Research And Implementation Of Heading Estimation Technology Using Mobile Intelligent Terminal

In recent years, large commercial shopping center, gymnasium,exhibition center, train stations and other public buildings increase due to the accelerated development of China's social economic and urbanization.People propose a higher request for the accuracy, real time, continuity of indoor positioning because of increasingly frequent indoor activities. As a key building block for indoor pedestrian navigation, heading estimation has important research value. Accurate heading estimation provide better location services for users. Moreover, with the rapid development of mobile Internet, a variety of mobile intelligent terminal electronic products appear in the public view. Intelligent terminal built in a variety of sensors, it can capture the user's movement data real-time. Heading estimation based on intelligent terminal has become a hot research topic.While most estimation techniques make assumption about the availability of infrastructure and need too many conditional limitation,this paper study a heading estimation algorithm using inertial sensor.During the study, this thesis starts with the position of the mobile phone detection algorithm and design a position detection method based on acceleration and gyroscope data. Completing position classification through the steps of data preprocessing, feature extraction and evaluation,decision making. Secondly, this paper studies the moving direction decision algorithm in a mobile phone coordinate system through the analysis of human walking process. This method extracts data segment which contains heading direction information based on collected accelerometer, then obtain the walking direction and expresses it in the phone's local coordinate system. Meanwhile, this paper studies a compass calibration algorithm by calibrating the compass to find out the real magnetic north vector, in order to eliminate the influence of geomagnetic disturbances. Finally, the local walking direction transform to the global geographic direction by using the vector operation, and the direction of pedestrian movement is determined.After analysis of actual scenario test, the method can calculate the heading direction in real time without relying on external conditions and without restricting the use of mobile phones, it can meet requirements of pedestrian heading estimation in indoor environment.