| 摘要 |
Disclosed is a shift control method for automatic transmissions. The shift control method includes the steps of determining if all conditions for performing closed-throttle upshifting are met after information of whether a vehicle is in a driving state is read; establishing an initial duty value, first and second ramps for performing duty control, and duty signal output times, all from a closed-throttle upshifting map data, and determining a duty compensating value from a hydraulic pressure compensating map table; adding the initial duty value and duty compensating value to calculate an initial duty control value, and outputting the initial duty control value as ramps to perform shifting; subtracting engine RPM from turbine RPM and determining whether the resulting value is equal to or less than a predetermined critical value in a state where shifting is being performed using the initial duty control value; adding a predetermined compensating duty value to the initial duty control value to increase duty control, then performing duty control to the determined ramps and shifting to a target shift range; determining if the conditions for open-throttle upshifting are met; determining if upshifting is completed; determining if a final duty control hold time has exceeded a critical hold time; and setting the duty value to "0" to maintain the present state of reacting and friction elements. <IMAGE> |
