Research And Optimization Of Two-speed AMT Pure Electric Vehicle Shift

Nowadays,the rapid development of automobiles has also burst out a series of problems.Environmental pollution and resource shortages have pushed new energy vehicles into the world’s important development.In recent years,China has also issued many relevant policies to promote the development of new energy vehicles,so in-depth research and development of new energy vehicle technology is an inevitable trend in the future.The automotive power system is the core part of the whole vehicle,and the technical development of new energy vehicles in the power system is still in the early stage of development.There has been no substantial breakthrough in the research of the shifting after the transmission is loaded.Therefore,this paper firstly installs AMT on the power system according to the design goals of the performance of electric vehicles.Under the premise that the basic parameters of a pure electric vehicle and the main reduction gear ratio are unchanged,the Cruise software is used for vehicle modeling simulation and analysis,and the optimal speed ratio combination is selected.The simulation results show that after installing the AMT transmission on the original car,the power performance and economic performance have been improved.Second,develop a set of shift strategies for electric vehicles loaded with AMT gearboxes.In order to improve the power and economy of pure electric vehicles,a shift strategy based on dual parameters is adopted,and the shock value of the shift is obtained.The MATLAB /simulink software was used to establish the vehicle shift model to simulate the shift process.Including the cab model,battery model,motor model,and transmission model,the feasibility of the shift strategy is evaluated according to the simulation results of the degree of shift shock.Then use the vehicle model built by Cruise software to simulate,to compare NEDC’s power consumption and acceleration time of 100 km / h before and after formulating the shift strategy to judge whether the power and economic performance have improved.The simulation results show that the developed shift strategy can be used for this AMT gearbox,and the impact degree during the shift process complies with national standards.At the same time,the power and economy have been improved,which initially proved the feasibility and effectiveness of the developed shift strategy.Finally,build a 1/2 pure electric vehicle experimental platform,using a combination of theoretical modeling and experimental modeling to verify the rationality and practicality ofthe shift strategy.The parameters of the shift actuator are automatically matched to match the AMT gearbox.The test platform integrates the drive motor and the power system of the two-speed gearbox.The motor control experiment was conducted before the formal shift experiment,and the experimental results proved that the motor can operate normally according to the instructions.Afterwards,a gear shift experiment was carried out using a bench.The impact degree of the gear shift was within the allowable range of error compared with the simulation result,which verified the correctness of the simulation model.At the same time,the optimized shift strategy is used to conduct the shift bench test.The experimental results show that the power and economy of the optimized shift strategy are improved.The impact of the shift is within the scope of the national standard.The gear shift strategy is feasible and effective,which has certain significance for the future development of multi-speed electric vehicles.