Here is a presentation made for a seminar during my training at the university RWTH Aachen. This is about solutions found to improve positioning systems for transportation systems. Feel free to contact me.

1. Bastien Terret
b.terret@gmail.com
Presentation
« Positioning Improvements for Intelligent Transportation Systems »
6/18/2015

2. Introduction
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3. Outline
• Introduction
• Intelligent Transportation Systems
• Global Navigation Satellite Systems
• How to improve the localization ?
• Conclusion
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Intelligent Transportation Systems

5. Intelligent Transportation Systems
“Intelligent Transportation Systems (ITS) can be defined as the
application of advanced information and communications technology
to surface transportation in order to achieve enhanced safety and
mobility while reducing the environmental impact of transportation”.
- [1]
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6. Intelligent Transportation Systems
• Helping to relieve congestion
• Safety and environmental benefits
• Making public transport more attractive
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7. Global Navigation Satellite Systems
GNSS : Global Navigation Satellite System
“System of satellites that provide autonomous geo-spatial positioning with
global coverage.” – [2]
Examples:
• GPS
• GLONASS
• BDS
• Galileo
• IRNSS
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8. How does GPS work ?
You need :
- Measure travel time with accurate timing
- Know the exact position of satellites
- Have sufficient number of satellites
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GPS constellation - [2]

9. How does GPS work ?
GPS Frequencies
Band
Frequency
(MHz)
L1 1575.42
L2 1227.60
L3 1381.05
L4 1379.913
L5 1176.45
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L1 & L2 -- Navigation signal
L3 & L4 -- Nuclear Detection System /
Ionospheric corrections
L5 -- Safety of Life
L2C -- Accuracy

10. How does GPS work ?
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GPS Navigation Message – [3]

11. How does GPS work ?
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Ambiguity resulting from measurements to two sources – [4]

12. How does GPS work ?
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Position ambiguity removal by additional measurement– [4]

13. How does GPS work ?
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Effect of measurement errors– [4]

14. Advantages & Drawbacks
STRENGTHS
• Self-calibrating
• Size of devices
• Works anywhere on earth
• Cost
• Updated system
WEAKNESSES
• Drain power
• Signal drawbacks : multipath, signal reception, can’t pass through solid
objects
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15. Requirements
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Position accuracy classification – [6]

16. How to locate something ?
• V2I, V2V & V2P
• Cellular systems
• Unlicensed-band
• Dead-reckoning
• Map-matching
• RFID
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17. V2I, V2V & V2P
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• V2I – Vehicle-to-Infrastructure
• V2V – Vehicle-to-Vehicle
• V2P – Vehicle-to-Pedestrian
“Linking road vehicles to their […] surroundings” – [3]

18. V2I, V2V & V2P
• How ?
DSRC – Dedicated Short-Range Communication
75 MHz spectrum band around 5.9 GHz - ISM band
Content :
ID, position, motion, control, basic
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19. V2I : Vehicle-to-Infrastructure
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V2I Illustration – [7]

20. V2I : Vehicle-to-Infrastructure
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Map setup – [8] Results of the simulation – [8]

21. Vehicle-to-Vehicle and Vehicle-to-Pedestrian
(V2V & V2P)
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V2V illustration – [9]

22. Vehicle-to-Vehicle (V2V)
• equipped & non-equipped vehicles
Ranging sensors & GPS receivers
• DSRC communication devices
Goals :
- recognize presence of non-equipped vehicles
- estimate positions of vehicles
236/18/2015

23. Vehicle-to-Vehicle (V2V)
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[10][10]

24. V2x – x : Infrastructure, Vehicle or Pedestrian
Limitations :
Privacy
Coordination
Maintenance
Security
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25. Dead-Reckoning (DR)
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Overcome limitations of GNSS technology
Calculate a current position using a previously determined position
How ? With sensors
But … Cumulative errors -> Cannot replace GNSS alone

26. Integrated Algorithm
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Plot of the proposed transportation network – [11]

27. Integrated Algorithm
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Plot of the proposed transportation network – [11]

28. Integrated Algorithm
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Plot of the proposed transportation network – [11]

29. Integrated Algorithm
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Plot of the proposed transportation network – [11]

30. Integrated Algorithm
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Plot of the proposed transportation network – [11]

31. Integrated Algorithm
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Plot of the proposed transportation network – [11]

32. Integrated Algorithm
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Plot of the proposed transportation network – [11]

33. Integrated Algorithm
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Plot of the proposed transportation network – [11]

34. Integrated Algorithm
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Plot of the proposed transportation network – [11]

35. Integrated Algorithm
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Plot of the proposed transportation network – [11]

36. Integrated Algorithm
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Plot of the proposed transportation network – [11]

37. Integrated Algorithm
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Plot of the proposed transportation network – [11]

38. Integrated Algorithm
Combination of V2I, V2V, V2P, RFID, and DR resources
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Cramer Rao Lower Bound (CRLB)
δ – current accuracy
ε – required accuracy
if δ < −0.15ε then
remove the worst connection
elseif δ > 0.15ε then
add the best connection
else
do not change the set
endif

39. Integrated Algorithm
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Localization error as function of time-step – [11]

40. Integrated Algorithm
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Localization error as function of time-step – [11]

41. Integrated Algorithm
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Localization error as function of time-step – [11]

42. Integrated Algorithm
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Localization error as function of time-step – [11]

43. Integrated Algorithm
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Localization error as function of time-step – [11]

44. Integrated Algorithm
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Localization error as function of time-step – [11]

45. Integrated Algorithm
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Localization error as function of time-step – [11]

46. Integrated Algorithm
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Localization error as function of time-step – [11]

47. Integrated Algorithm
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[11]
[11]

48. Integrated Algorithm
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[11][11]

49. Bibliography
[1] - its.dot.gov
[2] - Dr. Sergio Camacho-Lara, Handbook of Satellite Applications, “Current and Future GNSS and Their Augmentation Systems”,
2013, pp 617-654
[3] – Wikipedia.com
[4] - Elliott Kaplan, Christopher Hegarty , “Understanding GPS: Principles and Applications”, Second Edition, Artech House, 2005
[5] - wirelessdictionary.com
[6] - S. Stephenson, X. Meng, T. Moore, A. Baxendale, and T. Ford, “Accuracy requirements and benchmarking position solutions for
intelligent transportation location based services,” in Proceedings of the 8th International Symposium on Location-Based Services,
Vienna, Austria, 2011.
[7] - johndayautomotivelectronics.com
[8] - O. Hassan, I. Adly, and K. Shehata, “Vehicle localization n system based on ir-uwb for v2i applications,” in Computer Engineering
Systems (ICCES), 2013 8th International Conference on , Nov 2013, pp. 133–137
[9] – gizmondo.com
[10] - S. Fujii, A. Fujita, T. Umedu, S. Kaneda, H. Yamaguchi, T. Higashino, and M. Takai, “Cooperative Vehicle Positioning via V2V
Communications and Onboard Sensors,” 2011 IEEE Vehicular Technology Conference (VTC Fall), pp. 1–5, Sep. 2011
[11] - Amini, A., Vaghefi, R.M., De La Garza, J.M., Buehrer, R.M.: Improving GPS-based vehicle positioning for intelligent transportation
systems. In: Proceedings of IEEE Intelligent Vehicles Symposium, (2014), pp. 1023–1029
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50. Conclusion
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• GNSS : good but not sufficient
• Improvement with many different techniques
• Hope (self-driving vehicles ..)

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Thank you
Contact : Bastien Terret
b.terret@gmail.com