Self motions for a two robot closed chain system

Self-motions of a two-robot closed chain are discussed in this paper. Three categories of self-motion for the closed-chain system are introduced: primary self-motion, separable self-motion and partial self-motion. A kinematic model which describes constraints for self-motion is presented. The model consists of object Jacobian matrices, which are developed for individual robots and the entire system and the matrices map an individual joint space or the global joint space velocity into the task space velocity of the center of gravity of the object. Several examples are given to demonstrate the applications of the methods