| 摘要 |
<p>A traffic light system that comprises traffic lights for directing the passage of vehicles through art intersection; a control unit with a signal controller in communication with each of the plurality of traffic lights, a signal controller transceiver with a directional antenna, and a signal controller interface processing unit (SCIPU) in communication with the signal controller and with the signal controller transceiver; and a vehicle unit provided with a vehicle processing unit and a vehicle transceiver, which comprising a forwardly mounted directional antenna. The signal controller transceiver repeatedly transmits a wireless interrogating signal to approaches of the intersection, which identifies the control unit. The vehicle transceiver transmits a wireless return signal modulated by the vehicle processing unit with an identifier of the control unit and of the vehicle unit to the signal controller transceiver after having received the interrogating signal, reception of the return signal and an increase in RSSI value with time of the return signal being indicative that a vehicle carrying the vehicle unit is located upstream to the intersection. The SCIPU counts a real-time number of vehicles located on each of the one or more approaches and to allocate duration of green light time for each of the plurality of traffic lights in response to the real-time number of vehicles located on a corresponding approach.</p> |
