| 摘要 |
PROBLEM TO BE SOLVED: To suppress power consumption in a vehicle detector that transmits a detection result of vehicle existence to a master device. SOLUTION: A vehicle detection system, which includes a plurality of slave devices, each corresponding to a vehicle detector, and a master device, transmits vehicle-detection data at a predetermined period (750 ms intervals) from each slave device to the master device, the data including the detection result of vehicle existence in the period. In the slave device, usually, the operation state of a slave-side controller is in a sleep state, and the power source of a slave-side wireless device is shut off. When the detection result of vehicle existence changes, while the slave-side controller shifts to an active state, the power source of the slave-side wireless device is turned on, and accumulation of detection-result data from the change point of the detection result is started. Moreover, when broadcast notification from the master device is received, the vehicle-detection data, including the detection-result data accumulated up to the point, are transmitted to the master device through the slave-side wireless device, and when the transmission is completed, the power source of the slave-side wireless device is shut off, and thereafter the slave-side controller shifts to the sleep state. COPYRIGHT: (C)2010,JPO&INPIT
|
