Dynamic Route Optimization Of Multimodal Transport Under Mixed Time Windows

With the continuous growth of the global freight market,the freight volume is increasing yearly,which brings challenges and opportunities to the logistics industry.Although multimodal transport can alleviate certain traffic pressure,it is still vulnerable to traffic congestion,so it is urgent to explore effective measures to optimize the traffic network.The research on congestion mostly focuses on road congestion,ignoring the congestion of railway and waterway.In the process of optimizing multimodal transport,the time-varying and uncertain characteristics of congestion information between different transport modes will seriously affect the transportation decision-making and the choice of transportation schedule.The static method is easy to fall into the congested path,and will affect the feasibility of the subsequent transportation scheme,ultimately exceed the customers’ transportation time.According to the characteristics of different modes of transportation,this thesis fuzzily divided the congestion degree of each mode;established a hybrid time window by combining with the transportation schedule and customers’ demand for time;designed a process control optimization scheme through real-time feedback of congestion information between different transport modes in each sections,dynamically adjusted the optimal transportation decision,including transportation path,mode and schedule.On this basis,a bi-objective fuzzy chance constrained programming model with minimum transportation cost and maximum customer satisfaction under mixed time windows is constructed.Aiming at the discrete characteristics of the spatial distribution of the effective solution of the model and the shortcoming that PSO is easy to fall into local optimum,an IPSO is designed to improve the efficiency of the algorithm.The results show that the dynamic optimization can make the transportation enterprises grasp the transportation information in real time at each stage,and timely change the strategy according to the customer’s demand for time and the change of congestion,so as to realize the real-time process control of the transportation scheme.Considering both fuzzy congestion environment and transportation schedule in transportation decision-making can effectively avoid congestion path under the condition of customer satisfaction,reduce transportation cost and time,and improve the reliability of transportation decision-making.