Abstract: When grasping with a multifingered hand, a reasonable arrangement should be suggested for the contact points of the fingers on an object in order to guarantee stability. A planning method of grasping based on the maximum external wrench is proposed, which takes the maximum external wrench as a criterion to evaluate the performances of the planning. After force closed constraints are given, an optimal model of the maximum external wrench is established and the simulation by using the neural network method is carried out. To compare with the numerical method of generalized force ellipsoid, the present model overcomes its limitation and can clearly describe the relationship between the grasping positions and the balanceable external force wrench. The model can quantitatively describe the grasping stability so as to judge a grasping planning more directly and practically.

Key words: Force wrench, Grasping planning, Multifingered hands