Underwater Vehicles: The Rise of Dolphin-Inspired Technologies

Unmanned vehicles seem to be everywhere, including under the most contested waters around the world. These new technologies occupy a space from the deep sea to the surface.

Diverse environments on a long water column must be explored prior to sending these drones.

“You start putting a permanent resident [vehicle] together with roaming, and you end up with the persistent capability to monitor the pattern of life across the maritime domain,” said Philipp Stratmann, CEO of Ocean Power Technologies.

This data is then fed to an artificial intelligence (AI) model to improve the performance of reconnaissance vehicles. The natural inhabitants in the environment are not contacts of interest for warfighters. Therefore, they are noise to be separated from signal.

Machine learning and artificial intelligence are key elements to achieving this goal. Sound anomalies are crucial for underwater intelligence, surveillance and reconnaissance (ISR), and according to Stratmann, contact management allows operators to follow the anomalies beyond the regular activities of local biology.

When employing unmanned undersea vehicles (UUVs), there are missions better suited for unsupervised devices.

“Seafloor surveys, mine detection, and passive undersea cable monitoring for ships can all occur largely independent of human supervision,” according to a report by CIMSEC authored by Lt. Cmdr. James Landreth, USN, and Lt. Andrew Pfau, USN.

Nevertheless, in line with developments in the air, undersea warfare is evolving toward teaming manned and unmanned vehicles.

Unlike drone swarms in the skies, water poses increased difficulties.

“Due to the rapid attenuation of light and electronic signals in the undersea domain, data exchange between platforms occurs at relatively low speeds over comparatively limited distances unless connected by wire,” according to Cmdr. Landreth and Lt. Pfau.

In marine environments, electromagnetic waves do not propagate. This means that sound waves are the most effective means of communication. Nevertheless, tones take about 2 seconds to travel back and forth over a mile. Complex exchanges could take too long, rendering these vehicles operationally unusable.

Therefore, one of the consequences is that vehicles cannot maintain a continuous connection with the rest of the force.

Still, if messages need to be transmitted, technologies with decreased transfer rates could get the job done.

First, all the potential interferences, like noise, need to be factored in; this is done by employing a specific AI.

Once potential interference factoring is achieved, scientists conduct innovative research based on natural intelligence—specifically, natural dolphin intelligence—using a device called the ultra-short baseline (USBL). This system “is a type of acoustic reading that acquires positioning, acting as an extension to a computer modem. It contains a transceiver, which is usually mounted on a pole under a ship,” according to Oleksiy Kebkal of the Schmidt Ocean Institute.

The underwater drone establishes an acoustic data link with the surface vessel described in the example above. Part of the information is the location of the vehicle, as well as readable text.

Kebkal also plans swarms of unmanned vehicles that will link among themselves to improve performance.

Nevertheless, swarms pose new problems as coordination faces novel challenges in such an adverse environment.

The main task is understanding where each device is and how the medium works.

“In recent years, deep learning and reinforcement learning have been widely used in environmental perception, which are applied to the decision-making control of underwater robots by learning experience from rewards after decision-making,” a research team led by Wenyu Cai, professor at Hangzhou Dianzi University in China, concluded in a paper.

The technologies employed are group reinforcement learning models-based and cooperative positioning technology. The data acquired by each swarm member demands underwater communication, like the one mentioned above, to be effective.

Developments like these are beneficial not only to military technologies but also to civilian fields like marine environmental monitoring, underwater resource exploration, hull inspection and fishing.

The Navy and Congress have been at odds over funding unmanned programs to increase underwater capabilities.

The technological challenges of the programs have brought a new consensus, and there seems to be a way forward that resembles the additive research academics conduct.

“What we’re hearing now is a different strategy from the Navy that is focused, not so much on programs of record, but instead focusing on the various enabling technologies to build these programs,” said Michael Robbins, spokesman for the Association for Uncrewed Vehicle Systems International, before Congress.

This comes after the Government Accountability Office (GAO) found that various initiatives were over budget.

The Orca Extra-Large Unmanned Undersea Vehicle (XLUUV) was found to be “$242 million, or 64 percent, over its original 2016 cost estimate,” according to a June 2023 GAO report. The same report details that this program is expected to be three years behind schedule.

Still, the mission for these vehicles is laying mines, a dangerous task better served by assets that keep sailors in a safe environment.

According to a GAO assessment, the contractor supplying the five XLUUVs contracted did not undergo an appropriate production readiness review by the Department of Defense. This meant that the company was unable to deliver the capability required within the contracted schedule and cost.