Research On Indoor Trajectory Tracking Technology Based On Mobile Inertial Sensor

With the fast development of information technology,more and more indoor trajectory tracking and positioning technology is applied in people's daily work and life.The trajectory positioning and tracking technology is based on Global Positioning System(GPS).However,due to occlusion of the indoor environment,satellite signal cannot provide indoor positioning services to meet user requirements.Therefore,in the past decade the indoor positioning technology gradually become the focus of research and development.In the study,using the inertial sensor of mobile terminal to make research on Pedestrian Dead Reckoning(PDR).Based on the mobile phone embedded sensors for indoor trajectory tracking and positioning is not susceptible to interference from the outside environment,and it is flexible and convenient with low cost.According to the change of data which is collected by the inertial sensor in pedestrian movement process,we can detect step,estimate the step length and orientation.The adaptive gait estimation algorithm is proposed to resolve the pseudo-peak/trough phenomenon which would lead to misjudgment in step detection.In consider of the complementary characteristics of gyroscope and compass heading estimation bias,two kinds of heading estimation information are fused through the Kalman Filter,which could improve the heading estimation accuracy.In view of the bias of pedestrian trajectory tracking and positioning-based on inertial sensor.An improved matching candidate access rules is proposed according to the characteristics of the indoor environment,which draws on the experience of the vehicle navigation system.Combined with the spatial topological relation of the indoor environment,a map-match algorithm which is suitable for indoor positioning is proposed based on the Hidden Markov Model(HMM).By the aid of map information,the heading and coordinate position is corrected in PDR progress.And it also improves accuracy of trajectory positioning and tracking.Finally,according to the system model,the software system is developed,and the performance of the indoor trajectory tracking system is verified based on the Android platform.