Reliability Design And Implementation Of Train Passenger Information System

With the development of economy and the increase of urbanization rate, City's traffic congestion becomes serious. More and more people choose subway in daily travel. As a mean of transportation, subway has advantages of fixed route, small traffic interference, low cost and large transport capacity, so it plays an important role in city transportation. PIS runs in each train and its main function is to provide passengers with the relevant information of train. Each city has a number of subway lines and each line has a number of subway trains. In this case, a large number of PIS run continuously. Inevitably, PIS will fail and cause trouble to the passengers' travel. It is very important to guarantee the reliability of PIS. Therefore, the reliability of PIS is designed and implemented in this thesis.In this thesis, the reliability of PIS is designed in three aspects:communication reliability, system controller reliability and broadcast reliability. In the aspect of system communication, MVB is used as the system communication bus and its double line structure can be used to improve the system communication reliability. LED data communication protocol is made to ensure LED data communication reliability; System controller adopts the method of dynamic redundancy and hot standby redundancy so that the characteristic of the two machine operation can improve the system controller reliability; In the aspect of broadcast, this thesis adopts service restructuring and service degradation technology to ensure that the system provide broadcast stably. On the basis of hot standby redundancy of the system controller, two system controllers carry on the exchanging and the processing of the related data of semi-automatic broadcast and improve the reliability of semi-automatic broadcast.This thesis firstly introduces PIS, train communication bus and system reliability, then points out the significance of this thesis. Secondly, the related technologies used in this thesis are introduced, including redundancy technology, MVB protocol, service recovery technology, frame synchronization and ARQ. Thirdly, this thesis analyzes the system requirements, then designs and implements the reliability of the three aspects. Finally, test environment is set up to verify the correctness of the implementation presented in this thesis.