摘要 |
VEHICLE LOCATION SYSTEM An improved system of the type wherein the precise location of a vehicle is determined. The system includes a plurality of fixed position transmitters which are predeterminedly positioned along the intended route of the vehicle. Each transmitter broadcasts a sequence of data bits representative of its particular location, over a directive antenna. A receiver within the vehicle detects nearby transmitters and decodes the data bits, thereby establishing the vehicular general position. The precise vehicular location is established by logic circuitry which processes variations in the signal strength of the received signal along with position pulses generated by an odometer sensor at predetermined increments of vehicular travel. The logic circuitry produces an output detect signal corresponding to the precise vehicular position during which the vehicle is directly opposite the transmitter. |