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In this paper we present results of a study of an integrated aero-propulsion flight control system. The resulting problem is that of controlling the system in which actuators operate on different time scales. This is a difficult problem since the control strategy needs to balance between not using the slow actuator at all, and slowing down the overall system to the time scale of the slow actuator. In the case of aero-propulsion control design for F/A-18 aircraft, the part of the control derivative matrix associated with engines is not full rank so not all states of interest can be simultaneously forced to track the commands. A control strategy that takes this constraint into account has been developed. The proposed IRAP approach is illustrated through simulation of F/A-18 aircraft dynamics under flight-critical control effector failures.

In this paper the results obtained under a NASA Dryden Phase II Small Business Innovative Research (SBIR) project are described. At Scientific Systems Company, Inc. (SSCI) we developed an efficient Integrated Failure Detection, Identification and Reconfiguration (FDIR) system referred to as the FLARE (Fast on-Line Actuator REconfiguration) system. The FLARE system achieves very fast detection and identification of failures in Electro-Mechanical Actuators (EMA), and effective control reconfiguration in the presence of single or multiple failures and recoveries even while rejecting external disturbances. The FLARE system combines different FDIR algorithms with a disturbance rejection mechanism within a retrofit control architecture. In collaboration with Boeing Phantom Works, the performance of the FLARE system has been extensively evaluated using high-fidelity and piloted simulators.