Comparison of linear and nonlinear dimension reduction techniques for automated process monitoring of a decentralized wastewater treatment facility

  • Karen Kazor
  • Ryan W. Holloway
  • Tzahi Y. Cath
  • Amanda S. Hering
Original Paper

DOI: 10.1007/s00477-016-1246-2

Cite this article as:
Kazor, K., Holloway, R.W., Cath, T.Y. et al. Stoch Environ Res Risk Assess (2016) 30: 1527. doi:10.1007/s00477-016-1246-2

Abstract

Multivariate statistical methods for online process monitoring have been widely applied to chemical, biological, and engineered systems. While methods based on principal component analysis (PCA) are popular, more recently kernel PCA (KPCA) and locally linear embedding (LLE) have been utilized to better model nonlinear process data. Additionally, various forms of dynamic and adaptive monitoring schemes have been proposed to address time-varying features in these processes. In this analysis, we extend a common simulation study in order to account for autocorrelation and nonstationarity in process data and comprehensively compare the monitoring performances of static, dynamic, adaptive, and adaptive–dynamic versions of PCA, KPCA, and LLE. Furthermore, we evaluate a nonparametric method to set thresholds for monitoring statistics and compare results with the standard parametric approaches. We then apply these methods to real-world data collected from a decentralized wastewater treatment system during normal and abnormal operations. From the simulation study, adaptive–dynamic versions of all three methods generally improve results when the process is autocorrelated and nonstationary. In the case study, adaptive–dynamic versions of PCA, KPCA, and LLE all flag a strong system fault, but nonparametric thresholds considerably reduce the number of false alarms for all three methods under normal operating conditions.

Keywords

Multivariate statistical process control Nonlinear time-varying process Principle component analysis Kernel principal component analysis Locally linear embedding 

Supplementary material

477_2016_1246_MOESM1_ESM.pdf (102 kb)
Supplementary material 1 (pdf 102 KB)

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Karen Kazor
    • 1
  • Ryan W. Holloway
    • 2
  • Tzahi Y. Cath
    • 2
  • Amanda S. Hering
    • 1
  1. 1.Department of Applied Mathematics and StatisticsColorado School of MinesGoldenUSA
  2. 2.Department of Civil and Environmental EngineeringColorado School of MinesGoldenUSA