Underwater Robots - Gianluca Antonelli.pdf

oll, pitch, yaw [deg]
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Task−Space Position
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4.6 Conclusions 91
Position Error
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Fig. 4.10. Task-space trajectories (left column) and their errors (right column) for
the N. Sarkar and T.K. Podder algorithm
4.6 Conclusions
An overview over existing fault detection and fault tolerant schemes for underwater
vehicles has been presented. The case of failures for autonomous
missions in un-structured environment is, obviously, adramatic occurrence
to handle. In this sense, the underwater community would benefit from research
studies with astrong practical orientation rather than theoretical-only
approaches. Failures in aredundant sensor seem to be asolved problem; however,
aparticular attention needs to be paid to the tuning of the detection
gains, real-data experiments for off-line tuning seems to be areliable way to
select those gains. As far as thrusters are of concern, experiments have shown
that current AUVs can be controlled at low velocity with 6thrusters, also if
the original symmetric allocation islost, without astrong performance deterioration.
Some possible research areas concern the case of athruster-driven
AUV that becomes under-actuated and the case of vehicles controlled by means
of control surfaces that failed; inboth cases some practical approaches
might beuseful for the underwater community.