Research On Location Method Of Wearable Devices In Group Movement Scenes

With the development of electronic devices, wearable devices display a small part of its talent, having a significant share in the field of intelligent market. There is a growing frequency on using wearable devices. Consequently, people attach great importance to one of its basic functions——location. Hence, there are many scholars taking part in the research of moving people’s location method in recent years. There are 2 major ways in location technology, satellite navigation and wireless sensor network localization. The principle of satellite navigation is to receive at least 4 satellites’signals by user at one time, and simulcast the pseudo range observation equations. Then the position will be gotten by solving set of equations. Wireless sensor network localization has 3 major methods which on the basis of time of arrival, angle of arrival, and signal strength. It can be achieved by the technology of infrared, ultrasonic, Wi-Fi, RFID, Ultra wideband, and ZigBee, etc. To locating moving people, scholars bring forward some opinions that based on moving beacon nodes, which can be divided into 2 types. Only one beacon node is needed in the first type with some limitations on its movement to assure the accuracy of localization. The second type raises a solution that many beacon nodes are needed without limitations on movement. These two ways both have restricted applications and complicated implementations.Aiming at locating all moving people in a group, this thesis improves the existing one which is based on moving beacon node and propose a method using Beidou Navigation System combining with ZigBee. The present method, compared with the existing one, makes the localization of whole moving nodes come true by setting only one beacon node. Meanwhile, there is no specific requirement on beacon node’s movement path, and beacon node itself is in random motion. There is only one beacon node in the moving group, while the other are the normal ones. Beidou Navigation Satellite System gives the location information of beacon node. And normal nodes correspond with each other by self-organized network formed by ZigBee, located according to signal strength and Pedestrian Dead Reckoning. Emulation experiment indicates that the localization accuracy of this algorithm reaches 3m-7m which totally meet the requirement of people’s informal standard and can be used in real life. The proposed method could be applied in the wearable devices and locate the moving group.