A method of learning a clutch touch point for a DCT vehicle, and he method is performed to learn a touch point of an apply-side clutch in a torque phase process during gear shifting. The method includes: controlling an amount of slip of a release-side clutch in an allowable range by a controller, when gear shifting is initiated; performing torque crossing control by releasing a release-side clutch torque to a certain level while applying a clutch torque to an apply-side clutch to the same level as the release-side clutch torque by the controller, after the controlling an amount of slip of a release-side clutch; and performing learning determination so as to learn a touch point of the apply-side clutch by the controller, when the amount of slip of the release-side clutch is beyond the allowable range in the performing torque crossing control.

In a motor vehicle, a friction clutch is disposed between a drive unit and a transmission. The value of the contact point of the clutch is adapted at predetermined points in time. A method for controlling the friction clutch includes the steps of determining a value of the contact point of the friction clutch, this value having been modified as a result of an adaptation thereof, and of continuously reducing the value of the contact point at a predetermined ramp rate, without letting this value drop below a predefined contact point reduction value.

A control method of a clutch for a vehicle may include determining whether or not learning of clutch characteristics is possible; learning the clutch characteristics when the learning of the clutch characteristics is possible; determining a clutch torque for controlling the clutch in consideration of a change amount in the clutch torque before and after the learning and controlling the clutch by the determined clutch torque; and determining whether or not it is difficult to continue to learn the clutch characteristics.

A method for determining an engagement point (X) of a clutch (3). The clutch (3) has first and second clutch sides (3a, 3b), which are rotationally decoupled when the clutch (3) is disengaged/open and which are rotationally coupled when the clutch (3) is engaged/closed. The method includes the steps of disengaging the clutch (3) and then engaging the clutch (3), in order to determine the engagement point (X). During this, the first clutch side (3a) is driven in rotation and the second clutch side (3b) is accelerated, for at least part of the time, by an acceleration device (4). A control device actuates the clutch (3) in order determine the engagement point (X) of the clutch (3), and a computer program product with stored commands, brings about the sequence of the method when the program is operated on a suitable control unit.

A method of setting a clutch control reference value includes monitoring the pressure of a clutch while a controller applies test current having a predetermined amplitude and frequency to a solenoid valve in the manner of gradually reducing the magnitude of the test current from a predetermined entry value, applying, when the amplitude of the pressure of the clutch starts to change, predetermined checking current, the checking current vertically oscillating based on the magnitude of current when the amplitude of the pressure of the clutch starts to change as a central value, and determining a volumetric kiss point (VKP) by comparing the amplitude of the pressure of the clutch according to application of the checking current with a predetermined reference range.

A control method of a transmission of an electric vehicle provided with a transmission having a sleeve gear having an inclined chamfer on a first side of the sleeve gear and a flat chamfer on a second side of the sleeve gear, may include measuring a maximum movable stroke of a sleeve having the sleeve gear by moving the sleeve axially to both sides by a controller; determining a reference range to which the measured maximum stroke pertains from predetermined reference ranges by the controller; and determining and setting a neutral position of the sleeve using a predetermined determination method, depending on the determined reference range by the controller.

A control method of a transmission of an electric vehicle provided with a transmission having a sleeve gear having an inclined chamfer on a first side of the sleeve gear and a flat chamfer on a second side of the sleeve gear, may include measuring a maximum movable stroke of a sleeve having the sleeve gear by moving the sleeve axially to both sides by a controller; determining a reference range to which the measured maximum stroke pertains from predetermined reference ranges by the controller; and determining and setting a neutral position of the sleeve using a predetermined determination method, depending on the determined reference range by the controller.

A method determines the travel of a clutch in a hydraulic clutch-actuation system. A hydraulic signal which extends between a transmitting end and a receiving end is acted upon by an acoustic signal for the generation of a wave packet. The acoustic signal on the transmitting end of the clutch-actuation system is fed into the hydraulic fluid, a wave packet generated by the acoustic signal on the receiving end is reflected back to the transmitting end, a running time of the transmitted and reflected wave packet on the transmitting end is evaluated to determine the coupling travel.

Systems and methods for operating a vehicle that includes an engine and an electric machine are described. In one example, an actual total number of transmission gear downshifts are counted to determine whether or not a transmission clutch characterization is immature. The transmission clutch characterization may be adjusted if it is determined to be immature.

Disclosed is a clutch control reference value setting method including generating a current-hydraulic pressure model, setting a temporary VKP to a current causing a maximum difference between a model hydraulic pressure and a measured hydraulic pressure, determining that the temporary VKP is valid when a deflection amount calculated from a difference integral value acquired by integrating differences between the model hydraulic pressure and the measured hydraulic pressure while increasing the current is greater than a first reference value under a condition that the first target pressure is applied to the clutch, determining that the temporary VKP is appropriate when a deflection amount calculated from a difference integral value acquired by integrating differences between the model hydraulic pressure and the measured hydraulic pressure while increasing the current is proper under a condition that a second target pressure is applied to the clutch.