基于空域变换的叶尖定时信号预处理方法  

Preprocessing method of blade tip timing signal based on spatial transformation

作　　者：刘昊 段发阶[1] 李杰 李发富 钟国舜 Liu Hao;Duan Fajie;Li Jie;Li Fafu;Zhong Guoshun(State Key Lab of Measuring Technology and Instruments,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《仪器仪表学报》2022年第7期218-229,共12页Chinese Journal of Scientific Instrument

基　　金：中国航发四川燃气涡轮研究院外委课题(GJCZ-2020-0040,GJCZ-2020-0041);国家重点研发计划项目(2020YFB2010800);广东省重点研发计划项目(2020B0404030001)资助。

摘　　要：叶片振动参数的实时监测是保障航空发动机健康运行的关键。传统的叶尖定时传感信号预处理方法会因转子转速变化范围较宽(20~20 000 r/min),产生较大的定时误差,影响叶片振动参数的辨识精度。通过分析采样率转换模型,提出了一种基于空域变换的叶尖定时信号预处理方法,将叶尖信号的等时间采样转换为等角度空间采样,实现高精度叶尖定时信号的获取;使用基于三阶拉格朗日插值的Farrow结构并通过流水线优化技巧,在现场可编程逻辑门阵列上实现了逻辑资源占用与数据处理速率的均衡设计。实验验证表明,该方法可以有效完成等空间角度采样,降低了转速变化的影响,在实时转速为1 000~8 000 rpm,基准转速为3 000 rpm时,无论采用前沿时刻鉴别还是采用双边沿时刻鉴别,本文采用的方法振动位移测量误差均在20.19μm内,远低于传统位移测量方法的测量误差,提高了叶片到达时刻及叶片振动位移的测量精度。Real-time monitoring of blade vibration parameters is the key to ensure the healthy operation of aero-engines. The traditional blade tip timing sensor signal preprocessing method could produce a large timing error due to the wide range of rotor speed(20~20 000 r/min), which affects the identification accuracy of blade vibration parameters. By analyzing the sample rate conversion model, a blade tip timing signal preprocessing method based on spatial transformation is proposed, which converts the equal-time sampling of the blade tip signal into equal-angle spatial sampling to achieve high-precision blade tip timing signal acquisition. The third-order Lagrange interpolation Farrow structure and through pipeline optimization techniques realize the balanced design of logic resource occupation and data processing rates on the field programmable gate array. Experiments show that this method can effectively complete the equal spatial angle sampling and reduce the influence of rotation speed change. When the real-time speed is 1 000~8 000 rpm and the reference speed is 3 000 rpm, the vibration displacement measurement error of this method is within 20.19 μm, which is much lower than that of traditional displacement measurement methods. The measurement accuracy of arrival time and blade vibration displacement is improved.

关 键 词：叶尖定时 空域变换 模数转换器 拉格朗日插值 FARROW结构 FPGA 

分 类 号：TH17[机械工程—机械制造及自动化] TP2[自动化与计算机技术—检测技术与自动化装置]