The Study Of Railway VRP Based On Ants Colony Optimization Algorithm

Vehicle routing problem is a hot question during near decades and is studied such as operations research, applied mathematics, network analysis, computer application and traffic transport, etc.. Open vehicle routing problem is a VRP of another kind and has extensive application prospects. Main difference between OVRP and VRP is that the former is not to require the original starting point must be returned after the vehicle have accomplished the task transported. ACO (ant colony optimization algorithm) is a kind of new bionic algorithm, belong to random search algorithms. The research for many years has already demonstrated ACO superiority in solving complicated optimization question. ACO has some defects too, such as disappearing slowly and easy to fall into local optimization etc..This thesis has carried on the theoretical research to OVRP taking restraint terms and has realized that the railway transportation vector graph is showed different layer. Restraint terms mainly consider the system optimum equilibrium of railway transport, that is to say the overall situation is optimum, not only seek excellently users' route, so consideration makes the research contents have actual application value even more. After this thesis has compared ACO with other classical artificial intelligent algorithm through the experiment, it is found that ACO quality solved and cost of time are all obviously superior to other artificial intelligent algorithm, which has shown ACO competitiveness in solving the complicated optimization problem. To the shortcoming of ACO, a lot of scholars have proposed a lot of improved ACO. This thesis programms ACO and classical improved ACO, through the experiment it is proved that the performance of improved ACO obviously improve. Deriving from the thought of some improved ACO and combining railway VRP taking restraint terms, this thesis carries on new improvement to ACO in order to make it better and faster. Finally, to the practical studied problem, this thesis summes up the choosing rule of ACO parameter.The experiment of this thesis indicates that railway VRP taking restraint terms is effectual to solve with ACO, which indicates again that ACO has strong competitiveness in optimization field. The thesis has considered the restraint terms that can obtain the system optimum equilibrium. It makes that research contents laminate reality of railway transportation and the contents not only have theoretical research meanings but also are rich in actual appliacation value.