3-PRRR redundant planar parallel manipulator: Inverse displacement, workspace and singularity analyses

This paper presents a novel configuration for a kinematically redundant planar parallel manipulator. Advantages of redundant versus non-redundant parallel manipulators are first discussed. The inverse displacement problem is examined, and the workspace of the proposed manipulator is compared to that of a similar-sized non-redundant one. It is shown that both the reachable and dexterous workspaces of the redundant manipulator are significantly larger. The Jacobian matrices of the proposed manipulator are then developed, and the direct and inverse singularities, and the combination of both, are presented. The physical interpretation of each type of singularity is discussed and illustrated.