Real-Time Methods for Adaptive Suppression of Adverse Aeroservoelastic Dynamics

Adverse aeroservoelastic interaction is a problem on aircraft of all types causing repeated loading, enhanced fatigue, undesirable oscillations and catastrophic flutter. Traditionally, to suppress adverse aeroservoelastic interaction, notch and/or roll off filters are used in the primary flight control system architecture. This solution has pitfalls; rigid body performance is degraded due to resulting phase penalty and it is not robust to off nominal behavior. In Phase I, an approach was developed that is entitled, Modal Isolation and Damping for Adaptive Aeroservoelastic Suppression (MIDAAS). This adaptive technique determines an optimal blend of multiple outputs that effectively isolates a problematic lightly damped mode and simultaneously determines an optimal blend of multiple inputs to suppress the problematic mode via feedback. Adverse effects on aircraft rigid body performance are minimized, resulting in virtually no phase penalty. MIDAAS was validated against aeroservoelastic F/A-18C aircraft models with varying stores configurations and demonstrated very successful performance. In the proposed Phase II program, a robust real-time adaptive aeroservoelastic suppression solution will be developed with a buildup approach that includes further MIDAAS enhancements, extensive validation studies utilizing a high-fidelity CFD-based aeroelastic model of the NASA X-53 aircraft, and extensive validation studies utilizing real-time pilot in the loop simulation capability.