Development of virtual sensors to estimate critical aircraft flight parameters

Abstract

This paper addresses the estimation of flight parameters in nominal and degraded flight conditions when one or several specific sensors become faulty. Anticipating more stringent regulations for future aircraft, reconstructing through time the missing signals is a challenging objective for Flight Control Systems, especially because some of them are essential for control purposes. To this end, this paper proposes a solution based on virtual sensors which makes use of an Adaptive Extended Kalman Filter. This allows the longitudinal flight parameters of a civil aircraft to be estimated on-line before and after the occurrence of one or several failures. This solution offers interesting monitoring capabilities including the detection of common mode failures (i.e., simultaneous failures occurring on redundant sensors), and also provides the capability of correcting a wrong aircraft weight in addition to the sensors monitoring. Typical results using real flight test data are shown to evaluate the performances of the approach in terms of detection and estimation capabilities.