Survey on the kinematics of a 6RSS parallel robot based on manipulability indices

Abstract

The study of the kinematic performances of a parallel mechanisms an important aspect in terms of analysis and design. This paper presents a study on the kinematic manipulability and kinematic efficiency of a 6RSS parallel mechanism. The parallel mechanism consists of a fixed plate and a mobile platform connected by six independent kinematic chains. Each of the six kinematic chains has an actuated rotational joint and two spherical joints. The motion equations for the six kinematic chains of the parallel mechanism are defined when the characteristic point P moves on the spatial curve with constant speed. Based on the global Jacobian matrix determinant and the angular speeds of actuated arms was graphically represented the variation of the two kinematic indices. Kinematic indices allow for assessing the quality of the mechanism motion; they also help us avoid those critical configurations encountered in the case of parallel mechanisms.