A control device for a power transmission mechanism is provided, performing control so that a driving wheel reliably obtains torque when a vehicle is started. In a vehicle having a power transmission mechanism that includes a power transmission path transmitting power from a power source to a first driving wheel and a second driving wheel, and a power transmission element arranged in the power transmission path between the power source and the second driving wheel, a control device for a power transmission mechanism includes a control section controlling a fastening force of the power transmission element so as to control power transmission capacity of the power transmission mechanism from the power source to the second driving wheel, wherein when the control section acquires that the vehicle transitions from a traveling state to a stop state, the acquisition triggers the control section to increase the power transmission capacity.

A system and method for operating a vehicle equipped with an automatic stop and start system is disclosed. The vehicle includes an internal combustion engine, an automatic transmission and a fluid launch device with an impeller disconnect clutch. A controller may initiate an automatic stop or start of the engine under certain operating conditions. During an engine start/stop event, the engine is automatically shut down and the impeller clutch of the fluid launch device may be disengaged to decouple the engine and transmission from the driveline to provide for improved fuel economy and reduced emissions.

A controller adjust a clutch actuator position is response to movement of a clutch pedal. During an engagement or a disengagement, the controller monitors sensor signals to determine the actuator position corresponding to the touch point. The sensors may directly indicate clutch torque or may respond indirectly. A Giant Magneto Resistive (GMR) sensor provides a precise shaft rotational position signal which can be twice numerically differentiated to yield an accurate and stable acceleration signal. The controller updates the touch point based on a change in the sensed acceleration or torque. The controller then adjusts the relationship of actuator pedal position to clutch pedal position, making mechanical wear adjustment unnecessary.

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.

A vehicle includes a transmission, an engine, a disconnect clutch, an inertial measurement unit, and a controller. The transmission has an input shaft and an output shaft. The engine is configured to generate and deliver torque to the input shaft. The disconnect clutch is configured to connect and disconnect the engine from the input shaft. The disconnect clutch is also configured to crank the engine during an engine start. The inertial measurement unit is configured to measure inertial forces exerted onto the vehicle. The controller is programmed to, in response to a command to adjust a torque of the disconnect clutch to a desired value that is derived from the inertial forces and a vehicle velocity, drive the clutch actuator pressure to a value that corresponds to the desired value.

This clutch control device is provided with: a supply valve and a supply valve control unit, which control the supply of an operating fluid to a pressure chamber; a first discharge valve and a first discharge valve control unit, which control the discharge of the operating fluid in the pressure chamber; and a second discharge valve and a second discharge valve control unit, which control the discharge of the operating fluid in the pressure chamber. When it is determined that the engagement and disengagement switching of a clutch device 2, which is necessitated by the discharge of the operating fluid in the pressure chamber, is required, the first discharge valve is controlled to be opened and then the second discharge valve is controlled to be opened.

A method for controlling a clutch unit for a drive train of a motor vehicle, wherein the clutch unit comprises a wet-running friction clutch for controllably transmitting torque from an input element to an output element of the clutch unit, wherein the clutch unit comprises oil for cooling the friction clutch, wherein heat inputs which contribute to heating the oil of the clutch unit are calculated, heat outflows which contribute to cooling the oil of the clutch unit are calculated and, as a function of the heat inputs and heat outflows, a maximum admissible clutch torque is calculated, and wherein the current clutch torque of the friction clutch is limited to the maximum admissible clutch torque.

This transmission device includes a mode changeover switch (59) on which a mode changeover operation between a manual mode (M2) and an automated mode (M1) is externally performed, other operation unit (80) on which a predetermined shift operation is externally performed separately from the mode changeover switch (59), and a control unit (60) configured to control a mode changeover between the manual mode (M2) and the automated mode (M1). The control unit (60) executes the mode changeover between the manual mode (M2) and the automated mode (M1) on the basis of the mode changeover operation on the mode changeover switch (59). When the shift operation on the other operation unit (80) has been performed, the control unit (60) executes the mode changeover between the manual mode (M2) and the automated mode (M1).

A friction engagement element control system is provided, which includes a friction engagement element including friction plates, and an actuation system configured to engage an input-side friction plate with an output-side friction plate with a pushing force, the friction plates having a negative slope characteristic in which a friction coefficient thereof decreases as a rotational difference between the friction plates increases, a rotational difference sensor of the friction engagement element, a separator configured to divide a variation in the detected rotational difference into a high-frequency component that is a vibration component and other low-frequency components, and a controller configured to control a pushing force only for the vibration component of the rotational difference so that the negative slope characteristic becomes a positive slope characteristic in which a frictional force of the friction engagement element decreases as the rotational difference decreases, when engaging the friction engagement element.

An all-wheel-drive vehicle includes a primary axle operably coupled to an engine and a secondary axle having an input operably coupled to the engine a first halfshaft, a second halfshaft, a first clutch selectively connecting the first halfshaft to the input, and a second clutch selectively connecting the second halfshaft to the input. A transmission has an input coupled to the engine and output coupled to the primary drive axle. A driveshaft couples a power-transfer unit and the input, and a third clutch selectively couples the output to the driveshaft. A controller is programmed to, during a power-limiting routine, command a torque to the engine based on closed-loop feedback control such that the torque decreases when a calculated slip of a selected one of the first and second clutches is greater than a target slip of the selected clutch and increases when the calculated slip is less than the target slip.