Robust Aeroservoelastic Toolbox for Nonlinear Data-Based Modeling and Analysis

ZONA Technology and the University of Florida propose an R&D effort to establish a Robust Aeroservoelastic Toolbox (RASET) with emphasis on nonlinear identification, modeling and analysis. The RASET will serve the next-generation flutterometer. The toolbox augments the current mu-method analysis with nonlinear operators so limit cycle oscillations (LCO) can be predicted. Several representations of these nonlinearities, such as Volterra kernels and describing functions, are proposed. Flight data will be used to identify optimal estimates of these nonlinear representations and associated uncertainty. The resulting model will be used to compute stability margins that reflect both flutter and LCO instabilities. In Phase I, the developed RASET will formulate the foundation for the next-generation flutterometer. This toolbox will allow the computation of robust stability margins associated with explosive flutter or limit cycle oscillations (LCO). A feasibility study is proposed to validate this advanced flutterometer concept. In Phase II, RASET would be updated with advanced routines for system modeling, LFT representation, identification of nonlinearity, estimation of uncertainty, and stability analysis. The aim of the current approach is that the toolbox should be invaluable to the flight test community by extending the current modeling capabilities to include nonlinearity identified from flight data.