Modeling and Control of Torque Converter Clutch Using a Disturbance Observer based Tracking Controller

To meet the ever-increasing emissions and economy standards of the past 50 years, vehicle manufacturers have turned to sophisticated electronic control of all aspects of the powertrain. One of the areas gaining interest during the past 20 years has been torque converter clutch engagement and expanding the conditions when it operates. Slip mode, when the clutch is partially locked, allows the torque converter to transmit power very efficiently through the clutch while allowing a small amount of power through the fluid coupler. Allowing the clutch to slip dampens the engine vibrations from the rest of the drivetrain by allowing the fluid coupler to absorb and dampen the impulse. This paper presents a new disturbance observer based control scheme for the torque converter clutch during slip mode. Also, the performance of the proposed control scheme is demonstrated using simulation studies.