Adaptive control of nonminimum phase systems and application to a robotic welder

The authors describe ongoing research on the adaptive control of nonminimum-phase linear systems. They propose a new class of adaptive control laws which avoids projection of parameter estimates by the creation of an auxiliary model. By designing a control law for the auxiliary model, a generalization of model reference adaptive control for the original system is obtained. A robotic welder at the Construction Engineering Research Laboratory in Champaign, Illinois, is currently being used as a testbed for these theoretical results. The recent observations are described and future work is discussed