Abstract: In order to avoid local optimum for selecting client node in VRP,this paper introduced saving method combined with the path weight value and the distance heuristic factor to improve the decision rule of selecting client node.According to the characteristics of the actual process of particle motion and the gradual convergence characteristics of ITO algorithm in the iterative procedure,combining drifting operator and fluctuation operator,this paper proposed the path weight value update rule to enhance the convergence rate of the algorithm.By increasing fluctuation coefficient and raising the ambient temperature,local optimum is skipped and search stagnating is avoided.The local optimization algorithm named 2-opt was introduced to further optimize the current generating best solution.Experimental result shows that the improved ITO algorithm effectively promotes the convergence rate and the ability of searching the global optimal solution.

Key words: Path weight value,Convergence rate,Local optimum,2-opt