Linearization and Identification of Aircraft Turbofan Engine Models

Abstract Experiments are carried out to derive linearized models of aircraft turbofan engine dynamics from standard engine simulators used in industry, the ultimate objective being low complexity gain-scheduled control design. First, standard linearization techniques are applied on the OBIDICOTE model, a commercial aircraft engine model developed within a European project. Second, identification algorithms are applied on the model of a military engine developed by SNECMA Moteurs to power a fighter aircraft. Satisfying low-order linearized models are obtained. The choice of the linearization points (location, density) in the 3D flight envelope (engine power, altitude, Mach number), as well as the nature of the input signals used for identification, turn out to be key features for a sensible control design.