Considering that the vehicle routing problem （VRP） with many extended features is widely used in actual life, such as multi-depot, heterogeneous types of vehicles, customer service priority and time windows etc., a mathematical model for multi-depot heterogeneous vehicle routing problem with soft time windows （MDHVRPSTW） is established. An improved ant colony optimization （IACO） is proposed for solving this model. First, MDHVRPSTW is transferred into different groups according to the nearest principle, and then the initial route is constructed by the scanning algorithm （SA）. Secondly, genetic operators are introduced, and crossover probability and mutation probability are adaptively adjusted in order to improve the global search ability of the algorithm. Moreover, the smooth mechanism is used to improve the performance of the ant colony optimization （ACO）. Finally, the 3-opt strategy is used to improve the local search ability. The proposed IACO was tested on three new instances that were generated randomly. The experimental results show that IACO is superior to the other three existing algorithms in terms of convergence speed and solution quality. Thus, the proposed method is effective and feasible, and the proposed model is meaningful.
在配送过程中,VIP客户订货量较大,为其提供快速及时的服务能提高VIP客户的满意度,所以研究基于VIP客户的多配送中心车辆路径问题(Multiple Depot Vehicle Routing Problem based on VIP clients,MDVRPVC)模型具有现实意义.由于基本的蚁群优化(Ant Colony Optimization,ACO)搜索初期信息匮乏,导致信息素累积时间长,求解速度慢,所以结合具有快速全局搜索能力的遗传算法,自适应地改变信息素的挥发系数,引入平滑机制,有助于对搜索空间进行更有效的搜索,构成一种混合自适应蚁群优化算法(Hybrid Adaptive Ant Colony Optimization,HAACO).应用GA和HAACO对MDVRPVC求解,实验证明,求解算法HAACO是有效可行的,且HAACO优于GA.
针对带硬时间窗的水果运输调度问题(Fruits in Vehicle Routing Problem with Hard Time Windows,FVRPHTW),联系实际应用中水果易腐的特性及运输途中的路况因素,采用蚁群算法、模拟退火算法和禁忌搜索算法来对FVRPHTW求解,并分析3种算法的优缺点。实例证明,这些算法对求解水果运输调度问题是可行的,模拟退火算法略优于其他两种算法。
