Control And Scheduling Collaborative Design For Train Networked Control System

With increasing requirements of high speed, safety, comfort and intelligence for rail transit, the technical specifications of system control have become more and more high and the system architecture has become more and more complex; networking is the inevitable result with the development of high-speed train control systems, and the modern train control system has developed to be a network-based distributed train control system. The introduction of the computer network technology makes the train control system have simpler structure, stronger function and higher automation, but it also changes the information transmission way and the dynamic performance of the control system, which may influence the security and stability of the control system. In the meantime, with this new structure, in order to ensure the real-time, security, reliability of the control system, corresponding requirements about the running performance of the network have been made. Therefore, the researches on the real-time scheduling strategy and performance of the networked train control system become more significant.This dissertation focuses on how to improve and optimize the network performance to adapt to the requirements of the control performance from the perspective of collaborative design of control and scheduling in view of the determined network structure. The main work and innovative achievements of this dissertation are listed below:1. The optimization of the real-time periodic data scheduling targets at the load balance. The defects of the traditional method for creating the periodic information schedule table are pointed out based on the research and analysis of the MVB media access control methods and transmission delay. Three cases of the schedulable MVB periodic information are analyzed using the MVB periodic communication model, and then, the optimized model based on the load balance is proposed. The solving method based on forecast domain immune genetic algorithm is given, and the simulation is done. This new method solved the case which the traditional method may not be valid, while system reliability and real-time have been improved, and it is benefit to support more control subsystems for data transmission and help enhance the system control performance.2. Scheduling strategy targets at the optimization of the control performance and the bandwidth resource utilization. The media allocating method of the MVB real-time periodic data directly associated with the performance of the control system is modified based on the further analysis of the network delay and jitter on the networked control system. Moreover, the collaborative design optimization scheduling strategy based on jitter is proposed, thereby seeking a tradeoff between the performance of the control system and the occupation of the network resource. For reducing jitter, the problem of excessive consumption of network resources eventually leading to failure scheduling by the traditional algorithm is sloved. One kind of EDA algorithm based on PBIL is given to solve the optimal solution, and the convergence analysis and simulation are also performed.3. The bandwidth scheduling optimization problem of dual-layer train networked collaborative control system (TNCCS) is researched. A train networked collaborative control system based on the dual-layer structure is established for the train control system with such complex structure. On this basis, the system performance of TNCCCS is analyzed. The average sensitivities of reference are used in utility functions in order to evaluate the effects of network-induced delays for TNCCS. Moreover, a bandwidth resource allocation model of integrated control system for optimal performance is obtained using these utility functions.4. Dynamic optimal scheduling policy targets on the integrated control performance. For the networked train control system with limited bandwidth resources, the non-cooperative game theory is used to preliminarily discuss the allocation of the network resources in TNCCS, and the non-cooperation game model based on bandwidth scheduling is established, so that the mature economic theory can be used to optimize the network bandwidth scheduling. Then, based on the network pricing model and the method for evaluating the system performance with average sensitivities, the multi-objective bandwidth scheduling optimization strategy with multi-restriction on control and network is obtained. Thus, the problem of the network resource allocation of the networked control system has been converted to be the problem of solving the Nash equilibrium points under the non-cooperative game model. On this basis, the Nash equilibrium solution under this frame is obtained using the estimation distributed algorithm. Further, a time slice scheduling method with adaptive bandwidth reservation of the networked control system is provided and a simulation model of TNCCS based on the TrueTime is established. The simulation results verified the effectiveness of the proposed method. 5. The test platform which meets the TNCS’s testing demands is established. A UIC experiment platform which takes the typical standardized EMU network segment configuration as the model sample is designed. The train control network is established in a form of half object simulation, which comprises two-level field bus of WTB and MVB. Through testing and analyzing of the real time scheduling strategy proposed in this dissertation, the effectiveness of the real time periodic data scheduling strategy based on load balance model, collaborative design optimization strategy based on jitter, and flexible scheduling strategy based on network pricing theory and game model have been verified respectively.At last, based on the summary of the whole research content, the dissertation gives the considerations and conclusions in the study process, and proposes some problems which need further research in the future.