Abstract
To know positions where the fingers touch an object plays an important role to achieve a stable grasp of an unknown object by a multifingered robot hand. This paper proposes an algorithm for searching for a contact point between a multifingered hand and an unknown object. The algorithm is composed of two phases. One is the approach phase, in which each finger firstly is opened widely and approaches to an object until a part of a finger link is in contact with the object. The other is the detection phase, in which each finger posture is changed with slip while maintaining contact between object and finger. Using two selected postures during the detection phase, we can compute the intersecting point which leads to an approximate contact point. A series of motions during the detection phase is defined as self-posture changing motion (SPCM) , which is also discussed precisely for a general n-link system. Finally, the proposed algorithm is confirmed through simple experiments using a two-fingered robot hand with the capability of joint compliance control.
