Synchronous Control Strategy For Electric Vehicle Based On No Clutch Shifting AMT

The development of electric vehicles in recent years has made considerableprogress, but trapped in the current main problem is that electric vehicles with highinitial costs and not ideal mileage. For resolving this conflict has two key issues: thehigh-capacity battery development and high-performance motor drive systems. Electricvehicles trend to have multi-shift and integrated power drive, what’s more, multi-shiftreduce the requirements for the motor and battery, and expand the work of the drivemotor. For this reason, we can control the transmission system to ensure the drivemotor is always able to work in an ideal area, enhancing the vehicle’s power, economyand other indicators. As we know, the transmission is able to achieve shift on thecondition that the speed of input and output can be achieved simultaneously. At thesame time, because the motor control performance is better than the fuel-engine, so inthe variable speed motor drive system, we can remove the clutch to control the motorspeed and torque to achieve shifting directly.In this paper, we take a pure electric vehicle as the model, which was designed inan automobile R&D institution. Firstly, it analyzed and discussed the structure of thevariable speed motor drive system, which is able to change shift without the clutch,and the details of its mechanism. The shift quality was analyzed on the shifting process.Because the variable speed drives removed the clutch, so we analyzed the slidingfriction force characteristics of the study sites before and after the synchronizer, theestablishment of a synchronizer mathematical model derived by the formula shiftquality, improved method for the eventual shift to improve the quality provided.Secondly, we build the electrical control system model of the permanent magnetsynchronous motor drive motor (PMSM) based on the most commonly used vectorcontrol. Control the motor to meet the conditions to verify the two shifts variable speedsystem without the clutch and shift mechanism feasibility, and conducted upshift anddownshift operation simulations, which are to provide a theoretical basis formodeling.And then in order to the trends to shift in intelligence, add AMT automatictransmission to this system. Based on the shifting control strategy of AMT oftraditional fuel-engine, but for the difference between the motor and fuel machine,developed a new AMT shift control strategy. Conducted the Matlab/stateflow simulation on the whole vehicle, and developed driver control strategies underdifferent driving intention of automatic shifting. The simulation test results show thatthe real shift control strategy is feasible.Finally, we also conducted the bench test and vehicle running test on the motorshift control. The operation achieved satisfactory results and obtained a large numberof experimental data through the bench test, and made a foundation for the subsequentaddition of AMT automatic transmission. Through the car experiment, the prototypecar can shift smoothly during the running, and that meet the original designrequirements. What’s more, it has a good value to promote to other electric cars.