航空发动机MIMO系统的闭环辨识与故障诊断算法

Estimation and Fault Diagnosis Algorithm for Closed-Loop MIMO Aero-Engine Systems

针对航空发动机结构复杂、易发生故障的特点以及机理分析建模方法存在过程繁琐、运算效率低下等问题,提出了一种基于数据的航空发动机燃油机构MIMO(multiple-input multiple-output)闭环系统的参数辨识和故障诊断算法。算法先通过估计辅助模型系统的阶次间接求得时延参数,再通过多阶段最小二乘算法辨识得到前向通道和反馈通道的参数。以某型双轴涡扇航空发动机为例进行验证。结果表明,在应用中辨识结果与系统真值基本吻合,当遗忘因子取值随辨识结果的收敛程度变化时,算法可以有效地应用于气路故障的诊断当中,及时辨识出故障参数值。最后,对算法的两方面特点进行了说明:一是遗忘因子选取的重要性及选取的原则,二是算法可以有效排除噪声对辨识结果带来的干扰。

Aero-engines have characteristics with complex structure and prone to fault,in addition,conventional modeling methods based on mechanism analysis have troubles of complicated process and low operational efficiency.To solve these problems,an algorithm is proposed for parameter identification and fault diagnosis based on data,which could be used in closed-loop MIMO（multiple-input multiple-output） aero-engine systems.By choosing appropriate auxiliary parameters,auxiliary models are established.Then time delay is calculated by determining the order of the auxiliary model,parameters of forward channels and feedback channels are identified by multi-stage least square algorithm.An example of biaxial gas turbine engine system is given for certification.It shows drat the algorithm could be used for diagnosing gas path fault when the forgetting factor is changing by convergence of recognition result.Finally,two kinds of important characteristics are introduced,about importance and principium of selecting forgetting factor and excluding disturbance of noises by distinguishing it from the fault result.