Air data algorithm development for civil aviation aircraft

Modern aircraft avionics typically rely on physical sensors to estimate critical parameters such as airspeed V∞, angle of attack α (AoA) and sideslip angle β (AoS). The growing demand for more compact, reliable and cost-effective planes, particularly regarding light airplanes and UAVs (Unmanned Aerial Vehicles), has driven the development of synthetic sensors and the introduction of the concept of analytical redundancy. In fact, replacing redundant physical sensors with analytical ones has the potential to offer significant advantages. In this context, this work intends to contribute to the development of ASSE (Attack and SideSlip angles Estimator), a synthetic sensor developed by the Department of Mechanical and Aerospace Engineering of the Polytechnic University of Turin. Unlike commonly used synthetic sensors, ASSE is able to perform precise estimation of attack and sideslip angles without relying on specific aircraft configurations. However, it is capable of providing precise information only during manoeuvres. ASSE has undergone multiple tests involving simulated data and a technology demonstrator; this paper seeks to validate its potential with real flight data, obtained in collaboration with Airbus, Toulouse. Thanks to this experimental raw data, it will be possible to assess ASSE's real performance and explore its feasibility for implementation in actual aircraft. After an introduction to modern Air Data Systems (ADS) and the state-of-the-art in synthetic sensors, an in-depth description of the ASSE algorithm will be provided. This section will cover its analytical derivation, along with an evaluation of its benefits and limitations, highlighting the required conditions for existence and its operational boundaries. Additionally, examples with simulated data will be presented and analyzed. In the following section, experimental data will be introduced, along with pre-processing guidelines necessary for analysis using ASSE. The results will then be compared and reviewed to assess the performance of the proposed scheme. Finally, conclusions will be drawn, exploring potential improvements and future applications.