Position Location in AHS by Magnetic Pseudo-Noise Signals

This paper proposes a novel method for position location by automated vehicles in AHS. The proposed positioning system meets the desired accuracy for AHS and is economically feasible because it takes advantage of the infrastructure and characteristics of the automated roads. This positioning system is very similar to GPS in the sense of using pseudo-noise codes for range measurement. The phase of a pseudo-noise signal can be mapped to the receiver's range from a reference point where the signal correlation properties insure accurate phase estimation. The magnetic markers that are installed on the road for vehicles' lateral control are proposed as the medium to carry the signal. A magnetic pseudo-noise signal that is unique for each lane in the network of automated roads allows a vehicle to resolve its absolute position on the road by estimating the signal phase. The system can detect positioning errors with relatively short delays and correct them.