A process monitoring scheme based on independent component analysis and adjusted outliers

Abstract

Recently, the independent component analysis (ICA) has been widely used for non-Gaussian multivariate process monitoring. An elliptical type measure is traditionally used for ICA-based process monitoring. However, it will not work appropriately since the extracted ICA components exhibit skewed distribution. Thus, this study aims to develop a novel process monitoring scheme for ICA. The basic idea of the proposed method is to first screen out outliers in order to describe well majority for training dataset. Hereafter, a rectangular type measure is applied to monitor the process. The efficiency of proposed monitoring scheme will be implemented via a five variables simulation example and a case study of Tennessee Eastman process. Results indicate that the proposed method cannot only deal with the contaminated training dataset but also shows superior fault detection ability when compared with alternative methods.

Keywords:

• PCA
• ICA
• adjusted outlyingness
• Tennessee Eastman process

Acknowledgement

This work was supported in part by National Science Council of Taiwan (Grant No. NSC 97-2410-H-324-015)