auvs: current trends and open challengesdee10008/papers/201306_talk_kth_jmelo.pdf · –700...

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AUVs: Current trends and open challenges

José Melo Aníbal Matos, Bruno Ferreira, Nuno Abreu, Nuno Cruz, Rui Almeida Robotics and Intelligent Systems, INESC TEC Faculty of Engineering, University of Porto KTH| June 2013

KTH, June 2013 AUVs: Current trends and open challenges 2

Outline

• INESC TEC

• Robotics and Intelligent Systems @ INESC TEC

• Marine Robotics

• Ocean Systems Group: overview

• Projects

• Research

• Conclusion


INESC TEC: facts & figures

• R&D Institute working as an interface between academics and industry – ECE related areas

• Associate Laboratory since 2002, aggregates research groups from different higher education institutes – 700 researchers (~230 PhDs)


INESC TEC: facts & figures

• Associate Laboratory since 2002 – USE – Power Systems Unit

– UTM – Telecommunications and Multimedia Unit

– UOSE – Optoelectronics and Electronic Systems Unit

– UESP – Manufacturing Systems Engineering Unit

– USIG – Information and Computer Graphic Systems Unit

– ROBIS – Robotics and Intelligent Systems Unit

– UITT – Innovation and Technology Transfer Unit

– BRAIN - Biomedical Research and Innovation

– LIAAD – Laboratory of Artificial Intelligence and Decision Support

– CRACS – Center for Research in Advanced Computing Systems

– UGEI– Unit of Industrial Management and Engineering

– CISTER - Research Centre in Real-Time and Embedded Computing Systems

– HASLab – High-Assurance Software Laboratory


Robotics @ INESC TEC

• Team – 20 senior researchers, 25 PhD students, 2 tecnicians

– Students: ~15 graduate and ~12 undergraduate per year

• Budget > 1.5M€/year – National and European funded programs

– International contracts

• Facilities – Laboratories spanning > 1000 m2

– 2 test tanks

– Electronic and mechanical shops



• Design and implementation of innovative solutions within the areas of land and water robotics, industrial robotics and intelligent systems.

• Fields of actuation – Security and Defense

– Environmental Monitoring and Mapping

– Search and Rescue

– Industrial and Service Robotics

– Process Automation


Marine Robotics

• Why aquatic environments? – Large area: about 70% of the Earth surface

– amount of natural resources: oil, hydrocarbons, minerals…

– Important facilities: harbours, hydropower plants, …

• Increasing demand for efficient and effective technologies for underwater exploration and exploitation

• But underwater environments are highly hazardous – Pressure increases 1 atm / 10 meter

– salt water is highly corrosive

– Attenuation of electromagnetic waves

– Poor visibility conditions


Marine Robotics

• AUVs:

Dimensions

(m) Weight

(Kg) Autonomy

(h) Range (km)

Large-size 5 – 7 >1000 20 - days 100s

Medium-size

4 – 6 200-500 24 60

Small-size < 3 < 100 10 60


Ocean Systems Group

• Highly motivated researchers, with over 15 years of experience – design, development and operation of robotic systems.

• Advanced systems for the automatic collection and processing of data in aquatic environments – AUVs, ASVs, ROVs or Gliders

– Increasing number of applications: monitoring, military, search and rescue, among others.

• Current research thrusts: – navigation and guidance

– control

– planning

– real time adaptive sampling with autonomous vehicles.


Ocean Systems Group


Ocean Systems Group - Vehicles

• MARES AUV – Small-sized AUV for shallow waters

– operational since 2007

– Modular

– Low-cost

• Typical operations: – Environmental monitoring

– Bathymetry

– Inspection



• MARES AUV: main specs – Highly-maneuverable

– Thrusters-only actuation (no fins!)

– Ability to hover and navigate at very low speeds

– 4DOF Independent controllers (surge, heave, pitch, yaw)

– Reconfigurable payload

– Radio and WiFi communications

– GPS



• Zarco / Gama ASVs – small size (1.5 m long) catamaran type vessel, designed to operate in

quiet waters

– COST components

– Precise DGPS RTK positioning

• Customizable Payload

• Typical Operations – Bathymetry

– Environmental Monitoring

– Can be used as acoustic beacon



• Slocum Glider – Teledyne Webb Research – Gliders use small changes in its buoyancy in conjunction with wings and

control surfaces to convert vertical velocity into forward velocity

– Long autonomy (months)

– Requires very careful trimming process

– Vehicle operates in vertical sawtooth trajectory



• Slocum Glider

Wet Zone Wet Zone Dry Zone

Nose Fore Hull

-Displacement Pump - Emergency

Batteries - Foward Ballast Weights

-Displacement Piston & Diaphragm

- Altimeter

-Science Persistor - Sensors Mounts

-Flight Persistor - Iridium Modem - Freewave radio

- ARGOS - GPS - Main Batteries - Power Distibuction - Aft Ballast Weights

Flight Bay

-Pitch Batteries

Aft End Cap

- Air Bladder - Antennas -Power Plug

- Ejection Weight - DigiFin

Science Bay


Projects: WWECO (2008 – 2011)

• Environmental Assessment and Modeling of Wastewater Discharges using Autonomous Underwater Vehicles Bio-optical Observations

• Adaptive sampling approach for the AUV based on the optical data collected in real time – environmental impact assessment

– detailed maps of effluent dispersion and spatial distribution of resuspended sediments and corrected estimates of plume dilution,

– accurate data for evaluating plume models.

• Automatic mission planning system – Several in-situ data collection campaigns


Projects: LAJEADO (2010 – 2013)

• Automatic robotic system for underwater inspection and basin mapping and monitoring – Funded by CEB Lajeado (Tocantins)

– UFJF, INESC TEC

• Requirements: – Visual inspection of underwater structures

– Mapping of bottom the dam reservoir

– Environmental monitoring

• Why? – More reliable data, cost reduction

– Mitigation of environmental impact


Projects: LAJEADO

• Why and hybrid AUV/ROV? – ROV for inspection

– AUV / ASV for covering large area of the reservoir

• TriMARES characteristics – Optical fiber tether for real-time data

– Can hover in the water column

– Hydrodynamic efficient


Projects: LAJEADO

• TriMARES AUV specs: – Modular and reconfigurable

– AUV + ROV operation

– 5DOF (surge+sway+heave+pitch+yaw)

– Max depth: 100

– Max speed: 3 knots

– Up to 10hrs autonomy

– 1.3m long, 75kgs

– Payload

– Video camera

– Multibeam sonar

– (CTD, turbidity, …)


Projects: ICARUS (2012 – 2014)

• Integrated Components for Assisted Rescue and Unmanned Search Operations – Motivated by some recent disasters (earthquakes, tsunamis, etc…)

• Aims to develop robotic tools which can assist human crisis intervention teams.

• 24 partners! – Research Institutes

– SMEs

– Industry


Projects: ICARUS

• Development of cooperative Unmanned Surface Vehicle (USV) tools for unmanned SAR – Target detection and tracking.

– Mission planning and control (multiple vehicles)

– Capsule deployment system (life-rafts)

– INESC, Calzoni, CMRE, CINAV

• Collaboration between heterogeneous robotic SAR devices

• Integration of Unmanned SAR tools in the C4I systems of the Human Search And Rescue forces

• Development of a training and support system of the developed Unmanned SAR for the human SAR teams


Projects: COGNAT (2012 – 2014)

• Cooperative Glider Navigation and Acoustic Tomography – INESC, CINTAL

• Assess unknown environmental properties and predict the acoustic field in the area of the glider navigation, from hours to days

• Using the tomography data to improve the positioning accuracy of the glider.


Projects: other

• Increased autonomy for AUVs - Mission Planning and Obstacle Avoidance – Funding from EDA

– INESC, EDA, FFI, Saab underwater, AB, BWB, WASS

• Using AUVs in mine countermeasure operations – AUV mission (re)planning according to the vehicle and sensor

characteristics


On-going PhD thesis research:

• Bruno Ferreira – coordinated control of multiple vehicles

• Nuno Abreu: – Mission planning and re-planning under constraints

• José Melo – Guidance of AUVs according to natural features

– Terrain Based Navigation for AUVs


Cooperative navigation aid robotics

• Current (static) underwater localization solutions are of limited use – INS/DVL: unbounded error

– LBL based: bounded operation area

• Navigation aid robots has become a valid solution – Two types of robots:

• Exploration/survey robots: move freely in the space

• Navigation aid robots (NAR): provide meaningful measurements to exploration robot


Cooperative navigation aid robotics (2)

• Advantages – Moving beacons make it possible to improve the estimation

– Bounded error position estimates

– Measurements can be made at higher rates

– Combined EM-based and acoustic-based communications allow higher rates of communication than acoustic-based only

• Positioning of navigation aid robots is critical – Coherent motion must be ensured

– Formation-keeping and precision are desired in this approach

– Formation must be manipulated so that the localization of the survey robot is improved


Towards navigation aid robots and cooperative tracking

• Currently achieved goals – Common control layer for heterogeneous underwater and surface vehicles

– Coordination methods robust to different communication characteristics

• Latency, intermittence significantly vary depending on the physical layer (radio, acoustics)

– Optimal theoretical positioning of hydrophones for localization of a target in 3D

• On-going work – Implementation of the tracking

method using surface vehicles to follow a target underwater


Planning minehunting operations with AUVs (1)

• Millions of naval mines have been deployed

• Even if the location of some minefields is known, it is too dangerous and expensive to try to dismantle them – MCM vessel + hull-mounted/towed sonar

• Mine hunting techniques that will enable AUVs to: – clandestinely survey a region in the sea for mines

– collect data that enables accurate mine detection

– map of the surveyed area



• Advantages – easily transported anywhere given its relatively small size

– low cost when comparing with other traditional MCM assets

– may be deployed in groups and achieve large area coverage in a smaller period of time

– can carry different sensor payloads (sonar, optical and magnetic sensors) according to the target mine they are trying to hunt

– considered expendable so they can operate in close proximity to mines

– they usually do not operate close to the surface, avoiding the related problems of acoustic propagation

– high maneuverability

– operate without risking human lives

• Mission planning involves – the calculation of the trajectories that the AUV will have to follow

– maximizing the quality of the acquired data

– prediction of the performance of the AUV



• Currently achieved goals – Developed a 3D offline mission planner using Evolutionary algorithms

– Identified a set of solutions that represent distinct trade-offs in objective space (maximize probability of detection, minimize time and energy)

– Integrated an approximate model (NNs) that reduced the need for computation of expensive objective functions and increased speed of convergence and quality of the obtained solutions



• On-going work – Compare the planner’s performance with a simple geometrical planner

(only considering a flat sea bottom)

– Online mission replanning after evaluation of current mission performance

– Planning for multiple vehicles


• Bottom Following – "maintaining a fixed altitude above an arbitrary surface whose

characteristics may or may not be known”

• Bottom Following & Estimation – in addition to follow the bottom at a given distance, also dynamically

adjusts its attitude (pitch) to match the slope of the bottom

• Why? – Visual Inspection of the Bottom

Navigation according to Natural Features


• Traditional navigation systems of AUVs combine both Acoustic Navigation with Dead-Reckoning – Inherent INS drifts

– Cost of deployment of acoustic beacons/support vessel

• No need for external aiding devices in Terrain Based Navigation (TBN) – Navigation truly autonomous

– Need for a pre-existing map of the terrain

• TBN for AUVs still in research stage! – Lack of underwater terrain maps

– Experimental results only for high-end AUVs

Terrain Based Navigation


Terrain Based Navigation (ii)

• TBN produces vehicle horizontal position estimates – matching range measurements of the terrain against an a-priori DTM

– Position estimates bound the INS error growth

• In the last decades there has been extensive research on different TBN methods – Application for both manned and unmanned vehicles (missiles, aircraft)

• Alternative approaches – Correlation-based

– Bayesian


Terrain Based Navigation (iii)

• Assumptions: – Sensor-limited system (MEMs IMU)

– DVL measurements available

– Range Measurements given by multibeam sonar

– Billinear Interpolation of the points of the map

• Basic state-space model for an INS-based AUV system


Summary

• Increasing range of applications for marine robotics – Search and rescue

– Defense

– Offshore industry

• Very challenging sensing/perception of the environment

• Automatic planning and re-planning under constraints

• Paradigm shift: single vehicle to multiple vehicles – Decentralized cooperative navigation and control

– Very-low Bandwidth communications


Q & A

• Tak!

• Contact info: – [email protected]

– http://oceansys.fe.up.pt

auvs: current trends and open challengesdee10008/papers/201306_talk_kth_jmelo.pdf · –700...

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