Patent ID: 6702714
Filing Date: 2004-03-09
Classification: F16H,Y10T

Abstract:
An apparatus for controlling a vehicle automatic transmission having a hydraulically operated frictional coupling device operable to effect a shifting action of the automatic transmission, and an accumulator connected to said frictional coupling device, said apparatus comprising:accumulator-back-pressure learning compensation means for effecting learning compensation of a back pressure of said accumulator such that an actual value of a rate of change of a rotating speed of a selected one of rotary elements of said automatic transmission, which rotating speed changes as a result of said shifting action, approaches a predetermined first target value; and accumulator-back-pressure control means for controlling said back pressure of said accumulator, on the basis of an output of said accumulator-back-pressure learning compensation means, wherein said accumulator-back-pressure learning compensation means effects the learning compensation of said back pressure of said accumulator such that an actual value of an inertia-phase-staff time approaches a predetermined second target value while said actual value of said rate of change approaches said predetermined first target value, said inertia-phase-staff time being a period of time from a moment at which said automatic transmission is commanded to effect said shifting action, to a moment of initiation of a change of the rotating speed of said selected rotary element as a result of said shifting action.