Patent ID: 8234037

Claim:
A method for detecting at least one oscillatory fault relating to at least one slaving chain for slaving the position of at least one airfoil of an aircraft, said slaving chain forming part of a system of electric flight controls of the aircraft, being associated with a set of information sources which generate in real time the current values of parameters related to the aircraft, said method comprising: providing a movable airfoil, whose position with respect to the aircraft is adjusted by at least one actuator; adjusting the position of said airfoil by the actuator, as a function of at least one actuation order received by the actuator; measuring by at least one sensor, in real time, a current actual position of said airfoil; and receiving by a computer, which comprises piloting laws, said actual position measured by the at least one sensor and the current parameter values, generated by said set of information sources, with the computer computing and transmitting the at least one actuation order to said actuator, wherein the computer further carries out the steps of: a) determining a current value of a quantity related to the position of said airfoil; b) determining a threshold value; c) comparing said current value relating to the position of the airfoil with the determined threshold value to determine an overshoot of the threshold value by the current value; and d) counting the number of overshoots of said threshold value by said current value to detect an oscillatory fault, wherein the oscillatory fault, is represented by a periodic signal exhibiting a succession of rising and falling edges separated by break points: wherein in step b), an extremity value is determined, which varies successively and alternately between a maximum value Xmax and a minimum value Xmin during each overshoot generating a counting; and the threshold value is determined from said extremity value and a predetermined amplitude value S, with the threshold value being equal to Xmax−S when the extremity value corresponds to Xmax and to Xmin+S when the extremity value corresponds to Xmin; and in step d), an oscillatory fault is detected based on the counted number of overshoots of the threshold value being greater than a predetermined number.