Identification of Valve Stiction in Control Loops Using Refined Piecewise-Linear Hammerstein Models

Conference proceedings article

Authors/Editors

SARAWAN WONGSA

Strategic Research Themes

Other (Strategic Research Themes)

Publication Details

Author list: Pratvittaya J., Wongsa S.

Publisher: Hindawi

Publication year: 2019

ISBN: 9781728138466

ISSN: 0146-9428

eISSN: 1745-4557

URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85082997934&doi=10.1109%2fCACS47674.2019.9024740&partnerID=40&md5=a983b455aff6c7f8297a5e87feffe086

Languages: English-Great Britain (EN-GB)

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Abstract

This work is motivated by the modelling of sticky control valves via the piecewise linear Hammerstein (PWL-HMM) identification. In PWL-HMM, the nonlinear part of the valve, i.e. stiction, is described by a point-slope-based hysteresis model where a set of knots have to be defined for both the ascent and descent paths of the valve position signal. Traditionally, the knots are assumed to be uniformly distributed, as a result some irrelevant knots might be included in the model. We tackle this problem by proposing two methods, namely the constant threshold-based and BIC-based knot reductions, to identify such irrelevant knots and refine the PWL model of stiction. Numerical, experimental and industrial examples are provided to illustrate the effectiveness of the proposed knot refinement methods. ฉ 2019 IEEE.

Keywords

Control Valves, Hammerstein Modelling, Piecewise-Linear, Stiction