A reconfigurable flight control system is a control system which can automatically adapt itself to maintain the performance of a damaged aircraft to be as close as possible to that of the normal or undamaged one. This research focuses mainly on Multi-Input, Multi-Output (MIMO) reconfigurable flight control for an aircraft with damaged actuator(s) which may greatly affect the performance and control of the aircraft, and also pose a challenging flight control problem. The foundation of the control system is a baseline controller and an adaptive module which constitutes a reconfigurable part. The baseline controller ensures that the aircraft has acceptable performance and handling qualities throughout the flight envelope. The combination of a Quantitative Feedback Theory (QFT) Pre-Design Technique (PDT) and a Reduced-order, Linear, Dynamic Inversion (RLDI) control strategy yields a flight control system with good tracking performance and handling qualities with no Pilot Induced Oscillation (PIO) tendencies throughout the designated set of flight conditions. In addition, the system is highly immune to large uncertainties in the aircraft dynamics. The modified filtered-&egr; adaptive algorithm is developed and utilized in the adaptive module of the system. This adaptive algorithm performs well with MIMO system with the added advantage of not having to pre-identify the dynamics of the damaged aircraft, provided that the conditions of reconfigurability are met. An example of the proposed control system with the NASA F-18 HARV vehicle model and a damaged actuator demonstrates the effectiveness of the concept.
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