Lightweight seamless lane-level positioning with the integration of BDS-3 PPP-B2b and VINS: a case study using smartphone

Ground-based Global Navigation Satellite Systems (GNSS) augmentation services such as real-time service (RTS) facilitate smartphones in achieving real-time lane-level precise point positioning (PPP). However, in mountainous areas and similar regions, ground-communication network blind spots are common, leading to GNSS-augmented positioning failures. Additionally, although the integration of GNSS and Visual-Inertial Navigation System (VINS) can maintain high precision and continuous positioning, VINS consumes excessive battery power. Therefore, this paper proposes a lightweight seamless lane-level positioning method for smartphones with the integration of PPP and VINS based on BeiDou navigation satellite system (BDS-3) PPP-B2b services. The You Only Look Once V5 (YOLOv5) algorithm is employed to recognize road signs. When structures like bridges or highway toll booths are recognized, the factor graph algorithm combines PPP-B2b/VINS to achieve positioning. The experimental findings reveal that real-time PPP-B2b achieves a horizontal positioning accuracy of 1.48 m in dynamic scenarios. Upon implementing the PPP-B2b/VINS model, this accuracy improves to 0.99 m. Moreover, in instances where the PPP-B2b positioning solution is unavailable, smartphone VINS demonstrates the capability to maintain a horizontal positioning accuracy of 1 m within 20-30 s. This symbiotic relationship between PPP-B2b and VINS establishes a lightweight and seamless solution ideal for applications requiring continuous and precise positioning of smartphone, such as highway navigation, and various lane-level services.