Resumo

GUEVARA LOPEZ, Pedro; MEDEL JUAREZ, José de Jesús  e  DELGADO REYES, Gustavo. Description of execution time dynamics for a set of concurrent real-time tasks. Rev.fac.ing.univ. Antioquia [online]. 2011, n.61, pp.123-131. ISSN 0120-6230.

A Real-time System (RTS) implemented in a digital computer interacts with the physical world through knowledge variables (sensors, actuators, Analogical - Digital, and Digital-Analogical convertors) processing its requirements through real-time tasks (J_i: iZ₊). Each J_i. is formed by a set of instances {j_i,k: i,kZ₊, i is the task index, k is the instance index} with at least three time constraints: arrival, execution and, interval times (L_i,k, C_i,k, D_i,k). The execution time identification Ĉ_i,k, is based on Instrumental Variable parameter estimation and the recursive state space ARMA model. The execution times were measured experimentally using a Real-time Operative System QNX 6.5 Neutrino in an Intel Core i7 processor with a speed of 2.66 GHz. This paper presents a state of the art real-time task model, execution time measurements, an Instrumental Variable parameter estimator on recursive state space identification, experimentation and, results.

Palavras-chave : Tasks; Real-time; estimation; identifier; computing time; instance; error.

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