Damping control of diesel drivetrain oscillations

Modern diesel engines with direct fuel injection provide dynamic engine performance with good fuel economy. Elasticity within the drivetrain causes torsional oscillations that affect the vehicle in the range 3 - 6 Hz and are uncomfortable for the passengers. Because of this, Siemens has developed an active damping controller for drivetrain oscillations. The basis of the new approach is a state space model of the drivetrain, which includes simplified engine dynamics, the vehicle´s inertia, and the elasticity and damping of the driveshaft and gearbox. In conjunction with online measurements, the model provides the basis for a full-state observer, which tracks the corresponding state of the real system. To be useful for the automotive industry, model parameters are programmed into the engine control unit. The paper discusses the in detail the control method used.