1. A signal validation method for generating a reliable signal from a plurality of redundant received signals, comprising the following steps: simultaneously measuring samples of each of said received signals; memorizing the values of the last N samples (N.gtoreq.2) of each received signal; determining a plurality of model functions corresponding to the N memorized samples for each of said received signals, said model functions being defined as a plurality of parameters representing an approximate function for said N memorized samples; calculating a dispersion coefficient representing the difference between each sample of the N memorized samples and a sample, determined by the model functions; validating said model functions by comparing said dispersion coefficient with a predetermined dispersion threshold, said model function being valid if said dispersion coefficient is smaller than said predetermined dispersion threshold; and generating said reliable signal by determining a value for a sample of said reliable signal as a function of at least some of said valid model functions.