| 摘要 |
<p>PURPOSE:To suppress erroneous alarms and unnecessary primary alarms (for calling driver's attention) and to prevent the occurrence of am alarming delay when a vehicle excessively approaches a preceding vehicle by providing a means which recognizes a measurement impossible state and another means which recognizes that the distance between the two vehicles remarkably changes and setting alarming distance holding time and alarm suppressing time in accordance with the state. CONSTITUTION:After radar equipment 21 measures the distance L to a preceding vehicle from its own vehicle, an information processing circuit 25 calculates the relative speed Vr between the two vehicles when the distance L can be measured, does not change remarkably, and can be continuously detected by, for example, four values only. Then the circuit 25 calculates the alarming distance D0 which becomes a reference distance for issuing an alarm. The distance D0 is divided into a primary alarming distance D1 for awakening the attention of the driver of its own vehicle and secondary alarming distance D2 for emergency case and a primary alarm is issued when D2<=<D1. When L<D2, a secondary alarm is issued. When the distance L cannot be measured or remarkably changes, the circuit 2 holds the distance D0 immediately before recognition for a fixed period of time and actuates an alarm generator 27 after discriminating the need of issuing an alarm by comparing the distance D0 with a newly measured distance L.</p> |
