Virtual-metrology-based FDC scheme

Most conventional fault-detection-and-classification (FDC) approaches are to find out the target devices (TDs) required for monitoring and the TDs´ related key parameters needed to be monitored, and then by applying the statistical-process-control (SPC) approach to detect the faults. However, in practical situation, an abnormal key-parameter value may not be solely caused by its own TD; instead, it may also be resulted from the other related parameters. As a result, accurate fault classification or diagnosis may not be achieved. The purpose of this paper is to propose a virtual-metrology-based baseline FDC scheme that includes the TD baseline model and FDC logic. By applying this baseline FDC scheme, fault diagnosis can then be accomplished.