Optimization of multicomponent signals entered to the system using estimation of instantaneous frequency

Abstract

The frequency signal displays are not efficient for analyzing nonstationary signals because of their inability to represent frequency changes over time. In fact, because most of the signals are real, nonstationary, and time varying, analyzing the signals in the time–frequency domain to estimate the instantaneous frequency of a signal is inevitable. The methods of estimating the instantaneous frequency of the multicomponent signals are divided into three groups, which include the methods using signal phase derivatives that are sensitive to noise, methods that calculate the number of zero points of the signal and consider the signal frequency equal to half the frequency of the zero points and are suitable for signals that can be imagined as stationary, and methods based on time–frequency distributions and distributions such as Wigner for instantaneous frequency calculations and more for instantaneous frequency calculations on nonstationary noise signals that exhibit varied time–frequency distributions. In this article, a new hybrid algorithm is used to evaluate different distribution criteria and comparing their performance in investigating one or more features of time–frequency distributions, such as resolution and energy concentration.

Online frequency estimation of periodic disturbance based on FFT algorithm with application in repetitive control

“…It requires a proper model of the input signal and generally their computational requirements for real-time implementation on industrial systems are enormous and difficult (Pasand and Taherkhani, 2021). Also, recently some hybrid methods have proposed to extract instantaneous frequency of the signals (Daneshvar and Salehi, 2022; Liu et al, 2022).…”