| Nowadays,traditional Gasoline vehicles consume a huge amount of fossil energy,also cause air pollution and greenhouse effect that cannot be ignored.As one of the alternative Gasoline vehicles,pure electric vehicle has the characteristics of high energy efficiency,zero pollution and low emission.With the continuous development of electric vehicle technology and the implementation of favorable policies,electric vehicles will become an important tool for urban transportation in the future.Due to the temporary shortcomings of battery technology,the current range of electric vehicles is often less than that of fuel vehicles.The current development status of battery technology has profoundly affected the travel route choice behavior of electric vehicle users.The changes in the user’s travel rules at the micro level will be affected at the macro level.It has a huge impact on the distribution of traffic flow in the entire city,making the problem of urban traffic network distribution more complicated.In order to fully combine the characteristics of individual travel behavior with the overall distribution of the macro-transport network,this thesis takes electric vehicle users as the main research object.Starting from the most basic electric vehicle energy consumption hypothesis,and introducing the concept of energy reliability,this thesis analyzes,constructs and solves the reliability-based electric vehicle traffic allocation model under random travel demand.The specific research contents are as follows:First of all,this thesis discusses the necessity of studying the time reliability and energy reliability of electric vehicle users traveling under random travel demand.Due to the uncertainty of the travel demand of the urban transportation network,the travel time of electric vehicle users is often uncertain,at the same time,the energy consumption of electric vehicles is not only related to the user’s travel distance,but also closely related to the user’s travel time.Therefore,the energy consumption of electric vehicle users is also uncertain because of the uncertainty of the travel time of electric vehicles on the route.In the urban transportation network considering random travel demand,the time reliability of electric vehicle users exists as an optimization goal,and the energy reliability exists as a strict constraint.Secondly,through the analysis of the travel behavior characteristics of travelers under random travel demand,explore the results of electric vehicle users’ choice of routes when traveling with time reliability under the assumption of random travel demand and studies the equilibrium assignment state of urban traffic network when electric vehicles are widely involved in urban traffic network.By introducing the concept of energy reliability,this thesis presents an energy reliability hypothesis that the energy consumption of electric vehicles is related to the travel flow,deeply studies the path selection behavior of electric vehicle users based on the consideration of energy reliability,and establishes an electric vehicle traffic assignment model based on time reliability and energy reliability.The equilibrium conditions of the model was given.Finally,a heuristic algorithm is designed to solve the time reliability and energy reliability problems that the link cost functions are nonadditive.Through numerical examples,the results of electric vehicle models under the time reliability and energy reliability problems is discussed when the distribution results when the urban traffic network flow reaches equilibrium.The results show that the traffic assignment distribution based on energy reliability and time reliability will lead to the fluctuation of travel energy budget due to the fluctuation of travel flow,which makes it more sensitive than the electric vehicle traffic assignment model which is only considered time reliability.This thesis also uses two large-scale road networks to solve the heuristic algorithm,which is used to verify the practicability of the algorithm in solving largescale road networks.In summary,this thesis combines the energy consumption and travel time of electric vehicles with the random travel demand,establishes an electric vehicle traffic assignment model based on energy reliability,and designs a heuristic algorithm to solve the traffic assignment problem that the link cost functions are non-additive.Comparing with the results of models established based on other energy consumption assumptions,the results show that this more detailed assumption is often more realistic,brings more reasonable results,and has more theoretical and practical significance. |
