基于改进NSGA-II的轨道交通接驳公交线路优化

Optimization of Rail Transit Feeder Bus Routes Based on Improved NSGA-II

为解决接驳公交线路规划不合理和时间安排不完善的问题,提出了基于改进NSGA-II算法的环形接驳公交线路优化方法。首先,结合双层规划理论,以乘客出行时间成本最小化、公交企业运营收益和接驳公交服务率最大化为目标函数,以接驳公交线路站点数、线路长度和发车频率作为约束条件构建上层模型,采用Logit模型构建了下层接驳客流分配模型;其次,运用Floyd算法对NSGA-II算法的初始化种群进行了优化,针对所提出的模型设计了模型求解流程;最后,以哈尔滨市轨道交通1号线医大一院轨道交通站为案例,运用笔者提出的多目标双层规划模型和算法进行求解,并与原NSGA-II算法和基于Logistic混沌映射的NSGA-II算法进行对比。研究结果表明:基于Floyd算法改进的NSGA-II算法在多目标双层规划模型求解时,收敛速度更快效果更好,求解结果可以在Pareto前沿得到多个相互非支配的最优解;不同解集对应目标函数值不同,但可以达到接驳公交网络整体效益最优,采用折衷最优解集表述求解结果。

In order to solve the problems of irrational planning and imperfect scheduling of feeder bus routes,a loop feeder bus route optimization method based on improved NSGA-II was proposed.Firstly,combining with the bi-level programming theory,the upper layer model was constructed with the minimization of passenger travel time cost,the maximization of bus enterprise operation revenue and feeder bus service rate as the objective functions and the number of stops of the feeder bus line,the length of the line and the frequency of departure as the constraints.And the lower layer feeder passenger flow distribution model was constructed with the Logit model.Secondly,the initialized population of NSGA-II was optimized using Floyd algorithm,and the model solution flow was designed for the proposed model.Finally,taking Harbin City Subway Line 1 Medical University First Hospital Subway Station as a case study,the proposed multi-objective bi-level programming model and algorithm were applied for solution and compared with the original NSGA-II algorithm and the NSGA-II algorithm based on Logistic chaos mapping.The research results show that the improved NSGA-II algorithm based on Floyd algorithm has a faster convergence speed and better performance in solving multi-objective bi-level programming models.The solution results can obtain multiple mutually non-dominated optimal solutions at the Pareto front.Different solution sets correspond to different objective function values,but all of them can achieve the optimal overall benefit of the connecting bus network,and the solution results are expressed by the compromise optimal solution set.