A multi-fingered hand control structure with on-line grasping force optimization

Grasp stability in a multi-fingered hand requires an appropriate force distribution between fingers taking into account contact conditions. The optimal solution with either recursive or non linear programming methods usually involves many computations and is very often not suitable for on-line implementation. This paper describes the transformation of this constrained problem into an unconstrained one so that the optimization algorithm finds the optimal solution within a few iterations. Force determination is then included in a hybrid position/force controller to prove the effectiveness of such a solution for updating force references during the grasped object motion.