On the mobility and manipulability of general multiple limb robots

In this paper, the analysis of the differential kinematics and manipulability measures of robotic systems comprised of multiple cooperating limbs is considered. The goals of this study can be articulated in four points: 1) to enumerate the degrees of freedom of the manipulation system; 2) to describe analytically all possible first-order differential motions of the system at a given configuration; 3) to evaluate in the velocity domain the functionality of a manipulation system, with respect to the task it is required to perform; and 4) to calculate the bounds for the velocities achievable by the system, given bounds on the capabilities of joint actuators. The assumptions made on the robotic system are quite general, so that many complex devices (e.g., dextrous hands, legged vehicles, whole-arm manipulators, etc.) can be dealt with in a unified and convenient framework