Unmanned Naval Systems

VESSEL REVIEW | Royal Danish Navy acquires new autonomous minehunters

Baird Maritime

The Royal Danish Navy recently took delivery of the first three units in a series of lightweight autonomous underwater vehicles (LAUVs) built by Portuguese unmanned systems manufacturer OceanScan Marine Systems and Technology.

Each LAUV measures 2.3 metres long and 0.15 metres wide and displaces only 30 kilograms, enabling these craft to be deployed, operated, and recovered by only one person. The vessels were built as autonomous surveying tools capable of covering large areas, down to 200 metres of depth and operating for more than 10 hours with high positional accuracy. Powered by lithium-ion batteries capable of being fully charged in two hours, the craft can reach a maximum speed of five knots though the builder claims cruising at three knots will yield an endurance of eight hours.

To increase the system robustness without affecting the system performance, the fins and antenna mast are flexible. The weight of each LAUV can also be easily adjusted for freshwater and saltwater operations through the addition or removal of ballast weights from the external ballast rail.

Photo: OceanScan

These three LAUVs will be part of a larger fleet targeting mine countermeasures (MCM) applications. The LAUV units were configured specifically for this type of operation and include a dual-frequency, high-resolution side-scan sonar from Klein, an inertial navigation system from iXblue, a Doppler velocity log from Nortek, and multiple communication capabilities at surface and underwater. The state-of-the-art open architecture allows users to easily integrate new instruments, actuators, algorithms, and behaviors All payload and navigation options are integrated as independent modules that can be installed later or replaced by different modules and/or user developments.

OceanScan said an upcoming delivery to Denmark will also include an LAUV equipped with a Voyis imaging system that will be used for mine identification and bottom photogrammetry.

The LAUV operation is supported by Neptus, OceanScan's proprietary command and control software tailored for the operation of one or more vehicles. This advanced, but user-friendly, software framework covers all the different stages of the mission life cycle: configuration, planning, simulation, execution and post-mission data analysis.

A very simple operational setup including a laptop and a portable communication hub enables full operation of one or more vehicles. Also, because of their lightweight construction, the LAUVs can be deployed from shore, a pier, or a small boat without the need to use a crane or special tools.

The LAUVs also have a number of safety features including a system that informs operators of the vessels' condition and position via satellite communication or underwater acoustic modem.

Lightweight Autonomous Underwater Vehicle
SPECIFICATIONS
Type of vessel:AUV – Naval
Owner:Royal Danish Navy
Builder:OceanScan Marine Systems and Technology, Portugal
Length overall:2.3 metres
Beam:0.15 metres
Displacement:30 kilograms
Batteries:Lithium-ion
Sonar:Klein
Other electronics:iXblue inertial navigation system; Nortek velocity log