A hybrid integrity monitoring method using vehicular wireless communication in difficult environments for GNSS

Abstract

Vehicular communication using the DSRC (Dedicated Short Range Communication) standard is becoming an enabling factor for a wide range of Cooperative Intelligent Transportation System (C-ITS) applications, especially those with high requirements of safety assurance. The location information of connected vehicles is fundamental, and significant for ensuring safe driving and preventing traffic accidents under complex and uncertain conditions. In order to alleviate the drawbacks of GNSS (Global Navigation Satellite System) based positioning due to satellite signal non-availability under difficult environments such as dense urban areas, a hybrid integrity monitoring technique is proposed. The range-rate measurement from the DSRC unit in the vehicle is employed to assist integrity monitoring of observable satellites, and the DSRC measurements are sent to the target vehicle through a vehicle-to-vehicle channel along with the identified state of neighboring vehicles. With the assistance from surrounding neighborhoods and a road map database, a virtual satellite ranging solution is possible to expand the measurements for enabling autonomous GNSS integrity monitoring and fault detection without the limitation of satellite visibility. Simulations conducted with different vehicle operation conditions and GNSS fault models demonstrate that the proposed solution outperforms conventional RAIM (Receiver Autonomous Integrity Monitoring) methods making it promising for many location-based cooperative applications.