基于模拟退火的地下物流通道网络设计

Network Design of Underground Logistics Channel Based on Simulated Annealing

为研究网络通道在地下物流系统中的优化设计,以国内某地区物流概况为研究背景,结合国内外地下物流系统研究成果,考虑路径优化与运输成本,建立以总成本最小为优化目标的线性规划模型,并通过模拟退火算法进行优化求解,研究结果表明:基于模拟退火算法得到该地区地下物流网络通道设计全局最优解,地下物流通道及节点的建设成本为466.16亿元,货物运输成本为3.91亿元/年,按照年综合折旧率1%进行计算,地下物流网络总成本为8.57亿元/年;从物流园区运送出的货物通过地下物流通道运输的量较大,物流园区与一级节点之间的通道设计要求更高,其通道设计为双向四轨(10t)或双向双轨(10t),其余通道设计均为双向四轨(5t)或双向双轨(5t);所有物流园区对各需求点的总货运量表现出明显的波动性,各物流园区对所有需求点的总货运量偏差不大,对各个需求点的货运量均在一定范围内波动;各个服务节点对各个需求点的货运量各不相同,但大部分需求点的货物运输均来自于单一服务节点,且遵循就近原则,即每个物流需求点会尽可能从最近的服务节点获取物流;通过将部分货运量转至地下物流通道,各区域需求点交通拥堵系数降到4.0及以下,交通拥堵等级由轻度拥堵或中度拥堵下降到基本畅通。

To study the optimal design of network channel in undergroundlogistics system,taking a local overall logistics as the engineeringbackground,combining with the research results of underground logisticssystem at home and abroad,considering the route optimization andtransport cost,a linear programming model with the minimum total cost asthe optimization objective is established,and the model is solved bysimulated annealing algorithm. The research result shows that:(1) theglobal optimal solution of underground logistics network channel designin this area is obtained based on simulated annealing algorithm. Theconstruction cost of underground logistics channel and its nodes is46.616 billion yuan,and the freight transport cost is 391 million yuanper year. The total cost of underground logistics network is 857 millionyuan per year according to the annual comprehensive depreciation rate of1%.(2) Because of the large quantity of goods delivered from thelogistics park and transported by the underground logistics channel,thedemand of the channel design between the first level nodes and thelogistics park will be higher. Its channel design is 2-way 4-track(10 t)or 2-way 2-track(10 t),and another channel designs are 2-way 4-track(5t) or 2-way 2-track(5 t).(3) All the logistics parks show significantfluctuations in total freight volume at each demand point. There is alittle deviation among the total freight volumes of all demand points indifferent logistics parks,and the freight volume of each demand pointfluctuates in a certain range.(4) The freight volume of each servicenode to each demand point is different,but the freights transported frommost demand points come from a single service node,and follows theprinciple of proximity,that is,each logistics demand point will obtainlogistics from the service node as near as possible.(5) Transferringpart of the freight volume with underground logistics channel,thetraffic jam coefficient of each regional demand point is reduced to 4and less,the level of traffic jam is reduced from mild jam or moderatejam to basic unblocked.