On Fixed-Time Interval Estimation of Discrete-Time Nonlinear Time-Varying Systems With Disturbances

The aim of this paper is to cope with estimation issues of discrete-time nonlinear time-varying systems with input and output. Inspired by [12], a new design technique of fixed-time observers is proposed. It relies on the use of past values of the output and the theory of the monotone systems to construct dead bit observer or fixed-time interval estimator depending on the absence or the presence of uncertainties. Finally, simulations are conducted to verify the effectiveness of the proposed schemes.