Sensing of passing vehicles using a lane marker on a road with built-in thin-film MI sensor and power source

摘要

In a field test, we demonstrated the sensing of passing vehicles, using onroad lane markers with a built-in magneto impedance (MI) sensor and a self-contained power source. The vehicle-sensing rate was 100% in the field test and we found that the lane marker could detect vehicles with a high degree of accuracy. A thin-film MI sensor, which is very sensitive to small external magnetic fields, an analog circuit for driving/processing, and a digital circuit with EEPROM memory for storing the number of passing vehicles were incorporated into a thin aluminum plate marker. The lane marker also had a self-contained power source, consisting of a secondary battery and a solar battery, which eliminated the need for an external power supply.