Piezoelectric-based vertical tail buffet vibration suppression using adaptive modified positive position feedback

Aerodynamic buffet is a forced vibration because of the unsteady airflow exerting forces on a vertical tail, which can lead to premature fatigue damage to aircraft vertical tail structures, especially for aircrafts with twin vertical tails at high attack angles. In the paper, the Macro Fiber Composite was used as actuators, and the strain of a vertical tail root was adopted as the input signal of the feedback system. Modified positive position feedback uses two parallel compensators,which are respectively the first-order and second-order compensators.The firstorder term amplifies the damping, and the second-order term focuses on resonant modes of vibration. The phase lag between the input signals and output signals influences the control law in this non-collocated sensor/actuator plants. The phase compensation was identified experimentally. Additionally, frequency estimated method was applied to identify the natural frequencies of the vertical tail in order to update the parameters of the controller. The experiment results verify the effectiveness of MPPF. And the controller performs brilliantly in alleviating the vibration of vertical tail whose natural frequencies is variable to a narrow band external disturbance.