Monitoring systems for detecting failures in fly-by-wire aircraft flight control systems
AssigneeThe Boeing Company
InventorAlan B. Hickman
Life of this patent
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Abstract
A monitoring system for detecting failures, or impending failures, in subsystems of a fly-by-wire primary flight control system of an aircraft. The system monitor a critical variable of at least two controllers acting in concert, in real time. Differences between the critical variables are calculated and, after filtering to remove insignificant variations, structural fatigue damage is estimated based on significant detected variations. Depending upon the relative severity of the estimated fatigue damage, the aircraft's primary flight control computer is programmed to shut down the malfunctioning subsystem, display a message indicating need for repair, or take other appropriate action.
Claims14
A method of monitoring subsystems of a fly-by-wire primary aircraft flight control system, the method comprising:
- (a) communicating signals representing loads from each of a first and a second aircraft flight control surface controller to an aircraft onboard digital signal processor, said controllers normally operating in concert;
- (b) periodically determining a difference between magnitudes of loads of the first and the second controllers;
- (c) comparing a periodically determined difference with a difference in load of a prior period;
- (d) calculating fatigue damage resulting from a change of load on the controllers;
- (e) calculating a rate of change of fatigue damage based on steps (a) through (d);
- and
- (f) selecting at least one response from a range of alternative responses, the selecting based on the rate of change of fatigue damage.
A monitoring system for subsystems of a fly-by-wire primary aircraft flight control system, the monitoring system comprising:
- (a) an aircraft flight control surface;
- (b) a first and a second cooperating controller, each in mechanical communication with the aircraft flight control surface to urge the flight control surface into a predetermined orientation;
- and
- (c) a digital signal processor in electrical communication with a control electronic unit associated with each of the first and second controllers, the computer performing activities comprising:
- (i) determining a difference between magnitudes of loads on the first and second controller from signals from the electronic unit of each of the first and second controllers;
- (ii) periodically comparing the determined difference in load magnitude with a prior difference in load magnitude to determine localized maxima and minima;
- (iii) calculating fatigue damage based on determined local maxima and minima;
- (iv) calculating a rate of change of fatigue damage;
- and
- (v) selecting at least one response from a range of alternative responses based on the calculated rate of change of fatigue damage.
Dependencies are inferred from the claim text.