Abstract: The stabilizing problem was investigated for a class of uncertain nonlinear systems. First, an appropriate observer was introduced, and then based on the addition of a power integrator and adaptive technique, a new method was presented to construct a smooth adaptive output feedback controller. The main theoretical results show that the designed controller not only guarantees that all the states of the closed-loop systems are bounded, but also the states of the original system and the observer asymptotically converge to zero.

Key words: output feedback, uncertain nonlinear systems, adding a power integrator, adaptive technique