A method for learning a touch point of a transmission is disclosed. The method may include: moving a sleeve of a synchronizing device in a shift stage gear direction and calculating a predicted rotation speed based on an initial rotation speed and a rotation speed change rate of a transmission clutch; positioning a first point when a difference between an actual rotation speed and the predicted rotation speed occurs and positioning a second point when a difference value between the actual rotation speed and the predicted rotation speed reaches a set speed; calculating a determination time by subtracting a second time to move the sleeve from the first point to the second point from a first time to move the sleeve from the first point to a pre-stored touch point; and performing a correction and control on the touch point based on the determination time.

Provided is a method of learning a touch point of a dual clutch transmission (DCT), and more particularly, to a DCT touch point learning method in which a touch point is learned based on a difference between a virtual input shaft speed and a clutch non-drive shaft input speed using a virtual input shaft reference speed calculated based on the speed of a traveling vehicle. In a traveling situation in which the touch point cannot be learned using the non-drive shaft according to the related art because the input shaft behavior of the non-drive shaft is rotationally synchronized with the input shaft behavior of the drive shaft by drag characteristics of the DCT, a virtual input shaft speed may be calculated, and the touch point of the clutch may be learned using the virtual input shaft speed.

A method for learning a touch point of a transmission is disclosed. The method may include: moving a sleeve of a synchronizing device in a shift stage gear direction and calculating a predicted rotation speed based on an initial rotation speed and a rotation speed change rate of a transmission clutch; positioning a first point when a difference between an actual rotation speed and the predicted rotation speed occurs and positioning a second point when a difference value between the actual rotation speed and the predicted rotation speed reaches a set speed; calculating a determination time by subtracting a second time to move the sleeve from the first point to the second point from a first time to move the sleeve from the first point to a pre-stored touch point; and performing a correction and control on the touch point based on the determination time.

A method for learning a torque-stroke (T-S) curve of an electric motor controlled dry clutch system is disclosed. The method includes calculating a position change value A for allowing a position change point P3 corresponding to an arbitrary torque y3 on a previous T-S curve C1 to follow-up and be moved to an expectation T-S curve C3, by a control unit, calculating a probability Pr_X3 to allow the position change value A to consider various environmental factors of a clutch within a valid range, and multiplying the probability Pr_X3 to the position change value A to calculate a final position change value A, by the control unit, and calculating a new point P3 by applying the final position change value A to the position change point P3 of the previous T-S curve C1, and generating a final T-S curve connecting the new point P3 and a touch point to learn, by the control unit.

A method for learning a touch point of an engine clutch of a hybrid electric vehicle including a motor connected to a transmission and an engine selectively connected to the motor through the engine clutch includes determining whether a learning condition of the touch point of the engine clutch is satisfied, releasing a transmission clutch and controlling a motor speed when the learning condition is satisfied, increasing a coupling pressure of the engine clutch when a change amount of the motor speed is less than a first predetermined value, comparing a change amount of a motor torque according to the increased coupling pressure of the engine clutch with a second predetermined value, and learning the touch point of the engine clutch when the change amount of the motor torque is greater than or equal to the second predetermined value.

The present invention provides a method for searching a touch point of a clutch in a dual clutch transmission, including: (a) a step of checking whether a touch point searching condition for a non-driving clutch and a driving clutch is met or not; (b) when the search condition of the step (a) is met, a step of detecting a searching point at which an absolute value of a difference between an acceleration value of an engine and an acceleration value of the driving clutch is larger than a threshold value after applying a position value of the non-driving clutch to the engine; and (c) a step of determining a position of the non-driving clutch corresponding to the searching point as the touch point.

A method for learning a touch point of an engine clutch of a hybrid electric vehicle including a motor connected to a transmission and an engine selectively connected to the motor through the engine clutch includes determining whether a learning condition of the touch point of the engine clutch is satisfied, releasing a transmission clutch and controlling a motor speed when the learning condition is satisfied, increasing a coupling pressure of the engine clutch when a change amount of the motor speed is less than a first predetermined value, comparing a change amount of a motor torque according to the increased coupling pressure of the engine clutch with a second predetermined value, and learning the touch point of the engine clutch when the change amount of the motor torque is greater than or equal to the second predetermined value.

A method for learning a torque-stroke (T-S) curve of an electric motor controlled dry clutch system is disclosed. The method includes calculating a position change value A for allowing a position change point P3 corresponding to an arbitrary torque y3 on a previous T-S curve C1 to follow-up and be moved to an expectation T-S curve C3, by a control unit, calculating a probability Pr_X3 to allow the position change value A to consider various environmental factors of a clutch within a valid range, and multiplying the probability Pr_X3 to the position change value A to calculate a final position change value A, by the control unit, and calculating a new point P3 by applying the final position change value A to the position change point P3 of the previous T-S curve C1, and generating a final T-S curve connecting the new point P3 and a touch point to learn, by the control unit.

The present invention provides a method for searching a touch point of a clutch in a dual clutch transmission, including: (a) a step of checking whether a touch point searching condition for a non-driving clutch and a driving clutch is met or not; (b) when the search condition of the step (a) is met, a step of detecting a searching point at which an absolute value of a difference between an acceleration value of an engine and an acceleration value of the driving clutch is larger than a threshold value after applying a position value of the non-driving clutch to the engine; and (c) a step of determining a position of the non-driving clutch corresponding to the searching point as the touch point.

The present invention is directed to a method for determining a force transmission contact point of an actuating element (6) of an electric clutch actuator which comprises a linear drive assembly configured to linearly move the actuating element (6) towards a preload plunger (10) which is linked by a pushrod (12) to a clutch lever (14) and to move the pushrod (12) to turn the clutch lever, characterized by including the steps: monitoring an oscillation of the pushrod (12) by monitoring the position of the pushrod (12) and determining in consecutive time periods at least one of a maximum, minimum and centre value of the pushrod position, deriving a measure of non-oscillatory movement of the pushrod (12) based on a difference between at least one of the respective maximum, minimum and centre values of the pushrod position in a current and at least one of the preceding time periods or based on a difference between a combination of the respective positions in the current and at least one of the preceding time periods; and determining that the actuating element (6) has reached the force transmission contact point if the measure of non-oscillatory movement of the pushrod exceeds a predetermined threshold value.