Delay and state observation for SISO nonlinear systems with input delay

Abstract

This paper deals with the problem of state and delay estimation for SISO nonlinear systems with an unknown time-varying delay in the input. The main idea is to approximate the delayed input by using Taylor's theorem and to create an extended system with the delay as part of the extended state. Then, the construction of an observer is proposed to estimate both state and delay. The results are illustrated by simulations.