Research On Indoor Positioning Technology Based On Mobile Terminal

Because of the vigorous development of LBS and mobile internet, there is a sustained growth of the demand for the application of indoor positioning and navigation. The research of indoor positioning and navigation based on mobile terminal platform has become a hot research direction. As the traditional indoor positioning technology based on the realization of the single solution has some limitations, with related technologies involved, a new model of variety of technology integration has become a tendency. Under the background, the thesis take full advantages of traditional RSSI-based technology and inertial sensor technology to do some research.The application of indoor positioning and navigation which based on mobile terminal can be divided into two kinds scenarios:static scene and dynamic scene.In the static scene, it needs to get current location when terminal is in steady state. To reduce the dependence on indoor propagation model and the complexity of the traditional RSSI(received signal strength indication)-based localization algorithm, the thesis proposed the moving weighted localization algorithm based on RSSI. Firstly, the algorithm set up three kinds of reference marks through the environment modeling; After generating the RSSI from different locating tags and filtering the data with gauss filter and mean filter, it organized them into RSSI vector. The algorithm determined the location of the reference mark by the rules and transferred the RSSI vector into reference location. By using the indoor propagation model, the algorithm calculated out the moving weight. Finally it turned the reference location into the estimation location. The result of the comparison experiment indicated the proposed algorithm had better accuracy and stability than the comparison algorithms.In the dynamic scene, it needs to record the trajectory during terminal’s movement. By combining with the inertial sensors and indoor positioning,the thesis designed and implemented an indoor movement trajectory recording system on the iOS platform. In order to solve the tracking problem of movement of mobile terminals, the system firstly use iOS framework to monitor the output data of accelerometer, gyroscope and compass; With the data that iOS framework offered, the system implemented a real-time activity framework. By using the both framework together, the system could transfer the data into motion model which include heading direction, step counter, distance and activity. At last the system update the trajectory on the mobile terminals. The actual operation effect shows that the system could accurately detect and record the movement status and trajectory in real-time.