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US5801647A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for measuring road surface conditions

Assignee: Vaisala Oy
•
Filing: 1996-09-06
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Granted: 1998-09-01
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Expires: 2016-09-06
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Abstract

Abstract The present invention relates to a method and apparatus for measuring road surface conditions. In the method of measuring road surface conditions, the conditions prevailing on the surface of a road are measured by a sensor head mounted in the pavement of the road with the top surface of the sensor head aligned substantially flush with the pavement of the road. According to the invention, an optical signal is impinged from below the road to the top surface of the road, the reflection/backscatter of the optical signal is measured inside the pavement layer of the road, and weather/driving conditions prevailing on the road top surface are determined from the reflected and backscattered signal values.

Inventors

  • 👤 Petteri Survo
  • 👤 Taisto Haavasoja

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 15:25
CPC Classifications
G; G08; G08B; G08B19/00; G08B19/02

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 115 words
A method of measuring conditions of a road surface comprising: transmitting an optical signal from a fiber optic transmitter inside a sensor head through a medium outside the fiber optic transmitter adjacent the road surface, said sensor head being aligned substantially flush with the road surface; receiving reflection and back scatter of the optical signal moving from a surface of and through the medium spaced apart from the road surface through the medium by a plurality of fiber optic receivers inside said sensor head; and calculating at least one of weather and driving conditions prevailing on the road surface from the reflected and back scatter optical signal received from said plurality of fiber optic receivers.
Claim 2
Independent Claim 115 words
A method of measuring conditions of a road surface comprising: transmitting an optical signal from a fiber optic transmitter inside a sensor head through a medium outside the fiber optic transmitter adjacent the road surface, said sensor head being aligned substantially flush with the road surface; receiving reflection and back scatter of the optical signal moving from a surface of and through the medium spaced apart from the road surface through the medium by a plurality of fiber optic receivers inside said sensor head; and calculating at least one of weather and driving conditions prevailing on the road surface from the reflected and back scatter optical signal received from said plurality of fiber optic receivers.
Claim 3
Dependent Claim 66 words
The method as defined in claim 1, wherein said transmitting and receiving steps further comprise: transmitting the optical signal to the road surface by a circularly symmetrical optical fiber bundle and receiving reflection and back scatter of the optical signal from the surface of the medium spaced apart from the road surface by the circularly symmetrical optical fiber bundle, said bundle mounted in said sensor head.
Claim 4
Dependent Claim 58 words
The method as defined in claim 1, wherein the transmitting and receiving steps further comprise: transmitting the optical signal to the road surface by a first optical bundle and receiving reflection and back scatter of the optical signal from the surface of the medium spaced apart from the road surface by an adjacently placed second optical fiber bundle.
Claim 5
Dependent Claim 59 words
The method as defined in claim 1, wherein the transmitting and receiving steps further comprise: transmitting the optical signal to the road surface by a single optical fiber and receiving reflection and back scatter of the optical signal from the surface of the medium spaced apart from the road surface by at least two single adjacently placed optical fibers.
Claim 6
Dependent Claim 39 words
The method as defined in claim 1, wherein the receiving step further comprises: receiving the optical signal from the surface of the medium adjacent the road surface by optical fibers or fiber bundles having diameters different from each other.
Claim 7
Dependent Claim 40 words
The method as defined in claim 1, wherein the receiving step further comprises: receiving the optical signal from the surface of the medium adjacent the road surface by optical fibers or fiber bundles having numerical apertures different from each other.
Claim 8
Dependent Claim 23 words
The method as defined in claim 1, wherein said calculating step further comprises: using an AC amplitude-modulated measurement signal detected by phase-locked methods.
Claim 9
Independent Claim 106 words
An apparatus for measuring the conditions of a road surface, said apparatus comprising: a sensor head mounted in pavement material beneath the road surface with a surface of the sensor head aligned substantially flush with the road surface, said sensor head includes at least one fiber-optic transmitter emitting an optical signal from below the road surface and through a medium adjacent to the road surface, the medium including a surface spaced apart from the road surface, said sensor head further includes at least two fiber-optic receivers receiving the optical signal reflected or back scattered from the surface of the medium spaced apart from the road surface.
Claim 10
Independent Claim 106 words
An apparatus for measuring the conditions of a road surface, said apparatus comprising: a sensor head mounted in pavement material beneath the road surface with a surface of the sensor head aligned substantially flush with the road surface, said sensor head includes at least one fiber-optic transmitter emitting an optical signal from below the road surface and through a medium adjacent to the road surface, the medium including a surface spaced apart from the road surface, said sensor head further includes at least two fiber-optic receivers receiving the optical signal reflected or back scattered from the surface of the medium spaced apart from the road surface.
Claim 11
Dependent Claim 29 words
The apparatus as defined in claim 8, wherein at least one of said transmitter and receivers includes an optical fiber bundle with concentrically arranged fibers which enclose each other.
Claim 12
Dependent Claim 31 words
The apparatus as defined in claim 8, wherein said transmitter includes a fiber optic bundle and said receivers include a fiber optical bundle, said transmitter is disposed adjacent to said receiver.
Claim 13
Dependent Claim 31 words
The apparatus as defined in claim 8, wherein said transmitter includes a single optical fiber and said receivers include two single optical fibers, said transmitter is disposed adjacent to said receiver.
Claim 14
Dependent Claim 42 words
The apparatus as defined in claim 8, wherein said transmitter and receiver are made of a material that wears at a substantially similar rate with wear of the sensor head and the road surface without impairing the function of the sensor head.
Claim 15
Dependent Claim 15 words
The apparatus as defined in claim 8, said apparatus further comprises a phase lock detector.
Claim 16
Dependent Claim 81 words
The apparatus as defined in claim 8, wherein said transmitter includes a single optical fiber having a first diameter, said receivers include two single optical fibers having second and third diameters, said first and second and third diameters are substantially equal, the receiving single optical fiber with the second diameter is disposed adjacent to said transmitting single optical fiber with the first diameter, said receiving single optical fiber having the third diameter is spaced apart from said transmitting single optical fiber.
Claim 17
Dependent Claim 43 words
The apparatus as defined in claim 8, wherein said transmitter includes a single optical fiber with a first diameter, said receivers include two single optical fibers having second and third diameters, said transmitting single optical fiber is disposed between said receiving optical fibers.
Claim 18
Dependent Claim 63 words
The apparatus as defined in claim 8, wherein the transmitter includes a single optical fiber with a first diameter, said receivers include a single optical fiber with a second diameter and a single optical fiber with a third diameter, said transmitting optical fiber is disposed between the receiving second and third optical fiber, said first and second and third diameters are substantially equal.

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-08-31 2002-03-02 2002-09-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-08-31 2006-03-02 2006-09-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-08-31 2010-03-02 2010-09-01 $7700.00 Window Closed / Lapsed

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