Monitoring traffic flow
First Claim
1. A method for determining traffic flow, the method comprising:
- performing, by a distributed acoustic sensing interrogator unit, distributed acoustic sensing repeatedly to provide a measurement signal from each of a plurality of sensing portions of a first length of a sensing optical fibre, wherein the first length of the sensing optical fibre runs alongside a road having a plurality of lanes;
processing, by a processor connected to the distributed acoustic sensing interrogator unit, the measurement signals repeatedly from said sensing portions to detect vehicles travelling on the road and determine at least one detected traffic flow property;
using a traffic flow model, by the processor, to relate the at least one detected flow property to a modelled flow property, the traffic flow model modelling vehicle detections that will be missed by the distributed acoustic sensing; and
outputting, by the processor, an estimate of traffic flow on the road based on the modelled flow property.
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Accused Products
Abstract
This application relates to apparatus and methods for traffic monitoring, especially for monitoring of road traffic flow using fiber optic distributed acoustic sensing. The method involves performing distributed acoustic sensing (DAS) using a suitable interrogator unit (103) to provide a measurement signal from each of a plurality of sensing portions of a first length of a sensing optical fiber (102), where the first length of the sensing optical fiber runs alongside a road (101) having a plurality of lanes. The measurement signals from the sensing portions are processed to detect vehicles (104) travelling on the road and to determine at least one detected traffic flow property. The method further involves using a traffic flow model to relate the detected flow property to a modelled flow property, where the traffic flow model is configured to model vehicle detections that will be missed by the distributed acoustic sensing i.e. an indication of vehicles present on the road but not detected by the DAS sensor.
15 Citations
21 Claims
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1. A method for determining traffic flow, the method comprising:
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performing, by a distributed acoustic sensing interrogator unit, distributed acoustic sensing repeatedly to provide a measurement signal from each of a plurality of sensing portions of a first length of a sensing optical fibre, wherein the first length of the sensing optical fibre runs alongside a road having a plurality of lanes; processing, by a processor connected to the distributed acoustic sensing interrogator unit, the measurement signals repeatedly from said sensing portions to detect vehicles travelling on the road and determine at least one detected traffic flow property; using a traffic flow model, by the processor, to relate the at least one detected flow property to a modelled flow property, the traffic flow model modelling vehicle detections that will be missed by the distributed acoustic sensing; and outputting, by the processor, an estimate of traffic flow on the road based on the modelled flow property. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An apparatus for determining traffic flow, the apparatus being configured to:
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receive, by a distributed acoustic sensing interrogator unit, a first data set corresponding to distributed acoustic sensing measurement signals from each of a plurality of sensing portions of a first length of a sensing optical fibre, wherein the first length of the sensing optical fibre runs alongside a road having a plurality of lanes; process, by a processor connected to the distributed acoustic sensing interrogator unit, the measurement signals repeatedly from said sensing portions to detect vehicles travelling on the road and determine at least one detected traffic flow property; and using a traffic flow model, by the processor, to relate the at least one detected flow property to a modelled flow property, the traffic flow model modelling vehicle detections that will be missed by the distributed acoustic sensing, and wherein the apparatus outputs an estimate of traffic flow on the road based on the modelled flow property. - View Dependent Claims (18, 19, 20)
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21. A method of assessing a distributed acoustic sensor traffic monitoring system having a sensing optical fibre deployed to run alongside a first section of road with multiple lanes, the method comprising:
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monitoring traffic flow repeatedly over the first section of road using the distributed acoustic sensor (DAS) traffic monitoring system to provide a DAS detection value; monitoring traffic flow over at least part of the first section of road using a second different type of traffic monitoring system repeatedly to provide an indication of vehicle flow; applying, by a processor, a traffic flow model to the indication of vehicle flow to provide an estimate of an expected DAS detection value, the traffic flow model modelling vehicle detections that will be missed by the distributed acoustic sensor traffic monitoring system; and outputting an estimate of traffic flow on the road based on the modelled flow properly and the DAS detection value.
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Specification