Fusion of micro-macro data for fault diagnosis of a sweetening unit using Bayesian network.

Present study addresses a fault diagnosis system based on micro-macro data for monitoring chemical plants. Macro data are encapsulation of process history in terms of prior probability distribution of faults which is achieved using the fault tree analysis. Then, the fault diagnosis system is developed based on an imbalanced dataset, established by frequent and rare faults. In addition, micro data, records of sensors at each time step, are used to predict faults. The Bayesian network is proposed to integrate micro-macro data for diagnostic purposes. Efficiency of the proposed framework was evaluated for an industrial gas sweetening unit. It was shown that the diagnostic performance of the proposed approach is remarkable. Thus, it was concluded that fusion of micro-macro data enhances the performance of the fault diagnosis system. Furthermore, extraction of significant features using the principal components analysis promotes the diagnosis performance. The proposed framework, compared to conventional ones, shows 21% improvement in terms of accuracy. In addition, error bands of fault prediction decreased through implementing a hierarchical strategy. [ABSTRACT FROM AUTHOR]