A method for synchronizing a first drive element rotatable about an axis of rotation with a second drive element rotating about the axis of rotation at a target speed, of a powertrain of a motor vehicle, in which a synchronizing force is exerted on a synchronizing unit by an actuator. A speed, at which the first drive element rotates about the axis of rotation is adapted by the synchronizing unit to the target speed. The synchronizing force is increased during a first time span, so that the speed approaches the target speed. The synchronizing force is continuously reduced during a second time span following the first time span, before the speed corresponds to the target speed.

A method and a system for controlling a backlash of a powertrain included in a vehicle in connection with a gear shifting operation is presented. The method comprises: controlling, in connection with a first gear shifting operation, a clutch included in the powertrain to a slipping position, in which slipping position the clutch transfers a slipping torque that is less than a torque being transferred in a closed position for the clutch; analyzing a change of a rotational speed for an input shaft of a gearbox included in the powertrain; determining a position for the clutch, for which position the change of the rotational speed has a value corresponding to a backlash torque, the backlash torque having a predetermined value for eliminating the backlash; and utilizing the determined clutch position for controlling the clutch in connection with a second subsequent gear shifting operation.

The present disclosure relates to a technique for improving durability of a clutch and shifting stability. The present disclosure provides a method of controlling a clutch of an automated manual transmission (AMT) vehicle, which reduces a micro-slip control time in order to improve durability of the clutch by performing a full-lock control of the clutch after slip control for learning a clutch characteristic curve. Additionally, the method shortens time to open the clutch for a subsequent shifting by predicting the time when a shift restarts after the full-lock control and by resuming the micro-slip control.

A disconnect system for selectively coupling or disconnecting a drive member and a driven member. The disconnect system includes a clutch ring rotationally coupled to a drive member, a solenoid actuator, and a clutch ring configured to be moved by the solenoid actuator to selectively transition the clutch ring between an engaged position where the clutch ring is rotationally coupled to a driven member and a disengaged position where the clutch ring is disconnected from the driven member. A controller can be provided to control the axial velocity of the clutch ring (e.g., relative to the rotational axis thereof) to reduce unwanted noise, vibrations, or harshness that can occur during the transition between engaged and disengaged positions.

A vehicle includes a continuously variable transmission, a gear mechanism and a controller. The continuously variable transmission and the gear mechanism are provided in parallel with each other between an input shaft and an output shaft. The controller is configured to i) when the vehicle travels in a state where both a first clutch and a third clutch provided on the gear mechanism side are released, gradually increase a hydraulic pressure of the first clutch such that the first clutch is engaged, ii) calculate a command hydraulic pressure for setting the first clutch to a pressure regulating state on the basis of a command hydraulic pressure of the first clutch at a timing at which the amount of change in an output-side rotation speed of the first clutch becomes larger than a predetermined value, and iii) control the first clutch by using the calculated command hydraulic pressure.

A launch control method of a vehicle includes: a clutch hold step of maintaining a clutch torque until an engine torque becomes smaller than the clutch torque, when a driver releases an accelerator pedal during launch control; a time constant determination step in which a time constant for a rate of releasing the clutch torque is determined depending on a difference between the clutch torque and a target creep torque when the engine torque becomes smaller than the clutch torque; a filter processing step of processing the time constant and the target creep torque using a low-pass filter that has the time constant and the target creep torque as an input and has a nominal clutch torque as an output; and a clutch control step of controlling a clutch using the nominal clutch torque.

A power transmission device for a vehicle includes a control unit adapted to automatically control engagement or disengagement of a clutch, and is further equipped with a clutch lever for manually engaging or disengaging the clutch. The power transmission device includes a manual mode in which the clutch is engaged or disengaged by a driver performing an engagement or disengagement operation with the clutch engagement/disengagement operating element and an automatic mode in which the clutch is engaged or disengaged under the control of the control unit without the driver performing the engagement or disengagement operation. The manual mode or the automatic mode is selectable by the driver. In the manual mode, it is further possible to select a plurality of control modes with differing levels of intervention of the automatic control.

Oil pressure controller for an automatic transmission produces a pre-charge shelf pressure supplied to a starter clutch by rapidly decreasing a command hydraulic pressure to the starter clutch after temporarily rapidly increasing the command hydraulic pressure, also produces a capacity adjustment pressure (Pb1 or Pb2) of the starter clutch by gradually increasing the hydraulic pressure from a decrease point of the pre-charge shelf pressure (Pa), when a selecting operation is made from N-range to D-range. By changing capacity adjustment pressure (Pb1 or Pb2) according to brake-operating/nonoperating state, capacity adjustment pressure (Pb1) in the brake-nonoperating state is set to be higher than capacity adjustment pressure (Pb2) in the brake-operating state by an offset hydraulic pressure amount. With this, when the selecting operation is made from N-range to D-range, in the brake-operating state, selection shock of the starter clutch can be reduced. In the brake-nonoperating state, good vehicle startability can be achieved.

A control method for carrying out a gear shift in a transmission provided with a dual-clutch gearbox, so as to shift from a current gear to a following gear. The control method comprises the steps of; receiving a gear-shift command; filling with oil, always supplying the maximum possible oil flow rate, a second clutch associated with the following gear after receiving the gear-shift command; completely closing the second clutch at the maximum possible speed as soon as the oil filling ends; and completely opening a first clutch associated with the current gear A at the maximum possible speed as soon as the oil filling in the second clutch ends.

A driving force transmission apparatus includes: a meshing member that switches two rotating members between a coupled state and an uncoupled state; a piston member with a plurality of locked portions formed along a circumferential direction; an armature that moves the piston member forward and backward between a first position where the armature presses the piston member in an axial direction and a second position where the armature does not press the piston member; a biasing member that biases the piston member in the opposite direction from the pressing direction of the armature; and a locking member that locks the locked portions. The piston member has a mechanism that mitigates a possible shock when the locking member comes into abutting contact with an abutting contact surface of a first locked portion.