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Systematic methods for knowledge acquisition and expert system developmentNine cooperating rule-based systems, collectively called AUTOCREW which were designed to automate functions and decisions associated with a combat aircraft's subsystems, are discussed. The organization of tasks within each system is described; performance metrics were developed to evaluate the workload of each rule base and to assess the cooperation between the rule bases. Simulation and comparative workload results for two mission scenarios are given. The scenarios are inbound surface-to-air-missile attack on the aircraft and pilot incapacitation. The methodology used to develop the AUTOCREW knowledge bases is summarized. Issues involved in designing the navigation sensor selection expert in AUTOCREW's NAVIGATOR knowledge base are discussed in detail. The performance of seven navigation systems aiding a medium-accuracy INS was investigated using Kalman filter covariance analyses. A navigation sensor management (NSM) expert system was formulated from covariance simulation data using the analysis of variance (ANOVA) method and the ID3 algorithm. ANOVA results show that statistically different position accuracies are obtained when different navaids are used, the number of navaids aiding the INS is varied, the aircraft's trajectory is varied, and the performance history is varied. The ID3 algorithm determines the NSM expert's classification rules in the form of decision trees. The performance of these decision trees was assessed on two arbitrary trajectories, and the results demonstrate that the NSM expert adapts to new situations and provides reasonable estimates of the expected hybrid performance.
Document ID
19910059303
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Belkin, Brenda L.
(AT&T Bell Laboratories Middletown, NJ, United States)
Stengel, Robert F.
(Princeton University NJ, United States)
Date Acquired
August 15, 2013
Publication Date
June 1, 1991
Publication Information
Publication: IEEE Aerospace and Electronic Systems Magazine
Volume: 6
ISSN: 0885-8985
Subject Category
Systems Analysis
Accession Number
91A43926
Funding Number(s)
CONTRACT_GRANT: DAAG29-84-K-0048
CONTRACT_GRANT: NGL-31-001-252
Distribution Limits
Public
Copyright
Other

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