Early and robust detection of Oscillatory Failure Cases (OFC) in the flight control system: a data driven technique

摘要

This research study deals with a signal-based method for robust and early detection of Oscillatory Failure Case (OFC) in aircraft control surface servo loops. Detection of such failures is an important issue since they may cause additional structural loads and affect the overall efficiency of the aircraft. One of the latest solutions used on board Airbus aircraft is an analytical redundancy approach that has the advantage and the weakness of requiring an accurate model of the servo loop. This is why a technique independent of a model can be useful for different actuators and aircraft. Signal based approaches are appealing solutions. An ideal data-driven technique would be able, starting from the knowledge of command(input) and position(output), to detect the anomaly (OFC) without the need to determine the servo loop model. The main aim of this study is first to present an overview of signal-based methods that could be used for OFC detection, then to make a qualitative trade-off and finally to present a complete detection strategy that will be tuned and tested. The results based on distance and correlation measures are promising and show that the proposed technique can be applied, with slight modifications, to any type of actuator (Hydraulic, Electro-Hydrostatic (EHA) and Electro-Backup-Hydrostatic (EBHA) actuators). However, a refined index of similarity for OFC detection is still under study and it represents an interesting area of future research.