Use of Active Vibration Control to Improve Vehicle Refinement while Expanding the Usable Range of Cylinder Deactivation 2019-01-1571

Cylinder deactivation has been in use at Fiat Chrysler Automobiles for several years resulting in a fuel economy advantage for V8-powered vehicles. The size of the fuel-economy benefit, compared to the full-potential possible, is often limited due to the amount of usable torque available in four-cylinder-mode being capped by Noise, Vibration, and Harshness (NVH) sensitivities of various rear-wheel-drive vehicle architectures. This paper describes the application and optimization of active vibration absorbers coupled with interior active noise control, optimized as a system, to attenuate vibration through several paths from the powertrain-driveline into the vehicle. The use of this strategy for attenuating vibration at strategic points is shown to diminish the need for reducing the powertrain source vibration amplitude. This paper describes the process by which the strategic application of these active devices is developed in order to achieve the increased usage of the most fuel-efficient cylinder-deactivation engine-operating-points.