Patent ID: 7949439

Claim:
A method of diagnosing an aircraft by analyzing at least one spectrum (V{right arrow over (te)}st, V{right arrow over (te)}st 1 , V{right arrow over (te)}st 2 ) obtained from measurements made on the aircraft, in particular from vibration measurements, the method comprising the following successive operations: synchronizing a plurality of measurement time data series; calculating a mean series of measurement time data from a plurality of synchronized measurement time data series; transforming from the time domain to the frequency domain in order to obtain the measurement frequency data vector from the mean series of time data; imputing the frequency data vector(s) corresponding to the spectrum (spectra) for analysis to a calculation module ( 23 ) together with at least one first reference spectrum data vector ({right arrow over (VR)} 1 , {right arrow over (VR)} 2 , {right arrow over (VR)} 3 , {right arrow over (VR)} 4 ), the calculation module determining, for each input vector, a plurality of degree-of-membership vectors for the components of the input vector, specifying their respective degrees of membership to a plurality of classes, the calculation module determining a diagnosis value (Diag) as a function of the degree-of-membership vectors, and as a function of the spectrum (spectra) to be analyzed, of the reference spectrum (spectra), and of parameters (a m , b m , c m , α i,j , β i,j , δ i,j ) determined from at least two reference spectra including said first reference spectrum.