Random Non-calm And Stability Analysis Of The Complete System

State feedback stabilization problem for a class of more general high order stochastic nonholonomic control systems, and robust stable control problem via nonlinear state feed-back for a class of nonholonomic systems with unknown stochastic disturbances are mainly investigated in this thesis, which is divided into the following two parts.1. The state feedback stabilization problem for a class of more general high order stochastic nonholonomic systems.This part presents a state-feedback controller and a parameter update law for a class of high order stochastic systems in which the nonlinear drifts have the more general form. The proposed strategy ensures that the closed-loop system is almost asymptotically stabilized in probability and the state globally asymptotically regulates to zero in probability while the parameter estimation is bounded in probability. It can be also generalized the conclusion to multi-input systems. The main ideas in this procedure are nonlinear state transformation, Young's inequality and some flexible algebraic technique, and the inductive/backstepping method and the tuning function technique which effectively avoids the overparameteriza-tion. Meanwhile, in order to achieve the control objective, the switching control strategy based on the norm of the first state is also significantly exploited. The simulation example demonstrates the effectiveness and robust features of the proposed method.2. The robust stable control problem via nonlinear state feedback for a class of nonholo-nomic control systems with unknown stochastic disturbances.In this part, we investigate the robust stability of stochastic nonholonomic systems with unknown disturbances and unknown control directions. In order to make the origin be a solution of the closed-loop system and prevent the finite time escape phenomenon from happening, a new robust nonlinear switching law is proposed so that global asymptotic stability analysis can be dealt with for closed-loop system. The integrator backstepping technique based on a constructive manipulation is also applied to the design of the controller. A simulation is given to show the effectiveness of the proposed scheme.