| 摘要 |
<p>Location-representative signals are communicated to vehicles (12, 14, 16) by modifying existing traffic detector stations of the type utilizing an inductive coil (20) embedded in the roadway (22). Circuitry (44-52) is provided for generating a carrier signal modulated in accordance with a modulating signal representative of the location of an associated traffic detector station. A transformer (56) couples the modulated carrier signal into the existing inductive coil such that the coil establishes a magnetic field above the roadway which is modulated by the location representative signals The vehicles have inductive coils (70) mounted thereon for sensing the modulated magnetic fields. and circuitry (72, 74, 76) for extracting the location-representative signals therefrom. The location-representative signals may then be, e.g.. automatically transmitted to a central dispatching station (18).</p> |
