Drivability Improving Control During Mode Transition Process of Through-the-Road Hybrid Electric Vehicles

Drivability control in mode transition process of through-the-road hybrid electric vehicles (TTR HEVs) is focused in this article. There is more than one path of energy flow from the power sources to the wheels in TTR HEVs. The torque coupling is achieved through the road. The operation modes and transitions show more diversity than other HEVs. These distinguishing features imply the necessity of remodeling the TTR HEV powertrains for drivability control. In addition, how to handle the uncertainty resulting from clutch actuation, internal combustion engine (ICE) response lag, and modeling error is still a tough issue. To overcome these difficulties, first, operation modes and transition process of the concerned TTR HEV are discussed. The dynamic models of the front and rear powertrain are derived. Second, considering clutch torque change, ICE torque error, and model uncertainty, sliding mode controller (SMC) is designed to synchronize the rotate speed of the clutch driving and driven disks. Third, in order to reduce the reaching time as well as suppress the chattering near and on the sliding surface, a fuzzy sliding mode controller (FSMC) is proposed. Compared simulation results show that the proposed FSMC can improve vehicle drivability effectively.