PRESSURE VESSELS
Why So Many?
Instead of placing all our electronics in one vessel, we've opted to utilize several smaller ones. This is all in the spirit of adaptability. The simplest reason is that the Stingray can configure itself in a relatively flat profile like its namesake. Instead of the typical torpedo-esque AUV profiles, custom enclosures minimize unused space inside them and eliminate the need for extra ballast - effectively minimizing vehicle dry weight.
Battery Enclosure
Every time a pressure vessel is opened and closed an extra chance for failure is created - either through improperly resealing or damaging the o-rings. We've created a sealed enclosure for the battery that allows us to charge through it. The need battery can be accessed by opening the enclosure but need not be. This provides us with an efficient means to swap out charged batteries in the field.
Computer Enclosure
The Stingray 2.0 features two main electronics housings. The navigation box features a low power Intel Atom that is responsible for: the task planner, navigation, controls, and acquisition of sensor data (orientation, depth, temperature, etc). The vision box, which features an Intel i7, is solely responsible for processing the 3 image streams from the 2 forward and 1 downward looking cameras. Both of these enclosures allow easy access to the electronics once the lid is removed. The electronics are attached to the base with a thermal paste so the boxes actually function as water cooled heat sinks while the vehicle is running. Flat faced vessels obviously cannot handle the pressures that cylindrical vessels can, but they are sufficient for competition depths (~10-30 ft).
Camera Enclosure
Our three cameras are housed in individual, compact cylindrical vessels. The package space is 3.25 x 8.80in from dome to connector, and with camera, lens and fasteners it weighs 1.8 lbs. The vessels are made from 6061-T6 aluminum and are hard anodized to survive corrosion in ocean environments. The more robust design allows us to use these camera for more than the AUVSI tournament - we are collaborating with a younger student team building a vessel for a National Geographic sponsored expedition. The goal is to use a stereo pair of these cameras to map underwater ocean caves. The experience gained from participating in AUVSI has been invaluable in being able to help other students on related underwater engineering projects.
Technical Drawings
cylindrical enclosure
STRY-020 rev. A |
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connector plate
STRY-021 rev. A |
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dome
(needs update to rev A) |
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enclosure mounting horseshoe
STRY-022 |
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