SBIR-STTR Award

ARMADA Marine Robotics is partnering with Woods Hole Oceanographic Institution (WHOI) to address the Navy need for external payload deployment systems for cylindrical Unmanned Underwater Vehicles (UUVs). WHOI has previously developed and demonstrated both internal and external payload deployment systems for 7.5-inch and 12.75-inch UUVs, so our proposed approach is already partially validated. They invented a patented technique that uses a vacuum force in a cavity, sized to compensate for the negative buoyancy of the payload, such that the vehicle sees no net change in buoyancy when either transporting or post-delivery of the payload. The approach also uses native acoustics on the vehicle for commanding the release of the payload as well as to check the status of the payload for status such as battery health or leak detection so that no through-hull modifications are required. This prior work significantly de-risks our proposed solution, so that our Phase I effort can focus on the main technical challenge of how an external payload deployment system will modify the hydrodynamic behavior of the host UUV and affect its controllability and maneuverability. We will design and fabricate several

Benefit:
Our approach to external payload deployment systems is flexible and scalable to a wide variety of UUV platforms. In particular, our attention to the trade space of native UUV acoustics and available acoustic solutions will ensure that this capability is not limited to one class of UUV. We have discussed our approach with multiple UUV vendors, services providers, and technology integrators and they all have responded enthusiastically with applications such as deploying markers to aid and improve in navigation, improving the range and communication bandwidth available using relays, deploying markers for objects found during a subsea search, and deploying seismic or hydroacoustic data collection pods for exploration or scientific purposes. This wide ranges of applications, coupled with our flexible and scalable technical solution, dramatically increases the dual use potential of this technology beyond strictly defense applications to the rapidly growing commercial markets of offshore energy, both oil and gas as well as wind.

Keywords:
UUV, UUV, Payload Delivery, Acoustic Communication, Appendage Drag

The Navy has identified a need for External Payload Deployment Systems (EPADS) for cylindrical Unmanned Underwater Vehicles (UUVs) between 5 and 21 inches in diameter. ARMADA Marine Robotics has assembled a team of experts to address this need with this Phase II SBIR. This effort will build upon our successful Phase I Base effort that determined an A-Size (4.875 diameter x 36 ) payload body as a suitable form factor for delivering a 5kg module. Under Phase I work we validated hydrodynamic simulations with in-water testing to quantify the effects of multiple payloads and payload configurations on vehicle endurance and controllability. In-water tests were conducted with proprietary hydrodynamic A-Size dummy payloads carried on a REMUS 600 UUV. It was confirmed that two A-Size external payloads would not decrease the UUV mission time by more than 25% and the parasitic drag of the mounting hardware would be less than 10% over the unmodified vehicle drag. EPADS is based on previous work at the Woods Hole Oceanographic Institution (WHOI) in deliverable transponders. The approach uses a payload that can be neutrally ballasted in a range of seawater densities, including freshwater, so that it has no effect on host UUV buoyancy when attached. Upon receiving an acoustic release command from the UUV, a motor opens a valve that floods a vacuum, making the payload negatively buoyant, and the payload detaches and descends to the seafloor target location. The UUV, which sees no net ballast change upon release of the payload and maintains neutral buoyancy throughout the deployment. WHOI has expressed interest in licensing and we will continue to partner with WHOI for development in Phase II. Work under the Phase II Base effort will include fabrication of the A-Size prototype designed in the Phase I Option, followed by bench, dockside, and tank validation testing. After a Critical Design Review, a revised design will be made and four units fabricated. Tank and open-water testing will be conducted to quantify deployment accuracy under, leveraging a REMUS 600 UUV as the host vehicle for the open-water tests. A Phase II Option is proposed that expands external payload deployment capabilities to other module sizes and classes of UUVs.

Benefit:
UUVs have become a workhorse for a wide variety of defense, commercial, and scientific missions. Advances in both Artificial Intelligence and Machine Learning (AI/ML) and battery capacity, driven by well-capitalized related fields such as self-driving and electric automobiles, will enable unmanned platforms to perform longer, more complex, and increasingly adaptive missions. With these advantages in place, future unmanned assets will have more potency and enable new capabilities. The capability to deploy payloads, which can deliver a wide range of effects, represents a compelling action to future Naval assets. This modular system of systems approach also helps to achieve the Navys vision of a more distributed fleet. UUVs are routinely used for detecting and classifying targets on the seafloor using sensors such as sonars, magnetometers, and cameras. Detection and classification may occur between two different missions or two different vehicles. The navigation error accumulated between the two, which can be on the order of tens of meters, increases the likelihood of missing the target and prolongs the timeline between detection and reengagement. An EPADS module delivered near a target will allow for faster reengagement of the target by providing an acoustic reference in the same navigation frame as the sensor used for detection and classification. Furthermore, EPADS will have the capacity to deliver sensors as well as communication capabilities to specific locations on the seafloor. Leveraging the UUVs ability to conduct surveys and detect targets, EPADS can be adaptively delivered to those detected target locations and will provide the capability to monitor those target locations over longer timescales than the UUV mission itself affords. EPADS can also be adaptively delivered as acoustic nodes in an undersea communications network in locations that optimize sensor performance or fill gaps in network coverage areas. EPADS is designed to be host-agnostic, carrying its own battery and interfacing with the host platform via acoustic signals. While Phase II Base testing will utilize a REMUS 600 UUV, the Phase II Option is anticipated to adapt EPADS for the Mk 18 Mod 1 Small UUV (SUUV) REMUS 300 variant form factor. Either size EPADS will be readily adaptable to the Mk 18 Mod 2 Medium UUV (MUUV) Iver variant as well.

Keywords:
Acoustic Communications, UUV, External Payloads, sensor node, Hydrodynamics, Payload Delivery, buoyancy, AUV