Fusing Multi-Sensor Measurements to Improve Heading Estimation using Kalman Gain for Indoors Smartphone Positioning Solutions

Technology progression in the last decades leads to many smartphone advancements, such as embedding variety of sensors for various measurement and applications. Positioning sensors (Accelerometer, Gyroscope, and Magnetometer) are one of the significant developments. Besides this, indoor positioning services on smartphones are the main advantage of these sensors. There are many indoor positioning applications, for instance; indoor navigation, asset tracking, controlling in warehouse, rescue operation, and entertainment applications. Nevertheless, precise position information through current positioning techniques is the main issue of these applications. The pedestrian dead reckoning (PDR) technique is one of the techniques in which the integration of onboard sensors is used for locating smartphones. Estimated distance, heading, and typical speed can be measured to determine the estimated position of the smartphone via using the PDR technique. The PDR technique offers a low positioning accuracy due to an existing unpredictable error of the embedded sensors. To solve this issue, fusing multi-sensors measurements is proposed, in this paper, to reduce the existing sensors drifts and errors. Further, the sensors' measurements with the previously estimated position are fused by using KALMAN Filter to determine the current location of the smartphone in each step of walking with higher accuracy. The obtained positioning accuracy through the proposed approach and based on trial experiments is 2 meters, which is equivalent to 10% improvement in comparison with state of the art.