One consistent challenge to the scalable use of AUVs is their endurance, which is ultimately determined by balancing the vehicle’s onboard capacity, the power required to operate subsystems, and overcome hydrodynamic conditions presented by variable marine conditions. Given the depths that AUVs seek to scale, the efficiency of the chosen battery pack is a key determinant of the asset’s range and operational window. Traditional subsea battery configurations have always placed limitations on the use of AUVs in deeper, more remote waters, with most commercially available models suited to deployments only lasting from a few hours to perhaps two days. However, there is a growing cabal of AUV developers that are successfully bringing a new suite of long-range AUVs to market, offering enhanced operational flexibility than ever before. For the team
at Cellula Robotics, that means opting for an alternative energy source to propel the range and utility of our mid-sized and large AUV platforms: hydrogen.
SOLVING THE AUV ENERGY CHALLENGE
Hydrogen fuel cells offer more than twice the energy density of rechargeable batteries. By incorporating these cells into our AUV engineering design, Cellula Robotics can provide customers with a portfolio of efficient vehicles capable of persistent operations for campaigns lasting anywhere from two weeks to almost two months.
For example, our ENVOY AUV, a compact, mid-range endurance model, can run survey and inspection missions for up to 15 days and cover a range of 2,000 km on a hydrogen fuel cell, whereas our GUARDIAN AUV, specifically designed for extended deployments in more volatile environments, can last 45 days in the field, cover 5,000 km, and deploy various payload options at extended ranges. All our fuel cell powered systems are depth rated to 3,000 m, with plans to extend to full ocean depth already underway. The operational advantages that AUVs of this nature present will prove instrumental to a new era of deep-sea exploration, which in today’s world means leveraging emerging technologies to action leaner, greener ways to investigate and secure the subsea planet.
These long-range capabilities mean that operational practices can now focus on survey and environmental efficiency rather than the scheduling of launch and recovery activities every day or two. The capacity to deploy AUVs from shore and have them transit to their target survey site and back without the need for in situ surface support brings a new, game-changing dynamic to conducting remote survey campaigns.
IN-SITU PROCESSING & ADAPTIVE AUTONOMY
Over-the-horizon operations introduce new considerations to protect the asset, the data, and, in some cases, reduce potential latency challenges. Processing at the edge is essential to convert masses of raw data into actionable information. Whether that is relatively low-level bathymetric processing, or more complex object detection and classification, in-situ processing helps truncate the post-mission lag between recovery and decision making.
This new edge processing capability is also the first step required to enable adaptive outcome-based autonomy. Long-range mission success is dependent on vehicle survivability, data coverage, and quality. All these elements need to be evaluated by an introspective autonomy system that measures vehicle health and sensor performance to adapt the mission plan to ensure the outcomes are met. Working with partners, including Metron for their ANCC adaptive autonomy engine, we have implemented a backseat-driver interface on our AUVs for this very purpose. In short, building a long-range AUV is only solving part of the problem; implementing advanced processing and autonomy helps take us further.
This is a challenge that drives innovation and collaboration at Cellula Robotics, led by a team with more than 300 years of combined experience in developing and delivering complex subsea robotic solutions. We are excited about where the future of deep-sea exploration is taking us, and our industry’s rate of progress. Our AUVs and SUBSEA SENTINEL® seabed nodes are designed today to answer the long-range, persistent demands of tomorrow by using clean, green energy.
This opinion appeared in ON&T Magazine’s 2025 June Edition, Deep-Sea Exploration, to read more access the magazine here.
