TRAFIC MONITORING SYSTEM

• US 20070031084A1
• Filed: 06/20/2006
• Published: 02/08/2007
• Est. Priority Date: 06/20/2005
• Status: Abandoned Application

• Current Assignee: Fibera, Inc.
• Original Assignee: Fibera, Inc.
• Inventors: Lin, How, Wang, David, Tsai, John, Wang, Le-Heng
• Application Number:
  US11/425,392
• Publication Number:
  US 20070031084A1
• Time in Patent Office: Days
• US Class Current: 385/37
• CPC Class Codes: E01F 11/00 Road engineering aspects of Embedding pads or other sensitive devices in paving or other road surfaces , e.g. traffic detectors, vehicle-operated pressure-sensitive actuators, devices for monitoring atmospheric or road conditionspressure-sensitive elements G01L; traffic control systems G08G
• CPC Class Codes: G01B 11/18 using photoelastic elements
• CPC Class Codes: G01L 1/246 using integrated gratings, e.g. Bragg gratings
• CPC Class Codes: G02B 6/022 using mechanical stress, e.g. tuning by compression or elongation, special geometrical shapes such as "dog-bone" or taper G02B6/02204 takes precedence; optical modulation using photo-elastic effect G02F1/0131
• CPC Class Codes: G08G 1/02 using treadles built into the road pads or other sensitive devices responsive to passage of vehicles E01F11/00

Abstract

A system for monitoring traffic across a structure. A fiber Bragg grating (FBG) reflects a light wavelength. A mounting mechanism connects the FBG to the structure, such that physical change of the structure changes a stress to the FBG that changes the light wavelength. And optical fiber carries a first light beam to the FBG and carries a second light beam from the FGB. This permits first light beam including the light wavelength to be received from a light source, and permits the first light beam to be altered into the second light beam by passing the light wavelength through the FBG, and permits the second light beam to be provided to a detector to sense the light wavelength present in the second light beam. From this the stress in the structure and information about the traffic across a structure can be inferred.

Claims

1. A system for monitoring traffic across a structure, comprising:

a fiber Bragg grating (FBG) to reflect a light wavelength;

a mounting mechanism to connect said FBG to the structure such that physical change of the structure changes a stress to said FBG that changes said light wavelength;

optical fiber to carry a first light beam to said FBG and to carry a second light beam from said FGB, thereby permitting a said first light beam including said light wavelength to be received from a light source, permitting said first light beam to be altered into said second light beam by passing said light wavelength through said FBG, and permitting said second light beam to be provided to a detector to sense said light wavelength present in said second light beam and there from infer said stress in the structure and there from infer information about the traffic across a structure.