| This research develops a Vehicle-Based Augmentation System (VBAS) for GPS that has the capabilities of Ground-Based Augmentation Systems (GBAS) but without fixed ground reference stations. The proposed system targets low-cost automotive applications. Existing augmented GPS systems which can provide centimeters level of accuracy are not suitable for automotive applications due to their high infrastructural cost (e.g. one reference station is needed at approximately every 20 km for GBAS). In contrast, by setting up a vehicle-to-vehicle (V2V) network, the proposed system can improve positioning accuracy simply by sharing measurement data among vehicles in the network. The cost of "infrastructure upgrade" will essentially be free, since V2V communication equipment and GPS receivers are expected to become standard equipment on automobiles in the near future. With assistance of such system, the expected accuracy of GPS could reach the 20-centimeter level, which is critical for automotive applications such as automated driving, automated lane keeping, and highway collision avoidance.;To build this system, a new algorithm for differentiating GPS measurements will be investigated. A vehicle-to-vehicle (V2V) network-based collaborative navigating method will also be tested to enable the new algorithm. Simulations, as well as a physical test system will be set up to demonstrate the capabilities of the new algorithm. |
