This vehicle transmission system includes a transmission (21) in which a gear is shifted by an operation of a driver of a vehicle (1), a clutch device (26) that is disposed in a motion transfer path between the transmission (21) and an engine (13) of the vehicle (1), and is disconnected and connected by an action of a clutch actuator (50), and a clutch control unit (61) that is configured to control disconnection and connection of the clutch device (26) by the clutch actuator (50). In a case where the vehicle (1) is started with a gear position of the transmission (21) located at or above a gear that is set in advance, and a vehicle speed (V) is less than or no higher than a set value (v2) that is set in advance, the clutch control unit (61) transitions to clutch capacity-limiting control in which a clutch capacity is reduced below that during normal clutch control.

A start control device is a start control device that controls start of a vehicle including a clutch that is engaged by the hydraulic pressure supplied from a hydraulic pressure supply source and a start device that starts a vehicle driving source, and includes: a hydraulic pressure control unit that controls so that the hydraulic pressure supply source supplies the hydraulic pressure to the clutch if a start condition for the vehicle is satisfied; and a start device control unit that controls the start device so that the rotation speed of the vehicle driving source reaches the predetermined rotation speed after the clutch is engaged.

Operating a drive train of a vehicle having a clutch assembly, wherein the clutch assembly is actuatable via an actuating device for the switchable transmission of a torque, wherein a first state of the actuating device, and thus a second state of the clutch assembly, is settable via a position of a drive unit of the actuating device, comprises: a) determining that a first torque request to the clutch assembly is constant; and b) determining that a first position of the drive unit is constant within the interval; and then c) controlling the drive unit with a dither function, wherein a position of the drive unit is continuously varied about the first position; and d) ending the dither function when the conditions stated in steps a) and b) are no longer met.

A clutch control method is provided for a four-wheel-drive vehicle in which the main drive wheels are connected to a drive source, and the auxiliary drive wheels are connected via a friction clutch to the drive source. When the vehicle starts off due to an accelerator depressing operation, the friction clutch is engaged to distribute, a drive torque from the drive source to the main drive wheels and the auxiliary drive wheels. In this clutch control method, when the vehicle switches from a traveling state to a stopped state while maintaining in a travel shift position, a control is preformed to apply initial torque as an engagement torque control of the friction clutch while the vehicle is stopped. A magnitude of the initial torque is set to a magnitude that maintains a drive-system torsion state by transmitting torque to an auxiliary-drive-wheel drive system before the vehicle is stopped.

A hydraulic circuit device for a vehicle, includes a clutch, a flow path, a fluid pump, a pressure generating device, and a control valve. The control valve is configured to determine whether a transmission start-stop function activation condition other than a vehicle speed is satisfied, determine whether a system start-stop function activation condition related to a component of the vehicle is satisfied, the component being other than the transmission, determine whether the vehicle speed is equal to or lower than a first speed threshold, and boost a line pressure of the flow path to accumulate pressure in the pressure generating device for preparing activation of the start-stop function if it is determined that the transmission start-stop function activation condition and the system start-stop function activation condition are satisfied, and if it is determined that the vehicle speed is equal to or lower than the first speed threshold.

A method and device for controlling an engine clutch of a hybrid vehicle are provided. The method includes setting a target speed of an engine to change a driving mode of the hybrid vehicle from an EV mode to an HEV mode and operating a HSG to adjust an engine speed to reach the target speed. An engine clutch that connects the engine with a driving motor or disconnects the engine from the driving motor is engaged to start when the speed of the engine is maintained at the target speed. A kiss point generated when the engine clutch is in a slip state is detected to learn the kiss point of the engine clutch and an output of the engine is increased based on a driver required torque when the speed of the engine and a speed of the driving motor are synchronized after the kiss point is learned.

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 number of variations may include a clutch system having a clutch; a first cylinder operatively connected to the clutch; a passive valve operatively connected to the first cylinder; a hydraulic power pack actuator and a second cylinder operatively connected to the passive valve; an electronic control unit operatively connected to the hydraulic power pack actuator; and a clutch pedal operatively connected to the second cylinder.

A hydraulic circuit device for a vehicle, includes a clutch, a flow path, a fluid pump, a pressure generating device, and a control valve. The control valve is configured to determine whether a transmission start-stop function activation condition other than a vehicle speed is satisfied, determine whether a system start-stop function activation condition related to a component of the vehicle is satisfied, the component being other than the transmission, determine whether the vehicle speed is equal to or lower than a first speed threshold, and boost a line pressure of the flow path to accumulate pressure in the pressure generating device for preparing activation of the start-stop function if it is determined that the transmission start-stop function activation condition and the system start-stop function activation condition are satisfied, and if it is determined that the vehicle speed is equal to or lower than the first speed threshold.

A vehicle having a clutch which connects an engine with a driveline which includes a multi-ratio gearbox, the clutch having an actuator which can be operated by a vehicle driver to engage and disengage the clutch, the actuator also having a control system arranged to move the clutch between fully engaged and fully released positions through a range of positions allowing variable levels of clutch slip in order to automatically reduce torsional vibrations in the driveline. The control system is configured to recognize a plurality of predetermined Vehicle Operation Modes defined by the combination of a Clutch Slip Status criterion as hereinbefore defined with one or more of the hereinbefore defined operating criteria of Manual Clutch Position Control Input Interface Status, Release Bearing Position Status and Slip Velocity Demand Status and, dependent on the recognized Vehicle Operation Mode, the control system applies a different clutch control strategy to achieve the required level of clutch slip to damp vibration in the driveline and provide transition between the different Vehicle Operation Modes without exciting an uncomfortable level of vibration in the driveline.