Output Feedback Control Of Uncertain Nonlinear Systems

Nonlinear system control is an important topic in control theory. In all, we have got a lot of results in the area of state-feedback adaptive control for a class of nonlinear systems. But comparatively speaking, we have got fewer in the area of output-feedback adaptive control for a class of nonlinear systems, moreover, there are still many problems to be solved. Specially, the problem of output-feedback adaptive control for a class of nonlinear systems in strict feedback form with unknown control directions and globle output-feedback stabilization for uncertain nonlinear systems with constant incremental about witch we need to discuss and research futher. In this paper, what we will talk about these two kind of nonlinear systems.My thesis is organized as follows:Chapter 1, Introduce the background of this topic, internal and overseas research situations, theoretical and Practical significance, the main contributions of this dissertation.Chapter 2, Introduce the basic theory involved in my thesis, including some basic con(?)epts, related theory and some lemmas. Specifically we mainly introduce the definition of Lyapunov function, Nussbaum function and some related lemmas. In addition we make our focus on the introduction of the application of back-stepping design in nonlinear system.Chapter 3, Introduce the output-feedback adaptive control for a class of nonlinear systems with unknown control directions. Because of the unknown control directions, we pull in the concept of Nussbaum function witch has an advantage in solving this control problem for this kind of system.Chapter 4, Introduce the problem of globle output-feedback stabilization for uncertain nonlinear systems with output dependent incremental. Our systems is more general than any others., by designing a dynamic high gain observer and analyzing the error system between the original system and the observer,then we give the controller based on a recursive procedure. Chapter 5, Summarize this papers and propose the problem for further research.