Nonlinear System Identification and Analysis of Aircraft High Alpha Dynamics

Nonlinear system identification and global analysis techniques are proposed for modeling the high angle-of-attack stability and control characteristics of the new class of fighters such as F-18, F-229 V-22 and JAST. It is expected that large savings in flight testing time will be achieved by using these methods and the resulting models will have the required accuracy for simulation and control system design. The methods proposed are based on using Bifurcation Analysis and Chaos Theory Methodology (BACTM), Optimal Input design, Neural Networks and Global Maximum Likelihood parameter identification. Both simulated and flight test data will be used. The effect of inputs and maneuvers on the identifiability of the parameters will be investigated. It is proposed to use the data from the NAWC high fidelity CASTLE simulation environment and the F-18 High Alpha Research Vehicle (HARV) program since this data is known to be of good quality and is available for research purposes from NASA. SAIC's System Technology Group will provide support during all phases of the SBIR effort. In addition, Northrop Grumman and Bell Helicopter have agreed to provide data and support for the F-18 and V-22 aircrafts.