Identification d'un modèle global linéarisé de la dynamique de vol du Cessna Citation X à partir d'essais en vol

Abstract

A key element in aircraft enhancement is the availability of accurate models allowing controller synthesis for flight controls enhancement or new aerodynamic device design. Those models can be obtained from wind tunnel tests, computational fluid dynamics and flight test identification. This study concerns the Cessna Citation X business aircraft model identification, from flight tests achievement to identified model validation. Flight tests were carried out on a SimFinity ™ research simulator designed and manufactured by CAE Inc. and featuring a level D flight dynamics. The level D is the highest accuracy level discerned by the FAA, the United States civil aviation federal regulation authority. More than 1,000 flight tests were conducted for different configurations in speed (140 to 240 knots), altitude (10,000 to 46,300 feet), mass (24,000 to 33,000 pounds) and longitudinal center of gravity position (17% to 34% of the mean aerodynamic chord). Two identification approaches were used: the “black box” approach, where the modeler has no prior knowledge of the system under study and the “grey box” approach where the mathematical understanding of the system is embedded by the modeler into the model. The identified models were validated using a simplified Proof Of Match (POM) method and the level D FAA criteria. Despite experimental errors, very good results were obtained for both approaches. Nevertheless, based on the modeling experience and the results acquired on the Cessna Citation X, we believe that the “grey box” approach is more suitable for the global model identification of an aircraft because it allows the estimation of parameters which have a physical meaning. The Cessna Citation X identified model is still under development and could be augmented by other aircraft systems’ models or used as a base for more complex flight dynamics models. The know-how acquired with the conducted flight tests will allow, without any doubt, the realization of new innovative flight tests optimized for system identification. The methods used in this study could be used for the identification of the Cessna Citation X performance model. This is the first Master thesis obtained in this project on the Cessna Citation X model identification from flight test data.

Date	24 Sept 2014
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Ruxandra Botez (Supervisor)