LOCAL TORQUE MINIMIZATION FOR REDUNDANT MANIPULATORS - A CORRECT FORMULATION

Local torque minimization for redundant manipulators has been consider ed by using a redundancy resolution approach. Since its initial formul ation, however, proposed solutions have been plagued by performance in stabilities. Till now, the reason was not clear. In this paper it is s hown that the instability problem occurred because of incorrect formul ation. A correct formulation is proposed, which is used to analyze the reason for instability. Special attention is paid to joint accelerati on terms at the selfmotion manifold. This helps explaining the recent formulation of a stable scheme based on local joint velocity minimizat ion in terms of torque. The results obtained are related to dynamic re dundancy resolution in general.