Data Fusion of Four ABS Sensors and GPS for an Enhanced Localization of Car-like Vehicles

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Data Fusion of Four ABS Sensors and GPS for an
Enhanced Localization of Car-like Vehicles
by Philippe Bonnifait, Pascal Bouron, Paul
Crubille, and Dominique Meizel

• Wiwat Ruengmee
• ICS 280 Special Topic in Ubiquitous Computing
• Ubiquitous Computing for Post-Crisis Logistics
• 01/26/2006

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Motivations / Problems

• Wide availability of GPS and ABS systems in
  modern cars.
• GPS suffers from satellite masks.
• Classical solutions to satellite masks problem of
  GPS are an odometer, a gyro, and a magnetic
  compass.
• Implement and test the localization system using
  GPS, ABS sensors, and a driving wheel encoder.
• Improve the precision due to the redundancy of
  measurements.
• Odometry versus Dead Reckoning.
• This paper presents a new odometric technique and
  the data fusion using Extended Kalman Filter
  (EKF) to estimate the localization.

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Approach (1)

• Odometric technique using data from 4 ABS sensors
  together with a driving wheel encoder.
• Basics
• Displacement between two samples
• How to estimate ? and ??
• using the steering wheel ?and the distances
  travelled by each wheel

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Approach (2)
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Approach (3)

• Differential odometry estimation and their
  estimation

• Non-linearity leads to use of Extended Kalman
  Filter (EKF).
• Each (5) estimation of (?, ?) to provide an
  odometric location is called odometric EKF.

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Approach (4)

• Sampling is performed when
• Each time a GPS measurement is performed.
• Each time the car has travelled one meter and the
  steering angle has changed more than 0.5 degree.
• Sampling frequency is not constant and higher
  than 1 Hz

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Results of the Odometric EKF
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Architecture of localization system
GPS
1PPS signal
(x, y)
(x, y, F) P
ABS Computer Steering Angle
Odometric EKF
Localiser EKF
? S
v
? An estimation S Covariance matrix
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Results of Sensor Fusion Of GPS and Odemetry

• Experiments
• 9.6 km long course
• Three characteristics
• normal operation
• seven small GPS masks of ten seconds
• Large masks of 5 minutes
• Use of all the ABS sensors increases the
  precision of the positioning system.

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Results of Sensor Fusion Of GPS and Odometry
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Results of Sensor Fusion Of GPS and Odometry
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Question?