SPEED CHANGE CONTROL METHOD FOR AN AUTOMATIC TRANSMISSION

摘要

A speed change control method for an automatic transmission for realizing a smooth skipping downshift even when the driver steps on the accelerator in a gentle fashion at the time of kick-down. An electronic control unit (6) calculates a deviation between a throttle valve opening theta t1 at a time when a predetermined period of time has elapsed after it outputs an instruction to effect a downshift from the fourth gear to the third gear and a throttle valve opening theta ts when the downshift instruction is outputted and a variation rate ( theta t1)' of a throttle value opening at the elapsed time, and outputs (S12) an instruction to cancel the already-outputted instruction of the downshift from the fourth gear to the third gear in a case where the deviation so calculated is found to be greater than a threshold value DELTA theta and the variation rate so calculated is greater than a treshold value DELTA ( theta )' (S10, S11), and also outputs (S13) an instruction to effect a downshift from the fourth gear to the second gear.