Patent ID: 8755956

Claim:
A method for detecting a jamming of a control surface, a position of the control surface is controlled by a feedback loop that forms a part of an electrical flight control system of an aircraft, the feedback loop comprising: a plurality of actuators coupled to the control surface to adjust the position of the control surface in relation to the aircraft according to at least one actuation instruction received as a control command; at least one sensor configured to measure an actual position of said control surface; and at least one computer that is configured to produce a control surface control instruction, which receives said actual position and produces an actuation instruction that is transmitted to one of said plurality of actuators in a form of a control current, wherein the method comprises: receiving as input a first control instruction of the control surface from a device onboard the aircraft, the first control instruction limited to maximum operational values; filtering the first control instruction signal using a filter that models a behavior of the one of said plurality of actuators and the feedback loop; determining a control error corresponding to a difference between the filtered first control instruction of the control surface and a corresponding control surface position; forming a comparison signal with a difference between an absolute value of said control error and the absolute value of a second control instruction of the control surface, the second control instruction shielded from said control error; comparing the comparison signal with a threshold value; and detecting a jamming of said control surface if the comparison signal is greater than the threshold value during at least a confirmation period; reconfiguring a second one of the plurality of actuators to adjust the position of the control surface based on the detection of the jamming of the control surface.