AAWSAP DIRD, Cognitive Limits on Simultaneous Control of Multiple Unmanned Spacecraft, December 2010

Text

This text came with the file. It may have mistakes. When the text and the image disagree, the image is right.

UNCLASSIFIED//FOR OFFICIAL tt.!! 8HL>f
In an essential foundation study for introducing forms of augmentation to the ATC task,
Wickens modeled the dual task environment of pilot traffic avoidance using alarms to
augment detection of conflicts. The primary task was maintaining aircraft flightpath
using a simulated cockpit display of a crosshair inside a box: the crosshair indicated
aircraft direction and drifted toward the sides of the box if not corrected by the pilot
using a joystick control. The drift rate was variable and could increase or decrease the
difficulty of the primary task. The computer monitored for potential collisions and
warned pilots if another aircraft was within 3 miles.
Pilots were instructed to maintain their own aircraft flightpath first, and then detect
conflicts. Upon alarm, the pilot was to examine an ATC display and recommend re­
routing of the conflicting aircraft. Pilots were informed that the automated detection
system may erroneously label some situations as conflicts; therefore the pilot needed to
actually perform several ATC cognitive task functions to confirm the conflict before
recommending action. Participants in the study were 12 student pilots.
The results of this experiment showed that when augmentation was correct more than
about 80% of the time, performance decreased due to decreased vigilance in
confirming alarms properly on the ATC display. Additionally, with a high accuracy in the
alarm rate, pilots did not regularly check the ATC display to ensure that the
augmentation didn't miss possible conflicts. Auditory and visual binary alarms were
presented and the auditory alarms were more effective and did not interfere with the
primary task (visual tracking). The authors concluded that a 20-25% false alarm rate
was optimal" when it is intended for the pilot to work alongside the automation rather
than rely on it.42
The Wickens study was undertaken with the plan of moving ATC to a shared
responsibility of the controller and pilot: the goal being to increase airspace capacity by
removing some of the more mundane functions like en-route course correction and en­
route conflict detection to primarily cockpit control. This situation would be analogous to
a spacecraft pilot operating their primary vehicle manually while attending many semi­
automated ancillary vehicles. Although not exactly the same,
Landsdown studied TLX workload measures on drivers performing multiple in-vehicle
tasks. The authors here concluded that secondary tasks significantly increased
perceived workload in this arrangement of task control. 43
n This noise in the signal is analogous to adjusting the squelch level on a CB radio : too high a setting and you miss
traffic; too low a setting and all you hear is random noise.
UNCLASSIFIED//FOR OFFICl\l W&E 8HL'I
17