Intermittent Fault Detection with T 2 Control Chart ?

摘要

Multivariate statistical analysis using the HotellingsT2statistic (T2 control chart) is one of the most effective data-driven methods for fault detection. However, existing T2 control charts in the literature mainly focus on permanent faults, and intermittent faults are relatively rarely considered. In fact, due to the small magnitude and short duration characteristics, traditional multivariate statistical methods are not sensitive to intermittent faults, resulting in much missed detection. Thus in this paper, the T2 control chart with consecutive observations is designed for permanent fault detection and intermittent fault detection respectively. In order to analyze the detection ability of proposed methods, definitions of being guaranteed detectable are introduced both for permanent faults and intermittent faults. Then, sufficient conditions for the defined fault detectability are derived for both kinds of faults respectively. Moreover, optimal window length for intermittent fault detection is discussed. Finally a simulation study is carried out to show the effectiveness of the proposed methods.