Research On Driving Intention And Shift Strategy Of Hybrid Electric Vehicle Based On P2 Configuration

Affected by the energy crisis and the increasingly severe ecological environmental protection pressure,most auto manufacturers in the world are actively promoting new energy vehicles.China's current “double points” policy and subsidies for new energy vehicles have made new energy vehicles the focus.Higher requirements have been put forward for the cruising range,three-electric configuration and comprehensive fuel consumption of new energy vehicles.As a key technology in the development process of hybrid vehicles,the control strategy and shifting map of hybrid vehicles are decisive for improving the power and economy of vehicles.The traditional shifting map often only consider the single performance of the vehicle,and are limited to steady-state driving conditions.In the case of overtaking,uphill or congested,accidental shifting and cyclic shifting are prone to occur.Therefore,the comprehensive shift strategy based on driving intention can not only improve economic emissions,but also have important significance for driving performance and component life.Firstly,the basic configuration of the hybrid vehicle is introduced.From the power flow point of view,the working mode of the plug-in hybrid vehicle with P2 configuration is analyzed,and the development target is set according to the market research results.The parameters of the engine,P2 motor,transmission and power battery in the PHEV hybrid system were preliminarily determined by theoretical calculation.The vehicle dynamic and economic simulation model based on CRUISE is built,which provides a model basis for the development of subsequent control strategies and the formulation of comprehensive shift strategies.Secondly,think about the efficiency of the engine and the motor,the method of superimposing the optimal working curve of the engine efficiency and the external characteristic curve of the motor to obtain the output torque characteristic of the hybrid system is proposed.The corresponding driver demand torque is calculated at different throttle opening degrees.The torque distribution strategies of the four drive modes are described respectively,and the corresponding engine and motor torque distributions for different throttle opening degrees are discussed in detail.For the torque distribution strategy during regenerative braking in braking mode,the conditions for starting the motor braking are given.The correctness of the model is verified by the actual vehicle test,and the matched powertrain system meets the set dynamic performance index.Finally,for different driving modes,the basic shifting map of optimal power and best economy are obtained.The driving intention is classified,and the range of the intention factor corresponding to each level is specified.A recognition method based on T-S fuzzy neural network is proposed.The training data of driving intention recognition is obtained by real vehicle test.The intentional recognition model is used to output the intention factor to represent the quantitative driving intention.Based on the traditional basic shift rules,a comprehensive shift strategy based on driving intention is formulated.The research results show that the intent recognition model can accurately identify the driver's operation and output the corresponding intention factor.The gears output by the integrated shifting strategy are greatly improved compared with the traditional shifting.There is no accidental upshift during emergency braking.In the case of jam time,it is also possible to avoid cyclic shifts in time.Using the NEDC cycle test,the simulation results meet the economic goals.