FREEDOM: Validated Method for the Rapid Assessment of Incipient Multimodal Faults of Complex Aerospace Systems

Model-based Fault Detection and Isolation (FDI) methods allow to infer the health status of complex aerospace systems through a large quantity of data acquired in-flight, and evaluations of numerical models of the equipment. This results in an intensive computational procedure that can be addressed only grounding the aircraft. We introduce an original methodology to sensitively accelerate FDI by reducing the computational demand to identify the health status of the aircraft. Our scheme FREEDOM – Fast REliability Estimate and incipient fault Detection Of Multiphysics aerospace systems – proposes an original combination of a novel two-step compression strategy to compute offline a synthesized representation of the dynamical response of the system, and uses an inverse Bayesian optimization approach to infer online the level of damage determined by multiple fault modes affecting the equipment. We demonstrate and validate FREEDOM against numerical and physical experiments for the case of an ElectroMechanical Actuator (EMA) employed for secondary flight controls. Particular attention is dedicated to simultaneous incipient mechanical and electrical faults considering different experimental settings. The outcomes validate our FDI strategy, which permits to achieve the accurate identification of complex damages outperforming the computational time of state of the art algorithms by two orders of magnitude.