Xavier Blasco

Universitat Politècnica de València | UPV · Department of Systems Engineering and Control

Microgrids based on renewable energies are a topic of growing interest today. • The EMS is crucial in microgrids, many authors designed an EMS for a microgrid. • There is a lack of systematization of this process, from modelling to EMS design. • This article develops a complete standard methodology for MPC-based EMS design. • The methodology has be...

This paper presents a new approach for the multiobjective optimal design of robust controllers in systems with stochastic parametric uncertainty. Traditionally, uncertainty is incorporated into the optimization process. However, this can generate two problems: (1) low performance in the nominal scenario; and (2) high computational cost. For the fir...

Advanced control systems are tuned using dynamic models and optimization techniques. This approach frequently involves satisfying multiple conflicting objectives. Tuning robust controllers requires considering a framework that represents the system uncertainties, and its definition is not a trivial task. When dealing with a nonlinear model with man...

This paper offers the TRAM-FPV Racing open database. It results from indoor flights with five (5) racing drones at Cranfield University (UK). Strictly, at the Flight Arena. It is one of the largest indoor flight fields in the world for research goals. The flight data were recorded using an optical measurement system (OMS). The position and orientat...

En este trabajo se muestra la utilidad de las soluciones casi óptimas relevantes en el ajuste mediante optimización multiobjetivo de controladores robustos ante incertidumbre en el modelo. Una posibilidad muy común para este ajuste es incorporar la incertidumbre en el proceso de optimización, por ejemplo, incorporando la evaluación de la robustez d...

Las Jornadas de Automática (JA) son el evento más importante del Comité Español de Automática (CEA), entidad científico-técnica con más de cincuenta años de vida y destinada a la difusión e implantación de la Automática en la sociedad. Este año se celebra la cuadragésima tercera edición de las JA, que constituyen el punto de encuentro de la comunida...

En este artículo se presenta la aplicación de una metodología de selección de lazos de control y ajuste de controladores para controlar un sistema multivariable no lineal denominado unidad caldera-turbina. Se plantearon dos escenarios y se definieron dos conceptos de diseño (combinaciones de lazos de control), cada uno con seis objetivos. Se muestr...

In a multi-objective optimization problem, in addition to optimal solutions, multimodal and/or nearly optimal alternatives can also provide additional useful information for the decision maker. However, obtaining all nearly optimal solutions entails an excessive number of alternatives. Therefore, to consider the nearly optimal solutions, it is conv...

Including designer preferences in every phase of the resolution of a multi-objective optimization problem is a fundamental issue to achieve a good quality in the final solution. To consider preferences, the proposal of this paper is based on the definition of what we call a preference basis that shows the preferred optimization directions in the ob...

This paper presents a design for the multivariable control of a cooling system in a PEM (proton exchange membrane) fuel cell stack. This system is complex and challenging enough: interactions between variables, highly nonlinear dynamic behavior, etc. This design is carried out using a multiobjective optimization methodology. There are few previous...

In this work, the parametric identification of a cooling system in a PEM (proton exchange membrane) fuel cell is carried out. This system is multivariable and nonlinear. In this type of system there are different objectives and the unmodeled dynamics cause conflicting objectives (prediction errors in each output). For this reason, resolution is pro...

In the multivariable control literature there are few techniques that face the problem of selecting suitable loop pairings in non-linear multivariable systems. Most techniques analyze the linearized system at a specific operating point. This paper proposes a new methodology to optimally and simultaneously select the loop pairings and the tuning of...

The current environmental challenges require the implementation of environmentally friendly energy production systems. In this context, proton exchange membrane fuel cell stacks (PEMFC) represent, due to their high electrical efficiency and their low level of $CO_{2}$ emissions, a promising alternative technology. However, there are still many tech...

Solving a wide range of engineering problems can be approached from the point of view of multi-objective optimization (MOO), i.e. trying to optimize several conflicting objectives simultaneously. Solutions to these problems are not unique and the designer must choose from several optimal solutions (Pareto set), depending on his or her preferences....

In this paper, a posteriori multi-objective optimisation (MOO) is applied to tune the parameters of a second-order sliding-mode control (2-SMC) scheme commanding the grid-side converter (GSC) of a doubly-fed induction generator (DFIG) subject to unbalanced and harmonically distorted grid voltage. Two variants (i.e., design concepts) of the same 2-S...

Micro-combined heat and power systems (l-CHP) based on proton exchange membrane fuel cell stacks (PEMFC) are capable of supplying electricity and heat for the residential housing sector with a high energy efficiency and a low level of CO2 emissions. For this reason they are regarded as a promising technology for coping with the current environmenta...

This paper proposes a new method for the selection of input–output pairing in decentralized control structures for multivariable systems. This method proposes the input–output pairing problem as a multi-objective optimization problem (MOP). For each control structure and loop pairing analyzed, a different design concept is proposed and a MOP is sta...

In this paper we present the adjustment of controller parameters using multiobjective optimization techniques. Unlike other works, where only the Pareto optimal solutions are considered, we also consider the set of nearly optimal solutions nondominated in their neighborhood. These solutions are potentially useful for two reasons: 1) they are simila...

Given a finite dimensional asymmetric normed lattice, we provide explicit formulae for the optimization of the associated (non-Hausdorff) asymmetric “distance” among a subset and a point. Our analysis has its roots and finds its applications in the current development of effective algorithms for multi-objective optimization programs. We are interes...

Traditionally, in a multiobjective optimization problem, the aim is to find the set of optimal solutions, the Pareto front, which provides the decision-maker with a better understanding of the problem. This results in a more knowledgeable decision. However, multimodal solutions and nearly optimal solutions are ignored, although their consideration...

This article shows the application of multi-objective optimization techniques, both for the identification of parameters of a nonlinear model and for the adjustment of controllers. In particular, we propose a technique to identify the parameters of a first principles model of a rotational inverted pendulum (RIP) applying a methodology of multi-obje...

In this chapter, a multiobjective optimization design procedure is applied to the multivariable version of the Boiler Control Problem, defined in 2nd IFAC Conference on Advances in PID Control, 2012. The chapter follows a realistic approach, closer to industrial practices: a nominal linear model will be identified and afterwards a constrained multi...

In this chapter, controllers with different complexity for the control benchmark proposed in 1990 at the American Control Conference will be tuned using a multiobjective optimization design procedure. The aim of this chapter is two fold: on the one hand, to evaluate the overall performance of two different controller structures on such a benchmark...

In this chapter, a simple controller tuning statement by means of the multiobjective optimization design procedure is given. The aim of this chapter is to show a basic example in controller tuning and to focus on the importance of the chosen objectives and the basic use of Level Diagrams as tool for the decision making process. Additionally the mul...

In this chapter a Peltier cell is used for cooling and freezing purposes. The main challenge from the control point of view is to guarantee the setpoint response performance for both tasks despite the process nonlinearities. For this purpose, reliability based optimization approach is stated and tackled with the multiobjective optimization design p...

In this chapter, tools for the evolutionary multiobjective optimization process and the multicriteria decision making stage to be used throughout this book (as a reference) are presented. Regarding the optimization process, three different versions of a multiobjective evolutionary algorithm based on Differential Evolution will be commented; with th...

In this chapter, a multivariable controller is tuned by means of a multiobjective optimization design procedure. For this design problem, several specifications are given, regarding individual control loops and overall performance. Due to this fact, a many-objectives optimization problem is stated. In such problems, algorithms could face problems d...

Throughout this chapter, we intend to provide a multiobjective awareness of the controller tuning problem. Beyond the fact that several objectives and requirements must be fulfilled by a given controller, we will show the advantages of considering this problem in its multiobjective nature. That is, optimizing simultaneously several objectives and f...

In this chapter, a digital controller is tuned for the control benchmark proposed in 2008 by the ABB group at the 17th IFAC World Congress via multiobjective optimization. In some instances, a more realistic evaluation of a controller performance is sought, that is, the expected performance of the controller when it will be implemented. For this be...

In this chapter, the multiobjective optimization design procedure will be used in order to tune the controller of a Twin Rotor MIMO System (TRMS). For such process, a many-objectives optimization instance is tackled using aggregate objective functions. Two different controllers are compared: a decentralized PID structure and a State Space feedback...

In this chapter a background on multiobjective optimization and a review on multiobjective optimization design procedures within the context of control systems and the controller tuning problem are provided. Focus is given on multiobjective problems where an analysis of the Pareto front is required, in order to select the most preferable design alt...

In this chapter, the multiobjective optimization design procedure will be used to tune the autopilot controllers for an autonomous Kadett\(\copyright \) aircraft. For this aim, a multivariable PI controller is defined, and a many-objectives optimization instance is tackled using designer preferences. After the multicriteria decision making stage, t...

This chapter will illustrate the tools presented in previous chapters for the analysis and comparison of different design concepts. In particular, three different control structures (PI, PID and GPC) will be compared, analysing their benefits and drawbacks within a multiobjective approach. First, a two objective approach, where robustness and distu...

In general, the starting point for the complex task of designing a robust and efficient control system is the use of nominal models that allow to establish a first set of parameters for the selected control scheme. Once the initial stage of design is achieved, control engineers face the difficult task of Fine-Tuning for a more realistic environment...

When design problems are multiobjective, graphical representation of the optimization results has a great importance in the analysis and decision making steps. This paper wants to show some of the main features of an interactive tool for multiobjective Pareto front and set analysis. The tool is built in Matlab and uses the Level Diagram representat...

A design problem is usually solvable in different ways or by design alternatives. In this work, the term "concept" is used to refer to the design alternatives. Additionally, it is quite common that a design problem has to satisfy conflicting objectives. In these cases, the design problem can be formulated as a multiobjective optimization problem (M...

This paper presents a complete (charging, discharging and thermal characteristics) non-linear model identification of a lead acid battery by using a multi-objective (MO) approach. Batteries are a very important part for a lot of processes, hybrid electric vehicles (HEV) are an example. In an HEV, the battery model is critical because defines the el...

In this paper a new multi-objective approach for loop pairing in multi-input/multi-output processes is studied. Each controller structure of proposed input-output pairing is considered as a possible design concept. Under the meaningful objective space, defined by the control engineer, the concepts are compared and a final controller with a given tr...

In this paper a technique for identifying a first principles model of a Peltier cell using Multi-Objective Evolutionary optimization and experimental data is proposed. The methodology of multi-objective optimization applied together with the method of representation of the Pareto front called level diagram enables the analysis of the set of models...

Sonic crystals have been demonstrated to be good candidates to substitute for conventional diffusers in order to overcome the need for extremely thick structures when low frequencies have to be scattered, however, their performance is limited to a narrow band. In this work, multiobjective evolutionary algorithms are used to extend the bandwidth to...

In this paper a new approach to design sound phase diffusers is presented. The acoustic properties of such diffusers are usually increased by using single objective optimization methods. Here we propose the use of a multiobjective (MO) approach to design them in order to take into account several conflicting characteristic simultaneously. Three dif...

Visualization tools and techniques to analyze n-dimensional Pareto fronts are valuable for designers and decision makers in order to analyze straightness and drawbacks among design alternatives. Their usefulness is twofold: on the one hand, they provide a practical framework to the decision maker in order to select the preferable solution to be imp...

Multi-objective optimisation design procedures have shown to be a valuable tool for control engineers. They enable the designer having a close embedment of the tuning process for a wide variety of applications. In such procedures, evolutionary multi-objective optimisation has been extensively used for PI and PID controller tuning; one reason for th...

Multi-objective optimization design procedures have shown to be a valuable tool for control engineers. These procedures could be used by designers when (1) it is difficult to find a reasonable trade-off for a controller tuning fulfilling several requirements; and (2) if it is worthwhile to analyze design objectives exchange among design alternative...

Resumen— En este artículo se describe la aplicación del pa-quete de MATLAB xPC target en prácticas de laboratorio, como complemento a la docencia en asignaturas de control. Con estas prácticas se pretende que el alumno afiance los conocimientos adquiridos en las clases teóricas, en concreto que se enfrente con los problemas típicos que aparecen en...

In this work a method for designing parallel-distributed compensation fuzzy state-feedback controllers for BIBO stabilization of nonlinear systems affected by persistent disturbances is presented. First some methods proposed in the literature are analyzed and their weak points are discussed. Next a design scheme based on minimizing the 1-norm betwe...

Preference articulation in multi-objective optimization could be used to improve the pertinency of solutions in an approximated Pareto front. That is, computing the most interesting solutions from the designer's point of view in order to facilitate the Pareto front analysis and the selection of a design alternative. This articulation can be achieve...

PID controller remain as a practical and reliable solution for a wide range of industrial applications. Efforts to develop new tuning techniques fulfilling several requirements and specifications are worthwhile. A commonly used approach is by means of an optimization procedure to adjust its parameters. Stochastic optimizers has been well used for P...

In this work, we propose an hybrid multi-objective optimization design procedure for PI controller tuning. This procedure focuses on reliability-based optimization instances, where Montecarlo methods are used to evaluate quantitatively the performance degradation of a controller, due to unexpected or unmodeled dynamics. The procedure is evaluated o...

The Concurso de Ingeniería de Control (CIC) (Engineering Control Challenge) is a student challenge organized by the Comité Español de Automática - CEA (Spanish Committee of Automation) from Spain. It was set as an educational and motivational tool for control engineering students. Although originally devised for Spanish pupils, several non-spanish...

Hybrid vehicles have become a promising solution to mitigate the negative effects of pollution and fossil fuel dependency, consequences (among other causes) of an increasing demand on mobility of people and goods. A hybrid vehicle is integrated by many subsystems, where one of the most important is the energy management system, which coordinates wh...

Control engineering problems are generally multi-objective problems; meaning that there are several specifications and requirements that must be fulfilled. A traditional approach for calculating a solution with the desired trade-off is to define an optimisation statement. Multi-objective optimisation techniques deal with this problem from a particu...

A tool to draw Leveldiagrams, with utilities for decision making and design concepts comparison.

Obtaining multi-objective optimization solutions with a small number of points smartly distributed along the Pareto front is a challenge. Optimization methods, such as the normalized normal constraint (NNC), propose the use of a filter to achieve a smart Pareto front distribution. The NCC optimization method presents several disadvantages related w...

Link to free software that help drawing level diagrams. This toolbox draws Leveldiagrams for Pareto Set and its associated Front, and allows some basics graphics manipulations (coloring plot according preferences, axis manipulation and point selections) to help in decision making.

PID controllers are a reliable, robust, practical and easy to implement control solution for industrial processes. They provide the first control layer for a vast majority of industrial applications. Owing to this, several researches invest time and resources to improve their performance. The research lines in this field scope with new tuning metho...

A holistic multi-objective optimization design technique for controller tuning is presented. This approach gives control engineers greater flexibility to select a controller that matches their specifications. Furthermore, for a given controller it is simple to analyze the tradeoff achieved between conflicting objectives. By using the multi-objectiv...

In this work, we address the evaluation of design concepts and the analysis of multiple Pareto fronts in multi-criteria decision-making using level diagrams. Such analysis is relevant when two (or more) design concepts with different design alternatives lie in the same objective space, but describe different Pareto fronts. Therefore, the problem ca...

By today, PI-PID controllers remain as reliable control solutions in a wide variety of industrial applications. Several tuning techniques have been designed and proposed successfully over the years. However the difficulty for tuning procedures increase as multiple requirements and criteria to evaluate the closed loop performance are demanded to be...

A multiobjective optimisation engineering design (MOED) methodology for PI controller tuning in multivariable processes is presented. The MOED procedure is a natural approach for facing multiobjective problems where several requirements and specifications need to be fulfilled. An algorithm based on the differential evolution technique and spherical...

Este documento muestra en detalle el proceso de simulación y evaluación multiobjetivo de las propuestas al Concurso en Ingeniería de Control 2012, Control autónomo del seguimiento de trayectorias de un vehículo cuatrirrotor, organizado por el Comité Español de Automática (CEA). El concurso busca ofrecer una herramienta de trabajo adicional que pued...

This paper proposes an explicit solution to the model predictive control of linear systems subject to non-convex polyhedral constraints. These constraints are modeled as the union of a finite number of convex polyhedra. The algorithm is based on calculating the explicit solution to a modified problem with linear constraints defined as the convex hu...

By today, PI-PID controllers remain as reliable control solutions in a wide variety of industrial applications. Several tuning techniques have been designed and proposed successfully over the years. However the difficulty for tuning procedures increase as multiple requirements and criteria to evaluate the closed loop performance are demanded to be...

By today, PI-PID controllers remain as reliable control solutions in a wide variety of industrial applications. Several tuning techniques have been designed and proposed successfully over the years. However the difficulty for tuning procedures increase as multiple requirements and criteria to evaluate the closed loop performance are demanded to be...

In this paper, the results for the CEC 2011 Competition on testing evolutionary algorithms on real world optimization problems using a hybrid differential evolution algorithm are presented. The proposal uses a local search routine to improve convergence and an adaptive crossover operator. According to the obtained results, this algorithm shows to b...

Resumen Este trabajo propone una solución explícita para el control predictivo de sistemas lineales sujetos a restricciones poliédricas no convexas, modeladas como la unión de un número finito de poliedros. El algoritmo se basa en el cálculo de la solución explícita de los problemas sujetos a las restricciones convexas definidas por dichos poliedro...

In this work, an empirical study on multiobjective optimization algorithms based on Differential Evolution (DE) algorithm is performed. The study focuses on getting good initial choices for evolutionary parameters for DE algorithm to tackle the multiobjective problem of PI controller tuning. This is an important issue in the field of control engine...

This paper deals with the computation of the maximal closed-l