| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a railroad-crossing obstacle detector that stably detects an object regardless of the variations in reflection level. <P>SOLUTION: The railroad-crossing obstacle detector has the following configuration. A transmitter/receiver 1, 2 transmits radio waves into an area including a railroad cross 4 and receives reflected waves with respect to the radio waves so as to convert them into electric signals. A signal processing part 3 samples the electric signals, supplied from the transmitter/receiver 1, 2, in a fixed cycle. The device is configured to determine that there is an obstacle when the electric signals indicate a level, exceeding the detection threshold, a prescribed number of times or more in a plurality of times of continuous sampling included in a predetermined detection time period. <P>COPYRIGHT: (C)2012,JPO&INPIT |
