| 摘要 |
A cable (10) for traffic control and monitoring comprises a single mode optical fibre (11) and a plurality of elongate conductors (12) arranged around the periphery of the fibre. By combining the functions of longitudinal traffic sensor, distributed temperature sensor, local road condition data transmission and co-operating vehicle guidance wire into one cable there is the possibility of forming an integrated multi-function cable. The fibre may be used in a sensing mode to measure traffic flow and temperature. The electrical conductor may be used to both guide vehicles and transmit information back to the vehicles using a leaky feeder method. Several cables may be arranged in parallel in the road surface. Sensing techniques such as Rayleigh backscatter or Polarisation Optical Time Domain Reflectrometry (POTDR) may be employed. |
