A method of shifting a vehicle transmission including a first clutching device and a second clutching device is described. At least a portion of the first clutching device is coupled with or configured to be coupled with at least a portion of the second clutching device. The method may include the steps of engaging the second clutching device, where engaging the second clutching device includes controlling a state of the second clutching device by changing a state of the first clutching device. A transmission controller and a vehicle driveline are also described.

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.

A gear shift control device for an automatic transmission device includes a transmission including an output unit setting and outputting a target value of the hydraulic pressure to the hydraulic control device. The output unit, when the shift stage is changed from a shift stage to another, increases the target value for a first friction coupling portion in the decoupled state in the shift stage to a first value, reduces to a second value, increases to a third value after the value is reduced to the second value, sets to a fourth value after the value is increased to the third value, and sets to a fifth value after the target value is set to the fourth value, and the output unit sets the fourth value according to magnitude of input torque to the transmission.

A method for preventing an incorrect learning of a clutch torque of a transmission of a vehicle may include a controller estimating an engine-based clutch torque estimated based on an engine torque; the controller estimating a wheel-based clutch torque estimated based on a driveshaft torsional torque; the controller determining a torque error, which is a difference between the engine-based clutch torque and the wheel-based clutch torque: the controller allowing a learning of the clutch torque when the torque error is equal to or less than a predetermined reference torque; and the controller prohibiting the learning of the clutch torque when the torque error is greater than the predetermined reference torque.

A method to control the execution of a shift to a lower gear while an accelerator pedal is released in a drivetrain provided with a dual-clutch, servo-assisted transmission; the control method comprises the following steps: opening, in a first instant, an outgoing clutch; closing, in the first instant, an incoming clutch; completing the opening of the outgoing clutch and the closing of the incoming clutch in a second instant; synchronizing, between the second instant and a third instant, a rotation speed of the internal combustion engine with a rotation speed of the incoming clutch; and controlling the incoming clutch between the second instant and the third instant so as to have the incoming clutch temporarily transmit a greater torque than the torque that the clutch is going to transmit immediately after the shift to a lower gear and than the torque that the outgoing clutch transmitted immediately before the shift to a lower gear.

A method for operating a transmission for a motor vehicle having an input shaft, a first shaft connectable to the input shaft via a first input clutch and a second shaft connectable to the input shaft via a second input clutch, a plurality of gearshift clutches, and an output shaft. Different gear ratios between the input and output shafts are implementable by selective engagement of the plurality of clutches. A first torque transmission path between the first and second shafts is engageable with a first friction-locking clutch and a second torque transmission path between the first and second shafts is engageable with a second friction-locking clutch. The method includes actuating, at least intermittently during a synchronization phase in an upshift process of the transmission, the first friction-locking clutch to transmit a first torque and the second friction-locking clutch to transmit a second torque.

A dual clutch transmission for a motor vehicle including two sub-transmissions, each having at least one input shaft. An output shaft outputs drive from both sub-transmissions. The input shafts are arranged on an input shaft axis and the output shaft is arranged on the input shaft axis or a parallel countershaft axis. An intermediate gear system includes at least one countershaft which is arranged on the countershaft axis. At least four shifting elements are arranged such that, in each case, at least two shifting elements are arranged on the input shaft axis and on the countershaft axis. At least one input shaft can be connected to the output shaft by way of two wheel planes and/or at least one shifting element. Preferably half of the shifting elements are unsynchronized and at least one-third of the shifting elements are synchronized. Also a method for operating a dual clutch transmission.

A vehicle drive-force transmitting apparatus including: a mode switching clutch; a torque converter; a lock-up clutch included in the torque converter; a switching solenoid valve configured to output a switching pressure for switching an operating mode of the mode switching clutch between a one-way mode and a lock mode; and a lock-up clutch control valve configured to switch an operating state of the lock-up clutch between an engaged state and a released state. The mode switching clutch is to be placed in the lock mode when the switching pressure is supplied from the switching solenoid valve to the mode switching clutch. The lock-up clutch control valve is configured to receive the switching pressure supplied from the switching solenoid valve, and to switch the operating state of the lock-up clutch to the released state when the switching pressure is supplied to the lock-up clutch control valve.

A gear shift control device for an automatic transmission device includes a transmission including an output unit setting and outputting a target value of the hydraulic pressure to the hydraulic control device. The output unit, when the shift stage is changed from a shift stage to another, increases the target value for a first friction coupling portion in the decoupled state in the shift stage to a first value, reduces to a second value, increases to a third value after the value is reduced to the second value, sets to a fourth value after the value is increased to the third value, and sets to a fifth value after the target value is set to the fourth value, and the output unit sets the fourth value according to magnitude of input torque to the transmission.

A shift control method for a vehicle with a double clutch transmission (DCT) is configured such that when a power-on upshift is initiated, during a target time for a controller to perform a torque phase, a release-side clutch is gradually released, an engine torque is gradually increased to a basic engine torque or more, and an engagement-side clutch torque is increased according to an increase in the engine torque and a vehicle speed; and when the release-side clutch is completely released, the controller reduces the engine torque while gradually reducing the engagement-side clutch torque to be equal to the basic engine torque, to perform an inertia phase such that an engine speed is synchronized with an engagement-side clutch speed.