Design And Verification Of Route Control Function Of Urban Rail Transit Train Control System Based On Train-to-Train Communication

The new urban rail transit train operation control system based on the train-to-train communication is designed with train-centeredness as the design concept,integrating key advanced technologies such as train-to-train communication technology,autonomous train positioning,track map database construction,and train integrity self-inspection,and completely relying on train equipment to realize mobile occlusion operation control of trains.Based on the two-way communication between train to ground,the system carries out the information interaction of adjacent trains by means of the train-to-train communication,realizing the functions of autonomous allocation of line resources by train equipment,autonomous calculation of travel permission and automatic control of train movement.At present,urban rail transit mainly adopts Communication Based Train Control(CBTC)system,and the new train control system breaks through the existing CBTC system which mainly relies on station and trackside equipment to realize the inherent mode of train control,and streamlines the ground equipment to facilitate the arrangement and management of line equipment.Compared with the CBTC system,the new train control system can improve urban rail transportation capacity and reduce operation and maintenance costs,and can better solve the problems such as shortage of commissioning time,limited space of machine room and poor electromagnetic compatibility environment during the overhaul of old lines.In this paper,we design and verify the train approach control method for the approach control function of the new train control system,using the way of autonomous decentralized cooperative management of line resources.The main work accomplished in the paper is as follows:(1)Analyze the structure and characteristics of the new urban rail train control system and carry out the design of the on-board approach control method.Firstly,we analyze and explain the parts of the new train control system that change in function allocation compared with the CBTC system,and select the equipment related to the train approach control function as the main research object of this topic,including trackside resource management unit,trackside centralized object controller,on-board information management module and on-board interlocking module and other equipment.By analyzing the specific implementation method of each function and the information interaction between each module,the on-board approach control process is designed under the decentralized cooperative management mode of resources.According to the specific train online operation scenario,the approach control is divided into the stages of train power-on self-test and registration with Resource Management Unit(RMU),traffic plan receiving and analysis,approach triggering,front train identification,approach establishment,and approach unlocking.(2)Analyze and determine the idea and framework of train approach control model building using formal modeling.By comparing the characteristics and advantages and disadvantages of various formal modeling methods,a combination of Unified Modeling Language(UML)and colored Petri net theory is chosen to build the model.Considering the complex structure of the train control system and a large amount of information interaction,the top-down hierarchical modeling idea is adopted to establish the hierarchical colored Petri net model of each functional module in the train approach control,and the logic function verification and state space property analysis of the approach control model are realized by using CPN Tools model simulation tool.(3)Modeling and simulation analysis of the train approach control process built in the new train control system.According to the typical operation scenario of urban rail transit,firstly,a top-level model Hierarchical Colored Petri Net(HCPN)is established for the overall approach control of a single train online according to the operation plan,and sub-models are established for each functional module of the train approach control process,and the constructed model is verified and analyzed using CPN Tools to ensure that the model meets The model is validated and analyzed using CPN Tools to ensure that the model meets the requirements of reachability,boundedness,activity and fairness.Next,a multi-train approach conflict operation scenario is constructed according to the actual station map,and a Timed Colored Petri Net(TCPN)model is built according to the scenario to simulate the model.The results show that the results of multiple trains competing for line resources in the approach conflict scenario are not unique and uncertain,and the resource competition problem can lead to system The results show that the results of multiple trains competing for line resources in the approach conflict scenario are not unique and uncertain,and the resource competition problem can lead to the system "deadlock","live lock" or failure of both approach establishment,which has a large impact on the operation efficiency.(4)Solving the multi-train resource competition problem.For the resource competition problem existing in the stage of multi-train requisitioning line resources,a multi-objective decision model for resource allocation is established according to the basic principles of urban rail train operations,and the approach control method is optimized by using the entropy value method and TOPSIS,which is an approximate ideal solution,and the algorithm simulation analysis verifies that the method can solve the resource competition problem,ensure that train operations are executed in priority order,and improve the line capacity.