233 publications from this institution
Se presentan datos obtenidos por el proyecto Gestion Integral del Patrimonio Cultural Prehistorico del Parque Nacional Santa Teresa, correspondientes a las etapas de catalogacion de los bienes culturales prehistoricos y excavacion de dos sitios arqueologicos (La Moza y Antena). Mediante las actividades de prospeccion se identificaron y mapearon 24 sitios arqueologicos que se emplazan en distintas unidades del paisaje: linea de costa, microcuenca de la laguna de Pena y zona alta. Los datos recabados tanto en la prospeccion como en las excavaciones han contribuido a profundizar el conocimiento de las sociedades prehistoricas litorales desde el punto de vista cronologico y de su adaptacion a estos ambientes. Asimismo, la informacion obtenida en campo ha permitido realizar una valoracion patrimonial de los sitios arqueologicos identificados, de suma utilidad para el diseno de futuras estrategias de proteccion, conservacion y difusion de estos bienes culturales.
El ABP (Aprendizaje Basado en Proyecto) es una metodologia didactica en la que el estudiante aprende los conceptos de una materia mediante la realizacion de un proyecto o resolucion de un problema adecuadamente disenado y formulado por el profesor. Diversos estudios muestran que el ABP fomenta habilidades muy importantes, tales como el trabajo en grupo, el aprendizaje autonomo, la planificacion del tiempo, el trabajo por proyectos o la capacidad de expresion oral y escrita, y mejora la motivacion del estudiante, lo que se traduce en un mejor rendimiento academico y una mayor persistencia en el estudio. Este tipo de experiencias pueden ser beneficiosas tanto para el alumnado, que desarrolla nuevas habilidades que se acaban de mencionar, como para el profesor, que debe adaptarse a las nuevas exigencias tanto del entorno academico que plantea la adaptacion al EEES como del mercado de trabajo. En este trabajo se pretende utilizar la metodologia ABP en cada una de las asignaturas relacionadas con la robotica dentro del Master Universitario en Automatica y Robotica, para disenar, construir y programar un robot a lo largo del Master. Cada una de las asignaturas implicadas en la red definira como participara dentro del proyecto global. El alumno podra adquirir las competencias de cada asignatura al mismo tiempo que trabaja en un proyecto de gran envergadura en el que se obtiene finalmente un robot real.
Abstract Tower cranes find wide use in construction works, in ports and in several loading and unloading procedures met in industry. A nonlinear optimal control approach is proposed for the dynamic model of the 4-DOF underactuated tower crane. The dynamic model of the robotic crane undergoes approximate linearization around a temporary operating point that is recomputed at each time-step of the control method. The linearization relies on Taylor series expansion and on the associated Jacobian matrices. For the linearized state-space model of the system a stabilizing optimal (H-infinity) feedback controller is designed. To compute the controller’s feedback gains an algebraic Riccati equation is repetitively solved at each iteration of the control algorithm. The stability properties of the control method are proven through Lyapunov analysis. The proposed control approach is advantageous because: (i) unlike the popular computed torque method for robotic manipulators, the new control approach is characterized by optimality and is also applicable when the number of control inputs is not equal to the robot’s number of DOFs, (ii) it achieves fast and accurate tracking of reference setpoints under minimal energy consumption by the robot’s actuators, (iii) unlike the popular Nonlinear Model Predictive Control method, the article’s nonlinear optimal control scheme is of proven global stability and convergence to the optimum.
There is wide use of boom cranes in ports and on vessels for ships' loading and unloading. In this article a nonlinear optimal control approach is proposed for the model of offshore boom cranes. The dynamic model of the boom cranes undergoes approximate linearization with the use of Taylor series expansion around a temporary operating point which is recomputed at each iteration of the control method. For the approximately linearized model an H-infinity feedback controller is designed. The linearization procedure relies on the computation of the Jacobian matrices of the state-space model of the system. The proposed control method stands for the solution of the optimal control problem for the nonlinear and multivariable dynamics of the boom cranes, under model uncertainties and external perturbations. For the computation of the controller's feedback gains an algebraic Riccati equation is solved at each time-step of the control method. The new nonlinear optimal control approach achieves fast and accurate tracking for all state variables of the boom cranes, under moderate variations of the control inputs. The stability properties of the control scheme are proven through Lyapunov analysis.
Sensors provide robotic systems with the information required to perceive the changes that happen in unstructured environments and modify their actions accordingly. The robotic controllers which process and analyze this sensory information are usually based on three types of sensors (visual, force/torque and tactile) which identify the most widespread robotic control strategies: visual servoing control, force control and tactile control. This paper presents a detailed review on the sensor architectures, algorithmic techniques and applications which have been developed by Spanish researchers in order to implement these mono-sensor and multi-sensor controllers which combine several sensors.
Este libro sirve como texto basico de referencia para el estudio de las redes de computadores en las titulaciones de grado en ingenieria. Los contenidos que abarca se extienden a lo largo de nueve capitulos, que tratan tanto aspectos basicos como especificos de transmisiones y codificacion de datos, multiplexacion de datos, control de enlace de datos, conmutacion de paquetes, asi como algoritmos y protocolos de enrutamiento de las redes LAN mas extendidas. Para facilitar el proceso de aprendizaje cada capitulo presenta un resumen general, un breve indice de contenidos, una lista de objetivos basicos especificos que se pretende alcanzar y por ultimo un indice de palabras claves para facilitar la busqueda conceptual. Ademas, cada capitulo se acompana de ilustraciones, ejemplos y ejercicios modelo para presentar los contenidos de una manera concisa y precisa PABLO GIL, Jorge Pomares y Francisco Candelas, son doctores Ingenieros en Informatica y profesores titulares de la Universidad de Alicante. Ejercen su tarea docente impartiendo asignaturas sobre Redes de Computadores.
Neste artigo[1] procura-se salientar a importância do conhecimento do aluno no êxito das reformas educativas. Reflecte-se sobre a situação de dois países, Portugal e Chile, pondo em evidência a não participação dos alunos, em particular na Educação Secundária, nas mudanças educacionais. Relaciona-se o processo de massificação da educação com as mudanças culturais que ela arrasta consigo. Referem-se, seguidamente, os enormes avanços da tecnologia e as suas consequências na alteração profunda do quotidiano dos estudantes. Constata-se a distância existente entre a cultura escolar e a cultura juvenil. Conclui-se por último, da necessidade urgente de as reformas educativas serem feitas não só para os alunos mas também com os alunos.
 [1] Os autores deste artigo, escrito através de sucessivos e-mail, vivem em países de continentes diferentes, falam idiomas diferentes e não se conhecem pessoalmente, mas liga-os uma preocupação similar: os alunos.
In this paper an impedance control scheme is described in order to allow the joint use of visual and force information for controlling a robot during the tracking of a surface. A visual servoing system is employed for following a trajectory in the image space. The impedance control modifies the trajectory obtained from the visual servoing system allowing the system to maintain a constant force with respect the surface. In order to improve the system behaviour an adaptive approach is proposed so that the tracking velocity is modified depending on the value of the Generalized Likelihoot Ratio obtained from the interaction forces measured during the tracking.
The current trend in the evolution of sensor systems seeks ways to provide more accuracy and resolution, while at the same time decreasing the size and power consumption. The use of Field Programmable Gate Arrays (FPGAs) provides specific reprogrammable hardware technology that can be properly exploited to obtain a reconfigurable sensor system. This adaptation capability enables the implementation of complex applications using the partial reconfigurability at a very low-power consumption. For highly demanding tasks FPGAs have been favored due to the high efficiency provided by their architectural flexibility (parallelism, on-chip memory, etc.), reconfigurability and superb performance in the development of algorithms. FPGAs have improved the performance of sensor systems and have triggered a clear increase in their use in new fields of application. A new generation of smarter, reconfigurable and lower power consumption sensors is being developed in Spain based on FPGAs. In this paper, a review of these developments is presented, describing as well the FPGA technologies employed by the different research groups and providing an overview of future research within this field.
