Device, method and system for determining the road surface condition
First Claim
1. A device for determining a surface condition, said device comprising a reflectance spectrometer which is arranged to sense the reflectance properties of a surface at at least one wavelength and using said reflectance properties to determine the presence of at least one of liquid water or ice, characterised in that said reflectance spectrometer is a wavelength modulation spectrometer which modulates the wavelength of light at a frequency f, said wavelength modulation spectrometer being provided with means to detect the resulting amplitude modulation at more than one multiple of said frequency f.
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Abstract
The invention relates to a device, a method and a system for determining a road surface condition, where the surface condition is one of dry, wet or icy. The device comprises a reflectance spectrometer which senses the reflectance properties of the road at one or several wavelengths and uses these reflectance properties to determine the surface condition. The reflectance spectrometer is a wavelength modulation spectrometer, preferably for the near infrared region. The system determines the surface condition and indicates it to a user of the system.
25 Citations
10 Claims
- 1. A device for determining a surface condition, said device comprising a reflectance spectrometer which is arranged to sense the reflectance properties of a surface at at least one wavelength and using said reflectance properties to determine the presence of at least one of liquid water or ice, characterised in that said reflectance spectrometer is a wavelength modulation spectrometer which modulates the wavelength of light at a frequency f, said wavelength modulation spectrometer being provided with means to detect the resulting amplitude modulation at more than one multiple of said frequency f.
- 5. A method for determining a surface condition, said method using reflectance spectrometry for sensing the reflectance properties of a surface at at least one wavelength and using said reflectance properties to determine presence of at least one of liquid water or ice, characterised in that said reflectance spectrometry is wavelength modulation spectrometry, where the wavelength of the light is modulated at a frequency f, and the resulting amplitude modulation is detected at more than one multiple of said frequency f.
Specification