Onboard Estimation of Impaired Aircraft Performance Envelope

Abstract

*† ‡ § ** †† A methodology for estimating the flight envelope of impaired aircraft using an innovative differential vortex lattice algorithm, tightly coupled with an extended Kalman filter is presented. The approach exploits prior knowledge about the undamaged aircraft parameters to reduce the order of the estimation problem. Probing maneuvers are used to improve the observability of the system dynamics. Estimated aerodynamic parameters are then used to determine the aircraft aerodynamic, structural, structural dynamic, and aeroelastic parameters. These parameters are then used to estimate the aircraft performance envelope and maneuver limits. This data can be provided to the pilot to aid in managing the impairment, and for implementing safe maneuvering and landing guidance laws. I. Introduction odern flight control systems have enabled safer operation of civil and military aircraft by making the aircraft dynamics more compatible with the human pilot. This has been achieved through advances in automatic control theory, together with modern sensors and computing hardware. Design methods have now reached such an advanced level of sophistication that systematic methods are available for synthesizing flight control systems of extremely complex aircraft. The next frontier in this discipline is that of creating flight control systems that can maintain safe flight after significant damage to the aircraft, and allow it to land with no loss of life or property. This sentiment is succinctly expressed in the stated goal of NASA’s Integrated Resilient Aircraft Control program