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A UNIFIED METHOD FOR EVALUATING REAL-TIME COMPUTER CONTROLLERS: A CASE STUDY

IP.com Disclosure Number: IPCOM000128456D
Original Publication Date: 1983-Jun-01
Included in the Prior Art Database: 2005-Sep-16

Publishing Venue

Software Patent Institute

Related People

K.G. Shin: AUTHOR [+5]

Abstract

A real-time control system consists of a synergistic pair, that is, a controlled process and a controller- computer. We have defined new performance measures for real-time controller computers on the basis of the nature of this synergistic pair.

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

A UNIFIED METHOD FOR EVALUATING REAL-TIME COMPUTER CONTROLLERS: A CASE STUDY

K.G. Shin, C.M. Krishna and
Y.H. Lee
CRL-TR-23-83

JUNE 1983

THE UNIVERSITY OF MICHIGAN COMPUTING RESEARCH LABORATORY1 Room 1079, East Engineering Building
Ann Arbor, Michigan 48109
USA
Tel: (313) 763-8000

A UNIFIED METHOD FOR EVALUATING REAL- TIME COMPUTER CONTROLLERS: A CASE STUDY [ title ] 2 K.G. Shin, Senior Member, IEEE, C. M. Krishna, Student Member, IEEE, and Y.H. Lee, Student Member, IEEE

Computing Research Laboratory

Department of Electrical and Computer Engineering The University of Michigan
Ann Arbor, Michigan 48109

ABSTRACT

A real-time control system consists of a synergistic pair, that is, a controlled process and a controller- computer. We have defined new performance measures for real-time controller computers on the basis of the nature of this synergistic pair.

In this report we present a case study of a typical critical controlled process in the context of new performance measures that express the performance of both controlled processes and real-time controllers (taken as a unit) on the basis of a single variable: controller response time. Controller response time is a function of current system state, system failure rate, electrical and/or magnetic interference, etc., and is therefore a random variable. Control overhead is expressed as a monotonically non- decreasing function of the response time and the system suffers catastrophic failure, or dynamic failure, if the response time for a control task exceeds the corresponding system hard deadline, if any. A rigorous probabilistic approach is used to estimate the performance measures.

1 This research has been supported in part by NASA Grant No. NAG 1-296. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the funding agency.

2 This work has been supported in part by NASA Grant No. NAG 1-296. Any opinions, findings, and conclusions or recommendations expressed in this report are those of the authors and do not necessarily reflect the views of the funding agency.

University of Michigan Computing Research Laboratory Page 1 Jun 01, 1983

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A UNIFIED METHOD FOR EVALUATING REAL-TIME COMPUTER CONTROLLERS: A CASE STUDY

The controlled process chosen for study is an aircraft in the final stages of descent, just prior to landing. Control constraints are particularly severe during this period, and great care must be taken in the design of controllers that handle this process. First, the performance measures for the controller are presented. Secondly, control algorithms for solving the landing problem are discussed and finally the impact of our performance measures on the problem is analyzed, showing that the performance measures and the associated estimation method have great potential use for designing and/or evaluating r...