Device for detection of surface condition data
First Claim
1. Sensor device for non-contact detection of conditions of a surface, the sensor device comprising:
- a light source for emitting light towards the surface;
a first detector arranged for receiving a portion of said emitted light when reflected from said surface and producing a first output according to an intensity thereof;
a second detector arranged for receiving a portion of said emitted light when reflected from said surface and for producing a second output according to the intensity thereof; and
control means for receiving and evaluating the received output from the detectors based on an amount of diffuse reflected and mirror reflected light;
wherein the light source is arranged to emit light in a direction within 20°
from the surface normal, the sensor device further comprising;
a first linear polarization filter arranged in a path of the light from the light source and to the surface for the polarization of the emitted light; and
a second linear polarization filter arranged in a path of the light between said surface and one of the first detector and the second detector.
3 Assignments
0 Petitions
Accused Products
Abstract
A device is disclosed for detection of surface properties or conditions, in particular detection of water, snow and ice and in particular to read surfaces by means of detector means mounted on individual vehicles, and transmitting the data from the vehicle, preferably together with position data of the vehicle, to be used by drivers of other vehicles for warning of slippery road conditions ahead of the vehicle. According to a particular aspect, it has been realized that the fact that polarized light which is mirror reflected by e.g. ice or water on a surface, preserves its polarization, whereas polarized light which is diffuse reflected largely becomes depolarized, may be utilized to separate the two types of reflection and thus provide a much more compact sensor device for surface properties, in which the light may be emitted close to or parallel to the road surface normal.
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Citations
27 Claims
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1. Sensor device for non-contact detection of conditions of a surface, the sensor device comprising:
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a light source for emitting light towards the surface; a first detector arranged for receiving a portion of said emitted light when reflected from said surface and producing a first output according to an intensity thereof; a second detector arranged for receiving a portion of said emitted light when reflected from said surface and for producing a second output according to the intensity thereof; and control means for receiving and evaluating the received output from the detectors based on an amount of diffuse reflected and mirror reflected light; wherein the light source is arranged to emit light in a direction within 20°
from the surface normal, the sensor device further comprising;a first linear polarization filter arranged in a path of the light from the light source and to the surface for the polarization of the emitted light; and a second linear polarization filter arranged in a path of the light between said surface and one of the first detector and the second detector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 21, 22, 23, 24, 25, 26, 27)
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16. Sensor device for non-contact detection of conditions of a surface, the system comprising:
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a light source for emitting light towards the surface; a first detector arranged for receiving a portion of said emitted light when reflected from said surface and producing a first output according to an intensity thereof; a second detector arranged for receiving a portion of said emitted light when reflected from said surface and producing a second output according to an intensity thereof; and control means for receiving and evaluating the received output from the detectors based on an amount of diffuse reflected and mirror reflected light, one or more arrangements for detecting conditions of the surface, said arrangements comprising at least one of; an infrared light source for emitting light within a wavelength range of 930 nm to 970 nm towards the surface and an absorption detector for receiving a reflection of said emitted infrared light and producing an output to the control means accordingly, and a light source for emitting light towards the surface, a path of the light having an angle in a range of 15°
to 70°
to the surface normal and a retro-reflection detector arranged for receiving a retro-reflection of said emitted light in said path and producing an output to the control means accordingly,a light source for emitting polychromatic light towards the surface and at least two range detectors arranged to detect each a wavelength range of a reflection of said emitted light and producing an output to the control means accordingly, and a noise sensor for receiving noise from a vehicle traveling along a road and producing an output to the control means accordingly, on which vehicle the device is arranged.
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17. Sensor device for non-contact detection of conditions of a road surface, the sensor device comprising:
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a light source for emitting light towards the surface; a first detector arranged for receiving a portion of said emitted light when reflected from said surface and producing a first output according to an intensity thereof; a second detector arranged for receiving a portion of said emitted light when reflected from said surface and producing a second output according to the intensity thereof; control means for receiving and evaluating the received output from the detectors based on an amount of diffuse reflected and mirror reflected light, a first linear polarization filter arranged in a path of the light from the light source and to the surface for the polarization of the emitted light; a second linear polarization filter arranged in a path of the light between said surface and one of the first detector and the second detector; and a further light source for emitting light within an infrared wavelength range of high absorbance by water towards the surface and an absorption detector for receiving a reflection of said emitted light and producing an output to the control means accordingly. - View Dependent Claims (18, 19)
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Specification