A ROBUST TRACKING CONTROL SCHEME FOR RIGID ROBOTIC MANIPULATORS WITH UNCERTAIN DYNAMICS

In this paper, we develop a new robust tracking control scheme using a variable structure compensator for the feedback control of rigid robotic manipulators. It is shown that a robotic manipulator is treated as a partially known system, and the known dynamics is separated out to perform a linearization. Then a nominal feedback controller is designed using a nominal system model and a variable structure compensator is introduced based only on a system uncertain bound to eliminate the effects of the unknown portion of the plant. Using this scheme, the closed loop system behaves with a high degree of robustness with respect to large uncertain dynamics and guarantees that the output tracking error asymptotically converges to zero with desired transient error response on the sliding mode. A simulation is given in support of the proposed control scheme.