A model reference adaptive controller for systems with uncertain relative degrees \(r\), \(r+1\) or \(r+2\) and unknown signs of high-frequency gains
The aim of the paper is to present a new design method for the model reference adaptive controllers, to be applied to processes with uncertain relative degrees \(r\), \(r+1\), or \(r+2\) \((r\in\mathbb{N})\), and with unknown signs of high-frequency gains. The proposed method represents an extension of A. S. Morse's adaptive controllers (1987), where there was assumed that the relative degrees are uncertain but known to be 1 or 2. The new control scheme combines Morse's composite structures and extends them to the general relative degree case by applying recent backstepping procedures. The author succeeds to prove that single adaptive control schemes can deal with enlarged uncertainties of relative degrees and unknown signs of high-frequency gains. The resulting model reference adaptive control systems are shown to be asymptotically stable.
scientific article; zbMATH DE number 1443878