Adaptive Delta Modulation in Networked Controlled Systems With bounded Disturbances

This technical note investigates the closed-loop properties of the differential coding scheme known as Delta Modulation (Δ - M) when used in feedback loops within the context of linear systems controlled through a communication network. We propose a new adaptive scheme with variable quantization step Δ, by defining an adaptation law exclusively in terms of information available at both the transmitter and receiver. With this approach, global asymptotic stability of the networked control system is achieved for a class of controllable (possibly unstable) linear plants. Moreover, thanks to the globally defined switching policy, this architecture enjoys a disturbance rejection property that allows the system to recover from any finite-time unbounded disturbance or communication loss

Voltage Balance for Five-Level DCC Based on Mixed-Integer Linear Programming

In power converters, the modulation stage commands the switching devices to drive the converter outputs to the voltage required by the inner controllers in order to achieve their objectives. However, in multilevel converters, the modulation may be in charge of an ad ditional goal since it also has to tackle with the capacitor voltage balancing issue. This paper formulates the modulation of multilevel three-phase power converters, specifically a five-level diode-clamped converter (DCC), as a mixed-integer linear optimization prob lem. In this paper, it is shown that the presented optimization problem can deal with the capacitor voltage balance at the same time that the number of commutations is minimized. The problem is solved offline and its solution is stored in a lookup table to be used during normal operation. Then, an online procedure to obtain the levels that modulate each phase from the lookup table is given. Comparisons with model predictive control, space-vector based algorithms and other modulation approaches are presented in simulations. Several experimental results are presented showing the feasibility of this approach with changes in the operating conditions

Virtual assistant for individualized practical training on controller design

Abstract: In this work we present a virtual assistant to help instructors offer individualized practical training on controller design for linear systems. The virtual assistant is designed to be used together with Goodle GMS, a web application which offers services for the collection, storage and automatic grading of students exercises. Using the proposed scheme, an instructor can generate in an easy way and without having knowledge of programming, individualized exercises that can be graded automatically, ensuring that all the exercises have a solution and the same degree of difficulty. The platform has been teste

Hybrid Modelling and Control of a Class of Power Converters With Triangular-Carrier PWM Inputs

In this paper, a new control design procedure for a class of power converters based on hybrid dynamical systems theory is presented. The continuous-time dynamics, as voltage and current signals, and discrete-time dynamics, as the on- off state of the switches, are captured with a hybrid model. This model avoids the use of averaged and approximated models and includes the PWM as well as the sample-and-hold mechanism, commonly used in the industry. Then, another simplified hybrid system, whose trajectories match with the original one, is selected to design the controller and to analyse stability properties. Finally, an estimation of the chattering in steady state of the voltage and current signals is provided. The results are validated through simulation and experiments.MCIN/ AEI Project PID2019-105890RJ-I00MCIN/ AEI Project PID2019-109071RB-I0

Sistema de Evaluación Automática Vía Web en Asignaturas Prácticas de Ingeniería

En este trabajo se presenta una nueva herramienta web para educación que permite automatizar la recogida y evaluación de ejercicios prácticos de diferentes disciplinas de ingeniería con la complejidad típica que la formación técnica requiere. Una de las principales características de la herramienta propuesta es la posibilidad de personalizar los ejercicios para cada alumno. El sistema realiza una comparación funcional de las soluciones propuestas por los alumnos con las soluciones correctas proporcionadas por el profesorado y en función de los resultados obtenidos asigna una calificación al alumno de forma automática. La plataforma permite al profesor implementar técnicas innovadoras de docencia que fomentan el autoaprendizaje en cursos numerosos. Se presentan los resultados de uso del sistema de evaluación en dos cursos, uno de Teoría de Sistemas y otro de Fundamentos de Informática.Universidad de Sevilla I Plan Propio de Docenci

Fuzzy Model Predictive Control: Complexity Reduction for Implementation in Industrial Systems

In this paper, a new fuzzy logic-based control-design technique is presented. The method aims at reducing the complexity of Takagi-Sugeno Fuzzy systems via the reduction of fuzzy rules. This reduction is obtained by finding a function basis via the Functional Principal Component Analysis, and then the model is used for Model Predictive Control (MPC). This procedure is systematic, and eventually leads to feasible low-cost microcontroller-based implementations, which has become a generic need in the era of IoT. In order to validate the results, two experimental setups have been controlled using these principles. The first of these, a mechanical pendulum, presents nonlinear dynamics that suggests the use of linear discrete models at specific operating points. In the second, a pilot plant implementing an industrial process with a chemical reactor and a heat exchanger, presents nonlinear multivariate dynamics that are successfully handled with the Fuzzy MPC Controller

Voltage balancing in three-level neutral-point-clamped converters via Luenberger observer

This paper addresses the problems associated with the dc-link capacitor voltages of the three-level neutral-point-clamped power converter: the imbalance of the capacitor voltages as well as the presence of an ac-voltage low-frequency oscillation in the dc link of the converter. In order to cope with them, a mathematical analysis of the capacitor voltage difference dynamics, based on a direct average continuous model, is carried out, considering a singular perturbation approach. The analysis leads to a final expression where a sinusoidal disturbance appears explicitly. Consequently, the two problems can be handled together using the ordinary formulation of a problem of regulating the output of a system subject to sinusoidal disturbances, applying classical control theory to design the controller. In this way, the controller is designed including the disturbance estimate provided by a Luenberger observer to asymptotically cancel the disturbance, while keeping also balanced the capacitor voltages. Experiments for a synchronous three-level neutral-point-clamped converter prototype are carried out to evaluate the performance and usefulness of the converter working as a grid-connected inverter under the proposed control law.MICINN-FEDER DPI2009-09661Junta de Andalucía P07-TIC-0299

Evaluación continua con Goodle-GMS a más de 800 alumnos en Ingeniería Química

El objetivo de esta experiencia ha sido la de establecer un sistema de evaluación continua en asignaturas con gran cantidad de alumnos de forma que no supongan un excesivo trabajo para el docente, que permita generar una retroalimentación a los alumnos rápida, de forma que estimule el trabajo de los estudiantes. La experiencia ha sido realizada simultáneamente a 859 alumnos matriculados de la asignatura Química, correspondiente a 1º de los Grados de Ingeniería de la Energía (85), Ingeniería Aeroespacial (137), Ingeniería de las Tecnologías Industriales (459) e Ingeniería Química (141), durante el segundo cuatrimestre en la Escuela Técnica Superior de Ingeniería de la Universidad de Sevilla.L'objectiu d'aquesta experiència ha estat la d'establir un sistema d'avaluació contínua en assignatures amb gran quantitat d'alumnes de manera que no suposin un excessiu treball per al docent, que permeti generar una retroalimentació als alumnes ràpida, de manera que estimuli el treball dels estudiants. L'experiència ha estat realitzada simultàniament a 859 alumnes matriculats de l'assignatura Química, corresponent a 1r dels Graus d'Enginyeria de l'Energia (85), Enginyeria Aeroespacial (137), Enginyeria de les Tecnologies Industrials (459) i Enginyeria Química (141), durant el segon quadrimestre a l'Escola Tècnica Superior d'Enginyeria de la Universitat de Sevilla. S'han plantejat 5 problemes personalitzats als alumnes, en funció del seu DNI, de manera que s'han lliurat i corregit mitjançant la plataforma Goodle-GMS.The objective of this experience has been to establish a system of continuous assessment in subjects with large numbers of students so they do not involve too much work for teachers and allow providing scope for quick feedback to the students so that stimulates the students' work. The experience was carried out simultaneously to 859 students enrolled for the course Chemistry, corresponding to first course of Energy Engineering (85), Aerospace Engineering (137) Engineering Industrial Technologies (459) and Chemical Engineering (141), during the second semester in the School of Engineering of the University of Seville

Books and Monographies

[ES] Recensión del libro “Técnica e Ingeniería en España: Volúmenes I a V” de Manuel Silva Suárez (editor).Bordóns Alba, C.; Gómez-Estern Aguilar, F. (2009). Libros y Monografías. Revista Iberoamericana de Automática e Informática industrial. 6(2):108-110. http://hdl.handle.net/10251/146697OJS1081106