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Emissions and performance tradeoffs for advanced marine diesel propulsion
(1998)IFAC Proceedings Volumes ~ Control applications in marine systems : a proceedings volume from the IFAC conferenceA multivariable control scheme is designed that reduces smoke generation on an experimental marine Diesel engine equipped with a variable geometry turbocharger (v). The variable geometry turbocharger allows the improvement of the steady-state ship hydrodynamic and propulsion characteristics and requires coordination with the injected mass fuel to achieve a good transient performance.Conference Paper -
Capturing nonlinearities with perturbation models
(1997)IFAC Proceedings Volumes ~ IFAC Symposium on System Identification (SYSID'97)This paper investigates the use of robust control perturbation models for describing nonlinear systems. We use model validation techniques to find the smallest linear dynamic perturbation required to describe a particular behaviour of a nonlinear system. The Moore-Greitzer model of rotating stall in jet engines is used as a detailed example.Conference Paper -
Control-oriented model validation
(1997)IFAC Proceedings Volumes ~ IFAC Symposium on System Identification (SYSID'97)Model validation is a means of assessing model quality with respect to experimental data. In a robust control context this amounts to determining whether or not a perturbation model is consistent with observed data. T his paper offers a survey of recent results on model validation for H-infinity compatible perturbation models. Several model paradigms and experiment frameworks are considered. The first is a frequency-domain setting for ...Conference Paper -
The stability analysis of sampled-data systems with averaging samplers and time delays
(1996)IFAC Proceedings Volumes ~ Proceedings of the 13th World CongressAn exact analysis of the stability of a sampled-data feedback loop, involving an averaging sampler and continuous-time delays, is presented. An equivalent discrete-time model is derived and it is shown that the continuous-time behaviour at frequencies greater than the sample frequency can significantly affect the system stability, leading to counterintuitive analysis results. An optical fiber link synchronization application is studied ...Conference Paper -
Modeling and Control of a Metalorganic Chemical Vapor Deposition Process for III-V Compound Semiconductor Epitaxy
(1996)IFAC Proceedings Volumes ~ Proceedings of the 13th World CongressReal-time control of metalorganic chemical vapor deposition (MOCVD) processes has been shown to improve the composition and thickness precision in the growth of compound semiconductor films. A system model of the MOCVD process is developed to improve the application of control. The model is used to simulate growth of GaInAs. Estimates of the GaAs fraction, from simulated growths, are compared to measured composition results. The model ...Conference Paper -
Parameter Estimation in an Uncertain Model Framework
(1996)IFAC Proceedings Volumes ~ Proceedings of the 13th World CongressWe consider a preliminary investigation into the problem of estimating model parameters in a continuous time robust control model containing H-infinity norm bounded perturbations; this is performed on the basis of finite, sampled, input-output data. The technique used is derived from gradient methods for solving LMI formulations of norm constraints. The primary motivation for this research is as part of an identification scheme to ...Conference Paper -
Experimentally based calculation of robust control perturbation models
(1994)IFAC Proceedings Volumes ~ System identification : a postprint volume from the IFAC symposiumThis paper addresses the problem of obtaining robust control models from a combination of experimental data and a priori knowledge. A perturbation structure and nominal model may be obtained from a combination of system structural information and standard identification procedures. The problem considered here assumes the perturbation structure and a nominal model to be given. The objective is to calculate a suitable frequency dependent ...Conference Paper