Modelo para Tiempos de Arribo de Tareas en Tiempo Real Concurrentes
Arrival Times Model for Concurrent Real–time Tasks
Graduado: Daniel Cruz Pérez
Centro de Investigación en Computación – I.P.N.
Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada unidad Legaria – I.P.N.
E–mail:dcruzp@yahoo.com
Director de Tesis: Dr. Pedro Guevara López
Dirección de Gestión del Capital Humano – I.P.N.
Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada unidad Legaria – I.P.N.
E–mail: pguevara@ipn.mx
Graduado el 14 de Diciembre de 2007
]]>Resumen
Un Sistema en Tiempo Real (STR) implantado en una computadora digital, interactúa con el mundo físico a través de acondicionamientos de variables (sensores, actuadores convertidores Analógico/Digital A/D y Digital/Analógico D/A) y procesa sus peticiones mediante tareas concurrentes con restricciones temporales. En general cada una de las variables del proceso dinámico (entradas, salidas y estados) es relacionada con una Tarea en Tiempo Real específica; si se trata de un sistema multivariable, entonces se tendrá un conjunto de Tareas en Tiempo Real por cada arreglo de variables donde cada una tendrá que dar respuestas correctas acotadas temporálmente. En este trabajo se desarrolla un modelo matemático para la representación de tiempos de arribo de Tareas en Tiempo Real Concurrentes, en donde se incluyen las características generales del comportamiento de los arribos descritos por varios autores. Adicionalmente se propone un criterio para dar la estabilidad del sistema.
Palabras clave: Sistema en tiempo Real, Tarea, Evento discreto, Función de transición, Interarribo.
Abstract
A Real–time system implemented in a computer, interacts with the real physical world through variables conditioners (sensors, actuators, D/A and A/D converters) and processes each processing need as concurrent tasks with temporal deadlines. In general each variable of the dynamic process (inputs, outputs and states) is related with a specific task; if it is about a multivariable system then there is going to be a set of tasks for each variable where each will have to be answered correctly with temporal bounds. In this paper a mathematical model for the representation of arrival times of concurrent Real–time tasks is treated. Additionally a stability analysis is proposed.
Keywords: Real–time system, Task, Discrete event system, Transition function, Inter–arrivals.
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