Body-freedom flutter suppression for a flexible flying-wing drone via time-delayed control

This paper describes a novel time-delayed control scheme for suppressing the body-freedom flutter of a flexible flying-wing drone and verifies its robustness. The simple formulation and strong robustness of the proposed control scheme are of particular interest. The procedure of designing the proposed delayed controller includes the following three steps. First, the displacement and velocity signals from the wingtip are taken as the input signals to delayed feedback, and the ailerons are used as the control inputs. The proportional gain, derivative gain, and specific value of a time delay are taken as control parameters. Second, the proportional and derivative gains are determined by checking the stable region for various time delays. Finally, a single time delay is determined according to both the critical stability condition and the stability margins. The stability and robustness of the closed-loop system are analyzed in time domain and frequency domain. The numerical results demonstrate that the flutter boundary of the flexible flying-wing drone can be expanded by up to 35% while retaining strong robustness via the proposed delayed controller.