Active damping of automotive powertrain oscillations by a partial torque compensator

This paper deals with the problem of active damping of driveline oscillations in order to improve driveability and passenger comfort. Specifically, longitudinal vibrations which occur during transient changes in driver demand may affect driveability in a negative way. A robust and efficient controller is proposed, driving the engine in order to actively damp the driveline oscillations. The methodology considered is based on the prediction and compensation of the shaft torque at relevant frequencies. Contrary to previous work, it leads to a controller having only a few tuning parameters, with a clear meaning and can be adjusted directly on the vehicle.The whole design is described, including robustness analysis (μ analysis), backlash sensitivity, and discretization in a way that is compatible with the engine controller unit that works at a varying sampling rate. Finally, the results obtained with two different test cars are shown. They illustrate the efficiency of the proposed approach that allows reducing significantly the development time.