关键词: 快速存取记录器, 时间序列, 符号聚合近似算法, 相似性搜索, 故障诊断

Abstract: As the Quick Access Recorder (QAR) data is a kind of time series data which is of very complex structure and large amount of data, it cannot avoid some of the shortcomings appeared in aspects such as time series amplitude flex and timeline drift, directly using the traditional Symbolic Aggregate Approximation (SAX) method to describe, store, retrieve QAR data. The paper put forward an improved SAX algorithm. As stated in the paper, the QAR data was divided into three steps as take-off, cruise and landing. With the improved algorithm, the cruise stage was filled as well, and the different lengths of fault model sequence were carried out effective similarity search. Through experiments and application in the aircraft fault diagnosis project, its feasibility and validity has been proven, the improved algorithm greatly improve the efficiency of troubleshooting.

Key words: Quick Access Recorder (QAR), time series, Symbolic Aggregate Approximation (SAX), similarity search, fault diagnosis