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Complexity and Pilot Workload Metrics for the Evaluation of Adaptive Flight Controls on a Full Scale Piloted AircraftFlight research has shown the effectiveness of adaptive flight controls for improving aircraft safety and performance in the presence of uncertainties. The National Aeronautics and Space Administration's (NASA)'s Integrated Resilient Aircraft Control (IRAC) project designed and conducted a series of flight experiments to study the impact of variations in adaptive controller design complexity on performance and handling qualities. A novel complexity metric was devised to compare the degrees of simplicity achieved in three variations of a model reference adaptive controller (MRAC) for NASA's F-18 (McDonnell Douglas, now The Boeing Company, Chicago, Illinois) Full-Scale Advanced Systems Testbed (Gen-2A) aircraft. The complexity measures of these controllers are also compared to that of an earlier MRAC design for NASA's Intelligent Flight Control System (IFCS) project and flown on a highly modified F-15 aircraft (McDonnell Douglas, now The Boeing Company, Chicago, Illinois). Pilot comments during the IRAC research flights pointed to the importance of workload on handling qualities ratings for failure and damage scenarios. Modifications to existing pilot aggressiveness and duty cycle metrics are presented and applied to the IRAC controllers. Finally, while adaptive controllers may alleviate the effects of failures or damage on an aircraft's handling qualities, they also have the potential to introduce annoying changes to the flight dynamics or to the operation of aircraft systems. A nuisance rating scale is presented for the categorization of nuisance side-effects of adaptive controllers.
Document ID
Document Type
Technical Memorandum (TM)
Hanson, Curt (NASA Dryden Flight Research Center Edwards, CA United States)
Schaefer, Jacob (NASA Dryden Flight Research Center Edwards, CA United States)
Burken, John J. (NASA Dryden Flight Research Center Edwards, CA United States)
Larson, David (NASA Dryden Flight Research Center Edwards, CA United States)
Johnson, Marcus (NASA Ames Research Center Moffett Field, CA United States)
Date Acquired
May 13, 2014
Publication Date
February 1, 2014
Subject Category
Aircraft Stability and Control
Report/Patent Number
Funding Number(s)
WBS: WBS 284848.
Distribution Limits
Work of the US Gov. Public Use Permitted.
pilot workload metrics
complexity metrics
adaptive controls

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NameType 20140005730.pdf STI