The present invention is a hydraulic pressure control device for an automatic transmission that performs a gear shift by switching between engagement and disengagement of a plurality of friction engagement elements and includes solenoid valves, provided corresponding to the friction engagement elements, respectively, that switches between engagement and disengagement of the friction engagement elements by switching between supply and non-supply of hydraulic pressures to the friction engagement elements, and a control device that switches between supply and non-supply of the hydraulic pressures to the friction engagement elements by supplying a predetermined control current to the solenoid valves, in which the control device supplies a fixation preventing current lower than the control current to at least one of the solenoid valves corresponding to the friction engagement elements in a disengagement state of the plurality of friction engagement elements.

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.

The present invention is a hydraulic pressure control device for an automatic transmission that performs a gear shift by switching between engagement and disengagement of a plurality of friction engagement elements and includes solenoid valves, provided corresponding to the friction engagement elements, respectively, that switches between engagement and disengagement of the friction engagement elements by switching between supply and non-supply of hydraulic pressures to the friction engagement elements, and a control device that switches between supply and non-supply of the hydraulic pressures to the friction engagement elements by supplying a predetermined control current to the solenoid valves, in which the control device supplies a fixation preventing current lower than the control current to at least one of the solenoid valves corresponding to the friction engagement elements in a disengagement state of the plurality of friction engagement elements.

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 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 invention relates to a method for determining an engagement point of a hybrid clutch in a hybrid vehicle; which hybrid clutch is actuated by a hydrostatic clutch actuator and disconnects or connects an internal combustion engine and an electric traction drive; the engagement point is determined by slowly actuating the clutch starting from a position in which the hybrid clutch is in the non-actuated state, and monitoring a moment of the electric traction drive when a defined increase in the momentum is detected. In a method in which engagement point adaptation is optimized, a current engagement point (tp) is adapted during operation of the hybrid vehicle using a start-up routine, by which a first engagement point is determined when the hybrid vehicle is started; the hybrid clutch is moved close to a previously determined engagement point, and starting from said last determined engagement point, the hybrid clutch is displaced further until the defined increase in the moment is detected.

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 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 slip factor learning method of a dual clutch transmission (DCT) may include: determining, by a control unit, whether the DCT is up-shifted or down-shifted; comparing an engine speed to a shift start reference speed, and determining whether the engine speed enters an actual gear shifting period or actual gear shifting is completed, in response to the determined type of the gear shifting; comparing a magnitude of an engine torque to a magnitude of a clutch torque at a point of time that the engine speed enters the actual gear shifting period or the actual gear shifting is completed; and learning a slip factor at the point of time that the engine speed enters the actual gear shifting period or the actual gear shifting is completed, based on the magnitude comparison result between the engine torque and the clutch torque.

A vehicle control device includes a rotating machine, a clutch transmitting torque to the rotating machine when engaged, and a detection unit detecting a change in cogging torque of the rotating machine, and learns an engagement position of the clutch based on a change in the cogging torque during a change in a clutch stroke of the clutch in a case where the rotating machine is stationary.