Sampled-data adaptive control of a class of nonlinear systems

摘要

The paper considers the discrete-time implementation of a class of backstepping adaptive controllers for uncertain nonlinear systems in the parametric strict-feedback form. The stability of the resultant sampled-data system cannot be guaranteed when the direct discretization of the continuous-time backstepping controller is applied to the same system via a sampling and hold device. Therefore, the paper has presented a sampled-data control scheme which involves first modifying the existing continuous-time controller and then discretizing it using the forward Euler method. It has been shown that the proposed control guarantees in a semi-global sense the boundedness of all the variables of the overall sampled-data system under some conditions. Particularly, the state of the nonlinear system to be controlled can converge to any arbitrarily small neighbourhood of the origin.