Study On Two-speed AMT Shift Control And Test Of Miniature Pure Electric Vehicles

In the background of environmental pollution and energy crisis,pure electric vehicles has become the research hotspot because of its high efficient,zero emissions,low noise.At present,most pure electric vehicles are equipped with fixed speed ratio gearbox,which makes driving motors always run in low efficiency.Multi-speed transmission can improve the efficiency of transmission system,and improve the economic performance under the premise of ensuring the dynamic performance of pure electric vehicles.The drive motor has a wide range of speed regulation and precise torque control ability.Excessive gear shift will result in complex structure and make the gearbox difficult to control.Therefore,this paper takes the two-speed AMT of pure electric vehicle as the research object,match the parameters of the key parts of the two-speed AMT transmission system and formulate the shift schedule and shift control strategy of pure electric vehicles combined with a miniature pure electric vehicle development project.Finally,the feasibility of the shift strategy is validated on the AMT test bench of the pure electric vehicle.The research contents are as follows.The transmission system structure scheme of two-speed AMT is given,and the parameters of the key components of the transmission system are matched,and the parameters of the transmission and the motor are determined according to vehicle parameters and driving performance requirements.The method of formulating the best dynamic and economic shift schedule of pure electric vehicle is expounded based on the evaluation index of dynamic and economic performance,and the best dynamic and economic shift schedule are formulated according to the parameters of the whole vehicle.In order to improve the economic and dynamic performance,the genetic algorithm is used to optimize and formulate the comprehensive shift schedule.Vehicle dynamics model is establish to verify the shift schedule and shift control strategy which are formulated in this paper based on the AMESim-Matlab co-simulation platform.Simulation results show that the proposed integrated shift schedule based on genetic algorithm ensures dynamic performance and improves economic performance.The shift control strategy of two-speed AMT is formulated,and the feasibility of the control strategy is verified based on the dynamics model simulation.The two-speed AMT test bench of the pure electric vehicle is built to verify the feasibility of transmission shift strategy.The five-manual transmission is modified by using the cable rocker type shift mechanism,and the shift position is calibrated.The rapid prototyping control test of shifting process is carried out based on Controlbase-Simulink co-development platform.The results show that two-speed AMT shift strategy can realize dynamic shift.