基于基本刚性链平面机构运动构型分析

he kinematic configuration analysis is one of the most difficult problems in analysis and synthesis of mechanisms. According to the single-link transformation principle, and based on the topological characteristics investigations to planar closed kinematic chains (PCKCs), a general study of the kinematic configuration analysis of mechanisms with R-pairs is conducted in this paper. Firstly, two new concepts, contract link distance sequence and basic link group code sequence, are both defined in the paper, and a new approach for identification of multi-bar basic kinematic chains (BKCs) within the left kinematic chain from the single-link transformation, is proposed. Then another two concepts, weight code and similarity code, are defined for aid to link symmetry judgment, and two judgment theorems are proposed as well. As a further step, weight code or similarity code of the transformed single-link will be calculated for configuration analysis situations judgment. Finally, corresponding unified constraint equation groups are set up and solved with coefficient homotopy method, on the basis of different analysis results mentioned above. Research and application results show that the method is reliable, effective, easy to implement, and it is especially applicable for the kinematic configuration analysis of PCKCs with multi-bars and multi-freedoms.