Oceaneering Offers Path to ‘Freedom’

Freedom can be defined in any number of ways, but to Oceaneering, it is simply the future — and the name of their new autonomous underwater vehicle (AUV).

“The Freedom AUV is a new fresh approach to autonomous underwater vehicles. We're combining the benefits and features of an ROV [remotely operated vehicle] into an AUV system,” Casey Glenn, electrical engineering lead at Oceaneering, said.

Oceaneering’s Freedom AUV is the next step in a series of developments the company has been making toward autonomous vehicles operating under the sea.

Glenn said Freedom is able to collect many types of data, including “still images with high resolution and high dynamic range, laser imagery and multibeam imaging sonar.” It has a laser imaging system that projects a laser beam onto the seabed, enabling cameras to capture a contour map.

The AUV can be equipped with hydrophones, magnetometers, and cathodic protection sensors to monitor corrosion and hydrocarbon detection sensors to detect leaks.

“Our vehicle is a platform for our client to come up and say, ‘Hey, can you sense this? Can you detect this while you fly this pipeline? Or can you fly around here and, collect data?’” Glenn said. “If we can fit it on the vehicle, we'll put that sensor on there and do it.”

Freedom can travel as fast as four 4 knots, whereas traditional ROVs typically travel at one 1 knot. The increased speed gives the AUV faster turnaround time for inspections than ROVs scanning the seabed and pipelines in closer proximity than traditional AUVs. The torpedo-like build of Freedom is also equipped with both fins and thrusters for improved maneuverability.

“We've got thrusters all around the vehicle, enough thrusters to do vertical motion, to stop and pivot or to turn,” Glenn said. “We actually have two obstacle avoidance sonars, and a control algorithm… If an unknown obstacle comes up, we're actually able to not only just go around the object but to, if possible, go up, and over, mapping it as we go providing that data to the customer instead of just avoiding it.”

Freedom’s autonomy

The autonomous nature of Freedom makes it seem as if it has a mind of its own, which is exactly what Oceaneering was aiming for.

“Traditional autonomous underwater vehicles, they're really a vehicle executing a set of instructions planned from the surface, whereas Freedom is taking that autonomy to another level,” said Nick Rouge, Oceaneering’s subsea robotics product manager, said. “It actually reacts to what it finds in its environment and initiates and adapts its behaviors.”

Despite Freedom being able to react on its own, the biggest challenge for the developers with the AUV was being able to trust the vehicle, said Rouge. Reaching its current level of competency took more than 650 pipeline runs. Now the vehicle is at API Technology Readiness Level 6 (API TRL 6), with the next goal of being API TRL 7, which is “as qualified as it can get out in the field,” Glenn said.

Even though the autonomous capabilities of Freedom were tailor-made for the vehicle, the behaviors aren’t fundamentally limited to Freedom, as the same behaviors could be put into a work-class ROV. This level of compatibility was only able to be developed due to the experience Oceaneering had with previous subsea robotics systems.

“We developed this in Freedom in part because we, at the time, had the most total miles of pipeline survey executed with traditional AUVs,” Rouge said. “We had a lot of history with problems experienced with those system designs, their limitations, what we liked and what we didn't like. We had contributed a lot of feedback and field experience into the development of their control systems… so I think it's that track record that really showed us what we needed to do.”

“Traditional autonomous underwater vehicles, they're really a vehicle executing a set of instructions planned from the surface, whereas Freedom is taking that autonomy to another level. It actually reacts to what it finds in its environment and initiates and adapts its behaviors.” — Nick Rouge, Oceaneering

Another issue: traditional subsea vehicles operating without a fiber optic tether must rely on low-bandwidth communication. Airborne drones have the options of radio communication, 4G mobile phone signal via LTE coverage or satellite signals. There’s even GPS for positioning so the drone can be easily located. Underwater, communications and positioning systems don’t work as effectively through water. Freedom’s autonomy looks to solve that by putting the decision-making on the vehicle.

“So this autonomy and the capabilities of Freedom, they're going to enable us to open up underwater behaviors that look like modern aerial drone inspections where you issue an instruction, the vehicle goes and does its work, then it returns to home base, and you no longer need continuous monitoring of the vehicle from a vessel,” Rouge said. “You no longer need an expensive diesel-burning, CO₂-producing surface vessel to travel along with the vehicles.”

With only one Freedom AUV currently operational, Oceaneering has demonstrated its high level of technical capability to three international oil companies. Following extensive development testing Freedom is now ready to work on a global basis, starting in second-quarter 2023, Rouge said.

Moving forward

This is only the beginning, as Oceaneering is already working to have another vehicle out by 2024. This new vehicle might even have a different shape than the current Freedom, as Oceaneering looks to optimize the technology for different tasks, as they’re “never going to be done with testing phases,” Rouge said.

The team is always looking to develop and test new features and behaviors and prove out more autonomy to a high degree of confidence. The software within Freedom holds the key to the future of inspection within the energy industry, according to the company.

When talking about the impact that Freedom could have on the future of subsea, Rouge said,:

 “The autonomous flight control system and the physical hardware developed for Freedom are the stepping stones necessary to enable vessel-less operations over a large distance.”