Parameter identification in the grasp of an inner link mechanism

The identification of unknown parameters, such as external force and contact points, once an unknown object is grasped stably by an inner link mechanism is discussed. Once an unknown object is grasped stably, it is considered that the grasp will be made more stable and manipulations will thus be performed if unknown parameters can be identified by using data obtained during the initial grasp. The minimal structure required for grasping and manipulating an object is a three-fingered, nine degree-of-freedom (DOF) hand in three-dimensional space. In this case, the unknown parameters cannot be identified only by grasping an unknown object. It is shown that unknown parameters can be identified by appropriate changes in the distribution of joint stiffness and torques, using a minimal structured hand