Towards precise car navigation: Detection of relative vehicle position on highway for collision avoidance

In this paper, we focus on evaluating the performance of NTrip/RTK solutions for accurate and precise car navigation (analysis of both the accuracy and availibility of RTK data using mobile communication). Our approach is to develop a functional system of determining lane positions on highways. A system is based on wireless radio communication among surrounding vehicles what complement and enhance the current vehicle driving system needs (lane change collision avoidance systems, vehicle tracking, lane keeping and obstacle avoidance). Because lane change collision avoidance system requires very high relative accuracies between moving objects, therefore we are introducing "moving basestation" option into our system. Relative Moving Base Software (RMBS) package is implemented in real-time into NovAtel Propak-v3 GNSS receivers. This solution provides centimeter level baseline accuracy in relative vehicle positioning. For the RMBS implementation, the moving base position is only single point position, and must be recomputed for every epoch. Therefore, RTK/Ntrip base solution is required in this system. Exchanging Position, baseline and velocity information among surrounding vehicles using the twoway PacificCrest radiomodem link, definitely improves safety and efficiency of automobile transportation on the highways. Two experiments were conducted on test routes using two cars in the combined driving conditions (highway + downtown). Both tests took place at Wuhan University, GNSS Research Center, China. One additional test was performed using an NTrip stream delivered by a free-standing mount point obtaining data from the reference Trimble NetR5 receiver. We demonstrate the versatility of the system, showing the advantages and disadvantages of each component.