Anti-jerk Control Of Driving System In Electric Vehicle

With the development of vehicle industry, environmental and energy issues has become increasingly prominent, deterioration of air quality, global warming and scarcity of petroleum resources have seriously affected the life of modern society and sustainable development and these problems are also much concerned by governments. Strict standards of combustion efficiency and emissions promote the rapid development of energy-efficient vehicles. Pure electric vehicles as the representative of new energy vehicles are important breakthrough to achieve energy saving and environmental protection.Pure electric car and pure electric bus are the focus of pure electric vehicle development. Pure electric vehicles generally use the motor direct drive scheme and motor+AMT(automatic mechanical transmission) diver scheme. Motor direct drive scheme has higher requirements on battery and motor, while vehicle power performance is limited. Motor+AMT drive scheme is the trend of electric vehicle. Through different gear ratio, motor efficiency and vehicle power performance can be improved.In motor+AMT drive scheme, the elastic deformation of the drive shaft and the backlash of powertrain may cause longitudinal vibrations of the vehicle, the so-called "shunt and shuffle" phenomenon. This problem almost appears in all driving scenarios, especially in transient scenarios such as during gear shift, rapid acceleration and rapid deceleration process. Driveline torsional vibration can severely reduce the car’s driving comfort. This paper mainly studies about anti-jerk control of driving system in electric vehicle with motor+AMT drive scheme.The main research contents of this article are as follows:1. The powertrain structure of pure electric car and bus is introduced, multi-speed AMT is the trend of electric vehicle. A 2-speed AMT for electric car and a 4-speed AMT for electric bus are proposed. 2. The gear shift process of 2-speed and 4-speed AMT is introduced, the impact of powertrain backlash is described in detail. Backlash compensation control strategy is proposed and verified. 3. Based on 2-speed AMT with rear-mounted clutch scheme, the equivalent AMESim simulation model is established. Backlash compensation is considered. Three different gearshift strategies are analyzed by simulation, 4. Based on 4-speed AMT without clutch drive scheme, gearshift control strategy is studied. Backlash compensation is considered. By comparison, gearshift control strategy with backlash compensation is effective. 5. Based on 4-speed AMT without clutch drive scheme, tip-in and tip-out scenarios are studied. A controller to suppress torque vibration is proposed, it is proved to be effective through lots of simulation. 6. Finally, shifting control strategy and tip-in tip-out suppression controller have been tested in test bench and real vehicle of 4-AMT electric bus.