US 12,434,854 B2
Method and device for detecting a fault in a mechanical system comprising at least one rotating member
Hervé Morel, Aix en Provence (FR); Jérémy Jouve, Senas (FR); Anas Had, Roanne (FR); Hugo Andre, Roanne (FR); and Mohamed El Badaoui, Riorges (FR)
Assigned to AIRBUS HELICOPTERS, Marignane (FR)
Filed by AIRBUS HELICOPTERS, Marignane (FR)
Filed on Dec. 26, 2023, as Appl. No. 18/396,512.
Claims priority of application No. 2300829 (FR), filed on Jan. 30, 2023.
Prior Publication US 2024/0253811 A1, Aug. 1, 2024
Int. Cl. B64D 45/00 (2006.01); B64C 27/12 (2006.01)
CPC B64D 45/00 (2013.01) [B64C 27/12 (2013.01); B64D 2045/0085 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for detecting a fault in a mechanical system, the mechanical system comprising at least one rotating member that rotates about a rotation axis (AX) and a vibration sensor transmitting a temporal vibration signal x(t), an angular sensor transmitting a temporal angular signal θ(t) that varies as a function of an angular position of the rotating member about the rotation axis (AX) and a calculator,
the method comprising the following steps:
processing of temporal vibration signals xm(t) transmitted by the vibration sensor, comprising the following sub-steps:
transmission of M temporal vibration signals xm(t) by the vibration sensor, M being greater than or equal to 2, m being a positive integer varying from 1 to M, “t” being the operating time of the mechanical system;
first transformation, with the calculator, of the M temporal vibration signals xm(t) into M angular vibration signals xm(θ) as a function of the temporal angular signal θm(t), “θ” being an angle of the rotating member about the rotation axis (AX);
second transformation, with the calculator, of the M angular vibration signals xm(θ) into M frequency vibration signals xm(fθ) by means of a frequency operator ϑ, where “fθ” is a frequency channel; and
first determination of trend frequency channels ft as a function of the M frequency vibration signals xm(fθ), a trend frequency channel ft being a frequency channel fθ for which the M frequency vibration signals xm(fθ) satisfy a selection criterion relating to an increasing trend;
analysis, with the calculator, of the trend frequency channels ft, comprising the following sub-steps:
comparison of each trend frequency channel ft with linear combinations of fault frequencies fd relating to the fault of interest, the linear combinations respectively comprising sums of several of the fault frequencies fd multiplied by integer coefficients ni; and
second determination of fault frequency channels fx as a function of the comparison, a fault frequency channel fx being a trend frequency channel ft for which the differences from the linear combinations are less than a comparison threshold;
calculation, with the calculator, of an indicator Ioptimal of the presence of the fault in the mechanical system as a function of the number of the fault frequency channels fx and the number of the linear combinations of the fault frequencies fd; and
triggering of a fault presence alert as a function of a comparison between the fault presence indicator Ioptimal and a fault presence threshold.