Fusing the Data of Dual Foot-Mounted INS Based on a Heuristic Equality Constraint

Foot-mounted inertial navigation system (FM-INS) is suitable as the core pedestrian navigation system (PNS) in GPS denied environments for some applications (e.g., soldier and first responder positioning). However, to date the exiting ZUPT-aided FM-INS still possesses some drawbacks, such as systematic heading drift. Another alternative strategy that integrating the information of dual FM-INSs mounted on both feet is employed for achieving a more robust and reliable performance. In this paper, a new equality constraint method based on pedestrian movement model is proposed to fuse the information of two FM-INSs in the absence of any additional ranging equipment. Real field experiments demonstrate that the proposed algorithm could improve the performance of both FM-INSs.