Patent ID: 7706951
Filing Date: 2010-04-27
Classification: F16H,Y10T

Abstract:
1. A shift control method of an automatic transmission, comprising: detecting a vehicle speed and a throttle opening; determining whether a shifting condition is satisfied based on the vehicle speed and the throttle opening; calculating a required shift speed based on the vehicle speed and the throttle opening from a shifting pattern map table if the shifting condition is satisfied; calculating first hydraulic pressures of on-going and an off-coming clutch based on the required shift speed from a hydraulic pressure map table; performing a shifting process according to the first hydraulic pressures; determining whether a flare occurs during the shifting process; calculating a flare amount if a flare occurs; calculating second hydraulic pressures of the off-going and on-coming clutches based on the flare amount from the hydraulic pressure map table; controlling the off-going and on-coming clutches according to the second hydraulic pressures; determining, if the flare does not occur, whether a shifting time interval is smaller than a predetermined time interval; calculating a third hydraulic pressure of the on-coming clutch based on the shifting time interval from the hydraulic pressure map table if the shifting time interval is smaller than or equal to the predetermined time interval; controlling the on-coming clutch according to the third hydraulic pressure; determining, if the shifting time interval is larger than the predetermined time interval, whether the shifting process has begun; detecting a rate of change of a turbine speed during the shifting time interval if the shifting process has begun; determining whether the rate of change of the turbine speed is larger than a predetermined value; calculating fourth hydraulic pressures of off-going and on-coming clutches based on an excess rate of change of the turbine speed from the hydraulic pressure map table if the rate of change of the turbine speed is larger than the predetermined value; and controlling the off-going and on-coming clutches according to the fourth hydraulic pressures.