Application of variational Bayesian-based cubature information filter for UWB/INS tightly coupled positioning system

Accurate and reliable positioning is a crucial foundation for achieving sufficient autonomy and intelligence in positioning systems. The ultra-wideband (UWB) technology has significant potential for applications in the challenging and complex field of indoor positioning, and is often integrated with the inertial navigation system (INS) to enhance the overall performance of integrated positioning system. This paper proposes a novel variational Bayesian-based cubature information filter that enhances the positioning accuracy of tightly coupled UWB/INS navigation system. This approach aims to provide continuous and reliable navigation and positioning across various scenarios. The proposed integrated system applies the non-holonomic constraint to positioning in the elevation direction, thereby enhancing the system's overall positioning accuracy and performance. Real-world experimental results demonstrate that the proposed system delivers continuous, accurate, and stable positioning. In UWB line-of-sight (LOS) scenario, the proposed system achieves root mean square errors (RMSEs) of 0.085 m, 0.091 m, and 0.125 m in the east, north, and horizontal directions, respectively; the corresponding errors in non-LOS (NLOS) scenario are 0.286 m, 0.237 m, and 0.372 m. Furthermore, when integrated with a scheme for mitigating NLOS errors, the proposed system demonstrates a significant enhancement in positioning accuracy. In conclusion, the experimental results effectively validate the proposed system's effectiveness in achieving accurate and continuous positioning across various environments, demonstrating its application potential in complex scenarios.