Search

The nonlinear behavior of the airfoil-store system introduces complexity to its mechanical characteristics, making it essential to identify the system's nonlinear features. This study presents a novel nonlinear subspace identification approach in combination with an aerodynamic force. Based on the dynamic modeling of the airfoil storage system with random force, a linear elastic contribution related to the wind speed is introduced to two sides of motion equations, thereby transforming the original asymmetric linearity into the symmetric stiffness. A nonlinear state-space representation of the airfoil-store system is established, and the nonlinear parameters are identified by the proposed approach. Simulation examples are conducted considering different levels of nonlinearity, measurement noise, and flow speeds. The results demonstrate that the proposed method exhibits strong flexibility and robustness across various wind speeds in the airfoil-store system. It effectively identifies nonlinear stiffness, nonlinear damping, and various types of nonlinearity. [ABSTRACT FROM AUTHOR]