Static force analysis for general cooperating manipulators

In this paper, the problem of the analysis of the force systems acting in static conditions in a generic manipulation device is considered. By generic manipulation device we mean a manipulation system composed by one or more manipulators, each of them with one or more links in contact with an object. Different contact models may be taken into account, for example complete constraint, soft-finger, hard-finger, and so on. Two are the main goals of the analysis: to understand which sets of forces, belonging to the joint torque space, the contact force space, and the external wrench space, are present or applicable to the system, and in which manner forces in these sets can be obtained. In fact, the answer to these two questions, crucial in problems grasp optimization and control, is not trivial in the case that some or all of the manipulators in the system have limited mobility. In this paper, a technique is proposed aiming to solve these problems, and some examples are presented to illustrate the method