An apparatus to be applied to a vehicle including a transmission configured to execute a gear shifting operation for changing a gear ratio by engaging or disengaging friction engagement elements having friction members pushed by a piston that moves through hydraulic pressure supply to an oil chamber, the apparatus including: a memory storing mapping data for defining mapping, the mapping including a pressure variable and a period variable as input variables, the mapping including a stroke amount as an output variable, the pressure variable indicating a waiting pressure, the period variable indicating a waiting period; and a processor configured to: acquire values of the input variables, and calculate a value of the output variable by inputting, to the mapping, the acquired values of the input variables.

A transmission for an energy storage and recovery system comprises a variable slip transmission and a clutch arranged to transmit drive while slipping. The level of torque transmitted through the slipping clutch is dependent on the clutch force but is independent of the clutch slip speed. Preferably the clutch is provided by a plurality of clutches connected in parallel in a range extender. When drive is transferred between clutches in parallel, the clutch forces of both clutches are controlled to maintain the total torque transmitted by the clutches. This reduces torque fluctuations at the energy source/sink during clutch transfer. Where there are two slipping clutches in series, one clutch is controlled to provide the required torque and the other clutch is controlled in response to a clutch slip speed. This helps to control the speed of rotation of the mass between the clutches.

A clutch control method for a hybrid vehicle with a DCT of the present invention is provided. The method includes checking whether a current shift range is a D-range and determining a gradient of a current driving road and driver's vehicle stop requirement. In response to determining that the current shift range is the D-range, the gradient of the road is not a gradient that requires uphill driving, and there is driver's vehicle stop requirement, a controller reduces an operation current supplied to a clutch actuator of a clutch for transmitting power to a first gear to a regulation current. The regulation current is set based on an operation of the vehicle by the driver when the vehicle is restarted after the current reduction.

A method for operating a dual-clutch transmission of a motor vehicle, wherein a first clutch is operated closed or engaged and in this way a first transmission branch is driven, in which a current actual gear is engaged, and in a pre-selection phase for a gear changed to a desired gear in a second transmission branch, the desired gear is engaged, and in a second clutch, a clutch hydraulic system is filled and, in this way, the second clutch is closed. The gear change shall be made faster. The filling of the clutch hydraulic system is begun already during the pre-selection phase, and, in this case, the clutch hydraulic system is filled in the pre-selection phase but at most up to reaching a touch point of the second clutch.

Ideally, when a transmission is in Neutral, no torque should be exerted on the vehicle wheels by the powertrain. However, even with all clutches in a gearbox disengaged, some torque may be transmitted from a turbine shaft to the transmission output due to clutch drag and transmission component inertia. To avoid transmitting torque, a subset of clutches may be engaged to produce an input tie-up state, this holding the turbine shaft against rotation while permitting rotation of the output element.

A working vehicle includes a first hydraulic clutch connected to the first traveling shaft, a second hydraulic clutch connected to the first traveling shaft separately from the first hydraulic clutch, a first gear mechanism to transmit, to a second traveling shaft, power from the first hydraulic clutch when the first hydraulic clutch is engaged and not to transmit, to the second traveling shaft, power from the first hydraulic clutch when the first hydraulic clutch is disengaged, and a second gear mechanism to transmit, to the second traveling shaft, power from the second hydraulic clutch when the second hydraulic clutch is engaged and not to transmit, to the second traveling shaft, power from the second hydraulic clutch when the second hydraulic clutch is disengaged.

A hybrid module for a drive train of a motor vehicle, comprises an electric machine which has a stator and a rotor, a torsional vibration damper which has at least one rotary component, and an integrated clutch device which is constructed as a dual clutch. A rotor carrier which receives the rotor is connected directly via a permanent rotary connection to the at least one rotary component. The rotor carrier forms a clutch component of at least one part-clutch of the clutch device.

A method to control a road vehicle provided with a clutch, which connects an internal combustion engine to drive wheels and is arranged upstream of a servo-assisted transmission; the control method comprises the steps of: checking whether the tyres of the drive wheels are close to a grip limit; and opening the clutch so that the clutch transmits a torque to the drive wheels with a slip of the clutch that is constant and other than zero when the tyres of the drive wheels are close to the grip limit.

Methods and systems are provided for operating a driveline of a hybrid vehicle powertrain, where the driveline includes an electric machine downstream of a dual clutch transmission, which is downstream of an engine. In one example, a method comprises communicating from a transmission, a torque to accelerate transmission components from a first speed to a second speed with first and second clutches of a dual transmission open, the communicating performed while an electric machine coupled to the dual clutch transmission at a location downstream of the dual clutch transmission is providing torque to propel a vehicle. In this way, wheel speed may remain substantially constant while the transmission is shifted and the engine is stopped.

A transmission system includes a fluid-coupling device, an electro-hydraulic control system, and a clutch. The fluid-coupling device includes an input coupled to an impeller, an output coupled to a turbine, and a stator disposed between the impeller and the turbine. The electro-hydraulic control system includes a flow valve disposed in fluid communication with the input and the output of the fluid-coupling device that is movable between at least a first position and a second position, at least one trim valve system fluidly coupled to the flow valve, and a solenoid disposed in fluid communication with the flow valve that is electrically controllable between an energized state and a de-energized state. The clutch is disposable in fluid communication with the flow valve and controllable between an applied position and an unapplied position.