The new Intelligent Flight Controller (IFC) Gen 2a/2b was cleared for flight test in recommendations resulting from the July 30, 2008 Airworthiness and Flight Safety Review Board (AFSRB) briefing. This is a critical step to achieving the Agency Performance Goal (APG) milestone. Flight tests are scheduled to begin August 19th, at NASA Dryden Flight Research Center. Their objective is improving performance of a damaged aircraft without introducing destabilizing effects.
BACKGROUND: NF-15B aircraft flight test results obtained by testing an initial direct adaptive control scheme (Gen2) documented substantial stability improvements using the adaptive control scheme. In addition to the stability analysis, several implementation barriers were identified. Under the Integrated Resilient Aircraft Control (IRAC) project, NASA has successfully designed and implemented two improved adaptive control architectures (Gen2A & Gen2B) for the NF-15B vehicle. The two new designs provide incremental improvements that directly address the shortcomings of the initial Gen2 design.
The Gen2A system refined the selected inputs for the adaptive algorithm and provides a normalized learning rate to avoid over-learning during aggressive pilot inputs. The Gen2B system also incorporates a model performance seeking method for better adaptive properties. Both systems have been extensively tested in a high-fidelity nonlinear piloted simulation and have been cleared through the airworthiness review board. Flight evaluation of the stability and performance characteristics of the two new adaptive control designs is scheduled to begin in August 2008.
NASA PROGRAM FUNDING: Aeronautics Research Mission Directorate (ARMD), Aviation Safety Program (AvSP), Integrated Resilient Aircraft Control (IRAC) Project
COLLABORATOR: NASA Dryden Flight Research Center
Contact: John Kaneshige