Method and device for detecting an uncontrolled movement of an aircraft control surface

A detection device for an uncontrolled movement of a control surface of an aircraft which is servo-controlled in position by a feedback loop, said feedback loop belonging to an electrical flying command system the aircraft and comprising:

• said control surface being mobile and the position of which with respect to the aircraft is adjusted by at least one actuator;
• said actuator that adjusts the position of the control surface as a function of at least one actuating order received as a feedback command;
• at least one sensor measuring the effective position of said control surface;
• and
• one calculator developing a control surface command order, that receives said measured effective position and deducts from it an actuating order that is transmitted to said actuator as a feedback command,
• said device comprising:
• first means to determine a theoretical feedback current representative of said feedback command emitted by said calculator;
• at least one auxiliary sensor being connected to said actuator and which is provided so as to measure a parameter representative of the feedback command from which an effective feedback current is determined;
• second means to calculate the difference between said theoretical feedback current and said effective feedback current so as to create an error signal;
• and
• third means detect an uncontrolled movement of the control surface if a comparison value depending on said error signal is higher than a threshold value during at least one confirmation time.

An electrical flying command system of an aircraft, said system comprising:

• at least one means generate a command order for a control surface for at least one control surface the aircraft;
• and
• at least one feedback loop in position of such control surface , comprising:
• said control surface being mobile and the position of which with respect to the aircraft is adjusted by at least one actuator;
• said actuator that adjusts the position of the control surface as a function of at least one actuating order received;
• at least one sensor measuring the effective position of said control surface ;
• and
• one calculator developing a control surface command order, that receives said measured effective position and deducts from it an actuating order that is transmitted to said actuator,
• a detection device , which comprises:
• first means to determine a theoretical feedback current representative of said feedback command emitted by said calculator;
• at least one auxiliary sensor being connected to said actuator and which is provided so as to measure a parameter representative of the feedback command from which an effective feedback current is determined;
• second means to calculate the difference between said theoretical feedback current and said effective feedback current so as to create an error signal;
• and
• third means to detect an uncontrolled movement of the control surface if a comparison value depending on said error signal is higher than a threshold value during at least one confirmation time.