放宽条件定点集结模式下编组站车辆 集结排队系统分析

集结模式决定了货车集结过程的结束条件，定点集结是一种高效率的集结方式，有利于提高运输质量.针对放宽条件定点集结模式下编组站车辆集结过程，建立离散时间批到达批服务排队模型，利用嵌入式马尔可夫链方法求得离去时刻瞬时系统集结车辆队长分布，并求得任意时刻车辆集结队长分布，在此基础上分别分析了最小编成辆数，车组大小分布，车流到达强度，服务时间间隔分布对车辆平均集结队长，集结延误时间，效率，一昼夜发送车流量等系统指标的影响.分析结果表明，各因素对车辆集结排队系统影响明显.因此，利用本文提出的模型能为编组站的精细化管理和车流组织优化提供决策参考.

Performance Analysis of Car Assembly Queuing Model of Marshalling Station in the Time-fixed Mode with Softened Terms

The assembly mode determines the end condition of a car assembly process. Time-fixed assembling is a highly efficient mode, which is propitious to improve transport quality. For the problem that cars assemble in a marshalling station in the time-fixed mode with soften terms, a discrete time queuing model with batch-arrival and batch- service was built. Queue length distributions at departure epochs were obtained based on the embedded Markov chain technique. Next, queue length distributions at arbitrary epochs were derived. Based on these probabilities, various performance measures of interest such as the mean queue length, the mean accumulation delay, efficiency, traffic volume in one day were discussed though analyzing the impacts of minimum number of cars, batch size distributions, arriving intensity, service time distributions. The analysis shows that these factors have significant effect on the system performance. Therefore, this model can be used to provide decision references for the delicacy management of the marshalling yard and optimization of car flows.