Patent ID: 7227620

Claim:
An environment recognition system for recognizing a substance moving relative thereto, with using a modulated beam, comprising: a beam emitting portion for emitting the beam therefrom; a beam scanning portion for scanning the beam; a beam receiving portion for detecting a beam reflected from the substance; a distance measuring portion for obtaining a distance image upon basis of a signal received upon said beam receiving portion; a distortion removal portion for making comparison between plural numbers of the distance images obtained by said distance measuring portion, so as to remove distortion of the substance, which is included within the distance images; and a means for changing an interval between plural numbers of measurement joints, which are included within the distance image, wherein said means for changing the measurement interval establishes the measurement points all over an area of the distance image at a large interval in an initial stage, and after detecting the substance moving relative thereto within the distance image, which is measured with the large interval, determines the measurement points at an interval smaller than that before, in vicinity of an area including that substance therein.