METHOD AND DEVICE FOR DETERMINING MULTIPLICATIVE FAULTS OF A SENSOR INSTALLED IN A SYSTEM COMPRISING A PLURALITY OF SENSORS

A method is described for determining multiplicative faults of a sensor installed in a system comprising a plurality of sensors, comprising the steps of:-detecting an effective target signal (s) from a target sensor, representative of a target quantity of the system;-detecting one or more auxiliary signals respectively from one or more auxiliary sensors of the system besides the target sensor, representative of auxiliary quantities of the system;-determining an estimated target signal (s*) representative of the target quantity from the one or more auxiliary signals;-determining a first quadratic difference (r+) between the effective target signal (s) multiplied by a multiplicative positive factor (cr+) greater than 1, and the estimated target signal (s*);-determining a second quadratic difference (r) between the effective target signal (s) and estimated target signal (s*);-determining a third quadratic difference (r−) between the effective target signal (s) multiplied by a positive multiplicative factor (c−) smaller than 1, and the estimated target signal (s*);-determining a first ratio (r/r+) between the second (r) and lirst quadratic differences (r+);-determining a second ratio (r/r−) between the second (r) and third quadratic differences (r−);-comparing the first (r/r+) and second ratios (r/r−) with a first comparison factor (Kf);-determining the square of the effective target signal (s); determining the square of the estimated target signal (s*); comparing the square of the effective target signal (s) and square of estimated target signatl (s*) with a second comparison factor (Ke); establishing the presence of multiplicative faults of target sensor if at least one between the first (r/r+) and second ratios (r/r−) is greater than the first comparison factor (Kf), and at least one between the square of the effective target signal (s) and square of the estimated target signal (s*) is greater than said second comparison factor (Ke).