Adaptive Feedfoward Feedback Control Framework

An Adaptive Feedforward and Feedback Control (AFFC) Framework is proposed to suppress the aircraft's structural vibrations and to increase the resilience of the flight control law, in the presence of AE/ASE interactions. Specifically, the adaptive feedforward controller is designed to reduce any atmospheric induced structural vibrations of the aircraft. The adaptive feedback controller is applied as an additive perturbation of the flight control system to suppress any undesired AE/ASE interactions, and prevent the onset of Flutter/Limit Cycle Oscillation (LCO) instabilities within the flight envelope of a flexible aircraft. The proposed research effort fits very well within the scope of the NASA Dryden Flight Research Center topic "A1.10 Adaptive Structural Mode Suppression," specifically within the Integrated Resilient Aircraft Control (IRAC) effort under the Aviation Safety Program. This research will help the original flight control system to robustly recover from or adjust easily to any unforeseen change during its normal operation due to AE/ASE interactions. In addition, practical concerns will deal with the minimal interference with the original rigid-body controller, as well as its feasible implementation using the standard controller's sampling rate frequency.