Evaluation and determination of grasping forces for multifingered hands

Evaluation of grasping and determination of grasping forces in manipulation by multifingered hands are discussed. Based on the definitions of manipulating and grasping forces introduced previously, the advantages of determining a grasping force beforehand for the secure grasping against an anticipated class of external forces is described. For evaluation of a given grasping force, a criterion of the remaining ability of grasping is proposed. A method of grasping for a given manipulation tasks, in which grasping forces are determined as those with the maximum value of this criterion, for the expected external forces in each step of the task, is proposed