Indirect adaptive periodic control

In this paper, a new indirect adaptive control method is presented. This me thod is based on a lifted representation of the plant that can be stabilize d using a simple performant periodic control scheme. The controller paramet ers computation involves the inverse of the controllability/observability m atrix. Potential singularities of this matrix are avoided by means of an ap propriate estimates modification. This estimates transformation is linked t o the covariance matrix properties, and hence, it preserves the convergence properties of the original estimates. This modification involves the singu lar value decomposition of the controllability/observability matrix's estim ate. As compared with previous studies in the subject, the controller propo sed here does not require the frequent introduction of periodic n-length se quences of zero inputs. Therefore, the new controller is such that the syst em is almost always operating in closed loop, which should lead to better p erformance characteristics.