CONTROL METHOD FOR AN AUTOMATIC TRANSMISSION

摘要

Control method for effecting a gear shift in a stepped automatic transmission with an input shaft (7) and an output shaft (8) for transmitting power between two inertia components (1; 2) at distinct speed ratios with a first power transmission path (3, H, 6) and a second power transmission path (3, 4, L, 5, 6) being provided with a high clutch (H) having an adjustable torque transmitting capacity TH and a low clutch (L) having an adjustable torque transmitting capacity TL respectively, said method comprising the steps of determining a gear set input torque Tin to be transmitted by the transmission in the direction from the input shaft (7) to the output shaft (8) and controlling the said torque transmitting capacities TH and TL in dependency on the gear set input torque Tin to be transmitted such that: a) if Tin >= 0 then TH = Tin and TL = 0 b) if Tin< 0 then TH= 0 and TL = Ti.