Piloted Simulation to Evaluate a Real-Time Envelope Protection System for Mitigating In-Flight Icing Hazards

Development and Implementation of a Model-Driven Envelope Protection System for In-Flight Ice Contamination

“…A detailed discussion of these evaluations and results are presented in another paper presented at this conference (Ref. 19). …”

“…This interface with the subject vehicle is performed as though an autopilot is driving control deflections using multi-frequency orthogonal inputs (Ref. 19). Amplitudes of the inputs are adjusted to provide excitation while minimizing vehicle motion.…”

“…The least squares parameter vector estimate is obtained as the value of θ that minimizes the cost function in Equation (4) (Ref. 19).…”

Flight Test Maneuvers for Efficient Aerodynamic Modeling

“…The fact that the inputs are optimized for minimum perturbation amplitudes and maximum input energy make them applicable to practical problems where exciting aircraft dynamic response excessively would disturb the pilot or passengers. Initial investigations of this approach have already begun, with the development of an onboard envelope protection system for a commuter aircraft in icing conditions [7][8][9] , and work studying the minimum necessary excitation for accurate stability and control parameter estimation in real time 6 . American Institute of Aeronautics and Astronautics …”

“…Some of the problems that can be addressed are: multi-axis stability and control flight testing in off-nominal conditions such as high sideslip angles, near stall and departure, in post-stall flight, and during recovery from stalls and departures; multi-axis aerodynamic modeling over large portions of the flight envelope with a single maneuver; real-time monitoring of aircraft stability and control; efficient flight envelope expansion; and simultaneously estimating control effectiveness for a large number of individual control surfaces. The input design technique has been applied successfully to hypersonic stability and control flight testing 4,5 , real-time dynamic modeling for experimental fighter aircraft and subscale aircraft 2,6 , and as part of an envelope protection system for a commuter aircraft in icing conditions [7][8][9] . In this paper, novel maneuvers for efficient stability and control flight testing are described and demonstrated.…”