Method For Characterising One Or More Faults In A System

Method for characterising one or more faults in a system grouping together a plurality of internal physical quantities and delimited by a plurality of boundary physical quantities,

• the system being modelled by a healthy model establishing relationships linking said internal physical quantities with one another and with the boundary physical quantities in the absence of a fault, a fault being defined as an alteration in the relationships linking said internal physical quantities with one another and with the boundary physical quantities with respect to the healthy model,
• said system being provided with a plurality of sensors measuring values of internal physical quantities and external physical quantities,
• the method comprising:
• determining a vector of the measured measurements of a set of internal physical quantities by reading the values of internal physical quantities measured by the sensors,
• determining a vector of actual symptoms by the difference between the vector of measured measurements and a vector of expected measurements, said vector of expected measurements grouping together values of internal physical quantities obtained by simulation of the healthy model from the boundary physical quantities,
• wherein the method further includes the implementation of the steps of:
• for a determined number of iterations:
• determination of a proposed vector of faults from the current vector of faults by a pseudo-random sampling using a probability law on each of the fault values of the current vector of faults, a vector of faults grouping together values representative of one or more faults;
• determination of a probability of acceptance of the proposed vector of faults using the vector of actual symptoms, a fault matrix, the current vector of faults, a probabilistic distribution of the vector of actual symptoms given the current vector of faults, the proposed vector of faults, a probabilistic distribution of the vector of actual symptoms given the proposed vector of faults, and an a priori probability distribution of occurrences of a values of the fault vector, said fault matrix grouping together consequences of each fault on the internal physical quantities;
• replacement or not of the current vector of faults by the proposed vector of faults as a function of the probability of acceptance of the proposed vector of faults,
• characterising a fault by counting a number of iterations having involved said fault in a current vector of faults.