Analysis of object-stability and internal force in robotic contact tasks

The stability of an object manipulated by multiple robots (serial-link or wire-driven mechanisms) in contact tasks is investigated. We show that resultant force/moment applicable to the object through the contacts is represented as a polyhedral convex region in force/moment space. Then we propose a stability measure and a method of calculating it approximately by linear programming technique. We also present a linear programming-based algorithm to judge the possibility of excessive internal force in contact tasks by position-controlled robots