| Under the current energy environment background and the development trend of the automobile industry,the development of new energy vehicles such as electric vehicles has received the attention of automobile manufacturers and the policy support of the government,which has been greatly developed.The production,sales and ownership of electric vehicles have also increased rapidly year by year.However,there are still some problems in the development of electric vehicles,such as the high price of power batteries and their life,energy density and power density,which need to be broken through.Under the background of the development of Intelligent Network Unified Vehicle,the optimization method is used to optimize the energy consumption and life loss of batteries in the use of electric vehicles,and the driver is assisted by the on-board auxiliary driving system according to the optimization results.This paper focuses on the economic speed planning of two-speed electric vehicles.Under the background of the high price of electric vehicle power battery,this paper supplements the economic indicators of electric vehicle,and takes the aging cost of battery as a part of the economic indicators of electric vehicle.The main work is as follows:First,the background and significance of speed planning for two-speed electric vehicles considering battery life is explained.According to the current research status and hardware conditions,the importance of aging cost of batteries as part of the economic indicators of electric vehicles is further illustrated.Second,the basic structure of the battery is introduced.On this basis,the working principle of the battery is further introduced.According to the working principle of batteries,the aging mechanism of batteries is expounded from the aspects of anode and cathode,and the key factors affecting the life of batteries are listed.On the basis of three common aging models,the aging mechanism of batteries is numerically analyzed.Finally,based on the electrodynamic model and aging model of the battery,a control-oriented quantitative battery life model adapted to the high dynamic conditions of the vehicle is established,which lays a foundation for economical speed planning considering battery life.Third,the mathematical relationship between the economic driving speed planning problem of the two-speed pure electric vehicle is described.According to the optimal control theory,the state equation,system constraints,system boundary conditions and innovative performance indicators of economic driving speed planning problem are established.The generalized minimum residual method(GMRES)is used to construct the economic driving speed planning problem.A quick numerical solution.The last,the dynamic system of the simulation object is modeled from four aspects: vehicle parameters,power battery,drive motor and two-speed gearbox for electric vehicles.Then the battery dynamics was simulated and a map of the battery aging severity factor was established.Finally,based on the battery model,the economic optimization speed planning results of electric vehicles are obtained by using the established optimization problems and solving methods,and the different working conditions are compared and analyzed.The results show that compared with the economic indicators of pure battery energy consumption.In contrast,considering the battery aging cost in the economic indicators can achieve a significant increase in battery life at a lower energy cost.At the same time,compared with the singlestage reducer,the two-speed gearbox has a positive effect on delaying the battery life of the electric vehicle and reducing the battery energy consumption,and has great application potential in the electric vehicle. |
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