摘要 |
An area is divided by a plurality of parallel lines parallel to a vehicle body axis CL of a vehicle V, into fifteen detection areas K1 to K15 each having a width of 1.6 m, and each of the detection areas K1 to K15 is divided by a distance address at a distance of every 0.5 m to define a large number of measure-shaped regions. It is determined whether a target T exists in any of the regions, by adding together received reception level signals of laser beams reflected in the regions and comparing a value resulting from the adding with a threshold value. The widths of the detection areas K1 to K15 assume a constant value irrespective of distance to the target and hence, even when the target T exists at a point closer to the vehicle, the reception level signals of waves reflected from a wider area of the target T can be added together, leading to an enhanced detecting ability.
|