a marine robotics point of view for coastal … · robotics and oceanography ... embedded system...

A Marine Robotics point of view

for Coastal Oceanography

Benoît CLEMENT

Innovation & Blue Growth symposium, Qingdao, China, 28-30 October 2013 page 2

Outline

• Various robots

• Scientific issues linked to marine robotics

• Focus on VAIMOS, a sailboat robot

(collaboration Ifremer / Ensta Bretagne)

• Other fields for robotics


Robotics and Oceanography

• A robot can go where an oceanographic boat cannot

– Forbidden access as caves

– Dangerous areas as glaciers in Greenland

– Very deep

– Access to the first layer of subsurface

• A robot can be more discrete than an oceanographic

boat

– a sailboat robot or a glider has really low acoustic and thermal

signatures

– Robots can be very small

– It can be in a sleeping mode for a long time waiting for an event

Some Marine Robots


Marine robots 1/5 - ROV

• Remotely Operated Vehicle : need of an experimented

operator

• Commonly used for

– Offshore industry

– Inspection

– manipulation


Marine Robots 2/5 - AUV

• Autonomous Underwater Vehicle : Autonomous with

high level control

• Usage

– Observation

– Mine detection

– measurements


Marine Robots 3/5 - Glider

• Variable buoyancy with long term

autonomy

• Mainly used for oceanography


Marine Robots 4/5 - bio inspired

• Inspired from marine animals

– Jelly fish, snakes, fishes…

• Usage

– Game, animation

– Pure knowledge

– Also some military ideas


Marine Robots 5/5 - USV

• Autonomous Surface Vehicle

– Motorized, sailboat

– Innovation in energy

• Usage :

– Observation

– Relay with underwater

Robotics limitations


Scientific issues

Some examples

• Perception

• Localisation

• Communications

• Swarm

• Control

• …


Issue 1/5 - Perception

• Underwater perception is acoustic or visual:

– Target characterization

– Structure inspection, following

Via

– form recognition

– 3D reconstruction

Sonar issues:

• Technology to be improved

• Low precision

Vision issues:

• Turbidity

• Colors absorption, light

• Classical methods are not

efficient


Issue 2/5 - Localization

• Objectives : data geolocalisation

• Main difficulties:

– no GPS signal

– Low resolution from sonar data

– Few landmarks (except in specific areas)


Issue 3/5 - communication

• Information transfer is needed

– Between underwater robots

– With the enduser

• Difficulties

– Very low rate of flow (from few bytes/sec to kbytes/sec)

– Diffraction, attenuation, reflexions


Issue 4/5 - Swarm

• The use of multiple marine robots

– Reduce the duration of exploration

– Simultanaously geographic and temporal observations

– Cost reduction

• Difficulties

– Communication

– Planification

– Reconfiguration


Issue 5/5 - Control

• Using small robots (<30kg)

– Ratio power/wheight is high

– Increase sensibility to disturbances, to model parameters

– Coupling between motors and structure

• Need : new control approach as PID control is not

enough anymore

– Adaptive control

– Model based control

VAIMOS : an oceanographic robot


The boat : VAIMOS

• Modified Miniji : initially for

disabled people


An oceanographic mission

• Sailing robot

– No thermal signature

– No acoustic signature

– Long term mission

• Oceanographic motivation:

– First layer may present surface singularities for bio-geochemical

parameters (temperature, salinity, turbidity, chlorophyll).

– common view is a homogeneous mixed layer but it remains largely

unknown because of the lack of adequate instruments to sample

the first centimeters of the ocean

• Demonstration with sensors and pumps in the hull


Embedded system architecture

• 2 Sensors:

– a weather station : wind speed

and direction, air temperature,

atmospheric pressure, GPS

position, heading;

– IMU for reliable kinematic

parameters

• 2 actuators:

– a brushless motor for the

rudder;

– a stepping motor for the sail;

• An embedded Linux

• power supply: 2x12V

marine


The first long mission


Concluding remarks

• Robotic concepts are not limited

• Some technological issues are under investigations in

laboratories worldwide

• Other fields of interest for marine robotics


Questions

• contact :

– Benoît CLEMENT

• Email :

benoit.clement@ensta-

bretagne.fr

• Web : http://www.ensta-

bretagne.fr/clement/

mailto:[email protected]



http://www.ensta-bretagne.fr/clement/



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