Patent ID: 6292732
Filing Date: 2001-09-18
Classification: F16H,G06F,G16Z,Y10T

Abstract:
A control method for an automatic transmission including an on-coming clutch that is filled with hydraulic fluid in a preparation phase of shifting, and a controller for supplying hydraulic fluid at a commanded pressure to the on-coming clutch during the preparation phase, the method comprising the steps of:determining a cumulative volume of hydraulic fluid supplied to the on-coming clutch;comparing the determined cumulative volume to a reference volume representing a volume estimate for the on-coming clutch volume;predicting the achievement of on-coming clutch torque capacity when the determined cumulative volume exceeds the reference volume by a predetermined incremental amount;monitoring an input speed of an input shaft of the transmission to detect an aberration due to under-estimation or over-estimation of the reference volume; andadaptively adjusting the reference volume in response to a detected aberration so that the reference volume more nearly represents an actual volume of the on-coming clutch.