Force optimization of kinematically-redundant planar parallel manipulators following a desired trajectory

In this work, an optimization-based methodology for resolving the generalized forces for kinematically-redundant planar parallel manipulators following a desired trajectory is presented. The proposed methodology assumes that the manipulator is performing a task that is slow enough to allow kinetostatic analysis to be used. Two test trajectories were used to show the effectiveness of the proposed methodology. The results for a kinematically-redundant 3-PRPR manipulator were compared against the results for a non-redundant 3-RPR manipulator. The results show that the redundant manipulator has improved force capabilities compared to the non-redundant manipulator. In particular, the redundant manipulator is able to pass through singular configurations with feasible generalized forces, something the non-redundant manipulator cannot do.

► Force analysis of kinematically-redundant parallel manipulators is presented.
► Trajectories are tested and results are compared with a non-redundant manipulator.
► Required forces with redundancy are less than those required without.
► Problems with singular configurations are eliminated using redundancy.