Dynamic simulation of multi-fingered robot hands based on a unified model

In dextrous manipulation of multi-fingered robot hands, the contact motions between the fingers and the grasped object may frequently change between s ticking, rolling, and sliding. Furthermore, when a robot hand is to re-gras p an object, the number of fingers in contact with the grasped object will change and impulsive collisions will occur. In order to cope with these dif ferent cases, this paper proposes a unified framework to model the dynamics of a multi-fingered hand in free motion, collision, and different contact motions including sticking, rolling, sliding, and their combinations. The i ntroduction of a contact motion selection matrix enables us to unify dynami c equations for different motions into a single model. To calculate the col lision response, we adopt the impulse-based method proposed by Mirtich. A n ew contact transition model is also developed to identify the type of conta ct motion between a finger and the grasped object. Based on the unified dyn amic model, we have developed a 3D dynamic simulator to simulate dextrous m anipulation of a five-fingered robot hand. The validity of the dynamic simu lator is verified by examples. (C) 2000 Elsevier Science B.V. All rights re served.