A new insight into the geometric models and workspace volume of the 6RSS manipulator by disjunction of the translational and orientation subspaces

A new approach to the geometric model and workspace perception is suggested for the study of the 6RSS manipulator. Following the general method of closing equations of the spatial chains, the direct and inverse geometric models are developed. A rigorous analysis of 6-DOF mechanisms is very difficult to undertake because of the impossibility to represent intuitively spaces with six dimensions. Therefore, the six-dimension space is separated into two spaces with three dimensions, i.e. translations space and rotations space. Using specific algorithms, 2D cross-sections of 6D space and intuitive representations of the workspace are obtained, as required in the early design stage. Finally, three examples of separation method are discussed, in relation with the imposed trajectory of the tool in a certain manufacturing process.