Parameter Design And Shifting Control Strategy Optimization Of AMT For Pure Electric Vehicle

As energy crisis and environmental issues such as pollution and global warmingbecome increasingly worse, the automotive industry has put forward higherrequirements of energy saving and emission reduction. Pure electric vehicle (PEV) hasreceived worldwide attention because of its many advantages, such as low level of noise,zero-emission and easiness to operate. In order to improve the vehicle performance suchas the motor efficiency, the battery energy utilization and the endurance mileage, theautomatic transmission which is used in pure electric vehicle has gradually developed tomulti-speed. It is of great theoretical significance to make a research on pure electricvehicles powertrain parameter matching and integrated control, thus to improve pureelectric vehicles technology and performance levels. Therefore, the design method ofgear ratio number of AMT for PEV was proposed, the parameter of shifting actuator fortwo-speed AMT was designed, and the control strategy which can improve shiftingperformance and reliability was proposed based on analyzing fundamental shift controlstrategy and the characteristics of AMT for PEV. The main works in this paper are asfollows:(1) A set of relatively perfect comprehensive matching methods for gear rationumber of AMT for PEV was proposed, based on analyzing the relationship betweenthe motor and the transmission parameter.(2) The parameter of shifting actuator for two-speed AMT was designed to meetdemand for shifting time.(3) In order to improve the impact of the driving force fluctuation before and afterthe shift for shifting comfort and vehicle power performance and avoid circular shift, atorque compensation strategy for the torque recovery phase in the shifting process oftwo-speed AMT was proposed based on analyzing the reason of the driving forcefluctuation before and after the shift. The proposed torque compensation strategy wasverified by simulation based on the MATLAB/Simulink software.(4) The technical fault diagnosis and treatment strategy was proposed according tothe characteristics of two-speed AMT for PEV on the structure and principle of shiftingcontrol.(5) A transmission performance test-bench for PEV was built. The simulationmodel for test was set up based on the MATLAB/Simulink software and the dSPACE hardware, the shifting actuator for two-speed AMT was tested on the bench, the faultdiagnosis and treatment strategy for two-speed AMT was proved by the test.