多指ハンドによる対象物把持の指配置範囲の解析

抄録

Stable grasp of an object with a multifingered hand is an important issue on manipulation. This paper addresses an analytical approach for obtaining a successfully-grasping fingertip positions on the edges of an object and its acceptable fingertip forces. The successful grasp of an object can be achieved if the resultant fingertip forces and resultant moments acting on the object are zero. At first the equilibrium condition of fingertip forces is used to select candidate combinations of the object edges touched by fingertips which may be utilizable for successfully grasping. Then, by using the moment equilibrium condition the regions of the successfully-grasping fingertip positions on the edges are obtained. It is analytically introduced that the region is bounded by boundary hyperplanes induced by the moment equilibrium condition and edge-length-limits. Two propositions are proposed for obtaining the region of the successfully-grasping finger positions. If the region cannot be found out, the candidate combination of the edges will be abandoned. Finally an algorithm is given for the fingertip forces corresponding to a fingertip position in the successfully-grasping region. Several numerical examples are conducted to verify the validity of the proposed analytical approach.