Improving blade vibration measurement during speed changes with a convolution-based blade tip timing method

Abstract Rotating blades are critical components in aero-engines and fan systems for lighter-than-air vehicles. Reliable condition monitoring is essential, yet speed fluctuations often compromise measurement accuracy. To address the significant errors of traditional blade tip timing under such fluctuations, this paper proposes a Convolution-based BTT (C-BTT) method. By decoupling the Theoretical Time of Arrival from instantaneous speed calculations, the method effectively eliminates speed-induced errors. Numerical results show that C-BTT maintains a dimensionless error below 4 × 10 −4 rad across the full speed range. Additionally, convolution smoothing improves computational efficiency for real-time applications. Simulations and experiments demonstrate the effectiveness of C-BTT in various fluctuation scenarios, providing a robust basis for non-contact dynamic stress measurement.