Symbolic structural synthesis and a description method for planar kinematic chains in robotics

A new method for structural synthesis of planar link chains in robotics is presented. It is based on the notion of logical equations associating Modular Structural Groups (MSGs) and closed chains. After a brief reminder of the theory of MSGs, and of connectivity and mobility laws, various levels of abstraction are studied concerning the structural number. This permits the synthesis of planar chains with various degrees of complexity. The logical equation notion is introduced. It permits the association of MSG of type A and closed chains of type G. od for the description of chains by contours and molecules is also proposed. It permits the classification of topological robot structures taking into account their complexity expressed by the number of closed loops in their molecules. This method is applied for the description of chains thus obtained, and for the description of the main structure of industrial robots with closed planar chains.