“This simplifies everything” – The First Infinite Endurance Profiling Instrument Designed Specifically for USVs

Uncrewed Surface Vessels (USVs) are rapidly transforming the oceanographic industry: it is now indisputable that uncrewed survey is more efficient and cost effective than traditional crewed survey, and with ever greater endurance, the efficiency gains increase accordingly. Unfortunately, these advances have not been matched by paralleled growth in automated profiling capabilities. While USVs challenge conventional crewed survey vessels in many ways, they still rely on the frequent collection of accurate data profiles. In short, these revolutionary, powerful platforms are held back by their weakest link.

Profiling capability is limited by finite battery life and the fragility of mechanical connectors, forcing operators to compromise on deployment duration or the number of casts. Right?

Wrong. Introducing the Endura-3 and the Endura-6, the first connector-free, wirelessly charging instruments on the market. Designed specifically for USV deployments, the Endura Loggers unlock the potential to do unlimited casts for every parameter of interest. Did we mention we have the widest array of end-cap sensors on the market? Whether your mission is hydrographic, environmental, or scientific, the Endura Loggers enable unlimited profiling from your USV platform.

The Endura’s extended deployment capability is a direct result of its wireless charging. Wireless charging is simple enough in controlled conditions, but recharging in a harsh, uncontrolled environment is difficult. Doing it reliably is even harder.

External connectors may be considered the Achilles heel of any oceanographic instrument design, particularly when considering uncrewed platforms. They increase the probability of required human maintenance or intervention. So… we got rid of them. By removing the need for connectors (there is a USB connector on the instrument for convenience in the workshop) we also eliminate cabling from the profiling solution. By far, connectors and cabling are the most common cause of complication, wear, and tear.

Origin Story of the Endura Loggers

So why hasn’t this been done before? Well, it has… sort of. While the industry has seen earlier designs that demonstrated the potential for autonomous water column profiling, they ultimately fell short of meeting the rigorous demands of extreme environments. For years, the market relied on electromechanical cables – complex, expensive systems that require constant maintenance. We knew there had to be a better way.

In 2019, Saildrone approached AML with the need to conduct a hydrographic profile on their long-endurance uncrewed sailing surface vehicle. At the time, we developed an AML-6 wireless charging solution using technology based on modern Qi-compatible devices like smartphones. Saildrone included this solution into their Voyager and Surveyor bathymetry platforms, proving the first truly independent long endurance USV-based hydrographic survey. While it functionally met the requirement for wireless charging, the first generation of this solution had its limitations.

The primary limitation of the first-generation Qi charging system was the alignment requirements. The system worked well within its tightly prescribed operating window but required precise axial and radial alignment. Achieving this level of precision in a challenging environment was almost impossible.

The second-generation systems – Endura-3 and Endura-6 – simplify this requirement in two ways. The first is an increased axial tolerance for charging. The second-generation system has five times the range of the first, making it very compliant to harsh conditions. Further, the second-generation systems have no radial alignment requirement. The cylindrical form factor ensures alignment is a one-dimensional exercise. Systems can be aligned with any winch that provides rough alignment by winching to the set point or integrated into a hard stop to ensure alignment.

Additionally, the second-generation systems bring state indication to the USV toolset. Along with the LED indicator on the front panel (useful for humans in the workshop), a GPIO pin pattern (useful for the robot at sea) can be used to evaluate the operating state of the system. The state of the charger can be determined using three of the six pins on the charger; multiple error conditions can be diagnosed remotely.

Overall, the primary focus on this development was to deliver a charging system that provides reliable, robust performance in challenging uncrewed environments. The Endura Loggers were designed to “set and forget”.

The Endura-3 and Endura-6 development project has been meticulously and rigorously engineered. Extensive in-house bench testing, combined with thousands of hours of deployments – including extended deployments with Saildrone and SeaTrac’s remote platforms – has demonstrated its reliability under the most demanding conditions.

The Endura Loggers have transformed operations for early adopters, setting the industry standard for remote data collection.

With more than 50 years of experience manufacturing oceanographic data loggers, sondes, and probes, it’s our job to adapt to the evolving needs in our industry. Embrace change, or get left behind! With USVs becoming the go-to technology for more and more commercial organizations, reliability becomes more important than ever.