Public trial of an automated highway system (AHS) in Japan was conducted on an unopened portion of the Joshinetsu Highway in Nagano Prefecture in September 1996. A technique for separating the extraneous magnetic fields formed by the magnetized steel connecting beams of bridges from those generated by magnets in the road is particularly essential for automated driving on an actual highway. The trial showed that the signal processing procedure can recognize extraneous magnetic fields and differentiate them from the magnetic fields produced by magnetic markers embedded in the road. The results also confirmed that the magnetic sensor construction had been sufficiently optimized to facilitate test driving. These results thus indicated that automated driving by means of the magnetic sensor system is also possible on an actual highway.
Abstract