Abstract: The control strategy of the hybrid electric vehicle (HEV) plays an important role in the fuel economy
and emission performance. This paper presents a model predictive control (MPC) torque-split strategy for
parallel hybrid electric vehicle powertrains based on a simplified first-order diesel engine transient model. A
torque request prediction method based on the driver’s accelerator pedal is presented for the MPC strategy.
With consideration of the motor’s compensation to the engine’s dynamic torque response delay, the optimization
constraints and objectives were designed with the non-linear HEV torque-split problem simplified to a linear
programming problem. In the simulation the MPC torque-split strategy, which is potentially real-time-capable,
operates in less than 150 ms. Simulation results show that the MPC strategy can improve the fuel economy by
2.5% compared with a rule-based strategy.

Key words: hybrid electric vehicles (HEV), model predictive control, torque-split strategy, fuel economy