Key Technology Research On Integrated Positioning Of Modern Tram

In recent years, with the rapid development of cities and the urban population continues to increase, coupled with car ownership continues to rise in the city, causing road traffic congestion, environmental pollution problems have become increasingly prominent. In order to resolve the issue mentioned above, to develop new environmentally friendly, high capacity urban rail transit has become an inevitable trend. The modern tram has less investment, short construction period, large carrying capacity and high comfort and other advantages, that makes it a small city passenger transport and urban rail transit extension and supplement important choice. If you want to ensure that the tram operation control system, dispatching command system, color light signal safety and efficient operation of the system, you need to provide real-time, reliable and accurate location information for modern tram. Therefore, the study of modern trams positioning technology will have important practical significance.Positioning precision of single positioning technology is limited, improve its accuracy will be costly, but based on a combination of multi-sensor positioning technology can play to their respective advantages, complementary advantages. This paper is based on the above idea of the combination of positioning technology, integrated GPS and INS system to design a suitable for modern trams positioning system.This paper started on the way of train integrated positioning, selected the appropriate sensors, designed integrated positioning model, and focused on the research of sensor information fusion method which applied to train integrated positioning. On the basis of analysising the performances and features of the current navigation system, then choose the GPS and INS as the subsystems of the integrated positioning system. When establishing the subject of GPS/SINS integrated positioning model, the paper simplifies the INS system according to the actual working conditions under the urban railways, and the integrated model uses position and velocity combined mode. The paper analysis the data fusion algorithms which are being used in the integrated navigation system, on the basis of summarizing shortage of traditional Kalman filtering and H_? filtering, proposed a H_? filtering algorithm based on strong tracking properties, and comparing with the traditional Kalman filtering algorithm and H_? filtering algorithm, the simulation results verifies that the improved H_? filtering algorithm relative to the Kalman algorithm and H_? filtering algorithm can obtain better filtering effect.In order to improve the positioning accuracy of the modern tram, the induction loop is integrated into the structure of the GPS/INS combined positioning to correct the positioning information. Based on the analysis of setting locations and positioning performance of the induction loop positioning, the characteristics of modern trams operating environment, this thesis designed a revised general structure of the tram positioning system. In addition to carry on the simulation of the improved H_? filtering algorithm in GPS/INS/induction loop combination condition, the results show that the revised structure has better positioning effect.