Abstract: A lock-up clutch control method controls a torque converter comprising an input shaft through which a rotating force from an engine is input, an output shaft which outputs a driving force to the side of driving wheels and a lock-up clutch which operates in response to a hydraulic pressure. A control element controls an engaging pressure of the lock-up clutch by way of the hydraulic pressure. The engaging force of the clutch is controlled in accordance with calculated results of a target following up section for calculating a controlled variable so that a slip follows up a target slip and a control system stabilizing section for calculating the controlled variable so that the disturbance applied to the control system is compensated. Thereby, a stable control may be realized without receiving any effect of the disturbance. The disturbance may be estimated and learned for more accurate control.

Abstract: A slip control apparatus provides a smooth response of actual slippage amount during a transitional period when a lock-up clutch is shifting from a disengaged state to a slipping state, and quickly determines a response to external disturbances when the slipping of the clutch is in a steady state. The apparatus has a first control unit for outputting a first control value based on the difference between target slippage amount and actual slippage amount, a second control unit for outputting a second control value based on the actual slippage amount, and a clutch pressure regulating unit for controlling an electromagnetic valve to control a lockup system on the basis of the sum of the first and second control values. The first control unit performs control for the transitional state of the lock-up clutch between the disengaged state and the slipping state.