Roadway guidance system

A roadway guidance system comprising:

• a plurality of emitter strips disposed along a roadway in spaced intervals in a direction of travel, each said emitter strip comprising an emitter and a plurality of strip antennas configured to transmit a wireless signal, the emitter being in communication with each strip antenna of the plurality of strip antennas through a common feedline;
• a receiver apparatus associated with a passing vehicle travelling on the roadway, wherein said receiver apparatus includes at least three vehicle antennas spaced relative to one another and laterally disposed on the passing vehicle relative to the direction of travel of the roadway, each of said vehicle antennas being configured to detect the wireless signals transmitted by at least a respective subset of emitter strips of the plurality of emitter strips as said vehicle antenna passes said subset of emitter strips;
• and
• a controller for interpreting the relative signal strengths detected by the vehicle antennas for maintaining the position of the passing vehicle within a travel lane as the passing vehicle is moving along the roadway based on signal information transmitted by the emitter strips of the plurality of emitter strips to determine the position of the passing vehicle relative to one or more of the left edge, the right edge and the centerline of the travel lane;
• wherein each emitter strip of the plurality of emitter strips has a length less than 10 feet,
• wherein the emitter of each emitter strip is adapted to be excited by energy pulses transmitted from the passing vehicle, and
• wherein each of the plurality of strip antennas is configured to receive the energy pulses, generate excitation energy from energy of the energy pulses, and transmit the excitation energy to the emitter.

A method of using a roadway guidance system comprising the steps of:

• transmitting energy pulses from a vehicle to an emitter strip located on a roadway, the emitter strip having a length of less than 10 feet and including an emitter and a plurality of strip antennas, the emitter being in communication with each strip antenna of the plurality of strip antennas through a common feedline;
• receiving, by each of the plurality of strip antennas, the energy pulses;
• generating, by each of the plurality of strip antennas, excitation energy from energy of the energy pulses;
• transmitting, by each of the plurality of strip antennas, the excitation energy to the emitter;
• detecting, after the transmitting said energy pulses, whether return signals are received by a receiver apparatus associated with the vehicle;
• comparing, by the receiver apparatus, the received return signals in order to determine relative signal strengths of the received return signals;
• determining an estimated position on the roadway based on the determined relative signal strengths;
• comparing the estimated position on the roadway with a predefined position on the roadway;
• and
• sending at least one of steering correction and braking correction to a vehicle computer to adjust the position of the vehicle.