Method and device for determining the curve of a road

A method for determining data representative of a layout of a road in a two-dimensional Cartesian coordinate system, said coordinate system being associated with a vehicle travelling along said road, said coordinate system having an origin and being defined by a longitudinal axis and a lateral axis, the method comprising the steps of:

• determining a first set of first coordinate points (x1, y1) in said coordinate system on the basis of representative data of at least one image of a road environment in front of said vehicle, said first coordinate points being representative of a curvature of the road between a first minimum abscissa and a first maximum abscissa along the longitudinal axis, said first minimum abscissa corresponding to the origin of said coordinate system;
• determining a second set of second coordinate points (x2, y2) in said coordinate system on the basis of mapping data of the road environment of said vehicle, said second coordinate points being representative of the curvature of the road between a second minimum abscissa and a second maximum abscissa along the longitudinal axis, said second minimum abscissa corresponding to the origin of said coordinate system and said second maximum abscissa being greater than said first minimum abscissa, each first coordinate point of the first set corresponding to a second coordinate point of the second set because the first coordinate point and the corresponding second point have the same abscissa;
• determining a smallest first abscissa value (Xp) for which the absolute value of the difference between the ordinate of a first coordinate point and the ordinate of the corresponding second coordinate point is greater than a threshold value;
• modifying the value of the ordinate of each second coordinate point of the second set by adding said difference;
• and
• determining said data representative of the road layout on the basis of the first coordinate points of which the first abscissa is smaller than the smallest first abscissa value and on the basis of the second coordinate points of which the second abscissa is greater than the smallest first abscissa value.