Plant-Wide Process Monitoring: Multiblock Method

Abstract

Due to the complexity of the plant-wide process, many of the present multivariate statistical process monitoring techniques lack the ability to interpret the nature of a detected fault, hence, fault identification also becomes difficult. In this chapter, a two-level MultiBlock Independent Component Analysis and Principal Component Analysis (MBICA-PCA) method is introduced. Different from the conventional multiblock method, this two-level approach can incorporate block information into the high level for global process monitoring. Through this method, the process monitoring task can be reduced and the interpretation of the process can be made more efficiently. When a fault is detected, a two-step fault identification method is developed. That is, the responsible sub-block is first identified by contribution plots, which is followed by fault reconstruction in the corresponding sub-block for advanced fault identification.