Global robust output regulation for a class of nonlinear systems

The problem of global robust output regulation is solved for a class of non linear systems driven by a linear neutrally stable exosystem. The proposed scheme makes use of a dynamic controller which processes information from t he regulated error only. Robust regulation is achieved for every initial co ndition in the state space, and for all possible values of the uncertain pa rameter vector and the exogenous signal ranging over arbitrary compact sets . The regulator synthesis is based upon a recursive procedure, and takes ad vantage of both the special normal form of the plant equations and the pass ivity property of the internal model. (C) 2000 Elsevier Science B.V. All ri ghts reserved.