Verfahren zur Steuerung des Gangwechsels in automatischen Getrieben.

摘要

In an automatic transmission 16, upshifting is controlled by ramping down the pressure in an off-going clutch C1-C5 associated with a high speed ratio and increasing the pressure in an on-coming clutch C1-C5 associated with a lower speed ratio. The on-coming clutch C1-C5 has commanded pressure at a maximum value for an initial fill time, a lower increasing ramp value during the ramp of the off-going clutch until the on-coming clutch starts to engage, and then a closed-loop control until the clutch C1-C5 reaches a synchronous speed. The closed-loop control parameter is on-coming clutch slip speed which is controlled to a calculated slip speed profile. The profile has a first steep slope and a final less steep slope so that the actual slip can smoothly go to zero in a given time period.