HIGHWAY-RAIL GRADE CROSSING HAZARD MITIGATION

• US 20060022063A1
• Filed: 03/07/2005
• Published: 02/02/2006
• Est. Priority Date: 03/06/2004
• Status: Active Grant

• Current Assignee: Fibera, Inc.
• Original Assignee: Fibera, Inc.
• Inventors: Tsai, John C.
• Granted Patent: US 7,268,699 B2
• Time in Patent Office: Days
• US Class Current: 238/8
• CPC Class Codes: B61L 29/24 Means for warning road traffic that a gate is closed or closing, or that rail traffic is approaching, e.g. for visible or audible warning
• CPC Class Codes: B61L 29/30 Supervision, e.g. monitoring arrangements
• CPC Class Codes: E01B 26/00 Tracks or track components not covered by any one of the preceding groups
• CPC Class Codes: E01C 9/04 Pavings for railroad level-crossings

Abstract

A hazard mitigation system to detect an object in a highway-railway grade crossing. A structure is provided that includes a fixed foundation and a surface layer that is cushionably placed above the foundation, such that the structure is located between tracks at the crossing. At least one sensor is mounted between the surface layer and the foundation. This sensor senses the weight of the object upon the surface layer and provides a sensor signal representative of that weight. A control unit receives the sensor signal, processes it to determine whether the object represents a potential hazard, and, if so generates a warning signal. The sensor can particularly include a pressure or strain gage, or a fiber optic sensor. When a fiber optic sensor is employed, it can particularly include a fiber Bragg grating.

Claims

1. A system for hazard mitigation related to an object in a highway-railway grade crossing, wherein the railway has a pair of tracks at the crossing, comprising:

a structure including a fixed foundation and a surface layer cushionably placed above said foundation, wherein said structure is located between the pair of tracks at the crossing;

at least one sensor mounted between said surface layer and said foundation, wherein said sensor senses the weight of the object upon said surface layer and provides a sensor signal representative of said weight; and

a control unit to receive said sensor signal, to process said sensor signal to determine whether the object represents a potential hazard, and, if so to generate a warning signal.

2. The system of claim 1, wherein said sensor includes a pressure gage.

3. The system of claim 1, wherein said sensor includes a strain gage.

4. The system of claim 3, wherein said strain gage is fixedly mounted with respect to said foundation and said sensor further includes a tension wire fixedly connected at one end and at the other end to said strain gage such that movement of said surface layer due to the weight of the object activates said sensor to provide said sensor signal.

5. The system of claim 4, wherein said tension wire is of a low thermal expansion material.

6. The system of claim 1, wherein:

said sensor includes a fiber optic sensor; and

said control unit includes a light source to provide a light beam to said sensor, wherein said light beam includes at least one wavelength chosen based on a response characteristic of said fiber optic sensor.

7. The system of claim 6, wherein said fiber optic sensor is a member of the set consisting of athermal type devices and devices having a normalizing mechanism that compensates for temperature variation.

8. The system of claim 6, wherein:

multiple said sensors are employed in the system; and

said multiple said sensors are interconnected with optical fiber in a configuration that is a member of the set consisting of serial connections, parallel connections, and combinations thereof.

9. The system of claim 8, wherein said light source includes a narrow line-width tunable laser.

10. The system of claim 8, wherein said light source provides said light beam having a broadband spectrum of wavelengths consisting of all the wavelengths of said multiple said sensors.

11. The system of claim 6, wherein said fiber optic sensor includes at least one member of the set consisting of Fabry-Perot gratings, Mach-Zehnder interferometers, Fizeau interferometers, and Michelson interferometers.

12. The system of claim 6, wherein said fiber optic sensor includes a fiber Bragg grating.

13. The system of claim 1, wherein:

said control unit includes a signal comparator, a processor, a data storage, and a communications system; and

wherein

said signal comparator evaluates said sensor signal based on pre-stored data in said data storage; and

said control unit directs said signal comparator, monitors said sensor signal, determines whether the object represents a potential hazard based on externally obtained contemporaneous information about the crossing, generates said warning signal, and directs said communications system to externally communicate said warning signal, thereby permitting a human operator or an automated system to act based on said warning signal.

14. The system of claim 13, wherein said control unit further includes a weather station including at least one member of the set consisting of temperature sensors, humidity sensors, barometric pressure sensors, and rain gauges.

15. The system of claim 13, wherein said communications system includes a wireless telecommunications device.