Abstract: A method for guiding a robotic vehicle includes the steps of establishing a tracking position along a row of vehicle sensors at which the border is to intersect the row, positioning the vehicle on the border so that the border intersects the row at an intersecting position, generating a positive signal when a sensor senses any obstruction by vegetation of a path of radiation from a respective emitter to a respective detector, generating a negative signal when a sensor does not sense any obstruction, repeating said generating steps as said vehicle advances, sending a plurality of groups of said generated signals to a processor, averaging said signals, identifying the intersecting position by identifying an adjacent pair of oppositely signalling sensors on the basis of said averaging of said signals, determining whether the tracking position is at or to the right or left of the intersecting position, and steering the vehicle straight when the tracking position is at the same location as the intersecting positio