Methods and systems are provided for operating a vehicle driveline where the vehicle driveline does not include a torque converter. In one example, a method comprises controlling a capacity of a clutch configured to transmit torque between an engine and a transmission, and an output of an electric motor positioned in a driveline of the hybrid vehicle during a vehicle launch to emulate a performance of a torque converter positioned in the driveline of the vehicle. In this way, vehicle launch maneuvers may be conducted for vehicles that are equipped with a clutch and an electric motor, such that said launch maneuvers mimic those of a vehicle with a torque converter, which may improve customer satisfaction and improve engine efficiency.

Methods and systems are provided for starting an engine in a hybrid vehicle. In one example, a method includes cranking an engine of the vehicle by controlling a capacity of a clutch of a dual clutch transmission positioned downstream of the engine and compensating for driveline disturbance resulting from the cranking via controlling an electric machine positioned downstream of the dual clutch transmission. In this way, engine starting may be conducted under a variety of vehicle operating conditions.

A drive force control system to improve efficiency of a vehicle by controlling motors connected to drive wheels. A controller is configured to: calculate a total required torque of the drive unit; obtain combinations of a first interim torque of a first motor and a second interim torque of a second motor to achieve the total required torque; select a combination of the first interim torque and the second interim torque to minimize an output of a power source; and output the first interim torque of the first motor and the second interim torque of the second motor based on the selected combination.

A drive force control system appropriately controls motors each connected to a corresponding one of drive wheels, so that a vehicle can be propelled with high efficiency. First motor and second motors are controlled in such a manner that a sum of torques transmitted to a right front wheel and a left rear wheel equals to a total value of required torques of the right front wheel and the left rear wheel. A target torque of the first motor and a target torque of the second motor achieving a smallest amount of power output from an electrical power source, for the output torques from the first motor and the second motor are calculated. A torque is generated by the first motor based on the target torque of the first motor calculated, and a torque is generated by the second motor based on the target torque of the second motor calculated.

Systems and methods are shown for meeting wheel torque demand in a hybrid vehicle with an engine, a dual clutch transmission coupled to a driveline of the vehicle downstream of the engine, and an electric machine coupled to the driveline downstream of the dual clutch transmission. In one example, a method comprises transferring transmission input torque through a clutch of the dual clutch transmission controlled to a first capacity, and in response to a desired transmission input torque exceeding the capacity, increasing torque output of the electric machine coupled downstream of the dual clutch transmission to assist in meeting a wheel torque demand. In this way, a driver-requested increase in acceleration may be met under conditions where transmission input torque is limited by clutch capacity.

The present invention is capable of suppressing gear shift shocks or delays in acceleration with no interruption of driving force and reducing the weight. Disclosed is a transmission which is provided with multiple stage shift gears so arranged to shift a number of dog clutches to shift a gear to the upper stage of the multiple stage shift gears, and is characterized in that a guide part is provided to a shift operation section and the dog clutches on each of the sages so as to move the lower dog clutch in a neutral direction by a coasting torque acting on the lower stage by a shift rotation of the upper stage to release a meshing engagement when meshing engagements of the lower and upper dog clutches are simultaneously performed by an operation of the shift operation section.

To avoid occurrence of difference in level of torque in a case where direction of relative rotation between internal combustion engine and rotary electric machine is reversed, in starting internal combustion engine with shift clutch device brought into direct engagement state. Control device controls vehicle drive device including transfer clutch device, rotary electric machine, and transmission device each disposed on power transfer path connecting internal combustion engine to wheels. In performing internal combustion engine start control, control device reduces engagement pressure of transfer clutch device wherein transfer torque of transfer clutch device becomes zero on reverse in direction of relative rotation (T04), at which rotational speed (Ne) of internal combustion engine becomes higher than rotational speed (Nin) of rotary electric machine, in pre-transition completion period before transfer clutch device in slip engagement state is transitioned to direct engagement state, while maintaining transmission device at non-slip state.

A method for operating a drive device for a motor vehicle, which has an internal combustion engine and an electric motor. A drive shaft of the internal combustion engine can be coupled to a motor shaft of the electric motor by a shift clutch. The shift clutch is adjusted to a desired clutch torque over a dragging period for startup of the internal combustion engine. Prior to the startup, a quantity of heat that is expected to accrue in the shift clutch during the startup is predicted and, when the predicted quantity of heat exceeds a limit value, at least one operating parameter of the drive device that influences the startup is chosen in such a way that the quantity of heat expected to accrue is reduced.

A vehicle includes an engine, a transmission, a clutch, and a controller. The clutch is configured to couple the engine and transmission during engine starts. The controller is programmed to, in response to an actual engine start time being greater than an upper threshold time for an engine start event, alter an engine start torque apply schedule for the clutch such that the actual engine start time is less than the upper threshold time for a next engine start event. The controller may be further programmed to, in response to the actual engine start time being less than a lower threshold time for the engine start event, alter the engine start torque apply schedule for the clutch such that the actual engine start time is greater than the lower threshold time for the next engine start event.

A method for operating a drive device for a motor vehicle including an internal combustion engine and an electrical machine. A drive shaft of the internal combustion engine can be coupled to a machine shaft of the electrical machine by a shift clutch. The shift clutch is opened in a first shift state for decoupling the internal combustion engine and the electrical machine, and is closed in a second shift state for coupling the internal combustion engine and the electrical machine. When a switching occurs from the first shift state to the second shift state, a clutch target torque that is set at the shift clutch is determined in a first mode of operation by a closed-loop control, and in a second mode of operation is determined by an open-loop control.