Uncertain Stochastic Nonlinear Systems, Output Feedback Control

Stochastic nonlinear system control is an important topic in control theory. A lot of studies are designed and analysed for stochastic nonlinear control systems with uncertain parameters, while the output-feedback control of uncertain stochastic nonlinear system has been one of the hotspots in the modern control theory at present. For a class of stochastic nonlinear system with inverse dynamics and time-varying time delays, using stochastic Lyapunov stable theory and back-stepping method, discussing the problem of the design of the output-feedback controller, adapting the concept of stochastic input-to-state stability and the method of changing supply functions.My thesis is organized as follows:Chapter 1,Present the topics of internal and overseas research situations, theoretical significance, and introduces the research object, research contents of this thesis.Chapter 2, Introduce the basic theory involved in my thesis, including some basic concepts, related theories and main symbols.Chapter 3, Introduce a class of stochastic nonlinear systems with time delays and inverse dynamics, this chapter studies the adaptive output-feedback stabilization problem. First, it gives some sufficient conditions to ensure the existence and uniqueness of the solution process for stochastic nonlinear systems with time delays and introduce a stability notion and the related criterion, adapts a reduced-order observer. Then, in view of some uncertainties such as stochastic inverse dynamics, time-varying time delays, uncertain parameters in both drift and diffusion terms and a general constant virtual control coefficients, it presents a constructive design procedure for a memoryless adaptive output-feedback control law by using the back-stepping method. At last, it adapts a method of changing function. Under some mild conditions, the closed-loop equilibrium of interest is globally stable in probability and the solution process can be regulated to the origin almost surely.Chapter 4, Extending the system into large-scale systems based on chapter 3, studying the problem of decentralized adaptive output-feedback stabilization for large-scale stochastic nonlinear systems. Chapter 5,Summarize the main results of this paper and a prospect of the future research work.