Driving assistance: automatic fog detection and measure of the visibility distance
Driving assistance:Automatic fog detection and measure
of the visibility distance
Vehicle-Infrastructure-DriverInteractions Research Unit
Nicolas HAUTIEREPhD Student
Didier AUBERTResearcher
Nicolas HAUTIERE – Didier AUBERT
Presentation Overview
ConclusionConclusion
IntroductionIntroduction Fog, light and visionFog, light and vision Fog effects on road visionFog effects on road vision Modeling visual effectsModeling visual effects Algorithm overviewAlgorithm overview ResultsResults
Driving assistance: automatic fog detection and measure of the visibility distance
Introduction
Nicolas HAUTIERE – Didier AUBERT
Measuring the atmospheric visibility:Measuring the atmospheric visibility:
Constitutes a driving assistance.
Estimates the operation range of on-board perception sensors.
This work is part of the ARCOS project.
Driving assistance: automatic fog detection and measure of the visibility distance
Fog, light and vision
Nicolas HAUTIERE – Didier AUBERT
Fog microstructureFog microstructureFog is a concentration of water droplets suspended in the air,
bringing visibility below one kilometer.
Light scatteringLight scatteringThe daylight is scattered by fog droplets in all directions. This effect is described by an extinction coefficient k.
Visibility impairmentVisibility impairmentThe fog reduces distant contrasts. This effect is described by the meteorological visibility: the greatest distance at which a black object of suitable dimensions can be seen.
Driving assistance: automatic fog detection and measure of the visibility distance
Fog effects on road [email protected]
Attenuation effectAttenuation effect
e-kd1
e-kd2
e-kd
surface
Halo effectHalo effect
Veiling effect
Driving assistance: automatic fog detection and measure of the visibility distance
Koschmieder’s law (1924)Koschmieder’s law (1924)
Modeling fog visual effects
Intrinsic luminance of the object
Fog luminance at the horizon
Apparent luminance of the object
Extinction coefficient of
fog
Distance of the object to the
camera
Nicolas HAUTIERE – Didier AUBERT
International Commission on Illumination (CIE) International Commission on Illumination (CIE)
Driving assistance: automatic fog detection and measure of the visibility distance
Computation of ROI
Computation of a band of measure
Derivation of the curve of luminance
Extraction of an inflection point
Measure of the median luminance
Computation of the visibility distance
Algorithm overview
Nicolas HAUTIERE – Didier AUBERT
At the inflection pointKoschmieder’s law Resolving the equation
Driving assistance: automatic fog detection and measure of the visibility distance
Results
Low dense fog – Vehicle following
Nicolas HAUTIERE – Didier AUBERT
Driving assistance: automatic fog detection and measure of the visibility distance
Results
Nicolas HAUTIERE – Didier AUBERT
Dense fog – Vehicle crossing
Driving assistance: automatic fog detection and measure of the visibility distance
Dense fog – Curve
Nicolas HAUTIERE – Didier AUBERT
Results
Driving assistance: automatic fog detection and measure of the visibility distance
Conclusion
Nicolas HAUTIERE – Didier AUBERT
This original method has the following advantages:This original method has the following advantages:
detects the presence of fog and measures the meteorological detects the presence of fog and measures the meteorological distance of visibility,distance of visibility,
indicates if it is temporary inoperative,indicates if it is temporary inoperative,
is based on a physical model of fog,is based on a physical model of fog,
needs only the presence of the road and the sky in the image to needs only the presence of the road and the sky in the image to work,work,
isis real time performed,real time performed, works with a single camera.works with a single camera.
Driving assistance: automatic fog detection and measure of the visibility distance