Load changes in automotive powertrains may cause uncomfortable vibrations during vehicle acceleration. These driveline oscillations occur due to flexible and underdamped shafts. Furthermore, backlashes in the drive train represent hard nonlinearities and lead to challenges in control. Reducing vibration only by feedback control may destabilize the closed loop due to time delays in the powertrain system. This paper proposes a flatness-based feedforward control law based on a two-mass powertrain model with backlash to compensate oscillations. In addition, a proportional feedback controller is used to damp remaining oscillations arising from model mismatches and disturbances after the set-point transition. Simulation results show improved tracking performance in comparison to a feedforward approach without considering backlash explicitly.
