Antonio Hernández Zavala

Fuzzy Hardware: A Retrospective and Analysis

Worldwide, fuzzy systems are becoming a very useful mathematical tool to deal with nonlinear problems by inferring from a rule base that contains the necessary knowledge extracted from an expert. There are diverse forms to implement a fuzzy system depending on the desired response time, for which hardware implementations are best suited for high-speed demands. Fuzzy hardware has been exploited since the mid-1980s, and there have been many interesting architecture cases with different functional and performance characteristics that are reviewed in this paper from a categorical and historical point of view.

Generators of Fuzzy Operations for Hardware Implementation of Fuzzy Systems

The problem of effective hardware implementation of parametric operations of fuzzy systems is studied in this paper. The methods of generation of parametric classes of fuzzy conjunctions and disjunctions by means of introduced generators and basic operations are considered. Several types of generators of parametric fuzzy operations simple for hardware implementation are proposed. Examples of hardware implementation of proposed parametric operations are presented.

VLSI implementation of a module for realization of basic t-norms on fuzzy hardware

Fuzzy theory applications have been explored and analyzed on fields as pattern recognition, control, data classification, signal processing, expert systems, among others. To accomplish this, more complex calculations and faster processing speed are required, turning fuzzy hardware implementation to be the perfect choice. Fuzzy operations as t-norms and t-conorms are used in fuzzy systems as conjunction and disjunction operations respectively. Commonly used t-norms for hardware implementation are minimum and algebraic product, first one is cheaper to implement; second consumes more resources. On this work FPGA technology is used to implement basic fuzzy t-norms as minimum, Lukasiewicz and drastic product into an 8 bit single circuit that allows operation selection. Timing, resources and comparative results are presented.

Parametric Operations for Digital Hardware Implementation of Fuzzy Systems

Operations used in fuzzy systems to realize conjunction and disjunction over fuzzy sets are commonly minimum and maximum because they are easy to implement and provide good results when fuzzy system is tuned, but tuning of the system is a hard work that can result on knowledge lost. A good choice to tune the system without loss of previously stated knowledge is by using parametric classes of conjunction and disjunction operations, but these operations must be suitable to be efficiently implemented on digital hardware. In this paper, the problem of obtain effective digital hardware for parametric operations of fuzzy systems is studied. The methods for generation of parametric classes of fuzzy conjunctions and disjunctions by means of generators and basic operations are considered. Some types of generators of parametric fuzzy operations simple for hardware implementation are proposed. New hardware implementation for parametric operations with operation selection is presented.

Conjunction and disjunction operations for digital fuzzy hardware

Fuzzy systems have been explored in diverse application fields which require reaching fuzzy inferences at high computer rates. To accomplish this task, fuzzy hardware is the best choice. At inference engine, conjunction and disjunction operations play a very important role for decision making. Common operations in existing fuzzy hardware are minimum, maximum, algebraic product and probabilistic sum. In order to extend the applicability of existing fuzzy hardware, it is necessary to consider a wider range of operations. It is even desirable to have configurable circuits which take advantage of hardware resources. This work presents the hardware implementation of configurable circuits for the realization of diverse fuzzy t-norm and t-conorm operations. Resultant circuits are low hardware resource consumers which makes them efficient to be used as add-in modules for existing fuzzy hardware in FPGA or ASIC. Comparative results are presented showing the advantages of these circuits.

Generalized fuzzy operations for digital hardware implementation

Hardware implementation of fuzzy systems plays important role in many industrial applications of fuzzy logic. The most popular applications of fuzzy hardware systems were found in the domain of control systems but the area of application of these systems is extending on other areas such as signal processing, pattern recognition, expert systems etc. The digital fuzzy hardware systems usually use only basic operations of fuzzy logic like min, max and some others, first, due to their popularity in traditional fuzzy control systems and, second, due to the difficulties of hardware implementation of more complicated operations, e.g. parametric classes of t-norms and t-conorms. But for extending the area of applications and flexibility of fuzzy hardware systems it is necessary to develop the methods of digital hardware implementation of wide range of fuzzy operations. The paper studies the problem of digital hardware implementation of fuzzy parametric conjunction and disjunction operations. A new class of such operations is proposed which is simple for digital hardware implementation and is flexible, due to its parametric form, for possible tuning in fuzzy models. The methods of hardware implementation of these operations in digital systems are proposed.

Sistema de medición de distancia mediante imágenes para determinar la posición de una esfera utilizando el sensor Kinect XBOX

Resumen—En este documento se presenta un metodo para medir la distancia del centroide de un objeto segmentado en una imagen de color con respecto a un punto de referencia fijo. El algoritmo se probo mediante una secuencia de imagenes de color, analizando mas de 100 posiciones verticales diferentes de una esfera alojada en el interior de una columna cilindrica transparente de acrilico con diametro y longitud constante. El algoritmo propuesto integra tecnicas de correccion por balance de blancos y de calibracion de la camara con sus parametros intrinsecos, ademas, se prueba un nuevo metodo de segmentacion en color utilizado para calcular distancias del mundo real a partir de imagenes en color RGB. Los resultados obtenidos reflejan una alta confiabilidad ya que el 100% de las mediciones realizadas tuvo un error menor a 1.64% con un nivel de precision mas alto que el instrumento utilizado de referencia, en un rango de distancia de 0 a 1340 mm.

RISC-based architecture for computer hardware introduction

Nowadays, computers are indispensable tools for most of everyday activities ranging from consumer electronics to industrial process automation. Complexity of new applications leads computer engineers to use embedded systems in order to develop high performance technological solutions that can achieve high speed processing while exploiting hardware resources efficiently. In order to develop embedded systems is necessary to understand the basic operation of a computer system, mainly composed of memory, a peripheral controller and a microprocessor. This work presents the design and implementation of an 8 bit RISC soft core processor intended for computer architecture introduction considered to be an effective solution for computer comprehension. Final circuit can be used as a soft core for FPGA embedded designs mainly for control and automation applications.

Ultrasonic Arc Maps and Its Potential Application in Non-destructive Testing

The ultrasound is a widely extended technique in non-destructive testing (NDT). Some its advantages are: low cost, safety and simplicity to be implemented, environment friendly and reliability. The ultrasound probes are useful to detect gaps, corrosion, breakages, changes of density and impurities in materials. However, the C-Scan used to produce a 3D image is complex and requires the use of a special probe made of a transducers matrix and a powerful computer to run the image processing algorithm. The cross-talk, spurious echoes and the position uncertainty of the reflected point make it harder to locate in the space the true points. This work describes the ultrasonic arc maps (UAM) technique and proposes to use them in NDT. Originally, the UAM was developed in robotics, where it showed good features to locate the true reflected points using a simple pulse-echo transducer. The algorithms for data processing are fast, easier to program and could be embedded in a digital system like a microcontroller or a FPGA.

Discrete fuzzy systems: The aggregation operator

Knowledge-based systems have the ability to realize inferences out of pre-defined rules. As the antecedents are driven into the fuzzy system, the system infers to obtain the consequents. These consequents are used to obtain crisp output data. The aggregation operator combines these consequents to obtain a unified shape from which a unique result can be obtained. The way to handle the aggregation varies according to the type of membership functions involved. This paper presents a way of realizing aggregation operation when the membership functions are represented by means of a-levels, showing that this case is suitable for discrete fuzzy system implementations.