Research On Indoor Autonomous Positioning Technology Using Wearable Devices

In recent years,domestic large and medium-sized buildings increase due to the accelerated development of urbanization.While disasters happened in these buildings,which have complex structure and crowded people,threaten the safety of people's life and property at every moment.Therefore,in indoor emergency rescue,to ensure the timely and orderly rescue work and the safety of relief workers,it is very important to establish real-time positioning system to help relief workers to monitor their own position in real time.Currently,high-tech products become smaller and lighter.Small wearable devices with powerful function have gradually become a part of people's life and are widely used in various industries.In the field of indoor positioning,wearable technology also becomes a hot topic among research personnel for its outstanding advantages.Wearable device has a variety of sensors,which can sense changes of surroundings in real time and provide observed data.Therefore,positioning personnel can monitor their own position precisely in real time through relevant wearable devices.Aiming at scenario of indoor emergency rescue and based on domestic and international research on indoor positioning technology,this thesis proposes indoor autonomous positioning technology based on wearable devices.Attaching wearable devices with various sensors to their feet,relief workers can autonomously monitor their position without relying on the indoor environment.During the study,this thesis starts with indoor 2D plane positioning algorithm and proposes a shoe-mounted navigation algorithm based on inertial technology.Based on tradition inertial navigation algorithm,this algorithm integrates effective geomagnetic data to correct directions and uses zero velocity update to further improve the positioning accuracy.Secondly,using the law that air pressure varies with height,the thesis studies a floor detection algorithm based on air pressure,to achieve vertical positioning.Rescuers can use indoor 3D positioning through combining these two algorithms without the aid of any indoor infrastructure and pre-training.In addition,with efficient conditions,this thesis also provides a floor detection algorithm based on WiFi and the results of floor detection algorithm will be initialized and corrected,further improving the detection accuracy.Meanwhile,the thesis studies four position calibration technologies,which respectively use indoor occasionally available GPS signal,sequence of geomagnetic model value of indoor route,landmark points and particle filter algorithm based on indoor maps to calibrate the positioning result,effectively eliminating positioning deviation caused by the accumulated errors.After analysis of actual scenario test,the indoor positioning method described herein has high accuracy and is able to meet requirements of positioning in indoor emergency rescue.