Suboptimal algorithms for force distribution in multifingered grippers

A method is presented which addresses the problem of determinating the appropriate distribution of forces among the fingers of a multifingered gripper grasping an object. The finger-object interactions are modeled as point contacts. The system is statically indeterminate, and an optimal solution for this problem is desired for force control. A fast and efficient suboptimal method for computing the grasping forces is presented. In addition to determining the equilibrating forces (the forces required to maintain equilibrium), it is essential to superpose interaction forces (the forces which squeeze the object) to ensure that the fingers do not slip. The decomposition of the equilibrating forces into forces perpendicular and parallel to the load wrench provides a useful simplification. If it is assumed that the normals to the object at the point of contract pass through the centroid of the contact points, the computations required to find the interaction forces are considerably simplified. Some simple grasps are used to evaluate the proposed algorithms