufacturing error. Finally the error value was obtained by MATLAB ,which proved the error model was correct.