A cyclic switching strategy for parameter-adaptive control

The authors introduce a strategy called cyclic switching to deal with the well-known certainty equivalence control synthesis problem which arises because of the existence of points in parameter space where the design model Σ_D upon which certainty equivalence synthesis is based loses stabilizability. Unlike most previously suggested methods for handling this problem, the technique proposed can be employed with or without excitation. In particular, for the technique to work it is not necessary for there to be a mechanism for moving tuned parameters away from values at which Σ_D loses stabilizability, and no such mechanism is in fact used