Lock-up clutch engagement hydraulic pressure learning control can be precisely performed by starting lock-up clutch engagement control and executing the lock-up clutch engagement hydraulic pressure learning control after execution of shift control is completed, in a case where the lock-up clutch engagement control is limited in a shift stage before execution of the shift control, when the shift control is executed in a state where a multi-disc lock-up clutch is released. Meanwhile, a decrease in fuel efficiency performance and a direct steering feeling is minimized by starting the lock-up clutch engagement control during shift control in a case where the lock-up clutch engagement control is not limited.

An initial variation learning control is executed when a learning condition is satisfied each time the learning condition is satisfied, with the aim of absorbing initial variations of manufacturing errors or variations of components of a second clutch (CL2). When the number of times of learning control is counted and this becomes a predetermined number (e.g. five times), after that, a deterioration variation learning control, which is equivalent to the initial variation learning control, is executed only once a trip from ON of a key switch to OFF of the key switch. With this, a frequency of execution of the learning control can be reduced, and the number of times of the learning can be reduced. It is therefore possible to suppress energy consumption and improve energy efficiency in stand-by pressure learning control of the second clutch that serves as a starter clutch.

A transmission apparatus for a vehicle includes a shift spindle having a clutch actuator, and also includes a shift actuator adapted to operate a shift drum. The apparatus also includes a motor for rotating the shift spindle, and a controller for controlling the motor. In use, the clutch actuator is rotated prior to the shift actuator when the shift spindle is rotated to a shift-down side. The controller rotates the shift spindle to a shift-up side and stores, as a standard duty, a driving duty of the motor at the time when a rotary angle of the shift drum reaches a drum angle threshold. Then, the controller rotates the shift spindle to a shift-down side, and learns a rotary angle of the shift spindle at the time when the standard duty is generated, as a touch point at which the clutch is initially partially engaged.

The invention relates to a method for determining a characteristic curve of a clutch of a clutch activation system in a drivetrain, in particular of a motor vehicle, in which the clutch is activated by an actuator, wherein a bite point of the clutch is adapted as a first support point of the characteristic curve. In a method in which the accuracy of the specific clutch characteristic curve is improved, a preload point of the actuator, preferably of an electric central disengagement device, is used as a second support point of the characteristic curve.

A vehicle clutch control device is provided for switching from a two-wheel drive traveling to a four-wheel drive traveling. The vehicle clutch control device includes a dog clutch that separates a rear wheel drive from a front wheel drive by releasing the dog clutch, an electronically controlled coupling that distributes a driving force of a transverse engine to left and right rear wheels in accordance with a clutch connection capacity, and a four-wheel drive control unit. The four-wheel drive control unit switches the drive mode to one of a disconnect two-wheel drive mode in which the dog clutch and the electronically controlled coupling are released, a connect four-wheel drive mode in which the dog clutch and the electronically controlled coupling are engaged, and a stand-by two-wheel drive mode in which the dog clutch is engaged while the electronically controlled coupling is released.

A power generation control device is provided for a hybrid vehicle that prevents unintended engagement of a released engagement clutch during idle power generation. An internal combustion engine is operated during idle power generation so that the input-output differential rotation speed of engagement clutches for selectively connecting an electric motor and/or the internal combustion engine to the drive wheel becomes a value greater than or equal to a rotation difference threshold value at which the engagement clutches are not engaged.

A method for learning an engine clutch kiss point of a hybrid vehicle includes: controlling, by a controller, an engine clutch which connects an engine with a motor or disconnects the engine from the motor so that the engine clutch is engaged after the controller checks stop of the engine and of the motor and stabilization operation for a hydraulic pressure line of the engine clutch is performed; controlling the motor to have a certain speed after the stabilization operation; controlling the engine clutch to be engaged after speed of the motor is stabilized; determining whether torque variation of the motor when the engine clutch is engaged is equal to or greater than a threshold value; and determining a hydraulic pressure at which the torque variation is the threshold value as the kiss point of the engine clutch.

An apparatus and a method are provided for learning a touch point of an engine clutch of a hybrid electric vehicle that learns the touch point of the engine clutch based on a change of an engine torque while the hybrid electric vehicle is running. The method includes determining whether an engine clutch coupling after shifting is required and whether a learning condition based on a running state of the hybrid electric vehicle is satisfied when the engine clutch coupling after shifting is required. A coupling pressure of the engine clutch is increased when the learning condition is satisfied and a changing amount of an engine torque based on the increased coupling pressure of the engine clutch is compared with a predetermined value. The touch point of the engine clutch is learned when the changing amount of the engine torque is greater than or equal to the predetermined value.

A power transmission device for a hybrid vehicle with a first clutch (1a) and a second clutch (1b). The first clutch (1a) is capable of transmitting or cutting off driving power of an engine (E) to driving wheels (D). The second clutch (1b) is capable of transmitting or cutting off power of a motor (M) to the driving wheels (D). The power transmission device is capable of appropriately operating the first clutch (1a) and the second clutch (1b) in accordance with driving conditions of the vehicle. When the engine (E) is started by transmitting power from the motor (M) to the engine (E), via the first clutch (1a) and the second clutch (1b), the power transmission device slip-controls the first clutch (1a) and the second clutch (1b).

The present disclosure provides a control method and a control system of a dual clutch transmission for a vehicle. The method includes: a pre-engagement-determining step of determining whether any one of gears has been pre-engaged, by means of a controller; a clutch-moving step of generating an oscillation signal to the release input shaft and increasing a clutch position value of the release input shaft; and a signal-determining step of determining whether the oscillation signal generated to the release input shaft is sensed at the engagement input shaft.