Research And Simulation On RFID-based Indoor Localization System Of Logistics Center

With the continuous development of Logistics industry, the number of Logistics Centers is gradually increasing. The Logistics Center with large scale and multi functions is playing a pivotal part in the modern Logistics industry, whose level of control and dispatching on the scene and efficiency of logistics operation have a great impact on the efficiency of the whole supply chain. To put the real-time localization of goods in the Logistics Center into practice is the premise of control and dispatching behind the scenes as well as an effective means of improving efficiency of many logistics operations.RFID is a new auto-indentify technology, which has many advantages such as the RFID reader can identify many tags one time from a long distance away even in a non-visual condition. It is because of these advantages that FRID is suitable for radio localization and the research of FRID-based localization system becomes a central issue.In this thesis the author choose the logistics center as the localization room. Through the needs analysis and environment analysis, the author puts forward a method, which can achieve no-blind-area localization in Logistics Center and designs the structure of the system in detail. In the respect of specific algorithm of localization, the author advances a localization algorithm which is based on smooth disposal and which calculate the circumference models non-equally. On one hand, on the basis of the continuity of goods movement, this algorithm optimizes the stability and continuity of localization result by filtering the variable quantity of measure data and smooth disposal on localization result. On the other hand, this algorithm of localization uses a simple and convenient method of fixing the confidence level of circumference models, which is based upon the following consideration: the bigger RSSI value is, the nearer the distance is and the less the interference is. On the basis of it, this localization algorithm can get a superior result compared with the algorithm which calculates the circumference models equally. In the thesis, based on simplifying NLOS object in the logistics Center, all essential factors in the localization system are modeled, the author designed a simulation platform of localization system, which has features of logistics center, and the localization algorithm is tested. The simulation result shows that it has a smaller average error. The stability of localization system and the continuity of result are also improved to some extent. Furthermore, the test of localization for a large number of tags proves that the algorithm can obtain answer fast and the real-time performance can meet the demand of localization in logistics center.