Aeroelastic control of flexible wing with flying-wing configuration and wind tunnel tests

Flying-wing aerial vehicles have received extensive attention at home and abroad because of their strong stealth performance and excellent aerodynamic characteristics. However, due to the small rotational inertia of the fuselage and the low frequency of the low-order bending modes of the wing, complex aeroelastic problems such as rigidelastic coupled flutter vibration and aeroelastic vibration are likely to occur in the flight envelope region. An active aeroelastic control method based on estimation of experimental frequency response and robust controller theory is presented for aeroelastic vibration suppression of flying-wing aerial vehicles. The control objective is to simultaneously reduce the aeroelastic vibration of the aircraft structure and enhance the control robustness to external unknown disturbances. An open-loop frequency sweep test in conjunction with the modeling theory of aeroservoelastic dynamics is conducted to estimate the experimental frequency response and obtain the transfer function of a controlled system more closely aligned with the test conditions. Aeroelastic response controllers are designed using robust control theory, and by optimizing the weighting parameters, the number of norms H_∞ of the closed-loop system is minimized to improve the robustness and stability of the system. The effectiveness of the control method can then be estimated by wind-tunnel tests. The numerical results demonstrate that the aeroelastic response controller can significantly reduce the root-mean-square value of the wingtip acceleration of the aircraft in a specific wind speed range up to 35%, which in turn verifies the effectiveness of the robust aeroelastic controller and its robustness.