Abstract:

A method is proposed for the stable grasping control of the dexterous hand. At first the definition and calculating method of the degree of stability of grasping (DSG) are given, and then the DSG based control method for the grasping control of the dexterous hand is explored. The DSG based grasping control of the dexterous hand is a new kind control loop at the outside of the normal position and force control loop, and it works at the same time with the position and force control loop. During the manipulation of the dexterous hand the DSG at each sampling period is calculated and translated to fuzzy subsets. When the DSG is smaller than the given value, the system can increase it by adjusting the position and force control loop. A fuzzy reason system is employed by the controller to give out the adjusting scheme. Simulations have been done using the model of the BH 2 dexterous hand developed by Beijing University of Aeronautics and Astronautics and the results verified the effectiveness of the proposed method.

Key words: degree of stability of grasping, dexterous hand, grasping control, fuzzy sets