There is provided a transmission control device that controls a first prime mover and a second prime mover of which output responsiveness is different from each other. A processing circuitry of the transmission control device executes a process including: in response to a shift command, calculating each target rotational speed of the first prime mover and the second prime mover for a synchronous control that brings one of rotational speeds of a dog and a transmission gear at the second transmission gear position close to the other; and determining a first timing or a second timing such that the second timing is later than the first timing, the first timing being a time at which the synchronous control of the first prime mover is started, and the second timing being a time at which the synchronous control of the second prime mover is started.

A first transmission mechanism provided on a first power transmission path and a second transmission mechanism provided on a second power transmission path are provided in parallel with each other between a driving force source and a drive wheel. A first clutch mechanism transmits power or interrupts transmission of power in the first power transmission path. A dog clutch equipped with a synchromesh mechanism transmits power or interrupts transmission of power in the second power transmission path. An electronic control unit is configured to, when changing from the first transmission path to the second transmission path a state where the vehicle is stopping or is stationary and in a state where power of the driving force source is transmitted via the first transmission mechanism, actuate the first clutch mechanism and the second clutch mechanism such that the first clutch mechanism is released and the second clutch mechanism engages.

A coupling device for a motor vehicle includes a first coupling element associated with a first rotatable part of the motor vehicle, and a second coupling element associated with a second rotatable part of the motor vehicle. The coupling device moves one or both of the first coupling element and the second coupling element into an intermediate position before a target rotational speed differential between the first and the second coupling elements is reached. Specifically, the target rotational speed differential is reached before the coupling device moves the first coupling element and the second coupling element into form-lockingly coupling to couple the first and second rotatable parts.

Methods and system are described for changing a driveline gear range from a lower gear range to a higher gear range. The driveline may include two electric machines and four clutches in a four wheel drive configuration. The methods and systems permit a driveline to change from a lower gear range to a higher gear range in a way that may reduce torque disturbances that may result from gear lash.

An engagement operation of a dog clutch is carried out while an engagement operation of a second clutch is being carried out, that is, during a situation that an uplock is hard to occur because of a phase shift generated between meshing counterpart members of the dog clutch. Thus, the dog clutch is easily engaged, and it is possible to facilitate preparation for transmission of power through a first power transmission path. If the dog clutch is not engaged, the second clutch is engaged and a second power transmission path is established, so it is possible to start moving a vehicle by transmitting power through the second power transmission path. Thus, when the dog clutch is in a non-engaged state at the time of an N-to-D shift during a stop of the vehicle, it is possible to ensure the startability of the vehicle.

A method for operating a vehicle drivetrain (1) includes decoupling, in the presence of a demand for realizing a sailing operating state of the vehicle drivetrain (1) during which a drive machine (2) is active and the power flow between the drive machine (2) and a drive output (3) is disconnected in a gearbox (4), the active drive machine (2) from the drive output (3) by opening of one of a plurality of shift elements (A to F) that is held in a closed operating state in order to realize the operating state present before the demand for decoupling of the active drive machine (2). The method also includes then actuating the plurality of shift elements (A to F) in a manner dependent on the present operating state profile of the vehicle drivetrain (1) and with the active drive machine (2) decoupled from the drive output (3).

A method for operating a vehicle drivetrain (1) includes proceeding, in the presence of the demand for activation of the engine start-stop function of the vehicle drivetrain (1) and a simultaneously shut-down drive machine (2), from an operating state of the vehicle drivetrain (1) during which a sailing operating function of the vehicle drivetrain (1) is active, during which the drive machine (2) is decoupled from the drive output (3), during which the positively engaging shift element (F) is open and during which a rotational speed (n_ab) of the drive output (3) is higher than a defined rotational speed at which a rotational speed difference between shift element halves of the positively engaging shift element (F) lies within a rotational speed range within which the positively engaging shift element (F) is transferrable into the closed operating state, and actuating the positively engaging shift element (F) in a closing direction no later than when the defined rotational speed is reached.

A control apparatus of a vehicle obtains information indicating a relationship between an instruction value to be provided to an actuator in accordance with a driving condition of a vehicle and a torque capacity of a clutch. The control apparatus includes a table holding unit that stores a correction table to be applied under a condition when an output torque from the engine is increasing and a correction table to be applied under a condition when an output torque from the engine is decreasing, a gear change condition determining unit that determines under which condition a gear change is executed, and a correction table update unit that updates the correction table to be applied under the determined condition based on the information indicating a relationship between a target value and an actual value of the torque capacity generated at the inertia phase.

A drive-train for a vehicle with at least one electric drive, which can be coupled via a driveshaft (2) to at least a first transmission ratio stage (i1) and a second transmission ratio stage (i2). At least one shifting mechanism is provided for engaging the transmission ratio stages (i1, i2). To carry out powershifts, the shifting mechanism includes at least one interlocking shifting element (5) and at least one frictional shifting element (6, 6A). Each of the transmission ratio stages (i1, i2) can be engaged by the interlocking shifting element (5) and at least one of the transmission ratio stages (i2) can be engaged both by the interlocking shifting element (5) and by the frictional shifting element (6). Methods for carrying out a powershift, between a frictional shifting element (6, 6A) and an interlocking shifting element (5) in the drive-train, are also disclosed.

A shift control apparatus of an automatic transmission includes: an input detecting unit configured to detect a real rotational speed of the input shaft; an output detecting unit configured to detect a real rotational speed of the output shaft; an estimating unit configured to estimate an estimated rotational speed of the input shaft, which corresponds to a shift request, by multiplying the real rotational speed of the output shaft by a target gear ratio; and a control unit configured to control the rotation of the input shaft based on a detection result from the input detecting unit. The control unit controls the rotation of the input shaft such that an upper-limiting rotational speed of a variation in real rotational speed of the input shaft is lower than the estimated rotational speed.