Research on Integrity Monitoring of GNSS/AHRS Integrated Navigation

With the development of autonomous driving and UAV technology, users put forward higher demands for the integrity of GNSS positioning services in complex urban environments. Receiver Autonomous Integrity Monitoring (RAIM) is an essential means to ensure the integrity of location service. The conventional RAIM algorithm uses redundant observations for fault detection, availability judgment, and fault identification. However, in complex urban scenarios, users are faced with problems such as the reduction of visible satellites and the deterioration of satellite geometry distribution, which restrict the availability of user integrity monitoring services. In order to improve the availability of integrity services in complex urban environments, this paper proposes an integrity monitoring method based on GNSS/ Attitude and Heading Reference System (AHRS) information fusion. The attitude information provided by AHRS can improve the model strength, effectively reduce the requirement of RAIM algorithm on the number of visible satellites, and improve the availability of RAIM algorithm in complex urban environments. Compared with the traditional RAIM algorithm, the proposed method enhances the algorithm availability by about 29.8%.