Cobot Architecture

Michael A. Peshkin, J. Edward Colgate, Witaya Wannasuphoprasit, Carl A. Moore, R. Brent Gillespie, and Prasad Akella

IEEE Transactions on Robotics and Automation, Vol. 17, No. 4, pp. 377-390, August 2001.

AbstractóWe describe a new robot architecture: the collaborative robot, or cobot. Cobots are intended for direct physical interaction with a human operator. The cobot can create smooth, strong virtual surfaces and other haptic effects within a shared human/cobot workspace. The kinematic properties of cobots differ markedly from those of robots. Most significantly, cobots have only one mechanical degree of freedom, regardless of their taskspace dimensionality. The instantaneous direction of motion associated with this single degree of freedom is actively servo-controlled, or steered, within the higher dimensional taskspace. This paper explains the kinematics of cobots and the continuously variable transmissions (CVTs) that are essential to them. Powered cobots are introduced, made possible by a parallel interconnection of the CVTs. We discuss the relation of cobots to conventionally actuated robots and to nonholonomic robots. Several cobots in design, prototype, or industrial testbed settings illustrate the concepts discussed.