+ Full - Envelope Aerodynamic Modeling of the Harrier Aircraft

The status of an ongoing project to identify a full-envelope model of the YAV-8B Harrier using flight-test and parameter identification techniques is described. As part of the research in advanced control and display concepts for V/STOL aircraft, a full-envelope aerodynamic model of the YAV-8B will be identified. Mathematical model structures and parameter identification methods that are being developed for identification of a YAV-8B aerodynamic model are presented. A globalpolynomial model structure is being used as a basis for identification of the YAV-8B aerodynamic model. State estimation methods are used to ensure flight data consistency prior to parameter identification. Equation-error methods are being used to identify model parameters. A fixed-based simulator has been used extensively to develop flight test procedures and to validate parameter identification software. Using simple flight maneuvers, a simulated data set was created covering the YAV-8B flight envelope from about 0.3 to 0.7 Mach and about -5" to 15O angle of attack. A singular value decomposition implementation of the equation-error approach produced good parameter estimates based on this simulated data set.