Workspace analysis and architecture optimization of a 6 dof stewart-platform-based milling machine

This paper presents the workspace analysis of a 6 DOF Parallel Kinematic Machine (PKM) designed for machining. The analysis is based on kineto-statics indexes able to highlight different aspects of the manipulator performances. Beside the classical jacobian based indexes (kinematic manipulability, isotropy, stiffness) the analysis has been also performed using new indexes recently defined in order to remove dependencies on the adopted units used to measure length, angles, force and torques. Moreover the new indexes decouple the effects of rotations and translations. These indexes are used to optimise the geometrical design of the PKM.