Singularity analysis of a fully parallel manipulator with five-Degrees-of-Freedom based on Grassmann line geometry

This paper addresses the singularity analysis of a fully parallel manipulators with five degrees of freedom, based on line geometry. Starting from the inverse Jacobian matrix, which maps the moving platform’s twist to the actuated joint velocities, the singularity analysis is transformed into a search for specific geometric conditions, which apply, when the manipulator is in a singular pose. Furthermore a classification and physical interpretation of the manipulator singular poses are presented. We particularly discuss some cases, for which a pure mathematical analysis doesn’t provide a satisfactory explication regarding the inner behaviour of the manipulator in such singular poses.