Height Difference Determination Using Smartphones Based Accelerometers

Indoor navigation based on Pedestrian Dead Reckoning (PDR) is a highly researched topic in recent years. PDR is a two-dimensional dead reckoning technique that employs inertial sensors, such as those available in smartphones, to provide the user's position. If the vertical position component is also required, it can be obtained from the smartphones' barometer. However, unlike accelerometers, approximately, only 10% of the smartphones are equipped with barometers. In this paper, two methods for height difference estimation during stairs motion are proposed. Those are based only on the smartphones' accelerometers and do not require any prior calibration. The proposed approaches are evaluated on different staircases with different smartphone locations on the user. Results show that the proposed approaches yield an average percentage error in the range of 2.5% - 13% when calculating height difference of the examined staircases. Thus, the proposed approach can be implemented alongside traditional PDR approaches to enhance its capabilities to 3D PDR during stairs motion.