用户平衡算法中目标函数值与迭代次数关系研究

Relationship of Objective Function Value and Iterative Times in User Equilibrium Algorithm

在计算机实现用户平衡和随机用户平衡交通分配中应用较多的几种算法,如方向搜索法和相继平均法等的基础上,针对不同阻抗函数条件和多OD点对间流量分配问题中运用这几种算法的计算结果进行对比分析,得出目标函数值、检验数和迭代次数3者之间变化关系。结果显示,各种算法中目标函数值并不完全随着迭代次数的增加而严格递减,检验数的变化也不完全与目标函数值的变化同步,且不同条件下这种目标函数值、检验数与迭代次数的关系也不尽相同。

The algorithms frequently applied in the user-equillbrlum or stochastic user-equilibrlum traffic assignment problems were implemented by using computer programs, which included direction searching algorithm, method of successive averages algorithm, Frank-Wolfe algorithm, and so on. The results of the problems were comparatively analyzed based on the conditions of the both different impedance function and multi-OD traffic assignment. At last, the variable relationship among the objective functional values, check numbers, and iterative times were achieved. The results show that the objective functional values do not necessarily decrease with the increase of iterative times in different algorithms, that the variation of check numbers is not synchronous with that of objective functional values, and that the variable relationship among the objective functional value, check numbers and iterative times are not completely identical on different conditions.