AUVx

A miniaturized autonomous underwater vehicle


AUVx
The AUVx shortly after an experiment (Photo: Annemarie Popp, DFKI GmbH

Technical Details

Size: 393 x 188 x 200 mm³
Weight: 2.120g
Power supply: 9 NiMH Eneloop rechargeable batteries; 11,2 V / 2,3 Ah
Speed: 0.5m/s
Actuation/ Engine:
3 in-house developed thrusters, each turnable by +/- 180°. Thrust is generated by Maxon DC motors with integrated gears and encoders. Noteworthy is the magnetic coupling which prohibits water running into the motor housing.
Sensors:
IMU: Analog Devices ADXL345 acceleration sensor, Honeywell HMC5883L magnetometer, Invensense ITG3200 gyroscope
Drucksensor: Freescale MPX5100DP, Sensitivität 45 mV/kPa, Messbereich von 0 bis 100 kPa (4,5 mV/cm)
Kamera: 8 MP Pi camera
Embedded motor encoder to determine angular speed
Communication:
Optical communication modem or copper wire cable.
Computational Power:
Custom FPGA Board, DAEDALUS BaseBoard with STM32 and Raspberry Pi Zero
Maximum diving depth:
10m

Organisational Details

Partner: Fraunhofer IIS
Sponsor: Federal Ministry of Economics and Technology
German Aerospace Center e.V.
Grant number: The project DAEDALUS is funded by the German Space Agency (DLR Agentur) with federal funds of the Federal Ministry of Economics and Technology in accordance with the parliamentary resolution of the German Parliament, grant no. 50NA1312 (DFKI).
Team: Team II - Hardware Architectures
Application Field: Underwater Robotics
Space Robotics
Related Projects: DAEDALUS
Architectures and sensor data processing for energy-efficient control of self-powered tracking systems (08.2013- 01.2017)
EurEx
Europa-Explorer (12.2012- 04.2016)
Related Robots: µAUV
µAUV²

System description

The AUVx without pressure hull (Photo: Annemarie Popp, DFKI GmbH)
The underwater vehicle AUVx before an experiment (Photo: Annemarie Popp, DFKI GmbH)

The autonomous underwater vehicle AUVX is designed as a miniaturized exploration and research vehicle. Its shape is particularly adapted to the requirements of the EurEx project: with its small diameter it fits into the underwater vehicle Leng. In the EurEx context, the AUVX must be able to locate the μGliders, which act as reference points, and subsequently return to the starting point. Furthermore it is supposed to do near field exploration. Therefore the vehicle is equipped with a variety of different sensors. In addition, a camera allows to use image recognition algorithms under water. These properties make the system perfectly fit for its tasks in the EurEx mission scenario. Furthermore, in the project DAEDALUS the AUVX serves as a demonstrator for using the DAEDALUS specific trackingtag in a robotic context. To maintain a high degree of energy efficiency while doing underwater locomotion, the hull was hydro-dynamically optimized. Another unique feature are the magnetically coupled thrusters which ensure that the electronics inside the thrusters is hermetically protected against the surrounding water. The AUVX can also be operated remotely as a hybrid ROV (Remotely Operated Vehicle) with an optical communication or copper wire cable.

Navigation is based on fusing data coming from the IMU, a mathematical model of the system and a tag detection which was implemented on the Raspberry Pi Zero using both OpenCV and ROS.

Videos

DAEDALUS: Das AUVx im Missionsszenario von EurEx

In dieser Videoanimation wird die Aufgabe des AUVX im EurEx Missionszenario dargestellt: Nachdem der Eisbohrer durch den Eispanzer des Jupitermondes Europa geschmolzen ist werden mehrere µGlider freigesetzt. Das AUVX beginnt nun die Positionen der µGlider zu bestimmen und die ermittelten Positionen an das autonome Forschungsfahrzeug Leng zu übermitteln.

DAEDALUS: AUVx während eines Experiments am DFKI RIC

In diesem Video ist das AUVX im großen Becken des DFKI RIC zu sehen. Während seiner Fahrt durch das Wasser steuert das Fahrzeug selbständig Wegpunkte an die mit AprilTags markiert sind. Durch eine Fusionierung der Inertialsensorikdaten mit einem Modell des Fahrzeugs und den Daten aus der Bilderkennung ist das Fahrzeug dazu in der Lage, die komplette Mission autonom zu durchlaufen.

 

Fotogallery

µAUV² (left) and AUVx (right) side by side
µAUV² (left) and AUVx (right) side by side (Photo: Annemarie Popp, DFKI GmbH)
AUVx side view
AUVx side view (Photo: Annemarie Popp, DFKI GmbH)
AUVx after an experiment
AUVx after an experiment (Photo: Annemarie Popp, DFKI GmbH)
µAUVI (left), µAUV² (centre) und dem AUVx (right) side by side
µAUVI (left), µAUV² (centre) und dem AUVx (right) side by side (Photo: Annemarie Popp, DFKI GmbH)
AUVx during an experiment
AUVx during an experiment (Photo: Annemarie Popp, DFKI GmbH)
Results of two dimensional CFD-simulations of the main body of µAUV² at a cruise speed of 0.5m/s. Flow velocity fields with white streamlines for vortex visualization are depicted. Colour indication: Red: High velocity magnitude; Blue: Low velocity
Results of two dimensional CFD-simulations of the main body of µAUV² at a cruise speed of 0.5m/s. Flow velocity fields with white streamlines for vortex visualization are depicted. Colour indication: Red: High velocity magnitude; Blue: Low velocity magnitude. (Photo: Aljoscha Nicolai Sander, DFKI GmbH)
Results of two dimensional CFD-simulations of the main body of AUVx at a cruise speed of 0.5m/s). Flow velocity fields with white streamlines for vortex visualization are depicted. Colour indication: Red: High velocity magnitude; Blue: Low velocity magnitude
Results of two dimensional CFD-simulations of the main body of AUVx at a cruise speed of 0.5m/s). Flow velocity fields with white streamlines for vortex visualization are depicted. Colour indication: Red: High velocity magnitude; Blue: Low velocity magnitude. (Photo: Aljoscha Nicolai Sander, DFKI GmbH)
Results of three-dimensional CFD-simulations without thrusters of µAUV² at a cruise speed of 0.5m/s. Q-Criterion (iso-surface for Q=50) for visualization of vortical structures and grey streamlines for visualization of the wake velocity field. Colour indication: Red: High pressure; Blue: Low pressure.
Results of three-dimensional CFD-simulations without thrusters of µAUV² at a cruise speed of 0.5m/s. Q-Criterion (iso-surface for Q=50) for visualization of vortical structures and grey streamlines for visualization of the wake velocity field. Colour indication: Red: High pressure; Blue: Low pressure. (Photo: Aljoscha Nicolai Sander, DFKI GmbH)
Results of three-dimensional CFD-simulations without thrusters of AUVx without battery module cladding at a cruise speed of 0.5m/s. Q-Criterion (iso-surface for Q=50) for visualization of vortical structures and grey streamlines for visualization of the wake velocity field. Colour indication: Red: High pressure; Blue: Low pressure.
Results of three-dimensional CFD-simulations without thrusters of AUVx without battery module cladding at a cruise speed of 0.5m/s. Q-Criterion (iso-surface for Q=50) for visualization of vortical structures and grey streamlines for visualization of the wake velocity field. Colour indication: Red: High pressure; Blue: Low pressure. (Photo: Aljoscha Nicolai Sander, DFKI GmbH)
Results of three-dimensional CFD-simulations without thrusters of AUVx with battery module cladding at a cruise speed of 0.5m/s. Q-Criterion (iso-surface for Q=50) for visualization of vortical structures and grey streamlines for visualization of the wake velocity field. The use of the battery module cladding drastically reduces vortex shedding and lowers the divergence of the streamlines in the wake of AUVX. Colour indication: Red: High pressure; Blue: Low pressure.
Results of three-dimensional CFD-simulations without thrusters of AUVx with battery module cladding at a cruise speed of 0.5m/s. Q-Criterion (iso-surface for Q=50) for visualization of vortical structures and grey streamlines for visualization of the wake velocity field. The use of the battery module cladding drastically reduces vortex shedding and lowers the divergence of the streamlines in the wake of AUVX. Colour indication: Red: High pressure; Blue: Low pressure. (Photo: Aljoscha Nicolai Sander, DFKI GmbH)
Motor housing with motor, magnetic coupling, duct and propellor (Image: Philipp Kloss, DFKI GmbH)
Motor housing with motor, magnetic coupling, duct and propellor (Image: Philipp Kloss, DFKI GmbH)
 
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last updated 05.10.2017
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