Transient Torsional Vibration Characteristic Analysis and Active Suppression of PHEV with Planetary Coupled Transmission System during Mode Transition Process

The coupled multi-source and wide-band excitations exist in the process of mode transitions of planetary-coupled PHEV, and it may cause large transient torsional vibration and significantly deteriorate the driving quality. This research takes the planetary-coupled PHEV as the studied object, the transient torsional vibration model of hybrid powertrain is built, where the nonlinear meshing stiffness of gears, tooth-side clearance and sliding of clutch are taken into consideration; for the typical operation conditions with engine start, based on the continuous wavelet transformation, a full-band influence analysis of transient torsional vibration is carried out for various excitation factors, then a hybrid model predictive controller considering gear vibration characteristics is developed to actively suppress the transient torsional vibration. The result shows that the tooth drop-collision caused by tooth clearance would stimulate the low-frequency torsional vibration at 10-100 Hz (longitudinal impact in whole vehicle level) as well as lead to high-frequency torsional vibration at 10-100 kHz (torque fluctuation in coupling system level), whereas the nonlinear fluctuations of gear stiffness primarily influence the high-frequency torsional vibration. The proposed hybrid model predictive controller considering the characteristics of torsional vibration can reduce 47.8% of the peak value of vehicle impact and 33.2% of root mean square value of torsional acceleration, which indicate the considerable elevation of driving comforts and service life of power coupling device for hybrid powertrain. © 2023 Editorial Office of Chinese Journal of Mechanical Engineering. All rights reserved.