Global practical tracking by output feedback for a class of non-linear time-delay systems

摘要

This paper considers global practical tracking problem of non-linear time-varying delay systems by output feedback. The class of systems under consideration is assumed to be dominated by a lower-triangular system which is linearly dependent not only on the unmeasurable states, but also on the unmeasurable time-delay states. With the aid of the ideas of universal control and dead zone, an adaptive high-gain observer is constructed with a high-gain exponent. Compared with the existing control scheme, the controller of this paper can be applied to a family of uncertain non-linear time-delay systems with time-delay zero-dynamics, which is due to the introduction of the high-gain exponent. By using a Lyapunov-Krasovskii functional, the time-varying delay phenomenon is successfully dealt with, and the complexity of the compensator and controller does not increase. Finally, an example is given to illustrate the usefulness of our result.