Computer-aided synthesis of planar mechanisms with one multiple-joint

Abstract

• An isomorphism identification algorithm is presented for multiple-joint mechanisms. • A method for synthesizing planar mechanisms with one multiple-joint is proposed. • The database of planar multiple-joint mechanisms with up to 16 links is created. In the innovative design for mechanism-based devices and robots, it is crucial to synthesize as many diverse kinematic structures of available mechanisms as possible. Despite the widespread applications of multiple-joint mechanisms in various mechanical systems, few contemporary approaches concentrated on the synthesis of multiple-joint mechanisms. Herein, a computer-aided method is presented to synthesize all feasible non-isomorphic mechanisms with one multiple-joint. First, tricolor topological graphs are introduced that denote the structures of multiple-joint mechanisms. Second, two vertex classification methods are proposed, based on the calculations for the distance and vertex degree, to reduce the number of times required for the isomorphism identification of the generated tricolor topological graphs. Third, an approach is presented to automatically eliminate isomorphic tricolor topological graphs whose fixed vertices exist in the same advance vertex group. Then, a computer-aided method is proposed for synthesizing the tricolor topological graphs of planar mechanisms with one multiple-joint. Finally, a database of synthesized multiple-joint mechanisms with up to 16 links and 11 degrees of freedom (DOFs) is created, and the synthesis results are compared and discussed.