Pedestrian Dead Reckoning System Using Dual IMU to Consider Heel Strike Impact

Abstract: In this paper, we propose pedestrian dead-reckoning (PDR) system using shoe and calf mounting inertial measurement units (IMUs) to consider heel strike impact. Generally, PDR system with shoe mounted inertial sensors often uses zero velocity update (ZUPT) for reducing the influence of the bias and white noises in the gyroscope and accelerometer signals. However, heel strike impact causes a large acceleration and angular velocity that cannot be measured by the accelerometer and the gyroscope. Accordingly, the designed extended Kalman filter (EKF) does not correctly reflect the actual environment, because conventional algorithms do not take into consideration the non-measurable acceleration. It is also difficult to compensate for un measurable values if the heel strike impact is large. In order to consider heel strike impact, we proposed the PDR system using dual IMU. Calf mounted IMU is less affected by heel strike impact than shoe mounted IMU because of the damping effect by shoe insole. Therefore, the proposed algorithm uses the joint constraint between two sensors considering heel strike impact. The experimental results show improved performance by comparing the proposed algorithm and conventional algorithm.