Fault tolerant air data system for pitot tube failure

Abstract

An integrated airspeed and angle of attack sensor failure detection, identification, isolation and accommodation scheme is presented. The proposed system uses information from the inertial measurement unit, available air data sensors, and an aircraft digital twin that provides virtual measurements of the aircraft’s aerodynamic and propulsion forces to feed a nonlinear estimator capable of detecting air sensor failure and suppress its effect on the aircraft air data prediction. The novelty of the proposed approach is that sensor fault detection, identification, isolation, and accommodation are integrated into a feedback scheme where the information produced by fault detection is used to modulate the noise covariance of faulty sensors so that the nonlinear estimator is able to maintain the air data estimate with a small error despite the presence of various failures in the air data sensors.