MRU Marine

The MRU Marine is a robust and waterproof motion reference unit designed specifically for marine applications, with flexible communication options and the option to include a magnetometer.

MRU Marine

Product overview

The MRU Marine is built to withstand harsh conditions, offering robust performance even in extreme weather and sea conditions. Equipped with state-of-the-art sensor fusion algorithms and advanced technology, it delivers accurate roll, pitch, and heave measurements, enabling operators to optimise vessel performance, enhance safety, and ensure the integrity of marine operations.

The versatility and durability of the Norwegian Subsea MRU Marine make it an invaluable tool for a wide range of applications, including offshore wind farms, subsea operations, marine research, and vessel performance analysis.

picture of our MRU Marine with degrees of freedom illustrated

High Accuracy

High accuracy roll, pitch and heave, even in irregular sea states.

Easy interface

Ethernet, serial ports and free software upgrades. Wide range of industry standard protocols. Custom NMEA and Binary protocol generator included in configuration software.

Robust and Waterproof

Robust and compact waterproof aluminum housing. The MRU Marine SW can even be used outdoors in the splash zone or in up to 50 m water depth.

Specifications

Download product brochure

Casing

Environment

Marine: IP68
Marine SW: 50 m water depth
Marine SW16: 50 m water depth

Casing material

Marine Anodized Aluminum 6061-T6

Dimensions

154 x 86 x 67 mm

Weight

1.2 kg

Interfacing

Connector

Marine: Lemo 16 pins
Marine SW: SubConn 8 pins
Marine SW16: SubConn 16 pins

Ports

Marine: Ethernet, RS-232, RS-485 (422), PPS
Marine SW: Ethernet & RS-232, Ethernet & 2-wire RS-485
Marine SW16: Ethernet, RS-232, RS-485 (422), PPS

Communication

Marine: TCP, UDP, Modbus TCP, ethernet/IP, Serial, Modbus RTU
Marine SW: TCP, UDP, Modbus TCP, ethernet/IP
Marine SW16: TCP, UDP, Modbus TCP, ethernet/IP, Serial, Modbus RTU

Output frequency

0-100 Hz

Performance

Roll & Pitch

3000 series: 0.05°
6000 series: 0.02°
9000 series: 0.01°
RMS (dynamic & static)

Heave (real-time)

5.0 cm or 5.0 %
Whichever is greater for 0 to 25 s periods, valid for irregular motions in real sea conditions

Heading (optional)

± 0.5 °
Magnetic heading

Range

Rotation speed

3000 series: ± 150 °/s
6000 series: ± 450 °/s
9000 series: ± 450 °/s

Acceleration

± 3 g (3000 series) / ± 4 g (6000 series) / ± 10 g (9000 series)

Heave

± 50 m

Roll / Pitch / Yaw

± 180 ° / ± 90 ° / ± 360 °
(no limits)

Output frequency

0 - 100 Hz
(adjustable output frequencies)

Gyro output

Scale factor error

0.2 % max/min

Angular rate noise

3000 series: 0.050 °/s RMS
6000 series: 0.025 °/s RMS
9000 series: 0.015 °/s RMS

Acceleration output

Acceleration noise

3000 series: 0.0025 m/s2 RMS
6000 series: 0.0020 m/s2 RMS
9000 series: 0.0015 m/s2 RMS

Acceleration accuracy

0.01 m/s2 RMS

Power & interface

Power consumption

6 W

Supply voltage

9 - 36 V DC (24 V nominal)

Internal storage

32 GB

Data protocols

Custom NMEA, ASCII and Binary, Atlas, Gyrocompas 1, Ifremer Victor, MDL, NORSUB 1-8, Simrad EM 3000, SMCA, SMCC, Tokimek PTVG, RDI ADCP, TSS1 and many more.
Read more

Configuration protocols

GET/SET through telnet, serial port and MRU configurator.
Read more

Time synchronization

Sync to host PC, Sync to NTP server, Sync to PPS

Features

PPS

PPS time synchronization

Aiding

Heading and velocity aiding
(on request)

Environmental specifications

Temperature range

Operating: -40 to +85 °C
Storage: -40 to +85 °C

Electromagnetic compatibility

IEC 60945/EN 60945
(immunity/emission)

Vibration

IEC 60945/EN 60945

Max shock

2000 m/s2 (half-sine 0.5 msec)
non-operational (10 ms peak)

MTBF (computed)

100 000 h

Easy to use

All Norwegian Subsea Motion Reference Units (MRUs) can be easily configured using the MRU Configurator (free of charge).

Simply define the communication ports and protocols as well as the MRU mounting orientation and location, and you are ready to go.

The MRU Configurator is also a great tool to monitor the outputs in real-time, plot the variables, check the on-board diagnostics and update the MRU firmware.

Read more about the MRU Configurator

Ultra-low-noise accelerometer

The ACC MARINE is a robust and waterproof Ultra-low-noise Accelerometer designed specifically for marine applications.

Featuring state-of-the-art MEMS technology 3-axis accelerometers, the ACC Marine is high performance, ultra-low noise, and affordable. Exceptional low noise density, velocity random walk (VRW) and bias instability make this accelerometer ideal for demanding vibration monitoring applications.

Read more about the ACC Marine

Some of the applications where our MRU Marine are used

Sonar Motion Compensation

Accurate measurements of roll, pitch, and heave are crucial for achieving optimal results when compensating sonar systems for vessel motion, without relying on GNSS or RTK.

Active Heave Compensation

Accurate measurement of vertical motion at the crane tip or winch is crucial for the operation of Active Heave Compensated (AHC) cranes and winches.

Dynamic Positioning

Dynamic positioning (DP) of vessels necessitates roll and pitch compensation of the GNSS antenna to ensure accurate positioning of the ship's control point.

Ship Motion Monitoring

Precise motion measurements are essential for vessel digitalisation, supporting fuel optimisation, route planning, cargo safety and structural health.

Helideck Monitoring

Accurate measurement of roll, pitch, and heave motions is crucial for assessing the safety of helidecks during helicopter landing and take-off operations.