Scielo RSS <![CDATA[Revista Facultad de Ingeniería - Universidad de Tarapacá]]> http://www.scielo.cl/rss.php?pid=0718-133720030002&lang=es vol. 11 num. 2 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[LA SOCIEDAD DEL CONOCIMIENTO]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-13372003000200001&lng=es&nrm=iso&tlng=es <![CDATA[ECOLOGÍA COGNITIVA EN ROBOTS TERRENOS]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-13372003000200002&lng=es&nrm=iso&tlng=es Con el propósito de incrementar la productividad de algunas actividades humanas en el desierto de Atacama, se plantea la participación de robots terrenos en dicho territorio. Sobre la hipótesis de que es factible concebir robots que manejen información del entorno tal como lo hacen los seres vivos y que tal manejo provoca un aumento del rendimiento del autómata; se establece como objetivo general la emulación a nivel conceptual fenómenos ecológicos cognitivos en un robot terreno. Luego de examinar varios fenómenos estudiados por la Biología, particularmente por su novel rama de la Ecología Cognitiva, se selecciona a) la cuantificación de la dificultad de tareas en función de las condiciones del entorno, reportando el decaimiento de su nivel de vigilancia tal como ocurre en animales localizados en cadenas tróficas intermedias y b) la identificación de zonas de peligro según el aprendizaje de animales solitarios. Puesto que la Biología y la Robótica tienen en común a entes que en todo o en parte funcionan por sí solos, es de esperar que esta última disciplina sea impactada favorablemente por la primera<hr/>With the aim to increase the productivity of some human activities in the Atacama desert, this paper proposes the participation of terrain robots in this territory. Over the hypothesis of the feasibility about conception of robots which manage information like live being and such management increases the performance of the automaton; the general objective is the emulation in a conceptual level of ecological phenomena in a cognitive system of a terrain robot. After analysing several phenomena studied by Biology and its new branch called Cognitive Ecology, two of them are selected: a) quantification of work difficulty in function of environmental conditions, reporting decreasing of its vigilance level, such as occurs in animals of intermediate tropical chains and, b) the identification of danger zones according to the learning of solitaire animals. Considering that Biology and Robotics have in common being function themselves in a total or partial aspects, the hope is that this discipline will be well impacted by the first one <![CDATA[DISEÑO DE UN SISTEMA ROBÓTICO CARTESIANO PARA APLICACIONES INDUSTRIALES]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-13372003000200003&lng=es&nrm=iso&tlng=es El presente artículo describe los principales aspectos de la formulación del modelo y del diseño de los sistemas de control y accionamiento, involucrados en el desarrollo del prototipo de un robot industrial estándar denominado Sistema Robótico Cartesiano (SRC)<hr/>This paper describes the main aspects of the model formulation and the design of control and electronic systems, that are involved in the development of a standard industrial robot, named Cartesian Robotic System (CRS) <![CDATA[New Trends in Sound Synthesis and Automatic Tuning of Electronic Musical Instruments]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-13372003000200004&lng=es&nrm=iso&tlng=es This paper is divided in two parts: first part corresponds to a review of newest sound synthesis techniques, while the second part contains the development of an automatic tuning system based on a fuzzy logic controller intended to emulate the human expertise in this field. As part of this work, two new concepts will be introduced: first, the idea of "tuning" a synthesized musical instrument, and second, the application of automatic tuning procedures by means of intelligent systems. If we consider the synthesis as a whole process which involves the reproduction of every aspect that determines the realistic sound of the musical instruments, tuning the synthesizer as a human expert does becomes meaningful <![CDATA[DESALINIZADOR SOLAR DE MÚLTIPLES EFECTOS A ALTA TEMPERATURA: DISEÑO, MODELACIÓN Y SIMULACIÓN]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-13372003000200005&lng=es&nrm=iso&tlng=es This paper is divided in two parts: first part corresponds to a review of newest sound synthesis techniques, while the second part contains the development of an automatic tuning system based on a fuzzy logic controller intended to emulate the human expertise in this field. As part of this work, two new concepts will be introduced: first, the idea of "tuning" a synthesized musical instrument, and second, the application of automatic tuning procedures by means of intelligent systems. If we consider the synthesis as a whole process which involves the reproduction of every aspect that determines the realistic sound of the musical instruments, tuning the synthesizer as a human expert does becomes meaningful <![CDATA[DESARROLLO DE HARNERO VIBRATORIO]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-13372003000200006&lng=es&nrm=iso&tlng=es Se presenta el desarrollo del cálculo de un harnero vibratorio terciario de pendiente variable, para ser construido en la Maestranza de Chuquicamata. La relevancia de realizar este proyecto radica en la necesidad de satisfacer los nuevos requerimientos de producción y acortar los tiempos de mantenimiento empleando nuevos conceptos de diseño (como variación de algunos parámetros de operación en terreno) y componentes de materiales avanzados de intercambio rápido. Como elemento de verificación del diseño, se construyó un prototipo de dimensiones mas reducidas, empleando cálculos para un equipo real, sin utilizar reglas de reducción de escala, por no disponer de esa información para equipos de minería . El bajo costo respecto a los equivalentes ofertados en el extranjero y la demostración de las bondades de su funcionamiento, indican que es rentable la fabricación de estas maquinarias en el país.<hr/>This paper shows the development of a calculation of a vibrating screen with variable slope, to be built in Chuquicamata. This project is relevant because it helps satisfy the new production demand and reduces maintenance time. It employs new design concepts and uses advanced materials of fast interchange. As comparison method, a reduced model was built and tested. The calculations were based on a machine of reduced dimensions because it was not possible to use those scale rules for mining equipment. The low manufacturing cost of the designed screen compared with the product supplied abroad, as well as the model good performance, indicates that the manufacture of these machines in Chile is profitable <![CDATA[HYBRID MODELING OF OPEN LOOP DC-DC CONVERTERS]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-13372003000200007&lng=es&nrm=iso&tlng=es Power electronic converters always have been circuits of difficult modelling because differential equations that describe them have discontinuities. Although this situation has been improved since the appearance of the Hybrid Systems theory, able to jointly describe both continuous and discrete behaviors exhibited by some physical systems, nowadays it is possible to obtain very precise models which help us in the study and design of such circuits. An excellent option for the discrete part model (reactive system) is to use statecharts, since this powerful language has recently been implemented and named Stateflow as a part of the Simulink toolbox of Matlab. So, today, the complete modeling of some hybrid systems within Matlab environment is possible. In this work the open loop hybrid modeling and simulation of the well-known dc-dc converters named buck and boost, using Matlab-Simulink-Stateflow, is presented <![CDATA[CONTROL DIFUSO PARA UNA PLANTA PILOTO DE SECADO POR LECHO FLUIDIZADO]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-13372003000200008&lng=es&nrm=iso&tlng=es En este trabajo se presenta un control difuso proporcional-prealimentado (CDPP) aplicado a un proceso de secado por lecho fluidizado de material húmedo. El CDPP se somete a diferentes experimentos y se compara ventajosamente con el control difuso proporcional-integral (CDPI). Los experimentos realizados permiten observar que el CDPP tiene un mejor comportamiento que el CDPI, ya que con él no se observan oscilaciones en la salida, aspecto clave para el correcto funcionamiento del proceso de secado por fluidización<hr/>In this work a fuzzy feedforward proportional control (FFPC) applied to a process of fluidized bed dryer of humid material is presented. The FFPC is submitted to different experiments and is adventagously compared with the fuzzy proportional- integral control (FPIC). The experiments show that the FFPC has a better behavior that the FPIC, since there is no evidence of output oscilations, key aspect for the correct functioning of the process of fluidized bed dryer <![CDATA[<b>GENERAL PACKET RADIO SERVICE PHYSICAL-LAYER PERFORMANCE SIMULATION</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-13372003000200009&lng=es&nrm=iso&tlng=es In this paper, we present some results on GPRS physical- layer performance based on a GPRS simulator. The simulator strictly abides by the GSM standards implementing the detailed transmission chain. We analyze the results of a comprehensive simulation of the GPRS traffic channels. We evaluate the GPRS performance under various environment and service rates. The reference channel model used for the simulations is entirely based on the Ricean channel model and provides a reasonable scenario for radio propagation. The results shown here provide an insight into how to assess the actual GPRS data channels performance under various service rates.