| 摘要 |
<p>PURPOSE:To achieve a higher accuracy of an alarm issuance by comparing an alarm issuance value calculated based on an approach angle of a target for a reference point set in an alerting area and expected arrival time with a multi-stage alarm issuance reference preset. CONSTITUTION:Target information 101 obtained from a sensor 8 is stored into a memory 1 and reference position information 201 is stored into a memory 2 pertaining a reference point preset in an alerting area. Then, based on the information 101 and 202, an approach angle of a target is calculated with an approach angle calculation circuit 4 and an expected arrival time is calculated 5 from a distance to the target from a reference position and a speed of the target. Then, an alarm issuance level calculation circuit 7 calculates an alarm issuance value from the approach angle and the expected arrival time and the value is compared with an alarm issuance reference value 601 stored previously in a memory 6 to determine at which level the alarm issuance value is contained. An alarm with the highest urgency therein is extracted thereby achieving a higher accuracy of alarm issuance while preventing overlooking.</p> |
