Application And Research Of GPS/ZigBee Technology In Modern Tram Positioning System

With the development of scientific and technological level, modern tram is increasingly used in more and more countries. Compared with the traditional trams,as a kind of new transport vehicles, modern tram has many advantages, such as large capacity, environmentfriendly and high intelligence etc. However, it is necessary to provide efficient and reliable,accurate and real-time location information for the tram to make each control subsystem run efficiently and reliably.Locating blind spots have been existed in modern tram positioning system, which affect the operational efficiency of the tram. According to the structure of operational control system in modern tram, combined with the actual operating conditions, the Global Positioning System and ZigBee(GPS/ZigBee) integrated positioning solution for the tram is determined.On this basis, the modern tram positioning system, which has been achieved functional simulation for the positioning system is studied.Firstly, the principles and characteristics of each hardware for the positioning system are analyzed. The thesis describes the principles and methods for achieving the ZigBee node location and GPS satellite positioning, which focus on two points: the location principle and implementation of ZigBee equipment location which is based on Received Signal Strength Indication(RSSI), and the processing of the $GPGGA data which is obtained by the GPS receiver.Secondly, in order to achieve specific functions of the positioning system more directly,the thesis uses CC2430/31 which is manufactured by TI company as positioning nodes module to build ZigBee wireless network. Then, the hardware location engine within CC2431 is used to implement node localization. After then, GPS receiver and ZigBee coordinator module are connected to access to the location information of satellites. All positioning equipments that are used to achieve the goal of locating the mobile node and the position of modern tram have been realized. The thesis selectes a certain case to conduct the system experimental and it can be achieved the desired results. According to the characteristics of the data output of the system, the thesis analyzes the integrated information which is used in the combinational positioning system. In order to improve the positioning accuracy of the tram and ensure traffic safety, the position system is used the federal Kalman filter algorithm to adjust the output of the Kalman Filter in the GPS/ZigBee integrated positioning system for modern trams.Finally, the entire positioning system of the modern tram is simulated with the field positioning data from the test section of a city modern tram. The simulation of the modern tram positioning system can not only modulate the control process repeatedly without destruction, but also lay a certain foundation for the simulation of the whole system ofmodern tram.