Fusion Hybrid Underwater Vehicle, United States of America
Fusion is a new hybrid underwater vehicle developed by Strategic Robotic Systems (SRS) for use in mine countermeasures (MCM), explosive ordnance disposal (EOD) and unexploded explosive ordnance (UXO) missions.
The underwater vehicle was first unveiled at the Euronaval maritime conference in October 2016. It was also on display at the 2017 Defence and Security Equipment International (DSEI) held in September 2017.
Fusion hybrid underwater vehicle design details
Designed using computational fluid dynamics (CFD), the Fusion serves as an autonomous underwater vehicle, remotely operated vehicle, and a diver navigation and propulsion vehicle. The multi-mode platform improves efficiency, while minimising training costs and capital expenditure.
The vehicle is principally made of composites to reduce magnetic signature. It also integrates stainless steel components to resist the marine environment. The robust design incorporates a suite of state-of-the-art sensors, while it maintains neutral buoyancy in fresh water.
The modern architecture of the Fusion avoids complex and excess interfaces such as interconnect cabling, connectors, and pressure vessels. The materials and systems on-board the vehicle are designed to meet the challenging underwater conditions, while a single exterior fastener further eliminates the need for an extensive tool roll.
The vehicle is 686mm-long, 477mm-wide, 275mm-high, has a depth rating of 300m, and weighs 25kg in the air. The tether cable measures 500m-long and can be optionally extended up to 2,000m.
The Fusion underwater vehicle comes fitted with a package of high-end sensors to cater to a range of missions. Each sensor on-board the vehicle is designed to enhance vehicle dynamics, while avoiding cables or connectors.
The navigation and imaging sensors suite includes a forward-looking multi-beam sonar, a side-scan sonar, a high-definition video camera, a doppler velocity log (DVL), and an ultra-short baseline (USBL) positioning system. It also has an attitude heading and reference system (AHRS), a global positioning system (GPS), a Wi-Fi data connection, and two lasers.
Its on-board imaging sensors enable the acquisition of imaging data, while the navigation sensors on the vehicle deliver positioning data. The vehicle can be added with a diver module with a large format screen, menu buttons, and thruster control to operate as a navigation and propulsion vehicle.
Operation and control of Fusion underwater vehicle
The underwater vehicle is controlled by the Xplore XSLATE D10 rugged tablet. It offers an intuitive human machine interface to operate the vehicle in full auto, stability control and manual modes. The Android-based platform enables mission planning, implementation, management, and reporting tasks.
It is commonly operated from a rigid hull inflatable boat (RHIB) and can be used to programme a mission from the field or an office through the detachable keyboard or the touch screen display.
The sunlight-readable display unit resists the harsh weather conditions on land and at sea. The built-in GPS and the Intel Core-series processor enables the operators to steer the underwater vessel and handle several mission data sets.
Propulsion and power
The vehicle is propelled by six identical brushless thrusters, including four in horizontal and two in vertical configuration. The DC motors of the thrusters are powered by two 457W/hr lithium-ion battery packs.
The propulsion system provides a forward speed of more than 4kt, lateral speed of 2.4kt and vertical speed of 2kt. It delivers a maximum bollard thrust of 16.4kgf against strong currents in all directions.
The dual battery packs supply enough power to endure water for up to four hours under typical conditions. The batteries can be easily swapped with additional sets and can be fully charged within four hours.
Packs integrate a built-in pressure release valve and an advanced battery management system (BMS). They are certified to UN38.3 standard for commercial air travel.