Neuro-fuzzy techniques to optimize an FPGA embedded controller for robot navigation

This paper describes how low-cost embedded controllers for robot navigation can be obtained by using a small number of if-then rules (exploiting the connection in cascade of rule bases) that apply Takagi-Sugeno fuzzy inference method and employ fuzzy sets represented by normalized triangular functions. The rules comprise heuristic and fuzzy knowledge together with numerical data obtained from a geometric analysis of the control problem that considers the kinematic and dynamic constraints of the robot. Numerical data allow tuning the fuzzy symbols used in the rules to optimize the controller performance. From the implementation point of view, very few computational and memory resources are required: standard logical, addition, and multiplication operations and a few data that can be represented by integer values. This is illustrated with the design of a controller for the safe navigation of an autonomous car-like robot among possible obstacles toward a goal configuration. Implementation results of an FPGA embedded system based on a general-purpose soft processor confirm that percentage reduction in clock cycles is drastic thanks to applying the proposed neuro-fuzzy techniques. Simulation and experimental results obtained with the robot confirm the efficiency of the controller designed. Design methodology has been supported by the CAD tools of the environment Xfuzzy 3 and by the Embedded System Tools from Xilinx. © 2014 Elsevier B.V.Peer Reviewe

Controlador difuso para problemas de navegación en presencia de obstáculos fijos

En esta comunicación se describe un sistema de control difuso para aplicaciones de navegación de robots móviles autónomos en presencia de obstáculos fijos. Las herramientas de CAD del entorno Xfuzzy 3, desarrollado en el IMSE, han facilitado el diseño del controlador. En la comunicación se procede a la verificación del controlador diseñado operando en un lazo cerrado con el modelo del robot móvil autónomo eléctrico Romeo 4R, diseñado y construido en la Escuela Superior de Ingenieros de la Universidad de Sevilla. Las simulaciones realizadas demuestran la eficiencia del controlador desarrollado.Comisión Interministerial de Ciencia y Tecnología TEC2005-04359/MICJunta de Andalucía DPI2005-0229

Digital implementation of hierarchical piecewise-affine controllers

This paper proposes the design of hierarchical piecewise-affine (PWA) controllers to alleviate the processing time or prohibitive memory requirements of large controller structures. The constituent PWA modules of the hierarchical solution have fewer inputs and/or coarser partitions, so that they can reduce considerably the hardware resources required and/or the time response of the controller. A design methodology aided by CAD tools is employed to design the parameters of the controller, implement its architecture in an FPGA, and verify the static and dynamic behavior of the digital implementation by applying hardware-in-the-loop testing.Comunidad Europea FP7-IST-248858Ministerio de Ciencia e Innovación TEC2008-04920 y DPI2008-03847Junta de Andalucía P08-TIC-0367

An automated design flow from linguistic models to piecewise polynomial digital circuits

This paper describes how the different CAD tools of the environment Xfuzzy 3, developed in Microelectronics Institute of Seville and University of Seville, allow to translate expressive linguistic models into mathematical ones, in particular, into a combination of piecewise polynomial systems that can be implemented efficiently in hardware. The new synthesis tool of Xfuzzy 3 automates communication with Xilinx System Generator in Matlab, thus facilitating implementation of the linguistic model into an FPGA from Xilinx. This is illustrated with the design of a navigation controller for an autonomous robot.Comunidad Europea FP7-IST-248858Ministerio de Ciencia y Tecnología TEC2008-04920Junta de Andalucía P08-TIC-0367

New features of the fuzzy logic development environment Xfuzzy

The characteristics of the new version of the fuzzy systems development environment Xfuzzy is presented. The environment covers the aspects related to the specification, verification, adjustment and implementation of fuzzy systems. It is an open environment (in the sense that the user can define many functional and structural aspects) and a free distribution tool that allows proving new formalisms and helps the definition and implementation of complex systems

Using Xfuzzy environment for the whole design of fuzzy systems

Since 1992, Xfuzzy environment has been improving to ease the design of fuzzy systems. The current version, Xfuzzy 3, which is entirely programmed in Java, includes a wide set of new featured tools that allow automating the whole design process of a fuzzy logic based system: from its description (in the XFL3 language) to its synthesis in C, C++ or Java (to be included in software projects) or in VHDL (for hardware projects). The new features of the current version have been exploited in different application areas such as autonomous robot navigation and image processing.Comisión Interministerial de Ciencia y Tecnología DPI2005-02293 y TEC2005-04359Junta de Andalucía TIC2006-635 y TEP2006-37

Automatic extraction of linguistic models for image description

This paper describes a methodology to extract fuzzy models that describe linguistically the low-level features of an image (such as color, texture, etc.). The methodology combines grid-based algorithms with clustering and tabular simplification methods to compress image information into a small number of fuzzy rules with high linguistic meaning. All the steps of the methodology are carried out with the help offered by the tools of Xfuzzy 3 environment, so we can define, simplify, tune and verify the fuzzy models automatically. Several examples are included to illustrate the advantages of the methodolog

Museum of the history of computers

El grupo docente de Arquitectura de Computadores tiene en su haber una gran cantidad de dispositivos relacionados con la historia del PC. Este material se encontraba confinado en un almacén y el objetivo principal a desarrollar en este trabajo se basa en explotar ese material desaprovechado para que nuestros alumnos de las titulaciones de los Grados en Informática (especialmente los alumnos de la especialidad de Ingeniería de Computadores), Física y Electrónica, se enriquezcan viendo físicamente materiales de los que se les habla en distintas asignaturas.The Computer Architecture group has a high number of devices related to the history of the computers. This material was stored in a warehouse and the aim to develop in this paper is based on exploiting these devices so that our students of degrees in computer science (especially students of the speciality of computer engineering), physics and electronics, can view physically the materials described in different subjects

Fuzzy models for fingerprint description

Trabajo presentado al 9th WILF celebrado en Italia del 29 al 31 de agosto de 2011.Fuzzy models, traditionally used in the control field to model controllers or plants behavior, are used in this work to describe fingerprint images. The textures, in this case the directions of the fingerprint ridges, are described for the whole image by fuzzy if-then rules whose antecedents consider a part of the image and the consequent is the associated dominant texture. This low-level fuzzy model allows extracting higher-level information about the fingerprint, such as the existence of fuzzy singular points and their fuzzy position within the image. This is exploited in two applications: to provide comprehensive information for user of unattended automatic recognition systems and to extract linguistic patterns to classify fingerprints.Peer Reviewe

An automated design flow from linguistic models to piecewise polynomial digital circuits

Trabajo presentado al ISCAS celebrado en Paris del 30 de mayo al 2 de junio de 2010.This paper describes how the different CAD tools of the environment Xfuzzy 3, developed in Microelectronics Institute of Seville and University of Seville, allow to translate expressive linguistic models into mathematical ones, in particular, into a combination of piecewise polynomial systems that can be implemented efficiently in hardware. The new synthesis tool of Xfuzzy 3 automates communication with Xilinx System Generator in Matlab, thus facilitating implementation of the linguistic model into an FPGA from Xilinx. This is illustrated with the design of a navigation controller for an autonomous robot.This work has been partially supported by European Community under the MOBY-DIC Project FP7-IST-248858 (www.mobydic-project.eu), by Ministerio de Ciencia y Tecnología under the Project TEC2008-04920 and by Junta de Andalucía under the Project P08-TIC-03674.Peer Reviewe