基于灰色理论的航空发动机剩余寿命预测

针对航空发动机健康监测数据繁杂、性能退化特征不明显、缺乏有效的健康指数构建与剩余寿命预测难的问题,提出了基于灰色理论的多监测参量优化选择与融合及全阶时间幂灰色预测模型(FOTP-GM(1,1))方法。首先,采用灰色关联分析法对航空发动机的高维监测物理参量的性能退化状态表征能力进行参数化度量,结合线性相关分析对监测参量进行优化选择;其次,利用灰色接近关联度对优化选择的特征进行加权融合,构建航空发动机的统一健康指标(HI),并以训练发动机HI失效阈值为参照,采用滑动窗欧氏距离比对法确定测试发动机的HI失效阈值;最后,采用FOTP-GM(1,1)对测试发动机的剩余寿命进行预测。通过实验分析,该方法能够有效地对航空发动机的剩余寿命进行预测,并比传统方法得到更高的预测准确度,该方法为实现航空发动机的故障预测与健康管理提供一种新的思路与手段。

Remaining useful life estimation for aero engines based on grey theory

For the problems of aero engines such as complicated health monitoring data, insignificant performance degradation characteristics, lack of effective health index construction method and difficulty in remaining useful life (RUL) prediction, an optimal selection and fusion based on grey theory for multi monitoring parameters and a grey forecasting model with full order time power terms (FOTP GM (1,1)) method are proposed. Firstly, the performance degradation state characterization capability of the high dimensional monitoring physical parameters of the aero engine are parametrically measured by the grey relational analysis (GRA) method, the linear correlation analysis is applied to optimally select of the monitoring parameters as well. Secondly, the grey approximate correlation degree was utilized to make weighted fusion of the selected features, which establishes the uniform health index (HI) of the aero engine. Taking the HI failure threshold of the training aero engines as reference, the HI failure threshold of the test aero engines was determined by the matching method of sliding Window Euclidean distance. Finally, FOTP GM (1,1) was adopted to predict the RUL of the test aero engines. Through the experimental analysis, this method can effectively predict the remaining useful life of the aero engine and obtain a higher prediction accuracy than the traditional method. This method provides a novel idea and means for realizing the fault prediction and health management of the aero engines.