OPTIMAL SYNTHESIS OF ROBOT MANIPULATORS BASED ON GLOBAL KINEMATIC PARAMETERS

A method to represent and measure the global manipulability of manipulators is presented. The method is based on a new concept, referred to as the global velocity ellipsoid, which represents the global motion manipulability or the velocity transmission characteristics of a manipulator. The global velocity ellipsoid is obtained by considering a weighted distribution of the end-effector position over the workspace of the manipulator. Parameters representing the global isotropy and the global magnitude of the velocity transmission of manipulators are used for analyzing and optimizing the kinematic structure of manipulators. The extension of the concept to force transmission characteristics and its utilization for minimizing error propagation and enhancing accuracy, task placement and planning are discussed. Several examples are presented.