MVB Aperiodic Information Scheduling Strategy Optimization

Multifunction Vehicle Bus (MVB) is an important part of train communication net-work system. In order to better understand the MVB, in this paper, we take the TCN as the breakthrough point, describe its definition, characteristics, bus and two layers topology of train communication network. We analyze and compare several common train communication bus, including MVB. This paper briefly introduces the real time protocol of MVB and the research status of train communication network at home and abroad. Because the TCN is a kind of special field bus, its development can not be separated from the progress of field bus technology. Therefore, the more important scheduling theory in the field bus is discussed in depth. The classification of scheduling algorithm and the typical algorithm, the feasibility analysis of the algorithm are summarized in this paper.On this basis, this paper makes a detailed analysis of the equipment, information type, media distribution and message of MVB. The scheduling mechanism of MVB aperiodic information is mainly studied. The process of scheduling, the key frame in the scheduling step and the arbitration process of the information collision are deeply studied. We find that the real time of concurrent aperiodic information is greatly influenced by the time delay of arbitration. Finally, several dynamic performance indexes of MVB are introduced.Through the analysis of the standard scheduling strategy in the protocol, in the process of scheduling, the delay caused by concurrent information has a great impact on the real-time information. The scheduling order of the same priority information is only in the order that the information is searched, this does not take into account the different time characteristics of different information requirements. Aiming at these problems, the optimization effect of the existing method is limited, and it can not meet the requirements of the actual situation. Based on this situation, in this paper, a new scheduling strategy is proposed. Through the use of the filling frame and the design of the information list, the scheduling process can avoid the search process of concurrent information. For the after-coming information from the same device, if they are more stringent requirements of the time limit, this strategy can greatly reduce their waiting time delay. In this way, the real-time of the information has been greatly improved. The same priority information schedules in accordance with the time requirements of information. This is more in line with the actual situation. Through experimental verification, compared with the standard strategy and the SFS scheduling policy. Experimental results in the four kinds of performance indicators fully dominantThis shows the effectiveness of the strategy in improving the real-time information. The experimental results show that the strategy of this paper in the case of the increase in the number of equipment, has the larger advantage.