| 摘要 |
PURPOSE: An initial duty rate compensating method of feedback control in shifting from 4 to 3-range is provided to shift actively according to traveling state by correcting the initial duty rate corresponding to turbine RPM(Revolution Per Minute) and vehicle speed in downshifting. CONSTITUTION: The change rate is measured by sampling turbine RPM from a turbine RPM detecting unit in downshifting from 4 to 3-range(S109,S110). The correction amount of the duty rate is set to increase or decrease hydraulic pressure according to change rate of turbine RPM. The initial duty rate is operated for feedback control by adding the set correction amount to the high speed duty rate according to turbine RPM change rate at high speed of the vehicle(S210), and output by adding the set correction amount to the low speed duty rate according to turbine RPM change rate at low speed(S220). Torque is controlled optimally by regulating hydraulic pressure according to the initial duty rate(S230). Shifting is performed actively according to traveling state of the vehicle.
|
