Description and Analysis of Multi-Fingered Hand Grasping with a New Finger-Object Contact Model

The proper description of finger-object contact state is critical to the analysis and control of multi-fingered hand grasping. At present, most studies assume that the finger-object contact state is invariable. However, in different stages of hand grasping, finger-object contact state is usually variable due to different contact factors, therefore, current finger-object contact models are not very suitable for describing it and the existing description and analysis of the hand grasping may be not appropriate. In this paper, we proposed a new method for describing and analyzing the multi-fingered hand grasping under various finger-object contact states, including a new finger-object contact model for describing the actual finger-object contact state, a grasp matrix for describing the hand grasping, and the condition number of the grasp matrix for analyzing the hand grasping. Taking a three-fingered hand grasping a sphere as an example, the hand grasping under four types of contact states was investigated. Simulations and experimental results both validated the effectiveness of the proposed method.