A vehicle includes a differential gear that transmits rotation of a propeller shaft to an axle. A differential lock switches the differential gear between a locked state and an unlocked state. A clutch is provided in a power transmission path between a prime mover and wheels of the vehicle. A controller controls an engaging force of the clutch during a moving start of the vehicle in accordance with which of the locked state and the unlocked state is selected by the differential gear.

A hybrid powertrain includes a torque provider, an automatic transmission without a torque converter, and a transfer case configured for providing four wheel drive low range. A controller receives a signal indicative of the transfer case being in low range and determines if brake pedal torque is indicative of a brake pedal being released and, if so, commands engagement of a launch clutch of the transmission up to maximum creep torque capacity at a predetermined maximum gradient. The controller determines when torque provider speed is synchronized with vehicle creep speed, and upon such determination, controls the launch clutch to fully engage to a lock up state to mimic behavior of engagement of a manual transmission gear when the hybrid powertrain is in low range to thereby substantially eliminate a time lag associated with automatic transmissions having a torque converter or a constantly slipping launch clutch.

A vehicle transmission system may include an engine outputting power from fuel combustion, a transmission coupled to the engine and including at least one clutch to control torque input from the engine, an supercharger compressing an intake air and supplying the compressed intake air to the engine, and a control unit, where, when a predetermined acceleration condition is satisfied, the control unit is configured to operate the supercharger and to control the transmission according to a transmission clutch stroke operation map corresponding to the operation of the electric supercharger, to vary an engagement speed of the clutch when the supercharger is operated.

Systems and methods for operating a vehicle that includes an engine and an electric machine are described. In one example, an actual total number of transmission gear downshifts are counted to determine whether or not a transmission clutch characterization is immature. The transmission clutch characterization may be adjusted if it is determined to be immature.

A vehicle includes a differential gear that transmits rotation of a propeller shaft to an axle. A differential lock switches the differential gear between a locked state and an unlocked state. A clutch is provided in a power transmission path between a prime mover and wheels of the vehicle. A controller controls an engaging force of the clutch during a moving start of the vehicle in accordance with which of the locked state and the unlocked state is selected by the differential gear.

A vehicle transmission system may include an engine outputting power from fuel combustion, a transmission coupled to the engine and including at least one clutch to control torque input from the engine, an supercharger compressing an intake air and supplying the compressed intake air to the engine, and a control unit, where, when a predetermined acceleration condition is satisfied, the control unit is configured to operate the supercharger and to control the transmission according to a transmission clutch stroke operation map corresponding to the operation of the electric supercharger, to vary an engagement speed of the clutch when the supercharger is operated.

A method for controlling a starting process of a vehicle includes activating a control sequence and setting a control sequence signal, defining a maximum engine drive torque, and detecting a drive request for a starting process. The method further includes, in response to the drive request, controlling a clutch-gearbox unit with an engagement process duration, controlling wheel slip of driven wheels by determining wheel speeds of the driven wheels and at least setting an output drive torque at the output shaft, and redefining the maximum engine drive torque depending on the wheel slip and a driving speed. The method also includes deactivating the control sequence and resetting the control sequence signal when limit values are reached.

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 launch control method is provided for a vehicle having an accelerator, a brake and a continuously variable transmission (CVT). The method comprises determining: (i) a braking torque set by a vehicle operator by pressing a brake pedal of the vehicle; and (ii) a holding torque required to hold the vehicle in a stationary position. The method also determines that the operator has released the brake pedal. The brake is released whilst engaging a launch clutch of the CVT, wherein the launch clutch is engaged by increasing a clutch engagement pressure at a first pressure ramp rate, such that the sum of the braking torque and a clutch torque of the clutch remains equal to the holding torque. An acceleration torque requested by the operator via the accelerator is determined. The clutch engagement pressure is increased at a second pressure ramp rate when it is determined that the braking torque is substantially zero, such that the clutch torque is increased by the acceleration torque. A fixed minimum pressure ramp rate is stored, wherein the minimum pressure ramp rate increases the clutch engagement pressure towards a maximum engagement pressure. The current pressure ramp rate is compared with the minimum pressure ramp rate, and the clutch engagement pressure is switched to the minimum pressure ramp rate if the current pressure ramp rate is less than the minimum pressure ramp rate.

A method for operating a drive device for a motor vehicle with an internal combustion engine and a dual clutch transmission. In a starting operation of the drive device directed at a startup of the motor vehicle, an electric machine coupled to a first input shaft is used, when the first shift clutch is at least partially engaged and the first sub-transmission is disengaged and when the second shift clutch is at least partially engaged and the second sub-transmission is engaged, for providing at the output shaft a starting torque used for starting the internal combustion engine and a drive torque directed at the startup of the motor vehicle, and/or in that, in the starting operation, the internal combustion engine is operated, when the second shift clutch is at least partially engaged and the second sub-transmission is engaged.