Analysis and coordinated control of mode transition and shifting for a full hybrid electric vehicle based on dual clutch transmissions

A Full Hybrid Electric Vehicle (FHEV) has been proposed with a single motor based on Dual Clutch Transmissions (DCT), which can take the advantage of the distinctive HEV structure and advantages of DCT. The dynamic model of hybrid system has been established taking the characteristics of engine, ISG motor and clutches into consideration. The working modes of the FHEV have been designed based on the optimal system efficiency and the shift schedule for the best economy has also been proposed. As a result, the integrated working mode and shift schedule of the FHEV has been achieved. Due to the mode transition and shifting of the FHEV maybe happen at the same time, the coordinated control strategy has been proposed to implement the mode transition and shifting simultaneously, which can solve the conflict between mode transition and DCT shifting. Simulation model of coordinated control of mode transition and shifting has been established based on Matlab/Simulink platform. The simulation results indicate that the control strategy proposed in this paper is effective to solve the conflict between mode transition and DCT shifting. Furthermore, comparing with mode transition and shifting sequentially, the duration of mode transition and shifting are greatly shortened and the repeated operation of power sources and actuators are also avoided. It also shows that the coordinated control strategy can take advantage of the FHEV equipped with DCT.