Journal ArticleDOI
Multivariate SPC for startups and grade transitions
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TLDR
In this article, a multivariate statistical method based on PCA and PLS is proposed to improve process transition performance using historical records of transition data, which is aimed at reducing the amount of off-specification materials and reducing transition time.Abstract:
Process transitions (grade changeovers, startups, and restarts) are very frequent in industry, and usually lead to the loss of production time, the production of off-grade materials, and to inconsistent reproducibility of product grades. Two aspects of using multivariate statistical methods based on PCA and PLS to improve process transition performance using historical records of transition data are discussed. First, multivariate SPC approaches are proposed to determine if the process conditions for the commencement of a transition (“startup readiness”) are correct and to assess the successful completion of a transition (“production readiness for the new grade”). The latter is illustrated using a simulated fluidized-bed process for the production of different grades of linear low-density polyethylene. Second, analysis tools are suggested for diagnosing the reasons for past transition problems and for monitoring new transitions to ensure repeatable high quality transitions. The latter methods are aimed at reducing the amount of off-specification materials and reducing transition time, as illustrated on industrial data from restarts of a polymerization process.read more
Citations
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Journal ArticleDOI
Application of latent variable methods to process control and multivariate statistical process control in industry
TL;DR: In this article, an overview of the latest developments in multivariate statistical process control (MSPC) and its application for fault detection and isolation (FDI) in industrial processes is presented.
Journal ArticleDOI
Multivariate dynamic data modeling for analysis and statistical process control of batch processes, start‐ups and grade transitions
TL;DR: This paper first takes a critical look at the true nature of batch process data, then some of the methods that have appeared in the literature are examined as to their assumptions, their advantages and disadvantages and their range of applicability.
Journal ArticleDOI
Stage-based soft-transition multiple PCA modeling and on-line monitoring strategy for batch processes
TL;DR: In this paper, a soft transition multiple PCA (STMPCA) model is proposed to detect process transition by analyzing changes in the loading matrices, which reveal evolvement of the underlying process behaviours.
Journal ArticleDOI
Inferential sensors for estimation of polymer quality parameters: Industrial application of a PLS-based soft sensor for a LDPE plant
TL;DR: In this article, a soft-sensor was used to predict the melt flow index of free radical polymerization (FRP) processes using data collected from an industrial autoclave reactor, which produces low-density polyethylene (LDPE) and EVA copolymer.
Journal ArticleDOI
Data-driven monitoring of multimode continuous processes: A review
TL;DR: This study includes advantages and drawbacks of every analyzed strategy of the data-driven modeling problem for monitoring multimode continuous processes and suggests promising research directions towards the Industry 4.0 and the Big Data era.
References
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Book
An Introduction to Multivariate Statistical Analysis
TL;DR: In this article, the distribution of the Mean Vector and the Covariance Matrix and the Generalized T2-Statistic is analyzed. But the distribution is not shown to be independent of sets of Variates.
Journal ArticleDOI
Introduction to Multivariate Statistical Analysis.
William G. Madow,T. W. Anderson +1 more
Journal ArticleDOI
Monitoring batch processes using multiway principal component analysis
Paul Nomikos,John F. MacGregor +1 more
TL;DR: The approach is contrasted with other approaches which use theoretical or knowledge-based models, and its potential is illustrated using a detailed simulation study of a semibatch reactor for the production of styrene-butadiene latex.
Journal ArticleDOI
Process monitoring and diagnosis by multiblock PLS methods
TL;DR: More detailed diagnostic methods based on interrogating the underlying PCA /PLS models are developed, which show those process variables which are the main contributors to any deviations that have occurred, thereby allowing one to diagnose the cause of the event more easily.
Journal ArticleDOI
Multi-way partial least squares in monitoring batch processes
Paul Nomikos,John F. MacGregor +1 more
TL;DR: Multivariate statistical procedures for monitoring the progress of batch processes are developed using multi-way partial least squares for extracting information from the process measurement variable trajectories that is more relevant to the final quality variables of the product.
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