Aliasing Pattern Study for Single Sensor Blade Tip Timing

Rotor blades in gas turbines and aircraft engines are subject to harsh conditions, making them prone to damage. Blade tip timing (BTT) is widely used to measure blade vibrations. However, its undersampling property causes spectrum aliasing, complicating frequency identification when monitoring the blade condition. Traditional anti-aliasing methods apply priors or require complex frequency identification steps. Therefore, this paper investigated the aliasing pattern for single-sensor BTT sampling under varying speeds. A simple frequency identification method based on aliasing pattern is proposed. The correctness of theoretical derivation and the feasibility of the proposed method have been verified by simulations and experiments.