Road Edge Tracking for Robot Road Following

The problem of navigating a robot along a road is approached by means of creating and updating a simple representation of the road from a sequence of images. The representation chosen is a 4-parameter model that describes the width, direction and simple curvature of the road in a vehicle centred (X,Y,Z) world coordinate system. The model is created from tracking along major edge features in an image and applying constraints to select road edge candidates. Updating consists of tracking a set of measured edge points from frame to frame (assuming that vehicle motion is known) and using a weighted least squares process to find the 4 parameters of the road model. A number of constraint and filtering processes representing knowledge of how a vehicle moves on a road have been applied.