Spatial-Vibration-Modulation-Assisted Blade Damage Localization for Industrial Quadrotor UAVs

The rapid development of unmanned aerial vehicle (UAV) market has triggered the demand for UAV structural health monitoring technology, and blade damage has received extensive attention as a common mechanical fault. In this study, the spatial vibration modulation method (SVMM) is proposed to assist in blade damage localization for an industrial quadrotor UAV. The key to SVMM is that, by arranging silicone-made ring-shaped vibrators with randomly selected structural parameters on the beams of the UAV, the frequency transfer functions of these beams with low cross-correlation are achieved. With SVMM, high-accuracy blade damage localization capability can be realized under single sensor strategies on the symmetrical UAV. The study considers the situations of one and two damage locations, and the recognition accuracies are both 97%, whereas those without SVMM are 90% and 86%, respectively. The results show that SVMM can effectively enhance the localization capability for blade damage. Due to the customized frequency transfer functions, the technique proposed in this study shows potential in the fields of UAVs or other mechanical equipment for structural health monitoring and damage assessment.