Engine torque management for engine speed flare suppression for clutch-to-clutch-upshifting

摘要

An improved powertrain control which recognizes the occurrence of engine speed flare during low torque upshifting, and effectively converts the shift to a power-off upshift via an override of the normal engine torque management controls. The engine spark timing is retarded by a predetermined amount during every power-on upshift for the reasons described above. However, when the occurrence of engine flare is detected, the control increases the spark retard to a maximum value, substantially eliminating the transmission input torque. As the on-coming element smoothly applies and decelerates the input, the flare condition terminates, and the spark timing is returned to the predetermined amount for completion of the shift.