SRS FUSION UUV takes IP68-sealed Fischer FiberOptic down to 1,000 feet (300 m)
- Ensure reliable connectivity down to 1,000 feet (304.8 meters)
- Transmit HD video at gigabit speed
- Must work both tethered (for real-time data) and untethered (upload data later)
- High number of mating cycles for connectors
Main technical requirements
- Ability to survive up to 1,000 feet deep (450 psi)
- Handle rugged oceanic conditions.
Challenges & Opportunities
When the team at SRS started on the design for their FUSION autonomous underwater vehicle in 2015, they wanted to differentiate it from other underwater robots on the market. It needed to be the right size to conduct military missions, help first responders with recovery efforts, and go on small-boat scientific explorations. This meant that it needed to be rugged enough to go underwater in all weather conditions down to a depth of 1,000 feet, and send sonar and sensor data, and HD video back to the surface. But that’s not all. They wanted it to be multi-functional, so that it could be tethered to the topside where information was being gathered in real time, or remotely operated to navigate into places where a tether might get in the way. And they wanted the price tag to be affordable.
It’s about the data
One of the first requirements, according to Jesse Rodocker, President of Strategic Robotic Systems, was that it had to be able to endure the rigors of underwater oceanic travel in all weather conditions. After that, it had to handle a ton of data. “We knew we needed HD video with a gigabit link to the surface. This, along with the distance that we needed, ruled out traditional copper. We knew right away that we had to use fiber optics.” The engineering team had to go on a mission to find a rugged fiber optic connector that could handle the data and the conditions.
“We chose the Fischer FiberOptic connectors because they’re reliable, they’re well made, and they come in at a good price point. All those things factored into our decision. We’re using them topside in our consoles and accessory devices, and underwater in the autonomous underwater vehicle itself.”
Jesse Rodocker President, Strategic Robotic Systems
The search for the right connectivity solution
The Fischer FiberOptic Series FO1 single-fiber connector is currently rated IP68 for 2 meters, 24 hours. That’s what’s in the literature. But upon inspection, the SRS team believed it could do better. The engineering team had already specified the single-fiber FO1 for the topside devices. There were receptacles on the consoles that transferred data into a network. The topside devices needed to stand up to weather and rough handling for military personnel, and Fischer Connectors’ products fit the bill. Since they’d already selected Fischer Connectors for the topside, and had a relationship with the Fischer Connectors team, they started looking at it for subsea as well.
Rodocker says that after seeing the connector on the top side, he believed it would work below the water, even though it wasn’t officially specified to go as deep as they needed it. “Typical subsea components were very, very expensive. They were big, they were heavy, and they weren’t easy to use. We needed something that was smaller, easier to install, easy to use, yet was robust and reliable that would still stand up to the job.”
“We have a pressure tank that we use to test the components under high pressure. We can test to 750 psi. It mimics the pressure at various depths underwater. So we got some samples, and went to work on the pressure testing.”