Centimeter vehicle positioning and lane keeping

Vehicle positioning with an accuracy of 10 cm or less will enable lane keeping assistance in addition to other safety benefits when enhanced lane-level digital map is in place. With constantly evolving technology and sensors, a high precision positioning system that fits into the automotive market can be expected within the next decade. Such a system will incorporate GPS and inertial system (INS) for enhanced positioning performance and availability. In this paper, the technology fields that will have a significant impact on the deployment of centimeter vehicle positioning system will be discussed. Vision based lane recognition systems are relatively mature and have already been introduced to market for lane departure warning etc. However both systems have some limitations. GPS/INS based systems may suffer from frequent satellite signal masking or blockage, while vision based systems do not work well in adverse weather condition or with poor lane signature. Effectively combining these two technologies can make a robust lane departure warning system. A precision map was made for the test area near Stuttgart using RTNA map-making approach. A Mercedes S-class equipped with both a vision system and a high precision GPS/INS was used for the test. The positioning map-matching results and the vision offset are compared and the complementary effectiveness is illustrated.