A road sensing function is crucial for AHS (advanced cruise assist highway system), and AHS principal services proposed by the Public Works Research Institute and AHSRA are examined. The necessity of infrastructure-based road sensors is clarified by showing the limitations of vehicle-based sensors. The differences in sensing requirements between the AHS road sensor and the conventional traffic sensor are discussed. The effectiveness of some candidate sensors is examined qualitatively and quantitatively and on the basis of these studies, basic guidelines in designing actual road sensors were developed. It is proposed that image sensors (daylight camera or infrared camera plus image processor) play a central role and that millimetre-wave sensors and laser sensors complement the image sensor. (A*)
Abstract