指数密闭混合运输排队网络的运行机理研究

Study on Operation Mechanism of Mixed Closed Loop Transportation Network with Exponential Queues

构建由单进路车站、多进路车站以并联形式和串联形式组成的密闭混合运输排队网络,且指定车辆达到间隔和服务时间服从负指数分布。利用Matlab中的SimEvents模块对指数密闭混合运输排队网络进行仿真实验,剖析指数密闭混合运输排队网络中各货运站内排队长度和等待时间的动态变化。进而研究运输排队网络中车辆分布变化规律,确定密闭混合运输排队网络的稳态车辆分布概率计算公式,分析密闭混合运输排队网络平均等待时间的变化规律,给出运行机理的解析流程。最后利用数值分析方法剖析车队规模对车辆分布类型和车辆等待时间的影响。

Mixed transport queuing network is composed of single route station road and multiple route station as parallel and series form.Two random variables to denote respectively time interval of vehicle arriving freight station and the service time of these handling platforms in freight station obeyed negative exponential distribution.The closed mixed transportation queuing network was simulated using SimEvents module in Matlab software.The dynamic changes of the queue length and waiting time in freight station were analyzed.Then vehicle distribution in mixed closed loop transportation network was analyzed.The formulation to compute vehicle distribution probability in steady state was given.The vehicle average waiting time in whole mixed closed loop transportation network was analyzed.The analytical methods on operation mechanism to closed mixed transportation queuing network were given.And it was analyzed numerically that the fleet size affected the vehicle distribution and vehicle waiting time in the transportation queuing network.