Nonlinear Reduced-Order Modeling for Multiple-Input/Multiple-Output Aerodynamic Systems

The paper presents a novel nonlinear reduced-order modeling approach for multi-input/multi-output aerodynamic systems. The nonlinear reduced-order model for an aerodynamic system includes a finite sum of Wiener-type cascade models. The nonlinear reduced-order model approach starts with fitting a Wiener-type cascade path between the inputs and outputs of the aerodynamic system first. Then, the approach computes the outputs of the path and subtracts them from the measured outputs. The second path is then fitted between the inputs and the output residuals. This process is repeated until the residuals contain only noise. To obtain an optimal path at each stage, a novel nonlinear model, a linear dynamic state-space element followed by a single-layer neural network model, is selected as the Wiener-type cascade model. The Wiener-type cascade model can be optimized by using the Levenberg–Marquadt algorithm. To demonstrate the performance of the proposed nonlinear reduced-order model in modeling the statically non...

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