Workspace Comparison of Kinematically Redundant Planar Parallel Manipulators

In the present work, the inverse displacement problem and the workspace of kinematically redundant planar parallel manipulators are discussed. Non-redundant and redundant planar parallel manipulators are compared. The advantages of redundant versus non-redundant parallel manipulators are discussed. Thereafter, two kinematically redundant planar parallel manipulators, one with 4 degrees of freedom (DOF), the other a new 6DOF design, are compared to similar non-redundant ones. It is shown here that both reachable and dexterous workspaces of the redundant manipulators are significantly larger compared to non-redundant manipulators of the same size. As a result, kinematic redundancy can be an appropriate solution for improving parallel manipulators’ characteristics.