A method of controlling a vehicle drivetrain by an electric motor, in order to synchronize the speed of an internal combustion engine and the speed of gears in the drivetrain, wherein if a speed synchronization error e.sub.sync(t) is controlled to remain within a prespecified region for a specific period of time, the synchronization is finished, and a gear may be engaged.

Methods and systems are provided for a dual motor electric transmission configured with two dual synchronizers to reduce torque interruption during gear shifting. In one example, a method may include dropping torque of a first electric motor, allowing a first synchronizer to shift from a first gear arrangement to a second gear arrangement, and compensating for dropped torque with a second electric motor. The method may be repeated to shift a second synchronizer from the first gear arrangement to the second gear arrangement, allowing uninterrupted torque supply during gear shifting.

A method for operating a dual-clutch transmission includes, to resolve a respective tooth-on-tooth position between a toothing of a sliding sleeve and a toothing of a gear wheel during an engaging operation for the respective gear, a relative rotation between the toothing of the sliding sleeve and the toothing of the gear wheel is effected by a twisting torque which acts on the respective gear where the twisting torque is a same size for all of the plurality of gears.

The present invention provides a shift control method implemented in a vehicle equipped with an automatic transmission for controlling an input shaft rotation speed to a target input shaft rotation speed during a shift. The method includes setting of a basic target synchronization rotation speed that is a basic target value of the input shaft rotation speed during the shift, and setting of a corrected target input shaft rotation speed as the target input shaft rotation speed when the shift is a downshift without a requirement for a driving force of the vehicle, The corrected target input shaft rotation speed is obtained by decreasingly correcting the basic target synchronization rotation speed. Further, a decreasing correction amount of the basic target synchronization rotation speed is set so as to become larger as a deceleration of the vehicle becomes larger.

A method of controlling a drive axle system. The method may include executing a gear upshift or a gear downshift after decreasing the torque that is provided by an electric motor to a transmission of an axle assembly and increasing the torque that is provided by another electric motor to a transmission of another axle assembly.

A method for controlling the stationary clutching of an idler gear on a secondary shaft of a parallel shaft gearbox, by movement of a sliding gear constrained to rotate with said shaft towards the idler gear without the intervention of mechanical synchronization members, characterized in that it involves:—activating the translational movement of the sliding gear towards the idler gear without previous synchronization, if the two parts are unable to rotate when clutching is requested, and—activating a rotation of the idler gear following the free flight travel of the sliding gear to position the teeth of one in place of the holes of the other, if the clutch engagement threshold has not been crossed following a time delay.

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.

The invention relates to a method for synchronising the common speed (ω p) of two concentric primary shafts (1, 6) of a hybrid transmission in a hybrid operating mode wherein said two shafts are rotatably connected by a first coupling means (5), with the speed (ω s) of a secondary transmission shaft (10) comprising at least one idler pinion for allowing the coupling of one of said pinions (11, 12) to the shaft (10) thereof by closing a second coupling means (13) that does not have mechanical synchronisation bodies, the torque (Te) of the electric machine being temporarily reduced during the synchronisation phase in order to meet the conditions of a perfect coupling when the value thereof caps at an upper limit value (T.sub.e.sup.max) or a lower limit value (T.sub.e.sup.min).

A control apparatus for a transmission including a gear engagement commander outputting a gear engagement command of a sleeve, an actuator controller controlling an actuator to move the sleeve from a neutral position to a gear engaging position when the gear engagement command is output, a gear engagement determiner determining whether an engagement of the sleeve is prevented in a course of moving the sleeve from the neutral position to the gear engaging position; and a motor controlling an electric motor to rotate a rotating shaft so as to change a rotational position of movable dog teeth relative to passive dog teeth when it is determined that the engagement of the sleeve is prevented.

A control device for a vehicle includes a fuel cell, a motor-generator, a power unit, a transmission, a motor-generator control unit configured to perform a power control on the motor-generator based on a driver request torque, and a generated power control unit configured to control the generated power of the fuel cell based on a load of the fuel cell including the motor-generator. The motor-generator control unit performs a shifting power control for decreasing a rotation speed of the motor-generator during an upshift of the transmission, and a power control on the motor-generator based on a limit torque of the motor-generator during the shifting power control. The limit torque of the motor-generator being calculated based on an actual generated power of the fuel cell per unit time and an acceptable power of the power unit per unit time.