Improved minimum variance distortionless response spectrum method for efficient and robust non-uniform undersampled frequency identification in blade tip timing  

作　　者：Ruochen JIN Laihao YANG Zhibo YANG Shaohua TIAN Guangrong TENG Xuefeng CHEN 

机构地区：[1]The National Key Laboratory of Aerospace Power System and Plasma Technology,Xi’an Jiaotong University,Xi’an 710049,China [2]The Higher Educational Key Laboratory for Flexible Manufacturing Equipment Integration of Fujian Province,Xiamen Institute of Technology,Xiamen 361021,China [3]Sichuan Gas Turbine Establishment Aero Engine Corporation of China,Mianyang 621000,China

出　　处：《Frontiers of Mechanical Engineering》2023年第4期165-181,共17页机械工程前沿（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.52105117 and 51875433);the Funds for Distinguished Young Talent of Shaanxi Province,China(Grant No.2019JC-04).

摘　　要：The noncontact blade tip timing(BTT)measurement has been an attractive technology for blade health monitoring(BHM).However,the severe undersampled BTT signal causes a significant challenge for blade vibration parameter identification and fault feature extraction.This study proposes a novel method based on the minimum variance distortionless response(MVDR)of the direction of arrival(DoA)estimation for blade natural frequency estimation from the non-uniformly undersampled BTT signals.First,based on the similarity between the general data acquisition model for BTT and the antenna array model in DoA estimation,the circumferentially arranged probes on the casing can be regarded as a non-uniform linear array.Thus,BTT signal reconstruction is converted into the DoA estimation problem of the non-uniform linear array signal.Second,MVDR is employed to address the severe undersampling issue and recover the BTT undersampled signal.In particular,spatial smoothing is innovatively utilized to enhance the estimation of covariance matrix of the BTT signal to avoid ill-condition or singularity,while improving efficiency and robustness.Lastly,numerical simulation and experimental testing are employed to verify the validity of the proposed method.Monte Carlo simulation results suggest that the proposed method behaves better than conventional methods,especially under a lower signal-to-noise ratio condition.Experimental results indicate that the proposed method can effectively overcome the severe undersampling problem of BTT signal induced by physical limitations,and has a strong potential in the field of BHM.

关 键 词：blade tip timing(BTT) frequency identification minimum variance distortionless response(MVDR) undersampled blade health monitoring(BHM) 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置]