Equipped with More Capability Than Ever, Today's AUVs Are Revealing the Ocean's Secrets

If I had to pick one word to describe the current state of autonomous underwater vehicle (AUV) development, I'd have to choose "flourishing." The marine robotics market has grown significantly over the past 20 years, from its infancy in the 90s through its adolescence in the 21st century. As it continues to grow and the technology improves, vital data-gathering capabilities expand and innovative new designs become possible thanks to enabling technologies that have been developed for other military, commercial, and even consumer applications.

AUVs: A History of Steady Progress

Years ago, exploration of the oceans and seafloor depended on manned submersibles. Eventually, however, those manned vessels were replaced by remotely operated vehicles (ROVs) and tethered systems towed by surface ships. By the mid-1990s, semi-autonomous platforms were, in turn, giving way to untethered, truly autonomous underwater vehicles. This shift was accelerated by increasing interest and investment from the military following the successes and acceptance of air and land-based robotics.

However, ocean engineers have had to contend with certain challenges that are ever present and often unique to the subsea marine environment. These challenges include operating without electromagnetic communications in poor visibility, at great pressures, in a changing environment, and with little or no human presence or infrastructure.

Among the hurdles engineers face with untethered systems is vehicle endurance. Like smartphones and laptops, AUVs are limited by their available energy—and while today's most sophisticated models can run for longer than ever before, they need to return to the surface so their batteries can be recharged or exchanged. Of course, endurance is also impacted by payload and overall design; developers of AUVs have grappled for years with the size and lack of energy efficiency of electronics, sensors, and other key components. New devices are now making their way into the market that are changing this landscape.

The challenges, unfortunately, do not stop with just energy. Unlike land and airborne robots that use satellites for communications and navigation, subsea systems require alternative technologies for successful deployment. Additionally, vehicle launch and recovery has its own issues in an environment where tides, currents, waves, and weather all conspire to make each mission different.

Developed by a veteran team of engineers, Hydroid's line of AUVs provide safe and reliable answers to the challenges that have hampered ocean exploration in the past.

Innovation Continues to Improve AUV capabilities

Today's state-of-the-art AUVs are rising to these challenges with innovative technologies that build on the past decades of research and reliable operations. The increasing availability of multifunctional sensors, better navigation systems, low-cost/low-power electronics, and open architecture middleware tools (such as ROS and MOOS) are enabling more capable and flexible systems that can perform operations and gather data like never before. For example, Hydroid, Inc., a subsidiary of Kongsberg Maritime and a leading manufacturer of marine robotic systems, recently announced its New Generation REMUS 100 AUV—a man portable vehicle that combines the reliability of the well-known REMUS 100 AUV with new features and capabilities. Innovative robotic vehicles like this are tackling the most difficult AUV challenges mentioned above:

  • Endurance/Energy. High-capacity battery packs allow today's most modern AUVs to carry significantly more energy than before. The New Generation REMUS 100, for instance, comes equipped with two of Hydroid's latest 18650 Li-Ion based packs. The packs have 50% more energy than the previous version.
  • Miniaturization. Advanced low-power electronics significantly reduce payload size and power consumption and are much more capable than their counterparts from just a few years ago. The New Generation REMUS 100 features cutting-edge core electronics (CE) designed to replace not only the previous motherboard, but also the CPU stack, emergency board, and six serial cards. The new CE board is smaller and lighter than the components it replaces, and it uses an ARM + FPGA architecture that makes it both potent and versatile while consuming less than 5W of power — about 25% of the power required by the earlier version.
  • Customization. More and more customers require software that is expandable with standardized interfaces. In other words, they want software that is interoperable across platforms so that it appears common among the various systems they're using. Customers also want to easily accommodate new "apps" providing capabilities such as goal-based mission planning and real-time autonomy. For example, the New Generation REMUS 100 expands on the capabilities of previous generations by adding an open architecture platform for advanced autonomy, making the vehicle more versatile. This platform is realized with a publish-subscribe database based on Robotic Operating System (ROS) middleware operating on a second processor. The new REMUS "front seat" controller performs control functions using well-tested, reliable proprietary control software. The "back seat" controller performs mission tasks, such as side-scan sonar data logging via the ROS publish-subscribe operating environment.

Loaded with advanced computing power and versatile capabilities like these, today's state-of-the-art AUVs are proving invaluable across a wide variety of commercial, military, and scientific applications.

What Does the Future Hold?

When a customer buys an AUV, they're not interested in the vehicle itself, per se. They're interested in the data the AUV can gather. An oil company may need to monitor its deep-sea infrastructure; a marine researcher is interested in studying mammal behavior; and the military is interested in AUVs for missions related to intelligence, surveillance, reconnaissance, mine countermeasures, and the like. Researchers want to gather the data needed to better understand how ocean systems impact marine and coastal ecosystems, climate, and overall global environmental health. Now that AUVs are better equipped and more capable than ever before, many predict that all of these applications are poised for tremendous growth.

For proof, look no further than the 2016 National Academies Keck Futures Initiative (NAKFI) Conference, which is devoted to Discovering the Deep Blue Sea: Research, Innovation, Social Engagement. Billed as a way to enable scientists from different disciplines to explore the frontiers of deep ocean science, this year's conference will focus on one of the least studied regions of our planet—the zone of transition between the ocean's solar energy-rich, productive euphotic zone and the energy-starved abyss. Researchers believe exploring this transition zone can lead to dramatic advances in the fields of climate change, biodiversity, aquaculture, adaptation and resilience, energy, and technology.

How will AUVs be even further refined as they continue to unlock mysteries of the ocean's "twilight zone" and complete other, increasingly complicated missions? In addition to incremental improvements to the areas outlined above, I expect to see a push toward self-learning capabilities that will make AUVs truly autonomous. Guided by perceptual robotics (machine learning) and artificial intelligence, AUVs of the not-too-distant future will be better able to comprehend their surroundings and execute non-programmed behaviors. These behaviors could even include cooperative activities, such as swarming and the transference of capabilities between AUVs. Additionally, we can expect to see vehicles that can harvest energy from the ocean using changes in temperature and pressure. They will traverse entire oceans using completely new navigation methods and power sources or remain as sentinel nodes gathering data and secreting data mules as required. Perhaps AUVs will be sleeping on the seafloor only to awake when needed or when triggered by a specific event. Some vehicles are now articulated and perhaps may evolve with reptilian behaviors to operate in multiple domains and perform interactive tasks.

Taken altogether, it's clear that this is an incredibly exciting time to be working in this field. The AUV industry is indeed "flourishing" and rich with opportunities for new approaches, collaborations, and projects.

By: Sandor Becz, Vice President of Engineering at Hydroid