[Show abstract][Hide abstract] ABSTRACT: Se está diseñando y construyendo una herramienta interactiva que sirva de apoyo a la enseñanza de las asignaturas de Control de Sistemas (Ingeniería Electrónica y Ciencias Físicas) en los nuevos planes de Estudio de la UCM. Esta herramienta permite el estudio de los conceptos teóricos más importantes, el desarrollo y ejercicios de prácticas de control y repasar conceptos y prácticas que son básicas y que el alumno debe conocer antes de cursar ciertos temas de asignaturas superiores. El curso se ha completado con cuestionarios de evaluación y un foro de discusión para ayuda en el estudio. Permite la comunicación directa alumno-profesor para la resolución de dudas y planteamiento de soluciones a los problemas propuestos.
[Show abstract][Hide abstract] ABSTRACT: This paper presents a path planner for multiple unmanned aerial vehicles (UAVs) based on evolutionary algorithms (EAs) for realistic scenarios. The paths returned by the algorithm fulfill and optimize multiple criteria that 1) are calculated based on the properties of real UAVs, terrains, radars, and missiles and 2) are structured in different levels of priority according to the selected mission. The paths of all the UAVs are obtained with the multiple coordinated agents coevolution EA (MCACEA), which is a general framework that uses an EA per agent (i.e., UAV) that share their optimal solutions to coordinate the evolutions of the EAs populations using cooperation objectives. This planner works offline and online by means of recalculating parts of the original path to avoid unexpected risks while the UAV is flying. Its search space and computation time have been reduced using some special operators in the EAs. The successful results of the paths obtained in multiple scenarios, which are statistically analyzed in the paper, and tested against a simulator that incorporates complex models of the UAVs, radars, and missiles, make us believe that this planner could be used for real-flight missions.
[Show abstract][Hide abstract] ABSTRACT: En este trabajo se definen los formalismos necesarios para construir un entorno gráfico de modelado de problemas de optimización de sistemas a gran escala. Dado un problema modelado bajo esta orientación se generan automáticamente las bases de datos que albergarán la información del problema, datos ficticios para la realización de pruebas iniciales y los modelos de resolución, así como modelos de depuración en caso de que el resolutor no encuentre solución factible. Además se generan automáticamente editores gráficos que permitan visualizar gráficamente los datos del problema representado y sus soluciones, permitiendo modificar estos de forma cómoda. Finalmente estos formalismos se han utilizado para implementar un editor de problemas de optimización, que contemple las características mencionadas.
[Show abstract][Hide abstract] ABSTRACT: This research study focuses on the modeling and simulation of a gas distribution pipeline network with a special emphasis on gas ducts. Gas ducts are the most important components of such kind of systems since they define the major dynamic characteristics. Isothermal, unidirectional flow is usually assumed when modeling the gas flow through a gas duct. This paper presents two simplified models derived from the set of partial differential equations governing the dynamics of the process. These models include the inclination term, neglected in most related papers. Moreover, two numerical schemes are presented for the integration of such models. Also, it is shown how the pressure drop along the pipe has a strong dependency with the inclination term. To solve the system dynamics through the proposed numerical schemes a based MATLAB-Simulink library was built. With this library it is possible to simulate the behavior of a gas distribution network from the individual simulation of each component. Finally, the library is tested through three application examples, and results are compared with the existing ones in the literature.
[Show abstract][Hide abstract] ABSTRACT: This paper presents a path planner for Unmanned Air Vehicles (UAVs) based on Genetic Algorithms (GA) that obtains a feasible and optimal 3-D path for the UAV. It uses 9 different objective values which are calculated with a realistic model of the UAV and the environment and which are structured with 3 levels of priorities. Our planner works globally offline as well as locally online, which means that the algorithm can recalculate parts of the generated path in order to avoid unexpected risks. Finally, the effectiveness of the solutions given by this planner has been successfully tested against a simulator that contains the complete model of the UAV and the environment.
FLINS Conference on Computational Intelligence in Decision and Control; 01/2008
[Show abstract][Hide abstract] ABSTRACT: This paper presents a path planner for Unmanned Air Vehicles (UAVs) based on Evolutionary Algorithms (EA) that can be used in realistic risky scenarios. The path returned by the algorithm fulfills and optimizes multiple criteria which (1) are calculated based on properties of real UAVs, terrains, radars and missiles, and (2) are used to rank the solutions according to the priority levels and goals selected for each mission. Developed originally to work with only one UAV, the planner currently allows us to obtain the optimal path of several UAVs that are flying simultaneously. It works globally offline and locally online to recalculate a part of the path when an unexpected threat appears. Finally, the effectiveness of the solutions given by this planner has been successfully tested against a simulator that implements a complex model of the UAV and its environment.
Genetic and Evolutionary Computation Conference, GECCO 2008, Proceedings, Atlanta, GA, USA, July 12-16, 2008; 01/2008
[Show abstract][Hide abstract] ABSTRACT: For certain operations the control of AUV motions is subject to difficulties, due to motion coupling. In this paper a high manoeuvrability AUV is considered, with only thrusters for motion control. A Genetic planning of the control actions has been devised, considering a multiobjective optimisation problem, which includes energy and time saving, and smooth operation with realistic control actions. Since the inertia of the submergible filters out control brisk changes, it turns out that there are many almost equivalent control strategies obtaining similar trajectories. This is why the characteristics of the control actions have been included as part of the multiobjective optimisation. Several diving scenarios have been specified, including obstacles. The paper begins with a description of the AUV and the control problem, then it focus on the multiobjective optimisation problem and the genetic planning to solve the problem, then it considers several scenarios and present optimal results; finally, the paper comes to conclusions and future research, which will be experimental.
[Show abstract][Hide abstract] ABSTRACT: We solve the problem of petroleum products distribution through oil pipelines networks. This problem is modelled and solved
using two techniques: A heuristic method like a multiobjective evolutionary algorithm and Mathematical Programming. In the
multiobjective evolutionary algorithm, several objective functions are defined to express the goals of the solutions as well
as the preferences among them. Some constraints are included as hard objective functions and some are evaluated through a
repairing function to avoid infeasible solutions. In the Mathematical Programming approach the multiobjective optimization
is solved using the Constraint Method in Mixed Integer Linear Programming. Some constraints of the mathematical model are
nonlinear, so they are linearized. The results obtained with both methods for one concrete network are presented. They are
compared with a hybrid solution, where we use the results obtained by Mathematical Programming as the seed of the evolutionary
Journal of Zhejiang University - Science A: Applied Physics & Engineering 01/2005; 6(1):9-19. DOI:10.1007/BF02842471 · 0.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Marine environments offer suggestive scenarios for Automatic control and Cooperation strategies to be applied. The present paper focus on a particular one: Two ships towing together an off-shore oil retaining boom. Basic dynamical equations are presented for the combined displacement of both ships plus the boom. Computer simulation of basic manoeuvres works out the basic control implications of the problem and suggests cooperation among the ships as a more reliable technique to fulfil ships goals and minimize boom strain.
[Show abstract][Hide abstract] ABSTRACT: Fast ships are taking a relevant role with a clear interest for military purposes. Fast sea transportation encounters several problems to be solved. This article refers to the difficulties originated by brisk vertical motions. The waves encountered by fast ships induce such vertical motions, and this has negative effects: navigation risks, sea sickness, structural damages, and load displacement. It is also interesting for military uses to stabilize the ship when an aircraft is landing or when precision firing is required. By means of submerged actuators, it is possible to alleviate vertical motions. In this research, a pair of transom flaps and a T-foil near the bow are used to counteract the waves. These actuators must move with the maximum efficiency, taking into account the dynamical characteristics of the ship. As a consequence, there is a problem of automatic control design. To carry out this design, it is important to obtain mathematical models of all the aspects involved in the problem: the ship, the waves, the actuators, and the effect on crew and comfort. The aim of this paper is to present the development of these models and the use of them for problem analysis and control design.
[Show abstract][Hide abstract] ABSTRACT: As a main part of a research study on the control of active flaps and a T-foil of a high-speed ferry, a control-oriented model of vertical motions of the ship has been developed. The objective of the control is to improve comfort, decreasing the impact of heave and pitch motions. We have experimental data from a towing tank institution and simulations with PRECAL. The model is based on a decomposition of the physic phenomena into two main aspects: the coupling of the ship with distance between waves and the dynamics of a semisubmerged mass. The model can be handled with MATLAB-SIMULINK, which is useful for studying control strategies. The model shows good agreement (model validation) with the experimental and simulated data for regular and irregular waves. The article shows a methodology, based on MATLAB tools, for obtaining control-oriented models from computer-aided design (CAD)based programs. That means that the control-oriented model can be derived from the ship design, even before the ship is built.
Journal of Ship Research 08/2004; 48(3):218-230. · 0.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A study was conducted to determine the effectiveness of using controlled flaps and a T-foil to smoothen a ship's vertical motion while navigating in head seas. The study comprised two steps: to develop a tool for control design in the form of a computer-based simulation and to use this tool to develop satisfactory controllers. The simulation was based on mathematical models of the ship, the actuators, the waves and the seasickness effect. Since the actuators have limited action, there is a limited margin for improvement based on more sophisticated control strategies. Possible improvements of motion sickness incidence (MSI) are linked to a control strategy that exploits better synchronization with incident waves.
IEEE control systems 05/2004; DOI:10.1109/MCS.2004.1275431 · 3.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This paper describes empirical research on the model, optimization and supervisory control of beer fermentation. Conditions in the laboratory were made as similar as possible to brewery industry conditions. Since mathematical models that consider realistic industrial conditions were not available, a new mathematical model design involving industrial conditions was first developed. Batch fermentations are multiobjective dynamic processes that must be guided along optimal paths to obtain good results. The paper describes a direct way to apply a Pareto set approach with multiobjective evolutionary algorithms (MOEAs). Successful finding of optimal ways to drive these processes were reported. Once obtained, the mathematical fermentation model was used to optimize the fermentation process by using an intelligent control based on certain rules.
Journal of Zhejiang University SCIENCE 05/2004; 5(4):378-89. DOI:10.1631/jzus.2004.0378
[Show abstract][Hide abstract] ABSTRACT: In this paper a new experimental system for studies about the integrated course and active appendages control is introduced. The research focuses on fast ships. The appendages considered are moving flaps, fins, and a T-foil. They are used for motion smoothing. The fast ships use powerful waterjets that can be oriented for course control, instead of using rudders. When an actuator moves, course control is disturbed. An integrated actuators and course control system is needed. This is a main target of our research. A departing point for the research is to provide an experimental system for control studies. This system consists of an autonomous scaled physical model and an external support system (ESS). The on-board control system is based on a CAN bus, using several smart nodes.. The paper describes the distributed control system of the physical model, and the ESS. The distributed architecture of the model on-board system can be easily ported to real ships, since the CAN bus can be extended to relatively long distances.
[Show abstract][Hide abstract] ABSTRACT: This paper is related with a research on vertical motion alleviation of fast ferries. A scaled down replica of a fast ferry was built, for experimental studies in a towing tank facility. Some submerged moving actuators were added to the replica: a pair of transom flaps, lateral fins and a T-foil near the bow. Two series of experiments with waves generated in a large basin must be done. One of the series is devoted to modelling, and the second for model-based control studies. Due to the fast motions of the experimental ship, it is not possible to attach it to a computerized carriage with instrumentation (it is part of the towing tank facility). Instead, the experimental ship must be autonomous, with all monitoring and control systems on board. Since there are six motions of the ship to be considered, the number of on-board sensors and actuators, and the complexity of control, take us to decide the design of a distributed electronic system. It is based on a central embedded PC, several microcomputer nodes, and the CANbus. The on board system interacts, using a wireless data link, with an off-shore experiment control and data processing system, with an interesting visualization performance. The purpose of the paper is to introduce this system and the associated experimental framework.
Industrial Electronics Society, 2003. IECON '03. The 29th Annual Conference of the IEEE; 12/2003
[Show abstract][Hide abstract] ABSTRACT: Heuristic methods are specially well suited to solve combinatorial problems. One of these problems is the distribution of petroleum products through oil pipelines networks. In this paper the problem is stated and solved using a multiobjective and constraint evolutionary optimization algorithm. Several objective functions has been defined to express the goals of the solutions as well as the preferences among them. Some constraints are included as hard objective functions and some has been evaluated through a repairing function to avoid infeasible solutions. An example of working is given.