Recent advances in nonlinear control

Summary form only given. Over the last two decades, the stability theory of nonlinear dynamical systems, on the one hand, and the geometric control theory, on the other hand, have jointly created foundations upon which it is possible to build constructive methods for nonlinear control design. This progress was described in "Constructive Nonlinear Control: A Historical Perspective", by P. Kokotovic and M. Arcak, Automatica, 37:637-662, 2001, with over 300 references. The main theme of that survey was that many earlier descriptive concepts, such as stability, optimality, passivity, are being \´activated\´ as design tools in recursive design procedures. In this talk, this theme is continued with some new developments of constructive methods and discuss a couple of their applications. In particular, \´maneuvering\´ method is reviewed, currently developed by Skjetne et al. 15th World Congress of IFAC, 2002 (to appear in Automatica, 2004) and applied to ship steering. Two recent control designs are presented, one for a jet engine axial compressor and the other for a turbo-charged diesel engine. Both designs have already been tested in the industrial type of experiments. A discussion of experimental results will conclude this talk.