A Tightly Coupled Integration Approach for Cooperative Positioning Enhancement in DSRC Vehicular Networks

Abstract

Intelligent transportation system significantly relies on accurate positioning information of land vehicles for both safety and non-safety related applications, such as hard-braking ahead warning and red-light violation warning. However, existing Global Navigation Satellite System (GNSS) based solutions suffer from positioning performance degradation in challenging environments, such as urban canyons and tunnels. In this paper, we focus on the positioning performance enhancement of land vehicles via cooperative positioning under a partial GNSS environment in a Vehicular Ad-hoc NETwork (VANET). The availability of Time-of-Flight (ToF) based inter-vehicle or vehicle-to-infrastructure ranges is verified via 5.9 GHz Dedicated Short-Range Communication (DSRC) vehicle-to-everything communication with RTS/CTS unicast mechanism. An inertial navigation sensor aided, tightly coupled integration approach for land vehicle cooperative positioning using DSRC ToF ranges and carrier frequency offset range-rates is proposed, where a digital map is used to constrain the position estimates. If available, the GNSS pseudorange and Doppler shift under partial GNSS environment can also be incorporated. A Rao-Blackwellized particle filter is utilized to estimate the unknown variables allowing for reduced computational complexity in comparison with the conventional particle filter. The posterior Cramer-Rao lower bound is also derived to give a theoretical performance guideline. Both simulation and experimental results show the validity of our proposed approach.

Factor Graph Weight Particles aided Distributed Underwater Cooperative Positioning Algorithm

“…Although GNSS DD techniques have been used by many researchers for inter-node ranging in CP methods, the availability and accuracy of double differenced GNSS is limited in dense urban environments due to multipath effects, NLOS delays and signal outages [14,15]. Different from GNSS-based CP methods, the range-based CP methods estimate the inter-node ranges by using radio ranging techniques such as time-of arrival (TOA) [16], angle of arrival (AOA) [17], receiver signal strength (RSS) [18] and round-trip time (RTT) [19]. The range-based CP methods are more suitable for the scenarios where the availability of GNSS is limited [20].…”