Institute of Agricultural Maschinery and Fluid Power Platzhalter für Bild, Bild auf Titelfolie hinter das Logo einsetzen

Precise relative positioning in machine swarms

Dipl.-Ing. Jan Schattenberg Dipl.-Ing. S. Batzdorfer Prof. Dr.-Ing. T. Lang Dr.-Ing. U. Bestmann Dipl.-Ing. M. Becker Prof. Dr.-Ing. P. Hecker Dr.-Ing. F. Andert 3 rd International Conference on Machine Control Guidance

Outline



Motivation and Introduction



IMU/GNSS and Vision integration



Swarm Positioning



Mobile Ad-Hoc Communication



First Results



Conclusion and Outlook

29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 2 Institute of Agricultural Machinery and Fluid Power

Motivation

Urban and alpine scenario  Shadowing of GNSS signals, degrading GNSS signals, multipath effects  Guidance with the help of known landmarks is limited  Fast search with high accuracy positioning Integration of IMU/GNSS including Failure Detection and Exclusion Methods Vision-aided relative localization Swarm Positioning using GNSS raw data exchange Mobile Ad-hoc communication for GNSS raw data exchange 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 3 Institute of Agricultural Machinery and Fluid Power

Introduction – “NExt UAV”

Joint research project “

NExt UAV

“ Institute of Flight Guidance Institute of Agricultural Machinery and Fluid Power Institute of Flight Systems Funded by 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 4 Institute of Agricultural Machinery and Fluid Power FKZ 50NA1002 and 50NA1003

Outline



Motivation and Introduction



IMU/GNSS and Vision integration



Swarm Positioning



Mobile Ad-Hoc Communication



First Results



Conclusion and Outlook

29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 5 Institute of Agricultural Machinery and Fluid Power

IMU/GNSS and Vision integration - FDE

System architecture   Main filter processes all measurements (N) Each subfilter processes (N i) measurements (i = 1…N-1) 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 6 Institute of Agricultural Machinery and Fluid Power

IMU/GNSS and Vision integration – Vision based localization

29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 7 Institute of Agricultural Machinery and Fluid Power

IMU/GNSS and Vision integration - Coupling

Monitoring INS/ GNSS IMU

Prediction

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

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GNSS

Correction

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 Vision

Predicted Feature World Position Predicted Pixel Position Feature Pixel Position Feature World Position

29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 8 Institute of Agricultural Machinery and Fluid Power

Outline



Motivation and Introduction



IMU/GNSS and Vision integration



Swarm Positioning



Mobile Ad-Hoc Communication



First Results



Conclusion and Outlook

29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 9 Institute of Agricultural Machinery and Fluid Power

Swarm Positioning - Standalone

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rover a  

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

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

t a a a err

     29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 10 Institute of Agricultural Machinery and Fluid Power rover b

Swarm Positioning – Double Differential

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rover a           

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x y



z a b b a b a

    29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 11 Institute of Agricultural Machinery and Fluid Power rover b

Swarm Positioning – Standalone & Double Differential

rover a

b ab b ac b bc

rover c 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 12 Institute of Agricultural Machinery and Fluid Power rover b

Outline



Motivation and Introduction



IMU/GNSS and Vision integration



Swarm Positioning



Mobile Ad-Hoc Communication



First Results



Conclusion and Outlook

29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 13 Institute of Agricultural Machinery and Fluid Power

Mobile Ad-Hoc communication - Requirements

   Quick and safe data exchange Flexible for dynamic changes in network topology Decentralized system to compensate loss of swarm participants

MANet or Mesh networks

 Scenarios: All2All, All2One, One2All 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 14 Institute of Agricultural Machinery and Fluid Power Without direct data link Direct data link Multi-hop data link

Mobile Ad-Hoc communication - Simulation

     1.

2.

3.

4.

Using MATLAB® Proactive routing – All2All 4 to 12 nodes 1000 simulations Steps: Generate random network Network discovery Routing Data Exchange 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 15 Institute of Agricultural Machinery and Fluid Power

Mobile Ad-Hoc communication - Implementation

    Network exploration Calculating the routing table GNSS raw data exchange Data processing 1 Hz update frequency syncronized by PPS Network Exploration 100ms Calculating Routing Table GNSS raw data exchange Data processing 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 16 Institute of Agricultural Machinery and Fluid Power

Mobile Ad-Hoc communication – Network Exploration

  Problem: No a-priori knowledge and no coordinator  Try and Error Tools: Clear Channel Assessment (CCA)  Scan energy level of channel   Compare detected energy with threshold If medium not clear wait random backoff time and try again   Problems: Hidden stations  No ACK available using broadcast messages 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 17 Institute of Agricultural Machinery and Fluid Power

Mobile Ad-Hoc communication – Network Exploration

29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 18 Institute of Agricultural Machinery and Fluid Power

Outline



Motivation and Introduction



IMU/GNSS and Vision integration



Swarm Positioning



Mobile Ad-Hoc Communication



First Results



Conclusion and Outlook

29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 19 Institute of Agricultural Machinery and Fluid Power

First Results – Reference systems

    Reference localization system (Leica Viva TS15 ) tracking with up to 6 Hz compare track with GNSS/INS solution Sync by GNSS-time using WLAN and NTP  Phase solution in post-processing UAV 2 UAV 1 Ref-Station UAV 3 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 20 Institute of Agricultural Machinery and Fluid Power

First Results - Measurements

29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 21 Institute of Agricultural Machinery and Fluid Power

Outline



Motivation and Introduction



IMU/GNSS and Vision integration



Swarm Positioning



Mobile Ad-Hoc Communication



First Results



Conclusion and Outlook

29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 22 Institute of Agricultural Machinery and Fluid Power

Conclusion and Outlook

   Absolute and relative position is indispensable Positioning techniques and controlling strategies require swarm communication Algorithm for network exploration fits simulation results    Test of all sub-systems together in one system Tests in different scenarios (urban, alpine, different constellations) Optimization of the required time  messages minimization of the required 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 23 Institute of Agricultural Machinery and Fluid Power

Thank you for your attention!

Institute of Agricultural Machinery and Fluid Power

www.tu-braunschweig.de/ilf [email protected]

comRoBS Dipl.-Ing. Jan Schattenberg J.Schattenberg@tu braunschweig.de

Tel.: +49 (0) 531 391-7192 Fax: +49 (0) 531 391-5951 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 24 Institute of Agricultural Machinery and Fluid Power

Technical Equipment

NExt UAV - GNSS µblox LEA-6T-chip (Precision Timing & Raw Data) Hybrid GPS/SBAS engine (WAAS, EGNOS, MSAS) Basis-Board layout and design by messWERK NExt UAV - IMU 2x dual axis MEMS acceleration sensor (Bosch SMB225) 3x 1-axis gyro sensor (Bosch SMG074 ) 1x “read-out”-board layout and design by IFF 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 25 Institute of Agricultural Machinery and Fluid Power

Technical Equipment

NExt UAV- NAV-Board • Seco Qseven™ Embedded Computer Module • Pico ITX-Standard (3,9”x2,0”, 100 x 72 mm) • Intel Atom (Z530) 1,6 GHz, 1 GB DDR2, 800 Hz bus • 8 GB Flashdrive, microSD-Slot (8 GB), SD-Slot (8 GB) • Operating system: linux with real time extension NExt UAV- Radio module • Wireless standard 802.15.4 XBee • Frequency Band 2,4 GHz ISM • Radio range up to 1.6 km • Serial Data Range up to 115.2 Kbps 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 26 Institute of Agricultural Machinery and Fluid Power

Technical Equipment

NExt UAV- Vision • 2x AlliedVisionTec Marlin F-131B with Pentax C815B • Self-made carrier for stereo camera system • Interface: IEEE 1394a - 400 Mb/s • Resolution: 1280 x 1024 • 25 fps on full resolution NExt UAV- Vision-Board • Lippert CXR-GS45 PCI104Ex with Core2Duo 9300 • 2 GB Ram • Firewire expansion board 29.03.2012 | Dipl.-Ing. Jan Schattenberg | Precise relative positioning in machine swarms | Slide 27 Institute of Agricultural Machinery and Fluid Power