Teaching control with Basic Maths: Introduction to Process Control course as a novel educational approach for undergraduate engineering programs

In this article, we discuss a novel education approach to control theory in undergraduate engineering programs. In particular, we elaborate on the inclusion of an introductory course on process control during the first years of the program, to appear right after the students undergo basic calculus and physics courses. Our novel teaching proposal comprises debating the basic elements of control theory without requiring any background on advanced mathematical frameworks from the part of the students. The methodology addresses, conceptually, the majority of the steps required for the analysis and design of simple control systems. Herein, we thoroughly detail this educational guideline, as well as tools that can be used in the classroom. Furthermore, we propose a cheap test-bench kit and an open-source numerical simulator that can be used to carry out experiments during the proposed course. Most importantly, we also assess on how the Introduction to process control course has affected the undergraduate program on Control and Automation Engineering at Universidade Federal de Santa Catarina (UFSC, Brazil). Specifically, we debate the outcomes of implementing our education approach at UFSC from 2016 to 2023, considering students' rates of success in other control courses and perspectives on how the chair helped them throughout the course of their program. Based on randomised interviews, we indicate that our educational approach has had good teaching-learning results: students tend to be more motivated for other control-related subjects, while exhibiting higher rates of success.Comment: 55 pages, 13 figures, Screening at the Journal of Control, Automation and Electrical System

Nonlinear Data-Driven Control Part II: qLPV Predictive Control using Parameter Extrapolation

We present a novel data-driven Model Predictive Control (MPC) algorithm for nonlinear systems. The method is based on recent extensions of behavioural theory and Willem's Fundamental Lemma for nonlinear systems by the means of adequate Input-Output (IO) quasi-Linear Parameter Varying (qLPV) embeddings. Thus, the MPC is formulated to ensure regulation and IO constraints satisfaction, based only on measured datasets of sufficient length (and under persistent excitation). Instead of requiring the availability of the scheduling trajectories (as in recent papers), we consider an estimate of the function that maps the qLPV realisation. Specifically, we use an extrapolation procedure in order to generate the future scheduling trajectories, at each sample, which is shown to be convergent and generated bounded errors. Accordingly, we discuss the issues of closed-loop IO stability and recursive feasibility certificates of the method. The algorithm is tested and discussed with the aid of a numerical application.Comment: 21 pages, 4 figure

Predicción para control /

Tese (Doutorado) - Universidad de Sevilla, Escuela Superior de Ingenieros

Tutorial: Implementando Controladores Preditivos N\~ao Lineares atrav\'es do Ferramental LPV

Recent works have demonstrated how Linear Parameter Varying Model Predictive Control (LPV MPC) algorithms are able to control nonlinear systems with precision and reduced computational load. Specifically, these schemes achieve comparable performances to state-of-the-art nonlinear MPCs, while requiring the solution of only one quadratic programming problem (thus being real-time capable). In this tutorial paper, we provide a step-by-step overview of how to implement such LPV MPC algorithms, covering from modelling to stability aspects. For illustration purposes, we consider a realistic implementation for a gas-lift petroleoum extraction process, comparing the LPV approach with the becnhmark nonlinear MPC software CasADi.Comment: Main text in portuguese, submitted to the 2023 Simp\'osio Brasileiro de Automa\c{c}\~ao Inteligente (SBAI 2023

On the Emergence of Islands in Complex Networks

Most growth models for complex networks consider networks comprising a single connected block or island, which contains all the nodes in the network. However, it has been demonstrated that some large complex networks have more than one island, with an island size distribution (Is) obeying a power-law function Is~s-α. This paper introduces a growth model that considers the emergence of islands as the network grows. The proposed model addresses the following two features: (i) the probability that a new island is generated decreases as the network grows and (ii) new islands are created with a constant probability at any stage of the growth. In the first case, the model produces an island size distribution that decays as a power-law Is~s-α with a fixed exponent α=1 and in-degree distribution that decays as a power-law Qi~i-γ with γ=2. When the second case is considered, the model describes island size and in-degree distributions that decay as a power-law with 2<α<∞ and 2<γ<∞, respectively

Propuesta de un conjunto de recomendaciones de accesibilidad para mejorar el posicionamiento de portales web empresariales

One of the key factors that contribute to improving the positioning of corporate web portals is accessibility, considering the large number of users and the volume of content available on the Web. Accessibility enables search engines to give priority to those portals that have incorporated these features. The objective of this article is to propose a set of accessibility recommendations to improve the positioning of corporate web portals, which were determined based on the guidelines and levels of conformity of the Colombian accessibility standard NTC 5854. For the methodological development of this research, the four phases of the iterative research pattern proposed by Pratt were considered: observing, identifying, developing and testing. These made it possible to define the recommendations and verify their relevance in accessibility inspections. As a main result, a set of recommendations was obtained for the accessible design of web portals, which were focused on improving the these sites’ positioning and grouped according to the four principles of the NTC 5854 standard. In addition, an automated tool was developed which allows conducting accessibility inspections of web portals using the defined recommendations. In conclusion, the inspection carried out on the JanuswWeb portal with the developed tool made it possible to verify the relevance of the recommendations, in order to enable a greater number of users to access, perceive, operate, and understand the content of the Web.Uno de los factores clave que contribuye con la mejora del posicionamiento de los portales web empresariales es la accesibilidad, teniendo en cuenta la gran cantidad de usuarios y el volumen de contenidos disponibles en la Web. La accesibilidad posibilita que los motores de búsqueda den prioridad a aquellos portales que han incorporado dichas características. El objetivo de este artículo es proponer un conjunto de recomendaciones de accesibilidad para mejorar el posicionamiento de portales web empresariales, las cuales fueron determinadas a partir de pautas y niveles de conformidad de la norma de accesibilidad colombiana NTC 5854. Para el desarrollo metodológico de esta investigación, se usaron las cuatro fases del patrón iterativo de investigación propuesto por Pratt: observar, identificar, desarrollar y probar. Estas permitieron definir las recomendaciones y verificar su pertinencia en una inspecciones de accesibilidad. Como resultado principal se obtuvo un conjunto de recomendaciones para el diseño accesible de portales web, enfocadas en mejorar el posicionamiento de estos sitios y agrupadas de acuerdo con los cuatro principios de la norma NTC 5854. Asimismo, se desarrolló una herramienta automatizada que permite la conducción de inspecciones de accesibilidad en portales web haciendo uso de las recomendaciones definidas. A modo de conclusión, la inspección desarrollada sobre el portal web Janus con la herramienta construida permitió verificar la pertinencia de las recomendaciones, de cara a posibilitar que un mayor número de usuarios puedan acceder, percibir, operar y comprender el contenido de la Web

Massive Star Forming Regions in the Galaxy using the Spitzer GLIMPSE Survey

We examine the thirteen most luminous sources in the WMAP free-free map using the Spitzer GLIMPSE and MSX surveys to identify massive star formation regions, emitting one-third of the Galactic free-free luminosity. We identify star forming regions by a combination of bubble morphology in 8 \micronm (PAH) emission and radio recombination line radial velocities. We find 40 star forming regions associated with our WMAP sources, and determine unique distances to 31. We interpret the bubbles as evidence for radial expansion. The radial velocity distribution for each source allows us to measure the intrinsic speed of a region's expansion. This speed is consistent with the size and age of the bubbles. The high free-free luminosities, combined with negligible synchrotron emission, demonstrate that the bubbles are not driven by supernovae. The kinetic energy of the largest bubbles is a substantial fraction of that measured in the older superbubbles found by Heiles. We find that the energy injected into the ISM by our bubbles is similar to that required to maintain the turbulent motion in the gas disk inside 8 kpc. We report a number of new star forming regions powered by massive (\textrm{M}_{*} > 10^4 \textrm{M}_\sun) star clusters. We measure the scale height of the Galactic O stars to be h_{\textrm{*}} = 35 \pm 5 \pc. We determine an empirical relationship between the PAH and free-free emission of the form $F_{\textrm{PAH}} \propto F^2_{\textrm{ff}}$. Finally, we find that the bubble geometry is more consistent with a spherical shell rather than a flattened disk.Comment: Submitted to ApJ; 29 Pages, 17 Figures, 5 Table