Modern civil commercial transport aircraft provide the means for the safest of all
forms of transportation. While advanced computer technology ranging from flight
management computers to warning and alerting devices contributed to flight safety
significantly, it is undisputed that the flightcrew represents the most frequent primary
cause factor in airline accidents. From a system perspective, machine actors such as the
autopilot and human actors (the flightcrew) try to achieve goals (desired states of the
aircraft). The set of activities to achieve a goal is called a function. In modern
flightdecks both machine actors and human actors perform functions. Recent accident
studies suggest that deficiencies in the flightcrew's ability to monitor how well either
machines or themselves perform a function are a factor in many accidents and incidents.
As humans are inherently bad monitors, this study proposes a method to automatically
assess the status of a function in order to increase flight safety as part of an intelligent
pilot aid, called the AgendaManager. The method was implemented for the capture
altitude function: seeking to attain and maintain a target altitude. Fuzzy systems were
used to compute outputs indicating how well the capture altitude function was performed
from inputs describing the state of the aircraft. In order to conform to human expert
assessments, the fuzzy systems were trained using a genetic algorithm (GA) whose
objective was to minimize the discrepancy between system outputs and human expert
assessments based on 72 scenarios. The resulting systems were validated by analyzing
how well they conformed to new data drawn from another 32 scenarios. The results of
the study indicated that even though the training procedure facilitated by the GA was able
to improve conformance to human expert assessments, overall the systems performed too
poorly to be deployed in a real environment. Nevertheless, experience and insights
gained from the study will be valuable in the development of future automated systems to
perform function assessment. / Graduation date: 1998
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/33694 |
| Date | 16 July 1997 |
| Creators | Zaspel, Joachim C. |
| Contributors | Funk, Kenneth H. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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