High-Precision Performance of Tightly Coupled Positioning in Urban Environment

Global navigation satellite systems (GNSS) such as the BeiDou Navigation Satellite System, Global Positioning System, Global Navigation Satellite System and Galileo are playing an increasingly pivotal role in autonomous driving. Given its importance for autonomous vehicles, positioning accuracy has become an important area of research. Stable and high-precision positioning is essential to ensure the safety of autonomous driving systems, and centimeter-level and lane-level positioning can, to a certain extent, achieve the required precision. Compared with a single GNSS, a multi-GNSS can provide greater positioning accuracy and availability. In the urban environment, buildings, viaducts, and tunnels can block GNSS signals. Thus, to obtain available and highly accurate positioning, an inertial navigation system (INS) can be helpful. Therefore, a tightly coupled multi-GNSS/INS system is introduced. To test the performance of this system, several typical urban scenes were selected. The results show that the system can provide centimeter-level positioning accuracy and maintain excellent positioning performance when GNSS signals are lost. This system may be used to meet the positioning requirements for autonomous driving until such time as urban road intelligence is comprehensively improved.