In-Motion Rapid and Robust Heading Alignment of Low-Cost Inertial Measurement Units Using Position Loci for Indoor Navigation

Low-cost microelectromechanical inertial measurement units (MIMUs) are widely used in various fields such as healthcare, sports, industry, and indoor navigation. However, rapid and robust heading alignment under dynamic conditions remains a challenge. A novel heading alignment method of low-cost MIMU using position loci for indoor navigation is proposed. Aiming at the state-of-the-art acceleration-based optimization-based alignment (ABOBA) method's vulnerability to dynamic disturbances, the observation equation of the initial attitude matrix is established based on velocity and position loci. On this basis, Davenport's q-method is adopted to estimate the initial attitude. Field tests are conducted under dynamic conditions with about 0.7 m/s to verify the performance of the proposed method and the effect of the referenced position error on the heading alignment is explored. Results show that the initial heading error could be quickly converged to less than 4° within 5 s, which is far better than the state-of-the-art method and is of significant merits to solve the challenge of in-motion accurate heading alignment under weak acceleration conditions.