A continuous time model for observer-based frequency tracking

Abstract

Frequency tracking has been the focus of several research works for decades. One common method is to utilize a state observer to dynamically estimate the frequency of the measured signal. Most of existing works rely on a discrete time dynamic model for frequency and make use of discrete time observers. This paper introduces a new continuous time model which facilitates the use of several continuous time state observers from the literature. Consequently, the paper compares performance of discrete time approaches to continuous time one. The simulation results show efficacy of the proposed continuous time model specially when combined with specific nonlinear continuous time observers. Some of discrete time models as well as a recent continuous time model used in combination with a finite time observer are shown to yield poor results in most of simulative scenarios.