考虑工作量均衡的成品油二次配送车辆路径问题

为避免工作量分配不均，研究了考虑工作量均衡的成品油二次配送车辆路径问题。以总配送成本极小化和不同车辆路径长度之差极小化为目标，建立了双目标混合整数规划模型；并设计了变邻域禁忌搜索启发式算法。利用改进的Solomon＿I1插入算法求出使总配送成本尽量小的初始解；再利用变邻域禁忌搜索算法改进初始解，得到近似最优解。模拟计算结果显示，通过变邻域禁忌搜索算法改进后的解，总配送成本仅增加6.2%，车辆路径长度差值降低了45%，验证了算法的有效性。

Vehicle Routing Problem with Refined Oil Secondary Distribution Considering Workload Balance

To avoid unbalanced workload assignment, we studied the vehicle routing problem with refined oil secondary distribution considering workload balance. A bi-objectivemixed integer programming model was built to minimize the total distribution cost and the maximum difference in vehicle route length. A heuristic variable neighborhood tabu search algorithm was designed. An improved Solomon_I1 insertion algorithm was developed to generate afeasible initial solution such that the total distribution cost was as small as possible. Then, the variable neighborhood tabu search algorithm was used to improve the initial solution and thereby obtain the approximate optimal solution. The simulation results show that in the solution improved by the variable neighborhood tabu search algorithm, the difference in vehicle route length is reduced by 45% when the total distribution cost is only increased by 6.2%, which verifies the effectiveness of the algorithm.