Powertrain calibration method to improve drivetrain oscillation after tip-in maneuvers with mechanical throttle body systems

When a vehicle is subjected to a transient torque event by its engine, the powertrain usually responds in an oscillatory manner. This is a characteristic of the system, due to the lashes and the stiffness. This oscillatory behavior disturbs the driver/passengers when showing high amplitude and/or a determined frequency. The powertrain calibration must act to attenuate oscillations in order to avoid driveability issues. One approach is to modulate the spark advance to absorb the oscillatory response. This paper proposes a method to calibrate this 3rd order high pass filter algorithm, making it less time consuming than a pure empirical and trial and error manner. Benefits of 80% reduction of time consumption were obtained by applying the proposed methodology. Besides that, for the same time invested, better results were achieved with the system presenting more robust responses over the vehicle operating ranges.