Research on fixed-time robust control allocation of the mode transition for CPS-HEV considering actuator uncertainties

The introduction of clutches provides more diverse operating modes for the compound power-split hybrid electric vehicle (CPS-HEV). However, it also introduces multiple control requirements and actuator uncertainties during the transient mode transition process (MTP). To address these challenges, this paper proposes a robust control allocation strategy for MTP based on fast fixed-time stability. First, a fast fixed-time terminal sliding mode control (FFTSMC) surface and reaching law are developed to create a fast fixed-time terminal sliding controller for MTP. Next, the weighted function of the Euclidean norm of torque control error and control input are defined as optimization objectives, with jerk as a constraint. A robust control allocator is then designed for the MTP redundant torque allocation system, accounting for actuator uncertainties. Subsequently, linear parameter-varying H∞ (LPV/H∞) robust feedback control is used to correct the target torque allocation command, coordinating the dynamic responses of different actuators. Finally, the hardware-in-the-loop (HIL) testing results demonstrate that the proposed control strategy effectively maintains the jerk within 10 m/s³ and significantly improves the quality of mode transition.