PLS-based optimal quality control model for TE process

The necessary and sufficient conditions of fault detectability under the PLS framework are discussed. A new partial least squares optimum detecting model (PLS-ODM) is proposed to improve the monitoring performance of the PLS method. This PLS-ODM is deduced according to the fault subspace and the VP index of the process variables that could be used to estimate the importance of the measurements to the quality. Compared with traditional PLS, PLS-ODM has the stronger fault detecting power, and could detect much weaker important process faults exactly in time. The application of it in Tennessee Eastman (TE) benchmark statistical quality control confirms that its detection performance is improved remarkably to make it possible to avoid process shutdown to reduce cost and stabilize product quality.