A linear tracking-differentiator and application to the online estimation of the frequency of a sinusoidal signal

Abstract

A simple linear tracking-differentiator is developed and the convergence is proved for any differentiable signal to be tracked. This enables us to design a relatively simple globally convergent online estimator of the frequency of a sinusoidal signal considered in Liu et al. (1999) by a complicated method. The polynomial convergence rate is also obtained.