Dynamic Coordinated Control For Driving-mode-switch Of Full Hybrid Electric Vehicle With Single Motor

HEV(Hybrid Electric Vehicle) is equipped with a variety of work-mode whichcombines a conventional internal combustion engine (ICE) propulsion system with anelectric propulsion system.It can achieve optimal energy consumption and emission bysuitability mode-switching process in the process of vehicle running.However, thedynamic process, such as engine starting, clutch engagement and torque distributionwith propulsion systems in the transformation process of vehicle running,can create achange of the system running state and target torque of engine and motor. If the controlisn’t reasonable, it can cause transmission produce a lot of torque fluctuation, whichcauses a larger pulse on the whole vehicle. The mode-change control problem ofrunning vehicle isincreasingly highlighted. Therefore, the control of above dynamicprocess is one of the key technologies to promote the industrialization of HEV.Aiming at dynamic control problem for driving-mode-switch of full hybrid electricvehicle with single motor, the main researches in this paper are as follows:①Structural characteristics of driving-mode-switch of full hybrid electric vehiclewith single motorare analyzed, and the parameter of key system components isgiven.Then the dynamic characteristic of key components and hybrid system isanalyzed,andpower-source and the critical transmission-componentsimulationmodelsare established.②The status of engine, motor, wet multi-plate clutch at each driving mode areanalyzed, and the equation of state isbuilt. Next, the status’s changing of engine, motor,wet multi-plate clutch and dynamic coupling mechanism are analyzed and the stateequation of different phase of the driving-mode-switch is built,which is classified intothree categories-typical by according to the wet multi-plate clutch changing state as soto makefollowing corresponding mode-switch control strategy.③Torque predistributionstrategy at each mode is studied, including totaldemanded torque, the mode-switching conditions, engine and the motor target torque.The clutch engagement processisdividedintotwopartsin terms of ignition time of enginestart andthe clutch pressure control algorithm of corresponding phase is formulated.Adynamic coordination control strategy which integrates with motor torque and clutchpressure control is put forwardwith regard to driving-mode-switch process with the wetmulti-plate clutch engagement. what’s more, an improved dynamic coordinated control algorithm is put forwardfollowing specific realizability analysis.④Based on Matlab/Simulink, a forward simulation model of full hybrid electricvehicle with single motor is built. Simulation analysis of given work situationand totalwork situation has succeeded in testifying the effectiveness of power source torquecoordination control strategy in the process of driving mode-switch.