Inverse Kinematics of Functionally-Redundant Serial Manipulators: A Comparaison Study

Kinematic redundancy of a pair of manipulator-task can be classified into intrinsic and functional redundancies. This paper compares two different approaches to solve the inverse kinematics of functionally-redundant serial manipulators. First, the augmented approach add a virtual joint to the manipulator in order to render the Jacobian matrice underdetermined and project a secondary task onto the null space of theaugmented Jacobian, while the twist-decomposition approach rather decompose the instantenous twist into two orthogonal subspaces of the tool frame. The numerical simulatution of an end-milling operation shown that the twist decomposition is more effective in termes of computation time and numerical robustness then the augmented approach.