Hybrid Underwater Vehicles Optimized for Expeditionary Missions

Expeditionary maritime operations remain a critical aspect of naval operations across the globe. The dynamic geo-political landscape, coupled with the pace of technological advancement, and a growing set of budgetary challenges are driving naval leaders to develop novel concepts of operations to tackle increasingly complex undersea operations with fewer resources.

This austere environment is precisely where the full value proposition of the FUSIONTM Hybrid Underwater Vehicle, developed by Strategic Robotic Systems, Inc., comes to life.

Founded in 2015, Strategic Robotic Systems set out to develop a compact, tightly integrated multi-mode undersea robot with a highly intuitive user interface that is optimized for expeditionary missions. The company delivered on that vision through the introduction of its FUSION platform in 2017, seamlessly integrating a high-resolution camera, lights, forward looking sonar, side scan sonar, Doppler Velocity Log, Ultra-Short Base Line (USBL) navigation pinger with integrated acoustic communications, GPS receiver, and an attitude and heading reference system—along with all the necessary electronics and onboard energy storage—into an underwater robot that weighs less than 28 kgs, or 62 lbs.

In addition to its single-person deployable weight profile, the team behind FUSION minimized the system’s deployment footprint to align with expeditionary requirements; eliminating the need for a topside power generator, employing a compact tether management system (TMS), and developing a tablet based human machine interface (HMI).

Today, the FUSION system can be deployed in three primary modes of operation—via a small (< 3mm diameter) fiber or copper tether to conduct undersea inspection and intervention tasks in Remotely Operated Vehicle (ROV) Mode, without a tether to conduct seabed surveys or gather intelligence, surveillance, and reconnaissance (ISR) data in Autonomous Underwater Vehicle (AUV) Mode, or in support of military dive operations by simultaneously providing a diver subsea navigation capabilities as well as augmented propulsion for increased range efficiency in Diver Mode.

ROV MODE

Designing a battery powered ROV system was foundational to ensuring the tactical utility of the system for expeditionary missions, however the design team at Strategic Robotic Systems also recognized the need to significantly reduce the cognitive burden levied on an operator under stress.

The team set out to develop an intuitive HMI and delivered a real-time vehicle control paradigm that is highly augmented by automation. Unlike traditional ROV systems, FUSION flight control algorithms are incorporated in every vehicle, allowing users to simply command a desired motion and supervise as the machine executes the task. Strategic Robotic Systems continues to pursue advancements in autonomy-augmented supervisory control to extend beyond traditional vehicle and manipulator controls in partnership with Reach Robotics based in Sydney, Australia.

AUV MODE

With all the necessary sensors for autonomous operation already incorporated into the vehicle to enable the ROV control paradigm described earlier, the team at Strategic Robotic Systems went on to further refine the autonomy algorithms, mission planning and post-mission analysis capabilities of the FUSION system to ultimately enable the robot to conduct fully autonomous, tether-less operations—all managed from the same intuitive HMI.

In this mode, the integrated USBL is leveraged to limit any navigational drift in the system and the acoustic communication capabilities are leveraged to provide in-stride mission adjustment, command ROV-like behaviors such as orbiting around a target of interest, or even drop a payload. FUSION systems outfitted with a payload delivery system (PDS), incorporated into the under-belly of the vehicle, can be programmed to drop a payload at pre-determined positions, or acoustically triggered to release by a human supervisor. Undersea autonomy is an area of increasing interest for Strategic Robotic Systems, and the company continues to develop new behaviors to meet emerging mission needs in collaboration with its customers and industry partners.

DIVER MODE

The FUSION system is transformed into its Diver Mode with the addition of a diver interface module (DIM) which is affixed directly onto the vehicle, as depicted on the cover of this issue of Ocean News & Technology. The DIM allows the diver to control the vehicle in real time and visualize the live stream sonar, camera, position, navigation, and status information on a large format screen.

Utilizing the DIM, an operator can use the vehicle to navigate underwater and gain efficiency in swim range by using the vehicle’s integrated thrusters. In addition to topside communications, the DIM also allows other users of the FUSION in Diver Mode that are within acoustic range to exchange text messages with each other to enable coordinated undersea action. The FUSION battery management system is designed to enable hot-swap of batteries while underway, providing divers the ability to extend the range and duration of their missions.

INDUSTRY COLLABORATION

This unique combination of capabilities in a single vehicle allows expeditionary teams the flexibility they need to adjust to operational needs in real time while reducing the number of assets they must carry into a theater of operations. Today, the FUSION platform is employed globally with a broad range of defense forces including the US Department of Defense, US Homeland Security, and numerous allied nations; yet the team at Strategic Robotic Systems continues to push the art of the possible in expeditionary undersea robotics.

Strategic Robotic Systems has been working with its strategic collaborators, Blueprint Subsea of the UK and SUEX of Italy, to enable an undersea “system of systems” concept wherein the FUSION extends the reach of tactical dive operations by enabling deployment and control of the FUSION system by a diver while remaining submerged.

In this new concept of operations, an ArtemisELITE system comprised of a long-range SUEX diver propulsion vehicle (DPV) fitted with a Blueprint Subsea Artemis Diver Navigation System is employed for transit into an area of operation. The FUSION is then deployed, either in AUV or ROV Mode, by the dive team to ingress further into harm’s way to conduct operations, allowing the warfighter to maintain their stealth and stand-off distance. The ArtemisELITE and the FUSION are designed to seamlessly communicate with one another, sharing position, mission, and status information, in addition to acoustic messaging, command, and control functionality.

For more information, visit: www.srsfusion.com.

This story was originally featured in ON&T April 2023. Click here to read more.