Record Details

A gap metric based multiple model approach for nonlinear switched systems

DSpace at IIT Bombay

View Archive Info
 
 
Field Value
 
Title A gap metric based multiple model approach for nonlinear switched systems
 
Creator HARIPRASAD, K
BHARTIYA, S
GUDI, RD
 
Subject Switched systems
Hybrid systems
Multimodel approach
Gap metric
Model clustering
Fuzzy approach for multiple model
Bayesian approach for multiple model
PREDICTIVE CONTROL
HYBRID SYSTEMS
MULTILINEAR MODELS
IDENTIFICATION
OPTIMIZATION
ROBUSTNESS
REACTOR
 
Description Many applications in chemical engineering often exhibit a switching character due to the presence of discrete modes in the course of their operation. First principles models of such systems constructed using process simulators are far too complex for use in online applications, especially in model-based control. For such systems, numerous control-relevant modeling approaches have been reported in the literature such as mixed logic dynamical (MLD) models [1] and piece wise affine (PWA) [2] models among others. These models describe the evolution of states in each discrete mode using linear equations. Fewer control-relevant models have been reported that address the nonlinear behavior of switched systems. To model nonlinear hybrid systems, Nandola and Bhartiya [3] proposed a multiple linear model approach wherein multiple linear models are used to describe the dynamic behavior in each mode of the hybrid system. However, no guidelines were provided to select the number of models necessary in each mode and their region of validity. In this work, we address these lacunae by presenting a systematic multiple model approach to describe nonlinear switched systems. The method involves a trajectory based linearization and employs a model bank with a set of local linear models for each discrete operational mode. The model bank is generated by linearizing the first principles model across a carefully designed trajectory based on accuracy of multi-step ahead predictions. The numerous models thus obtained are clustered using the gap metric as the distance measure and representative models are selected. The selected linear models are aggregated using Bayesian or Fuzzy approaches to obtain the global model for the nonlinear switched system. A simulation case study of spherical two-tank system and an experimental case study of a benchmark problem consisting of three tanks are used to validate the proposed modeling strategy. (C) 2012 Elsevier Ltd. All rights reserved.
 
Publisher ELSEVIER SCI LTD
 
Date 2014-10-16T13:02:13Z
2014-10-16T13:02:13Z
2012
 
Type Article
 
Identifier JOURNAL OF PROCESS CONTROL, 22(9)1743-1754
http://dx.doi.org/10.1016/j.jprocont.2012.07.005
http://dspace.library.iitb.ac.in/jspui/handle/100/15614
 
Language en