The control of flexible-link robots manipulating large payloads: Theory and experiments

The control problem for flexible-multilink robots carrying large payloads is revisited. A set of nonlinear approximate equations describing the payload-dominated dynamics of the flexible plant is used in conjunction with the passivity property satisfied by a suitably defined modified input-output pair for the system, to derive a globally asymptotically stable controller together with its adaptive counterpart. Experimental results involving a specially designed 3-degree-of-freedom planar arm with two flexible links, demonstrate their ability to combine end-point tracking with simultaneous active suppression of the vibrations. (C) 2000 John Wiley & Sons, Inc.