DETERMINATION OF THE FUNDAMENTAL FREQUENCY OF A PERIODIC SIGNAL INCLUDING HARMONIC COMPONENTS

摘要

The invention relates to a method for determining the fundamental frequency of a periodic signal including harmonic components, comprising: calculating, during a first rough estimation (200) of the fundamental frequency and from samples of the signal, a first estimated value of the fundamental frequency, said value being expressed in a frequency unit that is selected such that the entire portion of the first estimated value comprises at most three digits; and then using a step (300) of estimating the fundamental frequency to the nearest tenth, in said unit, in order to determine, from said first value, a second estimated value, in said unit, of the fundamental frequency to the nearest tenth, by searching, from among a first set of possible frequency values corresponding to variations, at a constant spacing of 0.1, in the estimated first value, for a first frequency value for which the corresponding signal amplitude, calculated from the discrete Fourier coefficients of rank 1, is at a maximum. Similar additional steps (400; 500) can then be used to obtain an estimate of the fundamental frequency to the nearest hundredth, in said unit, and then to the nearest thousandth, in said unit, respectively.