An electronic control unit performs lockup clutch engagement control in the sequence of fast fill control, constant-pressure standby control and command pressure raising control, and starts the lockup clutch engagement control from that one of the fast fill control and the command pressure raising control which is later in sequence than the other, as a command pressure for a control oil pressure at a transition time point for making a transition to the lockup clutch engagement control rises, in making the transition to the lockup clutch engagement control during the lockup clutch release control. Therefore, when the command pressure for the control oil pressure is equal to or higher than a predetermined value that is needed to carry out packing for narrowing a pack clearance of a lockup clutch, the lockup clutch engagement control is started from the command pressure raising control.

Disclosed is a method of controlling a damper clutch through learning. A controller determines whether a driving condition of a vehicle is a condition where a predetermined selected fluid pressure value is desired. When necessary learning conditions are satisfied, the controller applies a control current for realizing a relevant fluid pressure to the solenoid valve. The controller updates the control current of the solenoid valve to an appropriate value based on response of the damper clutch. Thereafter, the controller controls the solenoid valve based on the updated control current.

A system for a vehicle includes a desired pressure module, a valve actuation module, a filter module, and a capacity detection module. The desired pressure module selectively generates an increase in a desired pressure of hydraulic fluid for a clutch of an automatic transmission. The valve actuation module actuates a solenoid valve based on the desired pressure. The solenoid valve supplies hydraulic fluid to a regulator valve, and the regulator valve supplies hydraulic fluid to the clutch. The filter module filters an acceleration of a shaft of the automatic transmission to generate a filtered acceleration. The capacity detection module indicates whether the clutch reached torque carrying capacity based on the filtered acceleration.

At the time when a hydraulic actuator is operated to engage a dog clutch, after it is detected that a hydraulic pressure for operating the hydraulic actuator is higher than or equal to a predetermined hydraulic pressure, it is determined whether the dog clutch is not engaged. Therefore, non-engagement determination due to insufficient hydraulic pressure for operating the hydraulic actuator is prevented. Thus, at the time when the hydraulic actuator is operated to engage the dog clutch, it is possible to prevent consumption of time to engage the dog clutch due to unnecessary re-engagement operation.

A method of selectively controlling a power take-off (PTO) assembly includes positioning a clutch assembly radially between a shaft and a PTO gear, operably controlling the clutch assembly with a controller, and selectively engaging the clutch assembly with the controller. The controller monitors signals received from a plurality of sensors and compares the monitored signals with respective signal thresholds. The clutch assembly is engaged when the compared monitored signals are within the signal thresholds.

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.

This clutch control device includes an engine (13), a transmission (21), a clutch device (26) configured to connect and disconnect motive power transmission between the engine (13) and the transmission (21), a clutch actuator (50) configured to drive the clutch device (26) and change a clutch capacity, a clutch operating element (4b) configured to enable the clutch device (26) to be manually operated, and a control unit (60) configured to calculate a target value (Pt) of a control parameter (Ps) of the clutch capacity in accordance with an amount of operation on the clutch operating element (4b). When the clutch device (26) is operated on a connection side according to an operation on the clutch operating element (4b), the control unit (60) is configured to set the target value (Pt) to a quick connection target value (Pmax) obtained by making a change to the connection side of the clutch device (26) with respect to an operation correspondence target value (Pv) according to the amount of operation on the clutch operating element (4b) if a speed of the operation on the clutch operating element (4b) is higher than or equal to a predetermined specified speed (Sp1).

Setting a system pressure for a hydraulically actuated clutch comprises a) Providing a system comprising a pump drivable by an electrically operated motor controlled by a control unit that senses a motor current and rotational speed and a system temperature is determined; b) a characteristic diagram is provided specifying values for at least the motor current and rotational speed for different system operating points; c) Accessing the characteristic diagram while operating a vehicle; d) Sensing at least the motor current and rotational speed at at least a first operating point and determining the system temperature; e) Comparing the values, acquired in step d) for the current and speed with the values for the current and rotational speed from the characteristic diagram according to step b); f) Adapting the characteristic diagram for the system on the basis of the parameters determined in step d).

A method and a device for operating a drive train of a motor vehicle are provided. The drive train includes at least a first and a second shaft, a first clutch having at least one first friction surface pairing, and an electric drive, the first and the second shaft being coupleable to one another via the at least one first friction surface pairing, wherein for cooling the first clutch, a fluid is used via which a drag torque of the first clutch is influenced after the first clutch is disengaged, the method including: a) Rotating the first shaft and the second shaft when the first clutch is at least partially engaged; b) Disengaging the first clutch; c) Accelerating the first shaft by means of the electric drive and discharging the fluid from an area of the at least one first friction surface pairing;
wherein the drag torque of the first clutch is reduced by the accelerated discharge of the fluid.

A transmission includes a first hydraulic clutch, a second hydraulic clutch, a third hydraulic clutch, a pump and a controller. The first, second, and third hydraulic clutches are configured to established a parked-ready condition upon engagement of all three clutches. The pump is configured to generate hydraulic fluid pressure. The controller is programmed to, in response to a command to start an engine that powers the pump, engage the first and second clutches. The controller is further programmed to, in response to engagement of the first and second clutches and obtaining operating hydraulic fluid pressure, engage the third clutch.