Driveline stiffness relaxation systems and methods for DFCO operation

• Main Authors: HEARLD SCOTT A, WHITNEY CHRISTOPHER E, HORGAN JEREMY V, GOODE RYAN, BUUR LARS MIKAEL, KAR KRISHNENDU
• Format: Patent
• Language: Chinese; English
• Published: 19.09.2012
• Subjects: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE ORDIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; PERFORMING OPERATIONS; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TOTHE CONTROL OF A PARTICULAR SUB-UNIT; TRANSPORTING; VEHICLES IN GENERAL

The invention relates to driveline stiffness relaxation systems and methods for DFCO operation. A powertrain system includes an engine control module that generates a negative torque transition signal based on a pending negative torque event of an engine. A transmission control module receives the negative torque transition signal from the engine control module. The transmission control module increases a slip speed of a torque converter clutch in preparation for the pending negative torque event by adjusting pressure in the torque converter clutch prior to the pending negative torque event. The transmission control module decreases the slip speed in the torque converter clutch based on completion of a transition at least one of to the pending negative torque event and from the pending negative torque event.