The objective of this thesis is mainly focused on two major themes. In the first theme, two adaptive fuzzy backstepping control schemes, for a class of uncertain SISO nonlinear systems with state (or output) and input constraints and external disturbances, are developed. In the other theme, an adaptive fuzzy backstepping control scheme, for a class of uncertain MIMO nonlinear systems with actuator nonlinearities and a non-symmetric control gain matrices, is designed. In all control schemes, the fuzzy systems are used to approximate the unknown nonlinear functions of the system. In addition, the stability analysis is performed by a Lyapunov approach. The theoretical results are validated by numerical simulation examples.
