Adaptive statistic process monitoring with a modified PCA

In this paper, we propose a modified adaptive PCA method for process monitoring. The basic idea of our approach is to use the modified PCA to adaptively extract the essential feature components that drive a process and combine them with process monitoring techniques. The Combined Index chart, which puts SPE statistic and T² statistic together, is presented as online monitoring chart and then contribution plot of this statistical quality is also considered for fault identification. The proposed monitoring method was applied to fault detection and identification in a wastewater treatment plant (WWTP). The simulation results clearly show the power and advantages of the modified PCA monitoring in comparison to classical PCA monitoring.