Reliability of two REMUS-100 AUVs based on fault log analysis and elicited expert judgment

Reliability is especially important for autonomous
underwater vehicles (AUVs) that have made the transition
to operational use. However, in contrast to the unmanned
air vehicle community, there has been little sharing in the
open literature of detailed fault histories of commercial
AUVs from which an assessment of their reliability can be
made. In this paper, we declare the fault history of two
REMUS-100 AUVs manufactured by Hydroid Inc. and
operated by the Center for Coastal Marine Sciences at
California Polytechnic State University. The data set
contains the faults and incidents recorded from 186
missions between 5 November 2003 and 14 January 2009.
Interaction between the faults or incidents with the AUV
and the operating environment complicate matters when
it comes to estimating probability of loss. Through a
formal process of eliciting expert judgment the paper
provides optimistic and pessimistic estimates of loss of
the REMUS vehicles in open water, coastal, under sea ice
and under ice shelf operations. Vehicle-specific risk
mitigation methods are explored, and recommendations
made for reviewing the fault history data using
behavioural aggregation through interaction among a
group of experts rather than simple mathematical
aggregation as in this paper.