Low Involvement Key-Phase-Free Blade Tip Timing Method
ZHOU Lei1, YANG Zhibo1, CAO Jiahui1, FENG Junnan2, ZHANG Huan2, YANG Zhijun2, SUN Ruobin1, CHEN Xuefeng1
1. National Key Lab of Aerospace Power System and Plasma Technology, Xi’an Jiaotong University, Xi’an 710049, China;
2. AECC Commercial Aircraft Engine Co., Ltd., Shanghai 200241, China
旋转叶片是航空发动机的关键易损件，需要对其进行状态监测。叶端定时（Blade tip timing，BTT）是一种有效的旋转叶片非接触监测方法。然而，传统的叶端定时严重依赖键相信号，叶端定时信号存在严重的欠采样问题。对此，提出了一种基于叶片振动差的正交匹配追踪（Orthogonal matching pursuit，OMP）方法来提取叶片固有频率。首先，使用叶端定时传感器计算叶片振动差。然后，构建叶片振动差的稀疏模型，在变转速情况下使用正交匹配追踪方法对叶片振动差信号进行分解，提取叶片振动振幅和固有频率。通过数值仿真验证了该方法的有效性和鲁棒性，并在叶端定时试验台上进行试验。结果表明，该方法可以准确识别叶片异步振动的振幅和固有频率。
The rotating blade is a key wearing part of aero-engine, so it is necessary to monitor its condition. Blade tip timing (BTT) is an effective non-contact monitoring method for rotating blades. However, the traditional BTT relies heavily on the once-per-revolution signal, and the BTT signal has serious under-sampling problem. In this paper, Orthogonal matching pursuit (OMP) method based on blade vibration difference is proposed to extract blade natural frequency. Firstly, a BTT sensor is used to calculate the blade vibration difference. Then, the sparse model of blade vibration difference is constructed, and the blade vibration difference signal is decomposed by OMP method under the condition of varying speed, and the vibration amplitude and natural frequency of the blades are extracted. The effectiveness and robustness of the proposed method are verified by numerical simulation, and experiments are carried out on the blade tip timing test bench. The results show that this method can accurately identify the amplitude and natural frequency of blade asynchronous vibration.
2025, 
