Traffic monitoring using optical sensors
A system includes a sensor network comprising at least two optical fibers coupled to a pavement. Each optical fiber includes one or more optical sensors installed a predetermined distance from one or more adjacent optical fibers. The one or more optical sensors are configured to produce a wavelength shift signal. A processor is configured to determine one or both of one or more attributes of one or more objects travelling on the pavement and a traffic condition of the pavement based on the wavelength shift signal. A transmitter is configured to transmit the one or more attributes to a predetermined location.
1. A system, comprising:
a sensor network comprising at least two optical fibers coupled to a pavement, each optical fiber comprising one or more optical sensors installed a predetermined distance from one or more adjacent optical fibers, the one or more optical sensors configured to produce a wavelength shift signal;
a processor configured to:
determine one or both of one or more attributes of one or more objects travelling on the pavement and a traffic condition of the pavement based on the wavelength shift signal, the one or more attributes comprising a speed of the one or more objects, the speed of the one or more objects determined by:
aggregating data from two or more of the optical sensors of the one or more optical sensors; and
determining one or both of a median and a mean of the aggregated data; and
a transmitter configured to transmit one or both of the one or more attributes and the traffic condition to a predetermined location.
2. The system of claim 1 , wherein the processor is further configured to detect one or more of entry and exit of an object from a sensing zone.
3. The system of claim 1 , wherein the one or more attributes comprise one or more of a direction of travel, a number of axles of the one or more objects, a distance between axles of the one or more objects, a group of axles of the one or more objects, a lane of traffic that the one or more objects are travelling in, and a weight per axle for the one or more objects.
4. The system of claim 3 , wherein the processor is configured to aggregate the one or more attributes to determine one or more of an object classification, a road occupancy, and a traffic volume of the pavement.
5. The system of claim 1 , wherein the speed of the one or more objects is determined using a single sensor pair.
6. The system of claim 1 , wherein the speed of the one or more objects is determined using correlation between a first wavelength shift signal received from sensors disposed on a first optical fiber and a second wavelength shift signal received from sensors disposed on a second optical fiber.
7. The system of claim 1 , wherein the speed of the one or more objects is determined using a time shift of wavelength shift peaks of the wavelength shift signal.
8. The system of claim 1 , wherein the at least two optical fibers are installed parallel to each other.
9. The system of claim 1 , wherein the processor is further configured to detect lane straddling of the one or more objects based on the wavelength shift signal.
10. The system of claim 1 , wherein the processor is further configured to issue an alert based on the wavelength shift signal.
11. The system of claim 1 , wherein the one or more objects comprise one or more of vehicles and pedestrians.
12. The system of claim 1 , wherein the pavement comprises one or more of a walkway and a road.
13. The system of claim 1 , wherein the wavelength shift signal comprises a strain signal.
14. The system of claim 1 , wherein the processor is configured to:
determine the one or both of the one or more attributes of the one or more objects travelling on the pavement based on at least two disparate methods; and
merge results from the at least two disparate methods.
15. A method, comprising:
receiving a wavelength shift signal from a plurality of optical sensors coupled to a pavement, the plurality of optical sensors disposed on at least two optical fibers, each optical fiber disposed a predetermined distance from at least one other optical fiber;
determining one or both of one or more attributes of one or more objects travelling on the pavement and a traffic condition based on the wavelength shift signal, the one or more attributes comprising a speed of the one or more objects, the speed of the one or more objects determined by:
aggregating data from two or more of the optical sensors of the one or more optical sensors; and
determining one or both of a median and a mean of the aggregated data; and
transferring one or both of the one or more attributes and the traffic condition to a predetermined location.
16. The method of claim 15 , further comprising detecting one or more of entry and exit of an object from a sensing zone.
17. The method of claim 15 , wherein the one or more attributes comprise one or more of a direction of travel, a number of axles of the one or more objects, a distance between axles of the one or more objects, a group of axles of the one or more objects, a lane of traffic that the one or more objects are travelling in, and a weight per axle for the one or more objects.
18. The method of claim 17 , further comprising aggregating the one or more attributes to determine one or more of an object classification, a road occupancy, and a traffic volume of the pavement.
19. The method of claim 17 , further comprising determining the speed of the one or more objects using correlation between a first wavelength shift signal received from sensors disposed on a first optical fiber and a second wavelength shift signal received from sensors disposed on a second optical fiber.
20. The method of claim 17 , further comprising determining the speed of the one or more objects using a time shift of wavelength shift peaks of the wavelength shift signal.