多目标规划在铁路零担货运中转装车问题中的应用

结合顾客满意度与中转货物运到期限两者间的关系,将以货物的运到期限为要素的函数作为首要目标,将车辆的静载重利用率及车辆的轻重搭配合理程度作为次要目标,以车辆标记载重限制、车辆载货容积限制及车辆满载限制为约束条件,建立研究铁路零担货物运输中转装车问题的多目标规划模型。利用主要目标法,把首要目标作为主要目标、次要目标转化为约束条件,从而将多目标规划模型转化为单目标规划模型。应用模拟退火算法,设计算法的实现步骤,求得单目标规划模型的有效解。以同去向30件待中转货物装入2辆车为例,运用设计的模拟退火算法步骤,计算得到装车方案。计算结果表明:得到的装车方案满足车辆的载重约束与载货容积约束,提高了车辆静载重利用率,并体现客户需求至上的铁路货运服务理念。

Application of Multi-Objective Planning in Cargo Loading Problem for Railway LTL Relaying Process

This paper takes the correlation between customer satisfaction level and the cargo transmit time into consideration, and views the function taking into account cargo transmit time significantly as primary objective, carrying capacity utilization rate and the relationship between cargo density and railcars payload space as two secondary objectives. In addition it regards railcars weight capacity restriction, railcars cubic capacity restriction, and full loading restriction as constraint equations, so as to formulate one multi-objective planning for discussed cargo loading problem about LTL relaying process. On the basis of converting secondary objectives into constraint equations, furthermore primary objective is retained as unique objective, such a multi-objective planning is transformed into a single objective planning by adopting prime objective algorithm. Simulated annealing algorithm is proposed to work out the available solution to such a single objective planning. One example how 30 LTL cargos with same group indication can be loaded onto 2 railcars is presented, the railcar loading project can be solved by the designed step of annealing algorithm. The computation results reveal that such a stowage project can not only improve railcars capability of freight lading, but also accord with rail transporterrs customer oriented principle, additionally two restriction about railcar capacity can be satisfied.