Development and control of an active torsional vibration damper for vehicle powertrains

Due to environmental pollution concerns, emission regulations on internal combustion engines (ICEs) have been tightening and the importance of fuel efficiency has become pronounced. Thereupon, downsizing, downspeeding, turbo supercharging, and cylinder deactivation techniques have been implemented in designing modern ICEs. Despite their considerable benefits, these methods result in boosted torsional oscillations necessitating new vibration isolation technologies due to the limited performance of passive torsional vibration dampers. In addition, trade-offs are indispensable in the passive damper system designs since different engine operating points demand different values of oscillation attenuation parameters. Thus, this study was initiated to develop a novel active torsional vibration damper (ATVD) to attenuate the torsional vibrations of all engine operating points without making any trade-off and to open up a new comfort zone for the development of modern ICEs. Proposed ATVD is essentially a parametrically excited system that adjusts the stiffness rate, damping rate, and moment of inertia in accordance with a fuzzy logic control (FLC) law to maximize engine-borne torsional vibration attenuation capability. The ATVD performance is evaluated in a co-simulation environment by using a driving cycle with six engine operating points and its advantages over conventional passive dampers are demonstrated.