Driveline Oscillation Damping for Hybrid Electric Vehicles Using Extended-State-Observer-Based Compensator

Driveline oscillation is a significant concern in the context of hybrid electric vehicles (HEVs), because it can adversely affect the vehicles' sustainability. The reason for this is that the oscillation not only diminishes the longevity of components due to high mechanical contact stress but also results in poor driving comfort, which in turn reduces customer satisfaction. To address the issue of driveline oscillation effectively, two critical challenges, namely the time-varying torque load and driveline backlash, need to be tackled. To this end, this study constructs a control-oriented model of a second-order system plus a dead zone for the driveline backlash. An extended state observer is designed in order to estimate the unmeasurable load torque. As such, an extended-state-observer-based compensator is proposed to suppress driveline oscillations for HEVs. To evaluate the control and observation performance of the proposed extended-state-observer-based compensator, simulation and engine-in-loop experiments are conducted. Results obtained in the time and frequency domains reveal that the proposed control scheme substantially reduces driveline oscillation.