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Valencia-Palomo G.,Technological Institute of Hermosillo | Rossiter J.A.,University of Sheffield
Control Engineering Practice | Year: 2011

The prime aim of this paper is to embed a predictive control (MPC) algorithm with constraint handling capabilities into a programmable logic controller (PLC). In order to achieve it, this paper develops parametric approaches to MPC but differs from more conventional approaches in that it predefines the complexity of the solution rather than the allowable suboptimality. The paper proposes a novel parameterisation of the parametric regions which allows efficiency of definition, effective spanning of the feasible region and also highly efficient search algorithms. Despite the suboptimality, the algorithm retains guaranteed stability, in the nominal case. A laboratory test was carried out to demonstrate the code on real hardware and the effectiveness of the solution. © 2011 Elsevier Ltd. Source


Valencia-Palomo G.,Technological Institute of Hermosillo | Rossiter J.A.,University of Sheffield | Jones C.N.,Automatic Control Laboratory | Gondhalekar R.,Osaka University | Khan B.,University of Sheffield
Proceedings of the American Control Conference | Year: 2011

This paper looks at the efficiency of the parameterisation of the degrees of freedom within an optimal predictive control algorithm. It is shown that the conventional approach of directly determining each individual future control move is not efficient in general, and can give poor feasibility when the number of degrees of freedom are limited. Two systematic alternatives are explored and both shown to be far more efficient in general. © 2011 AACC American Automatic Control Council. Source


Valencia-Palomo G.,Technological Institute of Hermosillo | Rossiter J.A.,University of Sheffield
IET Control Theory and Applications | Year: 2012

This study presents a novel programmable logic controller (PLC) implementation of a constrained predictive control (MPC) algorithm based on Laguerre functions and multi-parametric quadratic programming (mp-QP). First, the study shows how Laguerre functions can be used in conjunction with mp-QP to achieve a large decrease in both the online computations and data storage requirements while increasing the feasible region of the optimisation problem for MPC; extensive simulation results are given to back this claim. Next, the study shows how the algorithm can be embedded on an industrial PLC using the IEC 61131-3 programming standard. A laboratory test was carried out to demonstrate the code on real hardware. © 2012 The Institution of Engineering and Technology. Source


Valencia-Palomo G.,Technological Institute of Hermosillo | Rossiter J.A.,University of Sheffield | Lopez-Estrada F.R.,Instituto Tecnologico de Tuxtla Gutierrez
ISA Transactions | Year: 2014

Simple predictive control (MPC) algorithms produce a feed-forward compensator that may be a suboptimal choice. This paper gives some insights into this issue and simple means of modifying the feed-forward to produce a more systematic and optimal design. In particular, it is shown that the optimum procedure depends upon the underlying loop tuning and also that there are, as yet under utilised, potential benefits with regard to constraint handling procedures, which helps to improve the computational efficiency of the online controller implementation. A laboratory test in a programmable logic controller (PLC) was carried out to demonstrate the code on real hardware and the effectiveness of the solution. © 2014 ISA. Source


Betancourt-Riera R.,Technological Institute of Hermosillo | Betancourt-Riera R.,University of Sonora | Rosas R.,University of Sonora | Riera R.,University of Sonora
Journal of Computational and Theoretical Nanoscience | Year: 2012

The differential cross section for an electron Raman scattering process in a semiconductor multiple GaAs/AlGaAs quantum well with the presence of an external uniform electric field is calculated for T = 0 K. A description of the confined phonon modes, considering the Fröhlich interaction is presented. We assume single parabolic conduction band with one electron. The emission spectra and the effect for different electric field values are discussed. Singularities in the spectra are found and interpreted. The ERS studied here can be used to provide direct information about the electron band structure of these systems. Copyright © 2012 American Scientific Publishers. All rights reserved. Source

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