Patent ID: 8311283

Claim:
A method for detecting lane departure of a vehicle, comprising: an image recognition process which includes the following steps: an image capturing step for capturing an image frame data of a road ahead of the vehicle by using an image capturing unit; a lane line recognition step for analyzing the image frame data and establishing a road geometry estimation model by using a quadratic curve fitting equation, a plurality of parameters solved by substituting a plurality of position data calculated by recognizing a plurality of lane lines in the image frame data to correct the road geometry estimation model and make the corrected road geometry estimation model approximating a practical lane line track; and a deviation estimation process which includes the following steps: an operation processing step: use the corrected road geometry estimation model and the quadratic curve fitting equation to calculate a transversal displacement, a traveling slope, and a lane curvature; and a pre-alert step: compare the transversal displacement and the corrected road geometry estimation model to determinate a distance between the vehicle and the lane line; if the vehicle is close to the lane line, a warning is issued; wherein the transversal displacement is calculated by the equation: Δ= y L −L×ε L where Δ is the transversal displacement of the vehicle; y L is a displacement of the vehicle from a reference point; L is a preview distance; and ε L is the traveling slope; the distance between the vehicle and the lane line is calculated by the equation: Δ ⁢ ⁢ y = { b R 2 - ( b V 2 + y L - L × ɛ L ) b R 2 - ( b V 2 - y L + L × ɛ L ) where b R is a lane width which is from the coordinate transformation from the lane width of one row in the image plane, which the lane width in the image plane is solved by the road geometry estimation model; b v is a width of the vehicle; y L is the displacement of the vehicle from the reference point; L is the preview distance; and ε L is the traveling slope.