Patent ID: 8160770
Filing Date: 2012-04-17
Classification: B64C,G05B

Abstract:
1. A method of detecting at least one oscillatory fault in at least one positional slaving chain for at least one airfoil of an aircraft, said slaving chain comprising: at least one mobile airfoil; at least one actuator that adjusts position of said at least one mobile airfoil, as a function of at least one received actuation command; at least one sensor which measures actual position of said at least one mobile airfoil; and a computer which receives information from an airfoil control command, receives said measured airfoil position information from said at least one sensor, calculates from the received airfoil control command information and the received measured airfoil position information an actuation command, and transmits the actuation command to said actuator, wherein the method comprises the successive steps of: wherein in step a): estimation of the reference position is based on a model represented in the form of an augmented non-linear state representation, which comprises a state equation and an observation equation; during an initialization phase: during a subsequent phase, the following successive operations α, β, γ and δ are carried out in an iterative manner: α for an arbitrary iteration k, the observation equation is updated a posteriori; β a Cholesky factorization of the covariance of the a posteriori estimation error and a prediction of the state vector at iteration k are carried out; γ the state vector is updated a priori; and δ the state vector is estimated a priori so as to obtain an estimation of said reference position and of said parameters.