Active control of hybrid electric vehicle launch vibration in pure electric mode

Abstract

Sudden torque changes and torque fluctuations caused by a traction motor in HEV (hybrid electric vehicle) can result in a driveline oscillation. This paper focuses on the HEV launch vibration in pure electric mode while only the electric motor is generating output torque. A relevant mathematical model has been built based on the working principle. According to the model, the torsional vibration characteristics of the electric propulsion system have been analyzed. Two active control methods, feed-forward control (FFC) and pole placement (PP) have been applied to suppress the HEV launch vibration. However, such longitudinal vibration may still be perceived by passengers, though they can attenuate the vibration to some extent. Therefore another method, wave superposition control strategy (WSCS), has been proposed to suppress the vibration more effectively. In order to prove the control effectiveness of WSCS, all these three active control methods have been applied in simulation for a comprehensive comparison of the vibration suppression effect. Simulation results demonstrate that compared with FFC and PP, WSCS minimizes the overshoot of wheel angular acceleration (WAA) most and doesn’t have much effect on the system response quickness, which can be regarded as the most effective control method.