Patent ID: 6872166
Filing Date: 2005-03-29
Classification: F16H,Y10T

Abstract:
1. A method for controlling an automatic transmission, a torque converter with a driving torque transmitting member so as to transmit driving torque from a crankshaft to the automatic transmission in response to rotation of the driving torque transmitting member, plural friction engagement elements housed in the automatic transmission and engaged or disengaged for attaining plural shift stages, and a control unit for controlling an oil pressure to be supplied to the friction engagement elements and for controlling an engaging operation or a disengaging operation of the friction engagement elements based upon the controlled oil pressure supplied to the friction engagement elements, wherein one of the friction engagement elements is disengaged based upon the oil pressure controlled by the control unit, a side of the one of the friction engagement elements is transmitted with the rotation of the driving torque transmitting member, and the other side of the one of the friction engagement elements is locked not to be rotated while a vehicle is at a stationary condition, comprising: detecting a variation of a rotation number of the driving torque transmitting member when the one of the friction engagement elements is controlled to be engaged and, learning an oil pressure characteristic value of the one of the friction engagement elements based upon the variation of the rotation number of the driving torque transmitting member when the other side of the one of the friction engagement elements is locked against rotation while the vehicle is at the stationary condition.