铁路调度区域内货物列车出发计划动态全局优化

Dynamic Global Optimization for the Freight Train Departure Plan in Railway Dispatching Region

为实现调度区域内货物列车出发计划的全局最优,提出1种基于车流不确定性的动态优化方法。影响货物列车出发计划的不确定性因素主要有事故、晚点、扣修等,将其中不确定性因素进行量化处理,并当作随机变量。以调度区域内货车中转停留时间最小为目标函数,以网络车流平衡、节点车流守恒、满轴限制、运到期限作为基本约束条件,以计划兑现率要求作为动态约束条件,建立制定列车出发计划的动态优化模型。利用确定性等价类将模型转化为确定性线性规划模型,采用编制的线性规划软件求解。通过算例证明该方法可以得到优化结果。分析计算结果可知:车流的不确定性会导致中时增大;计划兑现率要求越高,计划最后的执行指标就越差;考虑运到期限要求,会导致中时增大。

A dynamic optimization method was proposed based on the uncertain of the car flow in order to achieve the global optimization for the freight train departure plan in railway dispatching region. Accidents, delays and repairs were the main factors influencing the departure plan of freight train. The influence of those factors was treated as a random variable. The objective function of the model was to minimize the total transit residence time of the cars. The balance of the net flow, car flow conservation in the transit station, full axis and the time limit of delivery were the basic constraint conditions. The request of the realization rate of the plan was the dynamic constraint condition. The dynamic optimization model for freight train departure plan was established. The algorithm was to change the dynamic constraint conditions to their equivalence classes, so the model could be solved as a deterministic model by a linear programming software. A case was given to prove the effectiveness of this method. The analysis results of the case show that the model and the algorithm can give the suitable train departure plan of the whole railway dispatching region. It also shows some laws of the train departure plan. The uncertainty of the car flow may lead the residence time to grow. The higher request of the realization rate of the plan means the worse index of the plan realization. The time limit of delivery leads residence time to grow.