Calf-INS: A Calf-Mounted IMU-based Inertial Navigation System for Pedestrian

Pedestrian dead reckoning based on a wearable inertial measurement unit (IMU) is an important part of the pedestrian positioning system because it is not affected by the external environment. However, step model-based methods have the problems of low positioning performance, and zerovelocity update (ZUPT) based methods (i.e., foot-mounted inertial navigation system) are inconvenient for ordinary users to wear. This paper proposes a calf-mounted IMU-based INS (Calf- INS) for pedestrians. Based on the motion criterion, Calf-INS uses the lever-arm compensation combined with the raw IMU observations to obtain the specific force of the ankle and achieve accurate zero-velocity interval detection. Then, the lever arm compensation-based ZUPT is used to effectively limit the velocity error of the INS, so as to achieve the purpose of accurately estimating the user’s position. Test results based on straight-line and convex trajectories show that Calf-INS can achieve the same positioning accuracy as foot-mounted inertial navigation system.