Design And Research Of Indoor Positioning System Based On RFID

In recent years, the progress of location based service(LBS) makes people develop higher and higher requirements on the location, and as the social economy comes into prosperity gradually, large indoor environment(such as a large hospital, supermarket,underground car parks, museums, large buildings, underground mines, etc.) are increased,so do the time and scope of indoor activities people take. At this moment, indoor personnel positioning is particularly important, which can not only to a certain extent,improve the quality of life, but also can ensure the security of life. But different from the outside personnel positioning, the complexity of the indoor environment, higher requirements on accuracy and positioning equipment deployment, etc. will become the problems to be studied by indoor personnel on positioning system.Aiming at the problem of indoor personnel positioning system such as low positioning accuracy, low real-time performance, bad user experience, redesign and improvement are made in this paper. The main work is as follows:(1) Based on the study of a typical RFID system and the basic architecture of the underlying hardware, this paper analyzes the designing scheme, proposes a relatively accurate positioning scheme of indoor personnel, studies the communication mode of readers and tags, analyzes and selects the hardware structure of them.(2) The indoor personnel positioning system is built based on electronic tags,reader and positioning actuator, and the indoor personnel positioning system software is developed with C++ programming language in Visual Studio 2010. Then Software development process is expounded in detail, the application class diagram and part of the key code are given, and the function of the software is described combined with the interface of the software.(3) Two kinds of classic algorithms of indoor personnel positioning system are studied: LANDMARC algorithm and VIRE algorithm. LANDMARC auxiliary positioning algorithm is a way to calculate the target location with reference tags for assistant location as well as the weighting idea of "nearest neighbors"; VIRE algorithm is an improved one that introduces the algorithm of virtual reference tags on the basis of LANDMARC algorithm. Through the research on two kinds of algorithm, and finally on the basis of these two kinds of algorithm was improved, put forward lagrange interpolation polynomial is used to calculate the RSSI virtual reference tags, thesimulation experimental results show that the improved algorithm does improve the positioning accuracy.