Deterministic adaptive control based on Laguerre series representation

Abstract

The behaviour of adaptive controllers in the presence of unmodelled dynamics, and the need for reduced a priori information have led us to abandon the usual ARMA transfer function representation for a representation by an orthonormal series. The appeal of our new approach is that it eliminates the need for assumptions about the plant order and the time delay. The plant is modelled by an orthonormal Laguerre network put in state-space form. A simple predictive control law is proposed. An explicit deterministic adaptive controller is then designed. Simulations show that it is easy to use, able to handle non-minimum phase plants, and more robust than the conventional model-based approach. Although we chose Laguerre functions, other orthonormal functions may be used. We have already tested some with success.