Latis II Underwater Remotely Operated Vehicle Technical Report

CHALLENGES
One of the most difficult challenges faced by
the UMaine Team was preparing the ROV to
operate in a submerged environment. Due to
the extensive electronic systems both inside
and outside the electronics enclosure, excellent
waterproofing processes were essential. To
address this challenge, initial testing was
conducted on prototype, Latis I. The
information gained from these tests influenced
the final ROV design. For example, difficulties
with small leaks through the waterproof
connectors led to a final design with a
permanent wire configuration and only
installing a single removable part to access the
sealed enclosure. Furthermore, sealing
compounds such as potting epoxy were used
more on Latis II because of the hardening
capabilities not observed when using silicone or
polyurethane.
Another challenge faced by the team was
dealing with conflicting opinions within the
group regarding the steps to address a technical
issue or the particular technical issue itself. It
became obvious to the team that a process for
resolving such conflicts would increase the
productivity while avoiding interpersonal
aggravations. To solve this problem it was
agreed upon that testing would be conducted,
when possible, on each idea to determine its
viability. The criterion for selection was based
on design parameters for our project such as
cost, reliability, ease of implementation, and
integration into existing systems. This process
allowed a comparison between the ideas of the
individual, and the goals of the team, usually
resulting in one idea that best fit the situation
at hand.
15
LATIS II
TECHNICAL REPORT
Finally, one of the biggest challenges was
manufacturing the parts for Latis II. After
spending more time and effort than anticipated
on Latis I it was decided early on in designing
Latis II that the team should outsource
manufacturing responsibilities to a company
that specializes in the task. This however did
not work well due to the slow turn-around time
of the parts and frequent mistakes made by the
manufacturing company. To solve this problem,
the team decided to learn how to operate the
Computer Numerically Controlled (CNC)
machine available in the lab and manufacture
some of the simpler parts. The team fabricated
the remainder of the parts needed to finish the
ROV, control arms and power supply box.
TROUBLESHOOTING TECHNIQUES
To gain some knowledge and experience that
the UMaine ROV Team could later call upon
when troubleshooting issues on Latis II, the
team designed and constructed their prototype
Latis I in the fall of 2009. From this first attempt
the team gained valuable insight into the things
that may go wrong in the future.
WATERPROOFING
In designing Latis I the team decided to use
factory-made water proof electrical connectors.
However, finding such connectors at the 40A
current rating was problematic. Furthermore,
the waterproof connectors finally purchased
ended up being the weakest link in the entire
electronics enclosure for Latis I. After weeks of
trying different techniques such as greasing the
O-rings of the connectors, tightening the
connectors more than the specified torque, and
even creating a positive pressure inside the
electronics compartment, the team was still