Identification of Blade Vibration Parameters Based on Improved Composite Reference Blade Tip-Timing Method

As the core component of an engine, the vibration characteristics of blades directly affect the stability and lifespan of the engine. Thus, monitoring the vibration status of the blades is essential. This paper presents an improvement on the blade tip timing (BTT) method based on Composite Reference. The conventional BTT method, when computing blade vibration displacement, typically presumes a constant rotor speed per revolution, which fails to account for the rotor's instantaneous state conditions accurately. In this study, the state space equations for the rotor's instantaneous angular velocity and position are derived and solved via a Kalman filter to rectify the rotor's instantaneous speed. Furthermore, the composite reference method is improved by using the multi-sensor straight line fitting (SLF) method of all sensors, enhancing the precision of blade vibration displacement identification. The efficacy of this approach has been validated through simulation experiments.