Abstract: Methods and devices for detecting oscillatory faults in a positional servocontrol arrangement for an aircraft control surface are provided. The detection device estimates a reference position of the control surface and, with the aid of a model in which at each iteration a residual value of the previous iteration, multiplied by a dynamic gain, is injected, detects an oscillatory fault with the aid of this reference position.

Abstract: Method and device for detecting oscillatory faults in a positional servocontrol arrangement for an aircraft control surface. The detection device comprises means for estimating a reference position of the control surface, with the aid of a model in which at each iteration a residual value of the previous iteration, multiplied by a dynamic gain, is injected, and means for detecting an oscillatory fault with the aid of this reference position.

Abstract: Disclosed is a method of detecting at least one oscillatory fault in at least one positional slaving chain for at least one airfoil of an aircraft. The method involves estimating a reference position of the airfoil in the absence of a fault, and calculating a residual value based on the difference between the estimated reference position and the actual position measured by at least one sensor. The calculated residual value is compared with at least one predetermined threshold value to determine the number of successive and alternating overshoots of the predetermined threshold value by the residual value, and oscillatory fault is determined based on the determined number.

Abstract: The detection device (1) comprises means (19) for estimating, with the aid of a model, a reference position of the airfoil, as well as the values of parameters of said model making it possible to update it, and means (21, 23) for detecting an oscillatory fault with the aid of this reference position.