Sistema de control de tracción y salida para un monoplaza de la Fórmula SAE

En este proyecto de final de carrera se detalla el proceso de diseño, fabricación, montaje y ajuste de un dispositivo electrónico que sirva como sistema de control de tracción de un vehículo y que acoplaremos sobre un monoplaza de carreras que participa en la competición Formula SAE. La Formula SAE (Society of Automotive Engineers - Sociedad de Ingenieros de Automoción), es una competición de coches de carreras monoplaza a nivel universitario que promueve el desarrollo de la ingeniera aplicada a la automoción. Se pretende que este libro sirva de guía para el correcto manejo y desempeño del sistema fabricado. Además se ha pretendido que su lectura resulte fácil y comprensible para que la persona que lea este libro sea capaz de entender el sistema realizado para así poderlo mejorar. Gracias a la colaboración entre la Escuela Técnica Superior de Ingeniería y Sistemas de Telecomunicación (ETSIST) de la Universidad Politécnica de Madrid (UPM), la Escuela de Ingenieros Industriales de esta misma Universidad (ETSII) y el Instituto Universitario de Investigación del Automóvil (INSIA), se sientan las bases de una plataforma docente en la cual se posibilita la formación y desarrollo de un vehículo tipo formula que participa en la ya mencionada competición Formula SAE. Para ello, se formo en el 2003 el equipo UPMRacing, primer representante español en el evento. El equipo se compone de más de 50 alumnos de la UPM y del Máster de Ingeniería en Automoción del INSIA. Es por tanto, en el vehículo fabricado por el equipo UPMRacing, en el que se pretende instalar este sistema de control de tracción. El control de tracción es un sistema de seguridad del automóvil diseñado para prevenir la perdida de adherencia cuando alguna rueda presenta deslizamiento, bien porque el conductor se excede en la aceleración o bien porque el firme este resbaladizo. La unidad de procesamiento del sistema de control de tracción fabricado lee la velocidad de cada rueda del vehículo mediante unos sensores y determina si existe deslizamiento, en tal caso, manda una señal a la centralita para disminuir la potencia hasta que el deslizamiento disminuya a unos valores controlados. El sistema cuenta con un control remoto que sirve como interfaz para que el piloto pueda manejarlo. Por ultimo, el dispositivo es capaz de conectarse a un bus de comunicaciones CAN para configurar ciertos parámetros. El objetivo del sistema es, básicamente, hacer que el coche no derrape en aceleraciones fuertes; concretamente en las salidas desde parado y al tomar una curva, aumentando así la velocidad en circuito y la seguridad del piloto. ABSTRACT. The purpose of this project is to describe the design, manufacture, assembly and adjustment processes of an electronic device acting as the traction control system (TCS) of a vehicle, that we will attach to a single-seater competition formula SAE car. The Formula SAE (Society of Automotive Engineers) is a graduate-level singleseater racing car competition promoting the development of automotive applied engineering. We also intend this work to serve as a technical user guide of the manufactured system. It is drafted clearly and concisely so that it will be easy for all those to whom it is addressed to understand and subject to further improvements. The close partnership among the Escuela Técnica Superior de Ingeniería y Sistemas de Telecomunicación (ETSIST), Escuela de Ingenieros Industriales (ETSII) of Universidad Politécnica de Madrid (UPM), and the Instituto Universitario de Investigación del Automóvil (INSIA), lays the foundation of a teaching platform enabling the training and development of a single-seater racing car taking part in the already mentioned Formula SAE competition. In this respect, UPMRacing team was created back in 2003, first spanish representative in this event. The team consists of more than 50 students of the UPM and of INSIA Master in Automotive Engineering. It is precisely the vehicle manufactured by UPMRacing team where we intend to install our TCS. TCS is an automotive safety system designed to prevent loss of traction when one wheel has slip, either because the driver exceeds the acceleration or because the firm is slippery. The device’s central processing unit is able to detect the speed of each wheel of the vehicle via special sensors and to determine wheel slip. If this is the case, the system sends a signal to the ECU of the vehicle to reduce the power until the slip is also diminished to controlled values. The device has a remote control that serves as an interface for the pilot to handle it. Lastly, the device is able to connect to a communication bus system CAN to set up certain parameters. The system objective is to prevent skidding under strong acceleration conditions: standing-start from the starting grid or driving into a curve, increasing the speed in circuit and pilot’s safety.

Using the Cross-Entropy Method for Control Optimization: A Case Study of See-and-Avoid on Unmanned Aerial Vehicles

This paper presents an adaptation of the Cross-Entropy (CE) method to optimize fuzzy logic controllers. The CE is a recently developed optimization method based on a general Monte-Carlo approach to combinatorial and continuous multi-extremal optimization and importance sampling. This work shows the application of this optimization method to optimize the inputs gains, the location and size of the different membership functions' sets of each variable, as well as the weight of each rule from the rule's base of a fuzzy logic controller (FLC). The control system approach presented in this work was designed to command the orientation of an unmanned aerial vehicle (UAV) to modify its trajectory for avoiding collisions. An onboard looking forward camera was used to sense the environment of the UAV. The information extracted by the image processing algorithm is the only input of the fuzzy control approach to avoid the collision with a predefined object. Real tests with a quadrotor have been done to corroborate the improved behavior of the optimized controllers at different stages of the optimization process.

Co-simulation Methodologies for Hybrid and Electric Vehicle Dynamics

In recent decades, full electric and hybrid electric vehicles have emerged as an alternative to conventional cars due to a range of factors, including environmental and economic aspects. These vehicles are the result of considerable efforts to seek ways of reducing the use of fossil fuel for vehicle propulsion. Sophisticated technologies such as hybrid and electric powertrains require careful study and optimization. Mathematical models play a key role at this point. Currently, many advanced mathematical analysis tools, as well as computer applications have been built for vehicle simulation purposes. Given the great interest of hybrid and electric powertrains, along with the increasing importance of reliable computer-based models, the author decided to integrate both aspects in the research purpose of this work. Furthermore, this is one of the first final degree projects held at the ETSII (Higher Technical School of Industrial Engineers) that covers the study of hybrid and electric propulsion systems. The present project is based on MBS3D 2.0, a specialized software for the dynamic simulation of multibody systems developed at the UPM Institute of Automobile Research (INSIA). Automobiles are a clear example of complex multibody systems, which are present in nearly every field of engineering. The work presented here benefits from the availability of MBS3D software. This program has proven to be a very efficient tool, with a highly developed underlying mathematical formulation. On this basis, the focus of this project is the extension of MBS3D features in order to be able to perform dynamic simulations of hybrid and electric vehicle models. This requires the joint simulation of the mechanical model of the vehicle, together with the model of the hybrid or electric powertrain. These sub-models belong to completely different physical domains. In fact the powertrain consists of energy storage systems, electrical machines and power electronics, connected to purely mechanical components (wheels, suspension, transmission, clutch…). The challenge today is to create a global vehicle model that is valid for computer simulation. Therefore, the main goal of this project is to apply co-simulation methodologies to a comprehensive model of an electric vehicle, where sub-models from different areas of engineering are coupled. The created electric vehicle (EV) model consists of a separately excited DC electric motor, a Li-ion battery pack, a DC/DC chopper converter and a multibody vehicle model. Co-simulation techniques allow car designers to simulate complex vehicle architectures and behaviors, which are usually difficult to implement in a real environment due to safety and/or economic reasons. In addition, multi-domain computational models help to detect the effects of different driving patterns and parameters and improve the models in a fast and effective way. Automotive designers can greatly benefit from a multidisciplinary approach of new hybrid and electric vehicles. In this case, the global electric vehicle model includes an electrical subsystem and a mechanical subsystem. The electrical subsystem consists of three basic components: electric motor, battery pack and power converter. A modular representation is used for building the dynamic model of the vehicle drivetrain. This means that every component of the drivetrain (submodule) is modeled separately and has its own general dynamic model, with clearly defined inputs and outputs. Then, all the particular submodules are assembled according to the drivetrain configuration and, in this way, the power flow across the components is completely determined. Dynamic models of electrical components are often based on equivalent circuits, where Kirchhoff’s voltage and current laws are applied to draw the algebraic and differential equations. Here, Randles circuit is used for dynamic modeling of the battery and the electric motor is modeled through the analysis of the equivalent circuit of a separately excited DC motor, where the power converter is included. The mechanical subsystem is defined by MBS3D equations. These equations consider the position, velocity and acceleration of all the bodies comprising the vehicle multibody system. MBS3D 2.0 is entirely written in MATLAB and the structure of the program has been thoroughly studied and understood by the author. MBS3D software is adapted according to the requirements of the applied co-simulation method. Some of the core functions are modified, such as integrator and graphics, and several auxiliary functions are added in order to compute the mathematical model of the electrical components. By coupling and co-simulating both subsystems, it is possible to evaluate the dynamic interaction among all the components of the drivetrain. ‘Tight-coupling’ method is used to cosimulate the sub-models. This approach integrates all subsystems simultaneously and the results of the integration are exchanged by function-call. This means that the integration is done jointly for the mechanical and the electrical subsystem, under a single integrator and then, the speed of integration is determined by the slower subsystem. Simulations are then used to show the performance of the developed EV model. However, this project focuses more on the validation of the computational and mathematical tool for electric and hybrid vehicle simulation. For this purpose, a detailed study and comparison of different integrators within the MATLAB environment is done. Consequently, the main efforts are directed towards the implementation of co-simulation techniques in MBS3D software. In this regard, it is not intended to create an extremely precise EV model in terms of real vehicle performance, although an acceptable level of accuracy is achieved. The gap between the EV model and the real system is filled, in a way, by introducing the gas and brake pedals input, which reflects the actual driver behavior. This input is included directly in the differential equations of the model, and determines the amount of current provided to the electric motor. For a separately excited DC motor, the rotor current is proportional to the traction torque delivered to the car wheels. Therefore, as it occurs in the case of real vehicle models, the propulsion torque in the mathematical model is controlled through acceleration and brake pedal commands. The designed transmission system also includes a reduction gear that adapts the torque coming for the motor drive and transfers it. The main contribution of this project is, therefore, the implementation of a new calculation path for the wheel torques, based on performance characteristics and outputs of the electric powertrain model. Originally, the wheel traction and braking torques were input to MBS3D through a vector directly computed by the user in a MATLAB script. Now, they are calculated as a function of the motor current which, in turn, depends on the current provided by the battery pack across the DC/DC chopper converter. The motor and battery currents and voltages are the solutions of the electrical ODE (Ordinary Differential Equation) system coupled to the multibody system. Simultaneously, the outputs of MBS3D model are the position, velocity and acceleration of the vehicle at all times. The motor shaft speed is computed from the output vehicle speed considering the wheel radius, the gear reduction ratio and the transmission efficiency. This motor shaft speed, somehow available from MBS3D model, is then introduced in the differential equations corresponding to the electrical subsystem. In this way, MBS3D and the electrical powertrain model are interconnected and both subsystems exchange values resulting as expected with tight-coupling approach.When programming mathematical models of complex systems, code optimization is a key step in the process. A way to improve the overall performance of the integration, making use of C/C++ as an alternative programming language, is described and implemented. Although this entails a higher computational burden, it leads to important advantages regarding cosimulation speed and stability. In order to do this, it is necessary to integrate MATLAB with another integrated development environment (IDE), where C/C++ code can be generated and executed. In this project, C/C++ files are programmed in Microsoft Visual Studio and the interface between both IDEs is created by building C/C++ MEX file functions. These programs contain functions or subroutines that can be dynamically linked and executed from MATLAB. This process achieves reductions in simulation time up to two orders of magnitude. The tests performed with different integrators, also reveal the stiff character of the differential equations corresponding to the electrical subsystem, and allow the improvement of the cosimulation process. When varying the parameters of the integration and/or the initial conditions of the problem, the solutions of the system of equations show better dynamic response and stability, depending on the integrator used. Several integrators, with variable and non-variable step-size, and for stiff and non-stiff problems are applied to the coupled ODE system. Then, the results are analyzed, compared and discussed. From all the above, the project can be divided into four main parts: 1. Creation of the equation-based electric vehicle model; 2. Programming, simulation and adjustment of the electric vehicle model; 3. Application of co-simulation methodologies to MBS3D and the electric powertrain subsystem; and 4. Code optimization and study of different integrators. Additionally, in order to deeply understand the context of the project, the first chapters include an introduction to basic vehicle dynamics, current classification of hybrid and electric vehicles and an explanation of the involved technologies such as brake energy regeneration, electric and non-electric propulsion systems for EVs and HEVs (hybrid electric vehicles) and their control strategies. Later, the problem of dynamic modeling of hybrid and electric vehicles is discussed. The integrated development environment and the simulation tool are also briefly described. The core chapters include an explanation of the major co-simulation methodologies and how they have been programmed and applied to the electric powertrain model together with the multibody system dynamic model. Finally, the last chapters summarize the main results and conclusions of the project and propose further research topics. In conclusion, co-simulation methodologies are applicable within the integrated development environments MATLAB and Visual Studio, and the simulation tool MBS3D 2.0, where equation-based models of multidisciplinary subsystems, consisting of mechanical and electrical components, are coupled and integrated in a very efficient way.

PWM Control of a Buck Converter with an Amorphous Core Coil

Pulse-width modulation is widely used to control electronic converters. One of the most topologies used for high DC voltage/low DC voltage conversion is the Buck converter. It is obtained as a second order system with a LC filter between the switching subsystem and the load. The use of a coil with an amorphous magnetic material core instead of air core lets design converters with smaller size. If high switching frequencies are used for obtaining high quality voltage output, the value of the auto inductance L is reduced throughout the time. Then, robust controllers are needed if the accuracy of the converter response must not be affected by auto inductance and load variations. This paper presents a robust controller for a Buck converter based on a state space feedback control system combined with an additional virtual space variable which minimizes the effects of the inductance and load variations when a not-toohigh switching frequency is applied. The system exhibits a null steady-state average error response for the entire range of parameter variations. Simulation results are presented.

Physical data acquisition and PWM signal generation using a microcontroller allowing control for DC motor rotation speed

El objetivo de este proyecto es diseñar un sistema capaz de controlar la velocidad de rotación de un motor DC en función del valor de temperatura obtenido de un sensor. Para ello se generará con un microcontrolador una señal PWM, cuyo ciclo de trabajo estará en función de la temperatura medida. En lo que respecta a la fase de diseño, hay dos partes claramente diferenciadas, relativas al hardware y al software. En cuanto al diseño del hardware puede hacerse a su vez una división en dos partes. En primer lugar, hubo que diseñar la circuitería necesaria para adaptar los niveles de tensión entregados por el sensor de temperatura a los niveles requeridos por ADC, requerido para digitalizar la información para su posterior procesamiento por parte del microcontrolador. Por tanto hubo que diseñar capaz de corregir el offset y la pendiente de la función tensión-temperatura del sensor, a fin de adaptarlo al rango de tensión requerido por el ADC. Por otro lado, hubo que diseñar el circuito encargado de controlar la velocidad de rotación del motor. Este circuito estará basado en un transistor MOSFET en conmutación, controlado mediante una señal PWM como se mencionó anteriormente. De esta manera, al variar el ciclo de trabajo de la señal PWM, variará de manera proporcional la tensión que cae en el motor, y por tanto su velocidad de rotación. En cuanto al diseño del software, se programó el microcontrolador para que generase una señal PWM en uno de sus pines en función del valor entregado por el ADC, a cuya entrada está conectada la tensión obtenida del circuito creado para adaptar la tensión generada por el sensor. Así mismo, se utiliza el microcontrolador para representar el valor de temperatura obtenido en una pantalla LCD. Para este proyecto se eligió una placa de desarrollo mbed, que incluye el microcontrolador integrado, debido a que facilita la tarea del prototipado. Posteriormente se procedió a la integración de ambas partes, y testeado del sistema para comprobar su correcto funcionamiento. Puesto que el resultado depende de la temperatura medida, fue necesario simular variaciones en ésta, para así comprobar los resultados obtenidos a distintas temperaturas. Para este propósito se empleó una bomba de aire caliente. Una vez comprobado el funcionamiento, como último paso se diseñó la placa de circuito impreso. Como conclusión, se consiguió desarrollar un sistema con un nivel de exactitud y precisión aceptable, en base a las limitaciones del sistema. SUMMARY: It is obvious that day by day people’s daily life depends more on technology and science. Tasks tend to be done automatically, making them simpler and as a result, user life is more comfortable. Every single task that can be controlled has an electronic system behind. In this project, a control system based on a microcontroller was designed for a fan, allowing it to go faster when temperature rises or slowing down as the environment gets colder. For this purpose, a microcontroller was programmed to generate a signal, to control the rotation speed of the fan depending on the data acquired from a temperature sensor. After testing the whole design developed in the laboratory, the next step taken was to build a prototype, which allows future improvements in the system that are discussed in the corresponding section of the thesis.

Control of a solar dryer through using a fuzzy logic and low-cost model-based sensor

Solar drying is one of the important processes used for extending the shelf life of agricultural products. Regarding consumer requirements, solar drying should be more suitable in terms of curtailing total drying time and preserving product quality. Therefore, the objective of this study was to develop a fuzzy logic-based control system, which performs a ?human-operator-like? control approach through using the previously developed low-cost model-based sensors. Fuzzy logic toolbox of MatLab and Borland C++ Builder tool were utilized to develop a required control system. An experimental solar dryer, constructed by CONA SOLAR (Austria) was used during the development of the control system. Sensirion sensors were used to characterize the drying air at different positions in the dryer, and also the smart sensor SMART-1 was applied to be able to include the rate of wood water extraction into the control system (the difference of absolute humidity of the air between the outlet and the inlet of solar dryer is considered by SMART-1 to be the extracted water). A comprehensive test over a 3 week period for different fuzzy control models has been performed, and data, obtained from these experiments, were analyzed. Findings from this study would suggest that the developed fuzzy logic-based control system is able to tackle difficulties, related to the control of solar dryer process.

Transductive neurofuzzy-based torque control of a milling process: results of a case study

This paper presents the design and implementation of an intelligent control system based on local neurofuzzy models of the milling process relayed through an Ehternet-based application. Its purpose is to control the spindle torque of a milling process by using an internal model control paradigm to modify the feed rate in real time. The stabilization of cutting cutting torque is especially necessary in milling processes such as high-spedd roughing of steel moulds and dies tha present minor geometric uncertainties. Thus, maintenance of the curring torque increaes the material removal rate and reduces the risk of damage due to excessive spindle vibration, a very sensitive and expensive component in all high-speed milling machines. Torque control is therefore an interesting challenge from an industrial point of view.

Sistema de control de temperatura a través de Arduino y la tecnología GPRS/GSM

El principal objetivo de este proyecto consiste en estudiar las posibilidades de desarrollo de un sistema para el control de la temperatura basado en la plataforma Arduino. Con el fin de alcanzar dicho objetivo, se ha implementado un sistema que permite la consulta y control de la temperatura ambiente a través de la red de comunicaciones móviles. Tras un análisis previo de las distintas placas Arduino, se evalúan una serie de módulos de expansión (shields) compatibles con dicha plataforma que nos permiten ampliar sus funcionalidades, dotando al dispositivo de un sistema de comunicación basado en la tecnología GPRS/GSM. Se estudian los diferentes sensores de temperatura compatibles con Arduino, además de una serie de actuadores que contribuyen al accionamiento y control de un posible termostato, así como al desarrollo de un pequeño sistema de alarma capaz de detectar temperaturas extremas. El proyecto concluye con el diseño de una aplicación basada en el entorno de desarrollo Arduino que nos permita evaluar las distintas capacidades de nuestro sistema, así como comunicarnos con la plataforma a través de SMS para el control remoto de la temperatura. ABSTRACT. The goal of the project consists of studying the developmental possibilities of a temperature control system based on the Arduino platform. In order to this, there has been implemented a system to consult and manage the environmental temperature through mobile communication networks. After a previous assessment of the different Arduino boards, there are analysed a set of expansion modules (shields) compatibles with the platform that enables us to upgrade the device functionalities with the GPRS/GSM communication protocol. Different temperature sensors compatible with Arduino have been studied. In addition, there are evaluated a set of actuators for the operation and control of a thermostat and also the development of a small alarm system that alerts of extremes temperatures. The project concludes with the design of an application based on the Arduino development environment which allows us to evaluate the different capabilities of our system as well as the communication with the platform by SMS for the remote temperature control.

A quality assessment system for fresh fruits in hypermarkets and fruit trading centres.

When the fresh fruit reaches the final markets from the suppliers, its quality is not always as good as it should, either because it has been mishandled during transportation or because it lacks an adequate quality control at the producer level, before being shipped. This is why it is necessary for the final markets to establish their own quality assessment system if they want to ensure to their customers the quality they want to sell. In this work, a system to control fruit quality at the last level of the distribution channel has been designed. The system combines rapid control techniques with laboratory equipment and statistical sampling protocols, to obtain a dynamic, objective process, which can substitute advantageously the quality control inspections carried out visually by human experts at the reception platform of most hypermarkets. Portable measuring equipment have been chosen (firmness tester, temperature and humidity sensors...) as well as easy-to-use laboratory equipment (texturometer, colorimeter, refractometer..,) combining them to control the most important fruit quality parameters (firmness, colour, sugars, acids). A complete computer network has been designed to control all the processes and store the collected data in real time, and to perform the computations. The sampling methods have been also defined to guarantee the confidence of the results. Some of the advantages of a quality assessment system as the proposed one are: the minimisation of human subjectivity, the ability to use modern measuring techniques, and the possibility of using it also as a supplier's quality control system. It can be also a way to clarify the quality limits of fruits among members of the commercial channel, as well as the first step in the standardisation of quality control procedures.

Space-state robust control of a Buck converter with amorphous core coil and variable load

Pulse-width modulation is widely used to control electronic converters. One of the most frequently used topologies for high DC voltage/low DC voltage conversion is the Buck converter. These converters are described by a second order system with an LC filter between the switching subsystem and the load. The use of a coil with an amorphous magnetic material core rather than an air core permits the design of smaller converters. If high switching frequencies are used to obtain high quality voltage output, then the value of the auto inductance L is reduced over time. Robust controllers are thus needed if the accuracy of the converter response must be preserved under auto inductance and payload variations. This paper presents a robust controller for a Buck converter based on a state space feedback control system combined with an additional virtual space variable which minimizes the effects of the inductance and load variations when a switching frequency that is not too high is applied. The system exhibits a null steady-state average error response for the entire range of parameter variations. Simulation results and a comparison with a standard PID controller are also presented.

Effect of control method on impedance-based interactions in a buck converter

All the interconnected regulated systems are prone to impedance-based interactions making them sensitive to instability and transient-performance degradation. The applied control method affects significantly the characteristics of the converter in terms of sensitivity to different impedance interactions. This paper provides for the first time the whole set of impedance-type internal parameters and the formulas according to which the interaction sensitivity can be fully explained and analyzed. The formulation given in this paper can be utilized equally either based on measured frequency responses or on predicted analytic transfer functions. Usually, the distributed dc-dc systems are constructed by using ready-made power modules without having thorough knowledge on the actual power-stage and control-system designs. As a consequence, the interaction characterization has to be based on the frequency responses measureable via the input and output terminals. A buck converter with four different control methods is experimentally characterized in frequency domain to demonstrate the effect of control method on the interaction sensitivity. The presented analytical models are used to explain the phenomena behind the changes in the interaction sensitivity.

Integration of a data acquisition system based on FlexRIO technology with EPICS

EPICS (Experimental Physics and Industrial Control System) lies in a set of software tools and applications which provide a software infrastructure for building distributed data acquisition and control systems. Currently there is an increase in use of such systems in large Physics experiments like ITER, ESS, and FREIA. In these experiments, advanced data acquisition systems using FPGA-based technology like FlexRIO are more frequently been used. The particular case of ITER (International Thermonuclear Experimental Reactor), the instrumentation and control system is supported by CCS (CODAC Core System), based on RHEL (Red Hat Enterprise Linux) operating system, and by the plant design specifications in which every CCS element is defined either hardware, firmware or software. In this degree final project the methodology proposed in Implementation of Intelligent Data Acquisition Systems for Fusion Experiments using EPICS and FlexRIO Technology Sanz et al. [1] is used. The final objective is to provide a document describing the fulfilled process and the source code of the data acquisition system accomplished. The use of the proposed methodology leads to have two diferent stages. The first one consists of the hardware modelling with graphic design tools like LabVIEWFPGA which later will be implemented in the FlexRIO device. In the next stage the design cycle is completed creating an EPICS controller that manages the device using a generic device support layer named NDS (Nominal Device Support). This layer integrates the data acquisition system developed into CCS (Control, data access and communication Core System) as an EPICS interface to the system. The use of FlexRIO technology drives the use of LabVIEW and LabVIEW FPGA respectively. RESUMEN. EPICS (Experimental Physics and Industrial Control System) es un conjunto de herramientas software utilizadas para el desarrollo e implementación de sistemas de adquisición de datos y control distribuidos. Cada vez es más utilizado para entornos de experimentación física a gran escala como ITER, ESS y FREIA entre otros. En estos experimentos se están empezando a utilizar sistemas de adquisición de datos avanzados que usan tecnología basada en FPGA como FlexRIO. En el caso particular de ITER, el sistema de instrumentación y control adoptado se basa en el uso de la herramienta CCS (CODAC Core System) basado en el sistema operativo RHEL (Red Hat) y en las especificaciones del diseño del sistema de planta, en la cual define todos los elementos integrantes del CCS, tanto software como firmware y hardware. En este proyecto utiliza la metodología propuesta para la implementación de sistemas de adquisición de datos inteligente basada en EPICS y FlexRIO. Se desea generar una serie de ejemplos que cubran dicho ciclo de diseño completo y que serían propuestos como casos de uso de dichas tecnologías. Se proporcionará un documento en el que se describa el trabajo realizado así como el código fuente del sistema de adquisición. La metodología adoptada consta de dos etapas diferenciadas. En la primera de ellas se modela el hardware y se sintetiza en el dispositivo FlexRIO utilizando LabVIEW FPGA. Posteriormente se completa el ciclo de diseño creando un controlador EPICS que maneja cada dispositivo creado utilizando una capa software genérica de manejo de dispositivos que se denomina NDS (Nominal Device Support). Esta capa integra la solución en CCS realizando la interfaz con la capa EPICS del sistema. El uso de la tecnología FlexRIO conlleva el uso del lenguaje de programación y descripción hardware LabVIEW y LabVIEW FPGA respectivamente.

Discriminación del estado de la carretera mediante procesado acústico en vehículo

La rápida adopción de dispositivos electrónicos en el automóvil, ha contribuido a mejorar en gran medida la seguridad y el confort. Desde principios del siglo 20, la investigación en sistemas de seguridad activa ha originado el desarrollo de tecnologías como ABS (Antilock Brake System), TCS (Traction Control System) y ESP (Electronic Stability Program). El coste de despliegue de estos sistemas es crítico: históricamente, sólo han sido ampliamente adoptados cuando el precio de los sensores y la electrónica necesarios para su construcción ha caído hasta un valor marginal. Hoy en día, los vehículos a motor incluyen un amplio rango de sensores para implementar las funciones de seguridad. La incorporación de sistemas que detecten la presencia de agua, hielo o nieve en la vía es un factor adicional que podría ayudar a evitar situaciones de riesgo. Existen algunas implementaciones prácticas capaces de detectar carreteras mojadas, heladas y nevadas, aunque con limitaciones importantes. En esta tesis doctoral, se propone una aproximación novedosa al problema, basada en el análisis del ruido de rodadura generado durante la conducción. El ruido de rodadura es capturado y preprocesado. Después es analizado utilizando un clasificador basado en máquinas de vectores soporte (SVM), con el fin de generar una estimación del estado del firme. Todas estas operaciones se realizan en el propio vehículo. El sistema propuesto se ha desarrollado y evaluado utilizando Matlabr, mostrando tasas de aciertos de más del 90%. Se ha realizado una implementación en tiempo real, utilizando un prototipo basado en DSP. Después se han introducido varias optimizaciones para permitir que el sistema sea realizable usando un microcontrolador de propósito general. Finalmente se ha realizado una implementación hardware basada en un microcontrolador, integrándola estrechamente con las ECU del vehículo, pudiendo obtener datos capturados por los sensores del mismo y enviar las estimaciones del estado del firme. El sistema resultante ha sido patentado, y destaca por su elevada tasa de aciertos con un tamaño, consumo y coste reducidos. ABSTRACT Proliferation of automotive electronics, has greatly improved driving safety and comfort. Since the beginning of the 20th century, investigation in active safety systems has resulted in the development of technologies such as ABS (Antilock Brake System), TCS (Traction Control System) and ESP (Electronic Stability Program). Deployment cost of these systems is critical: historically, they have been widely adopted only when the price of the sensors and electronics needed to build them has been cut to a marginal value. Nowadays, motor vehicles include a wide range of sensors to implement the safety functions. Incorporation of systems capable of detecting water, ice or snow on the road is an additional factor that could help avoiding risky situations. There are some implementations capable of detecting wet, icy and snowy roads, although with important limitations. In this PhD Thesis, a novel approach is proposed, based on the analysis of the tyre/road noise radiated during driving. Tyre/road noise is captured and pre-processed. Then it is analysed using a Support Vector Machine (SVM) based classifier, to output an estimation of the road status. All these operations are performed on-board. Proposed system is developed and evaluated using Matlabr, showing success rates greater than 90%. A real time implementation is carried out using a DSP based prototype. Several optimizations are introduced enabling the system to work using a low-cost general purpose microcontroller. Finally a microcontroller based hardware implementation is developed. This implementation is tightly integrated with the vehicle ECUs, allowing it to obtain data captured by its sensors, and to send the road status estimations. Resulting system has been patented, and is notable because of its high hit rate, small size, low power consumption and low cost.

Control de movimientos en presas de hormigón mediante DGPS. Comparación con otros métodos de auscultación e implicaciones para la seguridad. Estudio de caso en la presa de La Aceña (Ávila)

Las normativas que regulan la seguridad de las presas en España han recogido la necesidad de conocer los desplazamientos y deformaciones de sus estructuras y cimientos. A día de hoy, son muchas las presas en explotación que no cuentan con un sistema de auscultación adecuado para controlar este tipo de variables, ya que la instalación de métodos clásicos de precisión en las mismas podría no ser viable técnicamente y, de serlo, supondría un coste económico importante y una dudosa garantía del proceso de ejecución de la obra civil correspondiente. Con el desarrollo de las nuevas tecnologías, la informática y las telecomunicaciones, han surgido nuevos sistemas de auscultación de desplazamientos. Los sistemas GPS actuales, diseñados para el control de estructuras, guiado de maquinaria, navegación y topografía, estabilidad de taludes, subsidencias, etc. permiten alcanzar precisiones centimétricas. El sistema de control de movimientos basado en la tecnología DGPS (GPS diferencial) combinada con un filtro estadístico con el que se alcanzan sensibilidades de hasta ±1 mm en el sistema, suficientes para una auscultación normal de presas según los requerimientos de la normativa actual. Esta exactitud se adapta a los desplazamientos radiales de las presas, donde son muy comunes valores de amplitudes en coronación de hasta 15 mm en las de gravedad y de hasta 45 mm en el caso de las presas bóveda o arco. La presente investigación tiene por objetivo analizar la viabilidad del sistema DGPS en el control de movimientos de presas de hormigón comparando los diferentes sistemas de auscultación y su correlación con las variables físicas y las vinculadas al propio sistema GPS diferencial. Ante la necesidad de dar respuesta a estas preguntas y de validar e incorporar a la mencionada tecnología en la ingeniería civil en España, se ha llevado a cabo un estudio de caso en La Aceña (Ávila). Esta es una de las pocas presas españolas que se está controlando con dicha tecnología y de forma simultánea con los sistemas clásicos de auscultación y algunos otros de reciente aplicación La presente investigación se ha organizado con idea de dar respuesta a varias preguntas que el explotador de presas se plantea y que no se analizan en el estado del arte de la técnica: cómo hacer la configuración espacial del sistema y cuáles son los puntos necesarios que se deben controlar, qué sistemas de comunicaciones son los más fiables, cuáles son los costes asociados, calibración del software, vida útil y mantenimientos requeridos, así como la posibilidad de telecontrolar los datos. Entre las ventajas del sistema DGPS, podemos señalar su bajo coste de implantación y posibilidad de controlarlo de forma remota, así como la exactitud y carácter absoluto de los datos. Además, está especialmente indicado para presas aisladas o mal comunicadas y para aquellas otras en las que el explotador no tiene referencia alguna de la magnitud de los desplazamientos o deformaciones propias de la presa en toda su historia. Entre los inconvenientes de cualquier sistema apoyado en las nuevas tecnologías, destaca la importancia de las telecomunicaciones ya sea en el nivel local en la propia presao desde su ubicación hasta el centro de control de la explotación. Con la experiencia alcanzada en la gestión de la seguridad de presas y sobre la base de la reciente implantación de los nuevos métodos de auscultación descritos, se ha podido analizar cada una de sus ventajas e inconvenientes. En el capítulo 5, se presenta una tabla de decisión para el explotador que servirá como punto de partida para futuras inversiones. El impacto de esta investigación se ha visto reflejado en la publicación de varios artículos en revistas indexadas y en el debate suscitado entre gestores y profesionales del sector en los congresos nacionales e internacionales en los que se han presentado resultados preliminares. All regulations on the safety of dams in Spain have collected the need to know the displacements and deformations of the structure and its foundation. Today there are many dams holding not have an adequate system of auscultation to control variables such as the installation of classical methods of precision in the same might not be technically feasible, and if so, would cost important economic and guarantee the implementation process of the dubious civil works. With the development of new technologies, computing and telecommunications, new displacements auscultation systems have emerged. Current GPS systems designed to control structures, machine guidance, navigation and topography, slope stability, subsidence, etc, allow to reach centimeter-level accuracies. The motion control system based on DGPS technology applies a statistical filter that sensitivities are achieved in the system to ± 1 mm, sufficient for normal auscultation of dams as required by current regulations. This accuracy is adapted to the radial displacement of dams, which are common values in coronation amplitudes up to 15 mm in gravity dams and up to 45 mm in arch or arc dams. This research aims to analyze the feasibility of DGPS system in controlling movements of concrete dams, comparing the different systems auscultation and its correlation with physical variables and linked to differential GPS system itself. Given the need to answer this question and to validate and incorporate this technology to civil engineering in Spain, has conducted a case study in real time at the dam La Aceña (Ávila). This dam is one of the few Spanish companies, which are controlling with this technology and simultaneously with the classic auscultation systems and some other recent application. This research has been organized with a view to responding to questions that the dam operator arises and in the state of the art technique not discussed: how to make spatial configuration of the system and what are the necessary control points what communication systems are the most reliable, what are the associated costs, calibration software, service life and maintenance requirements, possibility of monitoring, etc. Among the advantages we can point to its low cost of implementation, the possibility of remote, high accuracy and absolute nature of the data. It could also be suitable for those isolated or poorly communicated dams and those in which the operator has no reference to the magnitude of displacements or deformations own prey in its history. The disadvantages of any system based on the new technologies we highlight the importance of telecommunications, either locally or from this dam control center of the farm. With the experience gained in the management of dam safety and based on the recent introduction of new methods of auscultation described, it has been possible to analyze each of their advantages and disadvantages. A decision table for the operator, which will serve as a starting point for future investments is presented. The impact of research, has been reflected in the publication of several articles in refereed journals and discussion among managers and professionals in national and international conferences in which they participated.

Integración del software de los subsistemas manager, plataforma y determinación y control de actitud para satélite UPMSat-2

El proyecto UPMSat2 aborda el desarrollo de un micro-satélite que se usará como una plataforma de demostración tecnológica. La mayor parte del proyecto se desarrolla en el Instituto Ignacio de la Riva de la Universidad Politécnica de Madrid, con la colaboración de empresas del sector del espacio. La labor del grupo STRAST se centra en el desarrollo del software de vuelo y del sector de tierra del satélite. Este Trabajo Fin de Grado trata del desarrollo de algunos componentes del software embarcado en el satélite. Los componentes desarrollados son: Manager, Platform y ADCS. El Manager está encargado de dirigir el funcionamiento del satélite y, en concreto, de su modo de operación. El Platform se encarga de monitorizar el estado del satélite, para comprobar que el funcionamiento de los componentes de hardware es el adecuado. Finalmente, el ADCS (Attitude Determination and Control System) trata de asegurar que la posición del satélite, respecto a la tierra, es la adecuada. El desarrollo de este trabajo parte de un diseño existente, creado por alumnos previamente. El trabajo realizado ha consistido en mejorarlos con funcionalidad adicional y realizar una integración de estos subsistemas. El resultado es un sistema operativo, que incluye unas pruebas preliminares. Un trabajo futuro será la realización de pruebas exhaustivas,para validar el funcionamiento de los subsistemas desarrollados. El desarrollo de software se ha basado en un conjunto de tecnologías habituales en los sistemas empotrados de alta integridad. El diseño se ha realizado con la herramienta TASTE, que permite el uso de AADL. El lenguaje Ada se ha utilizado para la implementación, ya que es adecuado para este tipo de sistemas. En concreto, se ha empleado un subconjunto seguro del lenguaje para poder realizar análisis estático y para incrementar la predecibilidad de su comportamiento. La concurrencia se basa en el modelo de Ravenscar,que es conforme con los métodos de análisis de respuesta.