François PEYRET, LCPC [email protected] Cooperative systems workshop and product launch 10 December 2008 Berlin Cooperative positioning in CVIS

François PEYRET, [email protected]

Cooperative systems workshop and product launch10 December 2008

Berlin

Cooperative positioning in CVISCooperative positioning in CVIS

Berlin, 2008-12-10 Cooperative systems workshop 2 2

Outline1. The importance of positioning in cooperative systems

– Position is needed everywhere

– Positioning is a very challenging task

– GNSS is absolutely central, but not enough

2. Which positioning ? – Absolute position is never used at the end of the chain, but map-matched position

– A position without integrity indicator is very risky and even dangerous

3. Cooperative positioning for cooperative systems – “Cooperative” = use of the infrastructure in the positioning/map-matching process

– Infrastructure: could be physical or virtual (digital)

4. The choices of CVIS – "EGNOS inside": the accuracy and integrity of EGNOS + availability

– Hybrid positioning: the best we can expect from data fusion for absolute positioning

– WLAN positioning: a support to hybrid positioning

– Map-matching after hybrid positioning: a reliable map-matched position with confidence

– Emap-matching: an innovative step towards lane-level positioning

5. Conclusion

The importance of positioning in cooperative systems

Position is needed everywhere

Positioning is a very challenging task

GNSS is absolutely central, but not enough


Position is needed everywhere

• All CVIS, SAFESPOT and COOPERS applications are based upon the knowledge of the vehicle(s) position, most of the time in real time

• The position is useless without the map information, the real interesting information is the estimation on the vehicle position on the map


Positioning is a very challenging task, GPS is not enough…

• The apparently easy positioning performed by the standard navigation systems is misleading…

• In reality, the quality of service of standard GPS in constrained environments is generally quite poor, although the global performance is really impressive

• Quality of service =– Availability– Accuracy– Integrity

Which positioning ?

Absolute position is never used at the end of the chain, but map-matched position

A position without integrity indicator is very risky and even dangerous


Absolute position is never used at the end…

GNSS sensor

Proprioceptive sensor 1


Sensor data fusionX, Y, Z, V…

D

d/dt

H

You are here, on this segment, at this abscissa !...

Digital road database

Map-matching

Position on the map

Relevant attributes of the road segment

You are here !...


Integrity mechanism

Acccuracy (error RMS)

Integrity (probability to remain inside the yellow circle)

8 cm 18 cm

10cm20cm

High accuracy but no integrityHigh accuracy but no integrity Low accuracy but with integrity

99 % 100 %


Interest of integrity for ADAS

System available

System unavailable

Protection level

Misleading information !…

True error

Alarm limit

Cooperative positioning for cooperative systems

“Cooperative” = use of the infrastructure in the positioning/map-matching process

Infrastructure: could be physical or digital


Cooperative positioning for cooperative systems

• GNSS alone is not enough• Absolute position is useless

cooperation with the infrastructure is mandatory• Cooperation can be:

– Digital for the map-matching

– Physical and digital to help the basic positioning• Use of geo-located landmarks in the environment• Use of digital map information to constrain the data

fusion (see Emap-matching further)

The choices of CVIS"EGNOS inside": the accuracy and integrity of EGNOS + availability

Hybrid positioning: the best we can expect from data fusion for absolute positioning

WLAN positioning: a support to hybrid positioning

Map-matching after hybrid positioning: a reliable map-matched position with confidence indicator

Emap-matching: an innovative step towards lane-level positioning


General architecture of on-board POMA positioning services

Time stampedDR Sensor

Data

EGNOS Data Collection & Translation

EGNOS Receiver

L1 GPS-EGNOS Receiver

EGNOS/PVTComputation

HybridPosition

Computation

DR Sensors

L1/L2 GPS Receiver

Raw data

EGNOSMessages

Geosat Data Flow

Preciserelative & absolute Position,

+ Error

PVT, Integrity, Sat PV, UERE

Processed Data

Sensor Data

Sensor Module

HybridPVT + EMAPComputation

Alcatel

L3

L1L1

L2

1

1

1

L1

Physical Interface

Logical Interface

L5

2b

3

L4

2c

LCPC(Livic)

LCPC(SMI)

UTC

DLR

Alcatel Office (Toulouse)

L7

Sensors

Computation Module within POMA

1

TimeStamp

PPSSync

SAPOSModule

2c

L4a

L1

Internet access

Optional local Reference Data

4

MapMatching

L14

(PVT = Position, Velocity, Time)

L4b

Router PC

Host PC

Map Data

Hybrid PVT, ErrorsPos.rel. to Map

5 6

L6

Hybrid PVT, Integrity, Errors

Position rel. to Map, Confidence

PPS sync.GPS Time

L5

L8

L7

L9

L11

Time Stamp Infrastructure based positioning

modules (WLAN, WSN)

Infrastructure based positioning

L11


“EGNOS inside”


Data


EGNOS Receiver

L1 GPS Receiver


HybridPosition

Computation

DR Sensors

L1/L2 GPS Receiver

Raw data

EGNOSMessages

Geosat Data Flow


+ Error


Processed Data

Sensor Data

Sensor Module


Alcatel

L3

L1L1

L2

1

1

1

L1

Physical Interface

Logical Interface

L5

2b

3

L4

2c

LCPC(Livic)

LCPC(SMI)

UTC

DLR


L7

Sensors


1

TimeStamp

PPSSync

SAPOSModule

2c

L4a

L1

Internet access


4

MapMatching

L14


L4b

Router PC

Host PC

Map Data


5 6

L6



PPS sync.GPS Time

L5

L8

L7

L9

L11


modules (WLAN, WSN)


L11


“EGNOS inside”: architecture

Egnos Inside Server

GPRS

EGNOS Inside Receiver

Application

VehiclePlatform (Toulouse Site)

GPS Raw Data (Pseudo Range…)

EGNOS Data (Corrections) Filtered Position +

Horizontal Protection Level

Broadcast of EGNOS message via mobile telecommunication is needed for urban application where the EGNOS satellite may be masked more than 60% of the time.


“EGNOS inside”: availability and SIS integrity

• EGNOS brings:– Improved accuracy (differential, corrections)

– Integrity of the Signal In Space (SIS)

• “EGNOS inside” brings additionally:– The availability of the EGNOS signals, normally send by a

geostationary satellite

• The POMA module provides:– The Kalman filtered GPS+EGNOS solution of the U-Blox receiver

– A GPS+EGNOS Least Mean Square solution, MOPS compatible, with an HPL (Horizontal Protection Limit) computation for integrity

– a GPS-only Least Mean Square solution


Hybrid positioning


Data


EGNOS Receiver

L1 GPS Receiver


HybridPosition

Computation

DR Sensors

L1/L2 GPS Receiver

Raw data

EGNOSMessages

Geosat Data Flow


+ Error


Processed Data

Sensor Data

Sensor Module


Alcatel

L3

L1L1

L2

1

1

1

L1

Physical Interface

Logical Interface

L5

2b

3

L4

2c

LCPC(Livic)

LCPC(SMI)

UTC

DLR


L7

Sensors


1

TimeStamp

PPSSync

SAPOSModule

2c

L4a

L1

Internet access


4

MapMatching

L14


L4b

Router PC

Host PC

Map Data


5 6

L6



PPS sync.GPS Time

L5

L8

L7

L9

L11


modules (WLAN, WSN)


L11


Hybrid positioning: Interactive Multiple Model

Simple linear models for specific dynamicsSimple linear models for specific dynamics

ikkX /

ˆ

GPS DataGPS Data

CTk

CVk CA

k

CACA

CTCT

CVCV

past ego positionpast ego position

Prediction for Prediction for CA modelCA model

ikkX 1/1

ˆ

: Constant Acceleration

: Constant Turning

: Constant Velocity

: Constant Acceleration

: Constant Turning

: Constant Velocity


Hybrid positioning: a continuous solution

Blue: Hybrid solution

Green: EGNOS only


WLAN positioning: a support to hybrid positioning


Data


EGNOS Receiver

L1 GPS Receiver


HybridPosition

Computation

DR Sensors

L1/L2 GPS Receiver

Raw data

EGNOSMessages

Geosat Data Flow


+ Error


Processed Data

Sensor Data

Sensor Module


Alcatel

L3

L1L1

L2

1

1

1

L1

Physical Interface

Logical Interface

L5

2b

3

L4

5 6

2c

LCPC(Livic)

LCPC(SMI)

UTC

L6

DLR


L5

L8

L7

L9

L11

L7

Sensors


1

TimeStamp

PPSSync

SAPOSModule

2c

L4a

L1

Internet access


4

MapMatching

L14


WLAN-based position

L4b

Router PC

Host PC

RSSI Measurementsat known locations

WLANInfrastructure

PositionAlgorithm

WLANOn Board

RSSIMeasurements

L13

6a

GPSTime Stamp

SupplyRSSI

L11

(RSSI, Exact Loc.) L13

CalibrationModule

SupplyPosition

L7

External


WLAN positioning: basic principles

RSSI Measurer

WLAN Positioning

Vehicle Position

Two steps:1. Off-line Calibration2. On-board Localization

(fingerprinting)

RSSI: Received Signal Strength Intensity

WLAN localization System works as a backup system to GPS in regions critical for GPS.


10

20

30

210

60

240

90

270

120

300

150

330

180 0

2D Error Dispersion

Estimation Error X [m]

Est

imat

ion

Err

or

Y [

m]

0 5 10 150

0.5

1

Cu

mu

lati

ve D

ensi

ty F

un

ctio

n (

cdf)

2D Error [m]

2D Error Distribution

0 5 10 150

0.1

0.2

Pro

bab

ility

Den

sity

Fu

nct

ion

(p

df)

GPSWLAN Posit

WLAN-based: preliminary tests results

ErrLoc_Mean: ~ 6 mErrLoc_Std: ~ 7 mErrLoc_RMS: ~ 9 m

Performance without hybrid and map-matching modules

251 points were computed, using 89 different Access Points (APs)

Average number of APs / point = 8 (after filtering)


Map-matching after hybrid positioning


Data


EGNOS Receiver

L1 GPS Receiver


HybridPosition

Computation

DR Sensors

L1/L2 GPS Receiver

Raw data

EGNOSMessages

Geosat Data Flow


+ Error


Processed Data

Sensor Data

Sensor Module


Alcatel

L3

L1L1

L2

1

1

1

L1

Physical Interface

Logical Interface

L5

2b

3

L4

2c

LCPC(Livic)

LCPC(SMI)

UTC

DLR


L7

Sensors


1

TimeStamp

PPSSync

SAPOSModule

2c

L4a

L1

Internet access


4

MapMatching

L14


L4b

Router PC

Host PC

Map Data


5 6

L6



PPS sync.GPS Time

L5

L8

L7

L9

L11


modules (WLAN, WSN)


L11

• map-matched candidates (up to 10)• vehicle estimated pose (position + heading)• timestamp• for every candidate:

- longitudinal accuracy - confidence (likelihood)


MM Longitudinal accuracy and confidence

*Accuracy

0.4

0.3 0.2

0.1

Confidence indicator attached to each segment


Emap-matching: an innovative step towards lane-level positioning


Data


EGNOS Receiver

L1 GPS Receiver


HybridPosition

Computation

DR Sensors

L1/L2 GPS Receiver

Raw data

EGNOSMessages

Geosat Data Flow


+ Error


Processed Data

Sensor Data

Sensor Module


Alcatel

L3

L1L1

L2

1

1

1

L1

Physical Interface

Logical Interface

L5

2b

3

L4

2c

LCPC(Livic)

LCPC(SMI)

UTC

DLR


L7

Sensors


1

TimeStamp

PPSSync

SAPOSModule

2c

L4a

L1

Internet access


4

MapMatching

L14


L4b

Router PC

Host PCMap Data


5 6

L6



PPS sync.GPS Time

L5

L8

L7

L9

L11


modules (WLAN, WSN)


L11

Emap Data


Emap-matching: a unique process for positioning and accurate map-matching

GNSS sensor



Sensor data fusionX, Y, Z, V…

D

d/dt

H

You are here, on this segment, at this abscissa !...

Digital road database

Map-matching

Position on the map


You are here !...


Emap-matching: a unique process for positioning and accurate map-matching

GNSS sensor



Sensor data fusion and map-matching

D

d/dtEnhanced digital road database:

Emap

You are here, on this segment, at this abscissa, on this laneon this lane !...

Position on the map


X, Y, Z, V…


Emap-matching: particle filter using map constraints

TmN

mN

TFC mdlyxXXX ,,,,,),(

Particle generation

State propagation model

Correction 1: geometrical and topological constraints

EGNOS measurement

Segment m

mNl

mNdD

P

Corrected estimated state

Corrected particle setComposite state vector:

Correction2: weights modification

DR measurements

Conclusion


ConclusionModule Status

EGNOS inside RT final version operational, under evaluation

Hybrid positioning RT final version operational, under evaluation

Map-matching RT final version operational, under evaluation

WLAN positioning Lab prototype OK

RT version under development and integration

Emap-matching Off-line Matlab prototype OK

RT version under development and integration

Development status

Next challenges:

lane-level positioning with Emap-matching and reliable EGNOS

use of integrity indicators at the application level

how to transform the present R&D POMA module into a commercial product ???

Thanks for your attention…

www.cvisproject.org

Documents

François PEYRET, LCPC [email protected] Cooperative systems workshop and product launch 10 December 2008 Berlin Cooperative positioning in CVIS