The Study On Buffer Time Optimization Method Of Train Operation Diagram In Urban Rail Transit

Urban rail transit in our country is in a booming period, from the existing historical traffic data mining variability of train operation in urban rail transit has an important meaning, is the basis of study on urban rail transit train set tracking interval travel time reliability, the buffer set optimization, reliability of train operation plan and other issues.First, from the background of train crash or collision accidents have occurred in recent years, we find the importance of improving train operation reliability by studying on the train operation variability and optimization of train running buffer time. Analyzing the achievements and defects of researches on train operation and buffer time at home and abroad, and expounds the innovation of this article.Secondly, on the basis of the historical traffic data in urban rail transit, making the statistical analysis on the train interval travel time, station actual residence time, and travel time difference value between the practical and the plan. With the method of curve fitting, mountain climbing algorithm, we got the train interval travel time probability density function’s key parameters and the distribution function, the study found that the train interval travel time distribution is not a common distribution, such as normal distribution, lognormal distribution, weibull distribution, poisson distribution, etc., is a kind of distribution that changing from the original normal distribution, and it is a piecewise function. Through the K-S test method, it is found that the trains residence time in the station obey normal distribution, and its probability density function and distribution function are obtained.Then, studied and analyzed the redistribution of the interval travel time of the later trail in track train set, and found it is a conditional probability density function, which is closely related to the front trail interval travel time. On the basis of defining tracking train interval travel time reliability, the track train set interval travel time reliability calculation method is given.Finally, to make the interval travel time reliability in track train set under the train operation plan to meet the desired reliabilityα0, study the method of track train set operation plan adjustment and the buffer time optimization. Set the Xixiang to Gusu interval of the NO1Shenzhen subway as example, calculated the track train set interval travel time reliability on tracking train set operation plan, and give interval travel time adjustment of tracking train set and the setting of buffer time under the track for the train set on the interval travel time reliability to achieve desired α0=0.8. With the two strategies of feasible solution, and the optimal solution, concluded interval travel time and buffer time that under the condition of the desired reliability. There are30figures,11tables, and84references in this study.