Generalized Alerting System Components
Examine the principal components of alerting systems from a generalized
perspective. Emphasis is given to those components that create
important tradeoffs and have an impact on system performance. This
information will aid in focusing design and evaluation efforts on those
parts of an alerting system that have important effects on system
Past, present and future concepts for alerting system design have been
collected and analyzed. The important components making up these
systems are then diagrammed and discussed.
The Figure shows a schematic drawing of the principal components of a
generalized alerting system. The primary components are:
- Measurement Sources provide estimates of the aircraft and
hazard states to the pilot and the alerting system.
- The Alerting System compares the state estimates with thresholds and
issues an appropriate level of warning using alerting displays (aural
- The Human Operator, when presented with alert information, reacts in
some manner to the hazard.
- The System Dynamics are affected by control inputs from the operator.
Alert System Diagram
Each component may contain uncertainties that degrade the ability of the
alerting system to correctly distinguish true threats from non-threats.
Changes in one component may also affect the performance of the other
components. For example, changing the alerting display may affect the
operator's response to an alert.
Having identified the primary areas where important design decisions
need to be made, efforts may be focused to examine in detail the
interrelationships between components. Trade studies between, for
example, increased sensor accuracy or an improved alerting display can
be quantified through a probabilistic analysis that has also been
developed through this work. Changes in alerting thresholds can also be
examined to determine their impact upon crew response and thus upon
overall system performance.
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