Internal Model Control During Mode Transition Subject To Time Delay For Hybrid Electric Vehicles 2020-01-0961
With the rapid development of series-parallel hybrid electric vehicles (SPHEVs), mode transition from pure electrical drive to hybrid drive has attracted considerable attention. The presence of time delay due to response capacity of actuators and signal transmission of communication may lead to decrease of speed tracking accuracy, even instable dynamics. Consequently, drivability of the SPHEV is unacceptable, and durability of the components is reduced. So far, plenty of control strategies have been proposed for the mode transition, however, no previous research has been reported to deal with the time delay during the mode transition.
In this paper, a dynamic model with time delay of hybrid electric system is established. Next, a mode transition time-delay controller is proposed by combining a two degree of freedom internal model controller (2DOF-IMC) and a Smith compensator. Considering the control plant has three inputs (the engine output torque, clutch transmitted torque and motor output torque) and two outputs (the engine speed and motor speed), the generalized inverse matrix is used to solve the non-square control problem for the inverse matrix calculation required by the IMC. Then, a tracking controller and anti-disturbance controller is designed to ensure the stability under arbitrary time delay. At the same time, a Smith compensator is developed to compensate time delay. Finally, the results from MATLAB/Simulink software simulation and hardware-in-the-loop test both demonstrate that the proposed controller cannot only guarantee the stability of the system and compensate time delay, but also improve speed tracking accuracy suffering model error and external disturbance.