On the velocity analysis of interconnected chains mechanisms

For parallel mechanisms, a system of linear input–output velocity equations can be obtained after the passive joint velocities are eliminated from the velocity equations via a screw-theory method. This approach can be considered standard. A general method for the elimination of the passive joint velocities, for mechanisms that are not purely parallel, has not yet been proposed. The paper addresses the problem by studying the instantaneous kinematics of two closed-loop mechanisms with kinematic chains not in the two-terminal series-parallel class.