On the stabilizability condition in indirect adaptive control

Many recent studies on overall stability of adaptive control systems require, among other conditions, that the identified model be stabilizable, at least asymptotically. In fact, the usual identification methods do not guarantee this property, in the passive approach (without exciting extra signals), or if the model order is subject to over-estimation. In order to solve this problem, it is shown in this paper that certain classical identification algorithms can be easily modified in order to ensure the above stabilizability condition, without affecting the other properties.