Control Strategy For Starting Up Of Pure Electric Vehicle

Under the dual pressures of global environmental pollution and energy shortages,the development of new energy vehicles especially the pure electric vehicles attractmore attention by worldwide. Pure electric vehicles with low noise, no pollution,diversifying sources of energy, energy efficiency advantages, is an important way tosolve the problem of the process of urbanization about the cars. The road conditions iscomplicated and the driving patterns change greatly in the starting process of pureelectric vehicles. So it has theoretical value and practical significance to research thestarting process of pure electric vehicles in order to fully reflect the wishes of thedriver’s driving,ensure the safety of the electric vehicle and satisfy the passengers’comfort. Launch control as an impoortant part of the pure electric vehicles controltechnology have its core and the difficulty that is the motor output torque in the startprocess.With the support of the Natural Science Foundation of Chongqing “electricvehicle powertrain matching optimization and integrated control”,the main contents ofthis paper is as follows:①Analysis of the arrangement and elaborated the principle of non-clutchautomatic transmission of pure electric vehicles. Carried out a detailed analysis of theactual starting process and starting process dynamics of the vehicle. Pointed out theinfluencing factors in starting process of vehicle through computer simulation,including the relationship among the speed of change,the driving torque,the quality ofvehicle and the road slope.②The general feedback control method for pure electric vehicle was proposedbased on its own characteristics. The automatically starting control for pure electricvehicle was proposed modeled on the characteristics of start-up torque convertervehicles without throttle open. According to the torque converter vehicles’ features,themotor torque output characteristics of under throttle open was determined and optimizedon the basis of performance testing on the engine and torque converter.Then, theautomatically start control process was described.③To solve the problem of pure electric vehicles starting in the big ramp,the HillStarting Aid was selected according to their own structural characteristics. Luenbergerobserver can identify the driving gradient based on the vehicle longitudinal dynamicsequation, it is the key technologies in the HSA system. The integrated start control method of pure electric vehicles based on HSA system was formulated,then the controllogic and control flow was also gave.④Established simulation models of the three launch control in Matlab/Simulink/Stateflow environment, simulation and analysis of the starting performance under thethree starting control strategy.