9 resultados para Fuzzy controllers

em Universidad Politécnica de Madrid


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The confluence of three-dimensional (3D) virtual worlds with social networks imposes on software agents, in addition to conversational functions, the same behaviours as those common to human-driven avatars. In this paper, we explore the possibilities of the use of metabots (metaverse robots) with motion capabilities in complex virtual 3D worlds and we put forward a learning model based on the techniques used in evolutionary computation for optimizing the fuzzy controllers which will subsequently be used by metabots for moving around a virtual environment.

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Intelligent Transportation Systems (ITS) cover a broad range of methods and technologies that provide answers to many problems of transportation. Unmanned control of the steering wheel is one of the most important challenges facing researchers in this area. This paper presents a method to adjust automatically a fuzzy controller to manage the steering wheel of a mass-produced vehicle to reproduce the steering of a human driver. To this end, information is recorded about the car's state while being driven by human drivers and used to obtain, via genetic algorithms, appropriate fuzzy controllers that can drive the car in the way that humans do. These controllers have satisfy two main objectives: to reproduce the human behavior, and to provide smooth actions to ensure comfortable driving. Finally, the results of automated driving on a test circuit are presented, showing both good route tracking (similar to the performance obtained by persons in the same task) and smooth driving.

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This paper presents a vision based autonomous landing control approach for unmanned aerial vehicles (UAV). The 3D position of an unmanned helicopter is estimated based on the homographies estimated of a known landmark. The translation and altitude estimation of the helicopter against the helipad position are the only information that is used to control the longitudinal, lateral and descend speeds of the vehicle. The control system approach consists in three Fuzzy controllers to manage the speeds of each 3D axis of the aircraft s coordinate system. The 3D position estimation was proven rst, comparing it with the GPS + IMU data with very good results. The robust of the vision algorithm against occlusions was also tested. The excellent behavior of the Fuzzy control approach using the 3D position estimation based in homographies was proved in an outdoors test using a real unmanned helicopter.

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The AUTOPIA program has been working on the development of intelligent autonomous vehicles for the last 10 years. Its latest advances have focused on the development of cooperative manœuvres based on communications involving several vehicles. However, so far, these manœuvres have been tested only on private tracks that emulate urban environments. The first experiments with autonomous vehicles on real highways, in the framework of the grand cooperative driving challenge (GCDC) where several vehicles had to cooperate in order to perform cooperative adaptive cruise control (CACC), are described. In this context, the main challenge was to translate, through fuzzy controllers, human driver experience to these scenarios. This communication describes the experiences deriving from this competition, specifically that concerning the controller and the system implemented in a Citröen C3.

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In this paper we propose a flexible Multi-Agent Architecture together with a methodology for indoor location which allows us to locate any mobile station (MS) such as a Laptop, Smartphone, Tablet or a robotic system in an indoor environment using wireless technology. Our technology is complementary to the GPS location finder as it allows us to locate a mobile system in a specific room on a specific floor using the Wi-Fi networks. The idea is that any MS will have an agent known at a Fuzzy Location Software Agent (FLSA) with a minimum capacity processing at its disposal which collects the power received at different Access Points distributed around the floor and establish its location on a plan of the floor of the building. In order to do so it will have to communicate with the Fuzzy Location Manager Software Agent (FLMSA). The FLMSAs are local agents that form part of the management infrastructure of the Wi-Fi network of the Organization. The FLMSA implements a location estimation methodology divided into three phases (measurement, calibration and estimation) for locating mobile stations (MS). Our solution is a fingerprint-based positioning system that overcomes the problem of the relative effect of doors and walls on signal strength and is independent of the network device manufacturer. In the measurement phase, our system collects received signal strength indicator (RSSI) measurements from multiple access points. In the calibration phase, our system uses these measurements in a normalization process to create a radio map, a database of RSS patterns. Unlike traditional radio map-based methods, our methodology normalizes RSS measurements collected at different locations on a floor. In the third phase, we use Fuzzy Controllers to locate an MS on the plan of the floor of a building. Experimental results demonstrate the accuracy of the proposed method. From these results it is clear that the system is highly likely to be able to locate an MS in a room or adjacent room.

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La perdiz roja es la especie cinegética por excelencia en la península ibérica, cuya cría en cautividad y suelta controlada comenzó a regularse en los años 70 con la aparición del ICONA. La incubación controlada de huevos de perdiz es imprescindible, con fines cinegéticos y de preservación de la especie, y se desarrolla con incubadoras comerciales de pequeña y mediana escala, distribuidas en zonas rurales con acceso limitado y/o deficiente al suministro eléctrico. En nuestras latitudes el aporte de energía solar térmica se perfila como una posibilidad de mejorar la eficiencia energética de éstas y otras instalaciones y de reducir la dependencia energética exterior. Hay diversos factores físico-químicos que influyen en la calidad de la incubación: temperatura, humedad relativa, y concentración de gases, de los cuales sólo los dos primeros son habitualmente supervisados y controlados en este tipo de incubadoras. Esta Tesis surge en el marco de dos proyectos de cooperación con la AECID, y tiene como objetivos: la caracterización espacial de variables relevantes (temperatura (T), humedad relativa (HR)) en la incubadora comercial durante el proceso de incubación, la determinación de la relación existente entre la evolución de variables ambientales durante el proceso de incubación y la tasa de nacimientos (35-77%), así como el diseño y evaluación del sistema de apoyo solar térmico para determinar su potencial de utilización durante las incubaciones comerciales. La instalación de un número limitado de sensores permite la monitorización precisa del proceso de incubación de los huevos. Los resultados más relevantes indican que en incubaciones comerciales los gradientes de T y HR han sido despreciables (1ºC de diferencia entre las posiciones con mayor y menor T media y un 4,5% de diferencia entre las posiciones con mayor y menor HR), mientras que el seguimiento y ajuste (mediante modelos de crecimiento) de la concentración de CO2 (r2 entre 0,948 y 0,987 en las 5 incubaciones, para un total de 43315 huevos) permite valorar la actividad fisiológica de los huevos e incluso predecir la tasa de éxito (nacimientos), basándose en la concentración de CO2 estimada mediante modelos de crecimiento en el día 20 de incubación (r2 entre 0,997 y 0,994 según el modelo de estimación empleado). El sistema ha sido valorado muy positivamente por los productores (Finca Cinegética Dehesa Vieja de Galapagar). El aporte térmico se ha diseñado (con mínima intrusión en el sistema comercial) sobre la base de un sistema de enfriamiento de emergencia original de la incubadora, al que se han incorporado un colector solar, un depósito, un sistema de electroválvulas, una bomba de circulación y sensores de T en distintos puntos del sistema, y cuyo control ha sido automatizado. En esta Tesis se muestra que la contribución solar puede aportar hasta un 42% de las demandas de energía en nuestras condiciones geográficas para una temperatura de consigna dentro de la incubadora de 36.8ºC, sin afectar a la estabilidad de la temperatura. Además, el rendimiento del colector solar se ha acotado entre un 44% y un 85%, de acuerdo con los cálculos termodinámicos; valores que se mantienen dentro del rango aportado por el fabricante (61%). En el futuro se plantea evaluar el efecto de distintas estrategias de control, tales como controladores difusos, que incorporan el conocimiento experto al control automático. ABSTRACT The partridge is the quintessential game species in the Iberian Peninsula, which controlled breeding and release, began to be regulated in the 70s with the emergence of ICONA. The controlled incubation of eggs is essential, and takes place in commercial incubators of small and medium scale, distributed in rural areas with limited and/or inadequate access to power. In our latitudes the contribution of solar thermal energy is emerging as a possibility to improve the energy efficiency of the facilities and to reduce external energy dependence. There are various physicochemical factors influencing the quality of incubation: temperature, relative humidity and concentration of gases, of which only the first two are typically monitored and controlled in such incubators. This PhD comes within the framework of two cooperation projects with AECID and aims: the spatial characterization of relevant variables in a commercial incubator (temperature (T), and relative humidity (HR)), determining the relationships in the changes in environmental variables during incubation and birth rates (35-77%) as well as the design and evaluation of solar thermal support system to determine its potential use during commercial incubations; the installation of a limited number of sensors has allowed accurate monitoring of incubation of eggs. The most relevant results indicate that in commercial incubations, the gradients in T and HR have been negligible (1°C difference between the highest and lowest positions T and average 4.5% difference between the highest and lowest positions HR), while monitoring and fit using growth models of the concentration of CO2 (r2 between 0.948 and 0.987 in 5 incubations, for a total amount of 43,315 eggs) allows assessing the physiological activity of the eggs and even predict the success rate (hatchability), based on the estimated concentration of CO2 by using growth models on day 20 of incubation (r2 between 0.997 and 0.994 depending on the fit model).The system has been highly valued by producers (Finca Cinegética Dehesa Vieja de Galapagar). The hybrid heat system is designed (with minimal intrusion into the commercial system) based on an emergency cooling device, original in the incubator. New elements have been incorporated: a solar collector, a tank, a system of solenoid valves, a circulating pump and T sensors at various points of the system, whose control has been automated. This PhD shows that the solar contribution is responsible for up to 42% of energy demands in our geographical conditions for a setpoint temperature inside the incubator of 36.8ºC, without questioning the stability of the temperature. Furthermore, the efficiency of the solar collector has been bounded between 44% and 85%, according to thermodynamic calculations; values remain within the range provided by the manufacturer (61%). In the future it is proposed to evaluate the effect of different control strategies, such as fuzzy controllers, which incorporate the expertise to automated control.

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The aim of this work was twofold: on the one hand, to describe a comparative study of two intelligent control techniques-fuzzy and intelligent proportional-integral (PI) control, and on the other, to try to provide an answer to an as yet unsolved topic in the automotive sector-stop-and-go control in urban environments at very low speeds. Commercial vehicles exhibit nonlinear behavior and therefore constitute an excellent platform on which to check the controllers. This paper describes the design, tuning, and evaluation of the controllers performing actions on the longitudinal control of a car-the throttle and brake pedals-to accomplish stop-and-go manoeuvres. They are tested in two steps. First, a simulation model is used to design and tune the controllers, and second, these controllers are implemented in the commercial vehicle-which has automatic driving capabilities-to check their behavior. A stop-and-go manoeuvre is implemented with the two control techniques using two cooperating vehicles.

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In this work we present an optimized fuzzy visual servoing system for obstacle avoidance using an unmanned aerial vehicle. The cross-entropy theory is used to optimise the gains of our controllers. The optimization process was made using the ROS-Gazebo 3D simulation with purposeful extensions developed for our experiments. Visual servoing is achieved through an image processing front-end that uses the Camshift algorithm to detect and track objects in the scene. Experimental flight trials using a small quadrotor were performed to validate the parameters estimated from simulation. The integration of crossentropy methods is a straightforward way to estimate optimal gains achieving excellent results when tested in real flights.

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Four longitudinal control techniques are compared: a classical Proportional-Integral (PI) control; an advanced technique-called the i-PI-that adds an intelligent component to the PI; a fuzzy controller based on human experience; and an adaptive-network-based fuzzy inference system. The controllers were designed to tackle one of the challenging topics as yet unsolved by the automotive sector: managing autonomously a gasoline-propelled vehicle at very low speeds. The dynamics involved are highly nonlinear and constitute an excellent test-bed for newly designed controllers. A Citroën C3 Pluriel car was modified to permit autonomous action on the accelerator and the brake pedals-i.e., longitudinal control. The controllers were tested in two stages. First, the vehicle was modeled to check the controllers' feasibility. Second, the controllers were then implemented in the Citroën, and their behavior under the same conditions on an identical real circuit was compared.