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Description:
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The Crew Exploration Vehicle (CEV ) necessitates higher levels of automation
than previous NASA vehicles due to program requirements for automation , including
Automated Rendezvous and Docking (AR &D ) . Studies of spacecraft development
often point to the locus of decision -making authority between humans and computers
(i .e . automation ) as a prime driver for cost , safety , and mission success . Therefore ,
a critical component in the CEV development is the determination of the correct
level of automation . To identify the appropriate levels of automation and autonomy
to design into a human space flight vehicle , NASA has created the Function -specific
Level of Autonomy and Automation Tool (FLOAAT ) .
This research develops a methodology for prototyping increased levels of automation
for spacecraft rendezvous functions . This methodology was used to evaluate the
accuracy of the FLOAAT -specified levels of automation , via prototyping . Two spacecraft
rendezvous planning tasks were selected and then prototyped in Matlab using
Fuzzy Logic (FL ) techniques and existing Shuttle rendezvous trajectory algorithms .
The prototyped functions are the determination of the maximum allowable Timeof -
IGnition (TIG ) slip for a rendezvous phasing burn and the evaluation of vehicle
position relative to Transition initiation (Ti ) position constraints .
The methodology for prototyping rendezvous functions at higher levels of automation
is judged to be a promising technique . The results of the prototype indicate
that the FLOAAT recommended level of automation is reasonably accurate and that FL can be effectively used to model human decision -making used in spacecraft rendezvous .
FL has many desirable attributes for modeling human decision -making ,
which makes it an excellent candidate for additional spaceflight automation applications .
These conclusions are described in detail as well as recommendations for future
improvements to the FLOAAT method and prototyped rendezvous functions . |