Energy-efficient Dynamic Route Planning For Electric Vehicle Based On Space-time Network

At present,the world is confronted with the problem of energy shortage and environmental pollution,and the problem of energy utilization has been paid more and more attention.With the popularity of private cars,people's daily travel is an important link of energy consumption and environmental pollution.It has gradually become the common choice of the world to improve the traditional high energy consumption and high-polluted development mode.Based on the characteristics of urban vehicles,electric vehicles have become an important technical direction to promote energy saving and emission reduction of automobiles.Compared with diesel locomotives,which only have 17-21%of the energy converted into the power of the wheel,electric vehicles can convert about 59-62%of the energy.It is expected to reduce dependence on oil,improve energy efficiency and environmental sustainability.As a result of government subsidies,battery technology progress,public acceptance of electric vehicles and other incentives,the market share of electric vehicles has increased significantly.Increased market penetration of electric vehicles will affect traffic flow,which will mean that a new path planning scheme is neededBased on the reasons above,this paper intends to carry out energy-saving dynamic route optimization research on electric vehicles,using scientific and reasonable route planning to achieve the goal of minimizing energy consumption and maximizing travel efficiency for electric vehicles.In detail,this paper does the research works as follows(1)The influencing factors and calculation methods of energy consumption in the driving process of electric vehicles are analyzed.The energy consumption curve of electric vehicles is closely related to driving speed,air resistance,friction,transmission terrain,battery charging status,temperature and other factors.In the case of large speed change,the energy consumption will increase significantly compared with that at constant speed.In unit distance,the energy consumption at medium speed is much lower than that at high speed.Therefore,in the process of electric vehicle travel,we can choose the energy-saving route in low and medium speed driving,which can avoid frequent acceleration and braking,eliminate driving high energy consumption and mileage anxiety(2)The whole model is described in the space-time network.In order to describe the real traffic network more clearly,the state-space-time network is established.Specifically,without considering the charging of electric vehicles,the intersection signal is regarded as the state latitude,which is an important part of reflecting the network dynamics.And the intersection signal is introduced into dynamic network to participate in the route planning.Considering the charging for electric vehicles,the state dimension is used to describe the remaining power of the electric vehicle.This description method not only reflects the dynamic characteristics of road sections,but also reflects the dynamic characteristics of each node state.(3)In this paper,energy-saving dynamic route planning is modeled and separately analyzed in the process of route planning under the two conditions of no charging and charging.Energy consumption and travel time are considered as two performance indicators to evaluate the effectiveness of planning route.Therefore,this paper designs a multi-objective mathematical model to minimize energy consumption and travel time.Based on the established mathematical model,label-correcting algorithm and genetic algorithm are designed to find the optimal solution.To verify the effectiveness of the model and algorithms proposed in this paper,a specific simulation calculation is carried out on the test network.The results show that the proposed energy-saving route planning method for electric vehicles can significantly reduce the travel time and energy consumption and get the corresponding planning route.