Generalized Alerting System Components

J. K. Kuchar (jkkuchar@mit.edu),
R. J. Hansman (rjhans@mit.edu)

Research Objectives

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 performance.

Approach

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.

Accomplishments

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 and/or visual).
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.

Significance

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.