Contact Force Modeling and Feasible Grasp Force Analysis of Power Grasp

Contact force modeling and grasp analysis methods of hyperstatic grasps with over-constraints are investigated,in order to obtain feasible grasp force and load condition in the capability design of manipulator and grip system. A general model to solve the constraint force in a grasp with friction contact is developed on the basis of Lagrange multiplier factor method and contact dynamic constraint condition. The indetermination of contact constraints in hyperstatic grasp is discussed. The feasible solution to constraint force of friction contact is characterized by an active internal force subspace,the basis wrenches of internal force subspace of object grasped is identified by double reciprocal of a pair of constraint force set at each two contacts. An explicit calculation of feasible contact force set is enabled under dynamic equilibrium condition. A method to solve the feasible grasp force and outside force balanced with dynamic load is performed.