Method for judgment out of lane of vehicle

PURPOSE: A deciding method of a lane-out vehicle is provided to prevent an accident caused by lane-out by deciding the lane-out states of a vehicle at a curve exactly. CONSTITUTION: A front lane video signal is input from a camera, and an edge is sampled by application of mask and limit to the input video signal. A new lane search area is designated when a driver does not find the sampled lane or tries to change the lane. Each edge point of an object is separated from the pixel width displayed on a monitor within the designated lane search area, corresponding to lane width. Then, a lane edge list is recorded. To remove noise or unnecessary edges from the lane edge list, the application limit is adjusted. Plural related edge points are made to a group, and a group having no lane characteristics is removed. To sample a traveling lane of plural lanes having the grouped edges, outside groups are removed except inside groups having a simple equation. The finally remaining edge points are made to a group to sample a lane equation available for description with the minimum error. The sampled lane equation is applied to the shape of a road, and a lane is sampled. The lane width and lane-out degree are calculated by the sampled lane equation, and deviation between the central point of a lane and the central point of a vehicle is operated. Deviation between x coordinates in the center of a monitor and x coordinates of the vehicle is subtracted from the operated deviation. The lane-out degree of a vehicle is decided depending on whether the subtracted deviation is lower than a lane-out alarm range. If so, alarm sounds are output. Therefore, the vehicle is prevented from escaping a lane.