Research On Subway Train Integrated Location Technology Based On CBTC

In recent years, with the rapid development of the country’s urban subway construction, subway train control technology (CBTC) is constantly evolving and upgrading. Now, in the subway train control system, CBTC, in our country, many different technologies of train positioning are applied, and many new technologies are emerging. The typical train positioning technologies are the train location based on the speed sensor, doppler radar, EUROBALISE and Radio Block Center and the combined positioning. These positioning technologies have different advantages and disadvantages. With the rapid development of communication technology, the new mobile terminal positioning technology based on wireless fingerprint location with its many significant advantages in WLAN(Wireless Lan) has been widely used.DCS(Data Communication System), a data communication system is currently used in CBTC(Communication Based Train Control). It is composed of the backbone optical network based on802.3and WLAN based on802.11. Through the communication system, the subway control center can realize management of subway trains to ensure the running safety of trains. the scheduling and safety management of the subway train are guaranteed by operating control center. Therefore, based on the current situation of CBTC system in China and analysis on localization principle and error model of the speed sensor, doppler radar, EUROBALISE, WKNN, this paper design a WKNN positioning system based on the DCS. At the same time, combining the new positioning technology and the existing positioning technology, this paper put forward a integrated positioning algorithm, which is based on the speed sensor/WKNN/EUROBALISE. Its positioning performance is superior to the traditional the train location based on the speed sensor/doppler radar/EUROBALISE. The main contents of this paper are as follows:First of all, this paper introduces the CBTC system and its development in China briefly, and analyzes advantages and disadvantages of the main position technology.Secondly, this paper focus on the analysis of the positioning principle and error model of the train location, including the speed sensor, doppler radar, EUROBALISE and RBC (Radio Block Center). The algorithm of the train integrated positioning based on the speed sensor, doppler radar and EUROBALISE is simulated and analyzed, combined with the Federated Kalman filtering.Thirdly, with the analysis on wireless part characteristics of DCS, subway train positioning requirements, typical fingerprint positioning algorithms, tunnel wireless channel models, and simulation on the integrated positioning technology of WKNN combined with track circuits, this paper designs a subway train integrated position system based on the DCS.Finally, with use of the estimated error covariance to allocate the coefficients, the the train location based on the speed sensor/EUROBALISE/WKNN and the train location based on the speed sensor/doppler radar/EUROBALISE/WKNN Federal Kalman filters based on the DCS are designed, and the train location based on the speed sensor/EUROBALISE/WKNN algorithm is better than the other one.