Rendition of Japan’s QZSS. Photo: Cabinet Office, Government of Japan.

Mitsubishi Electric announced it began field-testing autonomous driving technology on highways using a Centimeter-Level Augmentation Service (CLAS) broadcast from the Quasi-Zenith Satellite System (QZSS). The company will conduct driving tests to verify the possibility of infrastructural driving, using CLAS signals and high-precision 3D maps combined with Mitsubishi Electric’s sensing technologies such as millimeter-wave radar and cameras.

CLAS is a positioning-augmentation service for high-precision positioning, distributed free of charge in Japan from the QZSS, which operates under the auspices of the Cabinet Office. CLAS is scheduled to begin operating in April 2018 and is currently in the final stages of verification. The Cabinet Office expects CLAS to be used for practical applications such as safe-driving assistance and automated driving.

The precision of existing solutions is limited to within a few meters because of errors due to satellite orbits, satellite clocks and satellite biases as well as local environmental factors such as ionospheric and tropospheric delays. CLAS improves precision by using positioning-augmentation data from a network of Continuously Operating Reference Stations (CORS) administrated by the Geospatial Information Authority of Japan. The data is broadcast via the QZSS to high-precision positioning receivers installed in automobiles that can detect locations with centimeter-level accuracy.