Recovery following tether failure?


#1

Hi All,

So excited for this project. I just made my kickstarter contribution. I'm a deep sea ecologist interested in using an OpenROV to give students immersive (pun intended) experiences in underwater exploration, and am planning to use the robot in coastal North Carolina. Seeing as the tether is as thin and light weight as possible, I'm wondering if there's a secondary recovery protocol in case the tether is accidentally severed? ROV Nereus uses a simple "return to the surface" program in case it loses signal, but with the limited power supply, an active protocol might not work as well for this. Maybe something like a bladder and CO2 cartridge that discharge if communication is interrupted for more than a few minutes. That way you don't have to worry about losing it if it takes more than an hour to find, and the bladder would make it more visible if things get rough.

Excited to get my kit and start tinkering!


#2

Hey Andrew! So great to have you here! This is something we've talked a lot about. It's definitely possible to code this into the software - and we should do it!

A few other community members have talked about creating a payload device like the bladder you describe. Not sure if that discussion has made it onto the forums yet, though.

In short: Yes! Let's do this!


#3

Besides recovery via umbilical, and as David points out, a deployable SMB (surface marker bouy) would probably be the next possibility.

A failure code programmed into the on-board controller could activate a small firing pin to discharge a small CO2 cartridge connected to balloon/small SMB built-into the ROV.

I would probably consider some method of remotely (if the mechanism could do both) disconnecting the umbilical in the event of umbilical entanglement.

In my experience total on-board failure of the control module or umbilical entanglement are the two most common 'lost' ROV issues.