Kernel-Based KPI-Oriented Fault Detection Approach in the Presence of Outliers

Kernel partial least squares (KPLS) has poor robustness and cannot achieve effective monitoring for key performance indicators (KPI). This study investigates a new KPI-oriented robust KPLS approach to mitigate these drawbacks. In this methodology, the robust KPLS inspired by the gradient boosting principle incorporates a weighting matrix into the KPLS to mitigate the influence of outliers. Simultaneously, the associated coefficient matrix is derived in detail. Then, a decomposition approach is used to separate the process variable space into two orthogonal parts. Two strategies are discussed to obtain the unknown projection matrices based on the kernel principal component analysis and the elastic network frameworks. Finally, the performance of the proposed methods in terms of prediction, monitoring, and robustness to outliers is evaluated by the Tennessee Eastman process and the three-phase flow facility. The results show that the proposed methods have good prediction accuracy and monitoring performance in the presence of outliers, demonstrating the effectiveness and advantages of the proposed approaches.