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.

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.

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).

In a transmission with a lockup clutch, in a case where zero-slip control of the lockup clutch is not established (converged) within a predetermined time, a sweep increase of a lockup clutch hydraulic pressure starts at an increase rate smaller than a normal increase rate in a case where the zero-slip control is established within the predetermined time, the increase rate until the end of the sweep increase is set to be equal to or less than the normal increase rate, and in addition, a hydraulic pressure at the time of the end of the sweep increase is set to be equal to or greater than a hydraulic pressure in a case where the zero-slip control is established within the predetermined time. With such control, in a case where the zero-slip state is not brought, suppressing the occurrence of shock when complete engagement is carried out.

Provided is a control device for a four-wheel drive which can maintain driving stability while restraining noise and vibration. A control device includes: a second control device that, when at least one of front wheel has slipped, engages a dog clutch after rotating a propeller shaft by a rotational force transmitted via first and second friction clutches; and a third control device that, if a predetermined condition is satisfied when the front wheels are not slipping, engages the dog clutch after rotating the propeller shaft by the rotational force transmitted via the first and second friction clutches. The time required to synchronize the dog clutch by the third control device is longer than that required to synchronize the dog clutch by the second control device.

Actual pressure of a hydraulic clutch of a motor vehicle can be regulated by: a) providing a value for a desired pressure to be present in a clutch cylinder; b) filling the clutch cylinder with hydraulic fluid to achieve the desired pressure; c) wherein, if the desired pressure lies between 0 and 7 bar, the actual pressure in the clutch cylinder is adjusted by regulating a rotational speed of the pump of the electric motor, and if the desired pressure is greater than 7 bar, the actual pressure in the clutch cylinder is adjusted by regulating a motor current of the electric motor; d) regulating the actual pressure until the desired pressure is achieved.

A dual clutch device is provided with a first piston for engaging a first clutch by using hydraulic pressure supplied to a first hydraulic chamber and disengaging the first clutch by using a first spring, a second piston for engaging a second clutch by using hydraulic pressure supplied to a second hydraulic chamber and disengaging the second clutch by using a second spring, first supply lines for supplying hydraulic pressure to the first hydraulic chamber and a second hydraulic canceling chamber, second supply lines for supplying hydraulic pressure to the second hydraulic chamber and a first hydraulic canceling chamber, a first valve for allowing or blocking the hydraulic pressure supply to the first hydraulic chamber and the second hydraulic canceling chamber, and a second valve for allowing or blocking the hydraulic pressure supply to the second hydraulic chamber and the first hydraulic canceling chamber.

Provided is a system and method for controlling a clutch plate assembly of a vehicle. The system may include a first clutch control system, a second clutch control system, and a valve system. The valve system may have a first input fluidly connected to the first clutch control system for receiving a first pressure from the first clutch control system, a second input configured to be fluidly connected to the second clutch control system for receiving a second pressure from the second clutch control system, and an output configured to be fluidly connected to the clutch plate assembly. The valve system may be configured to provide at least a portion of at least one of the first pressure and the second pressure to the clutch plate assembly.

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.