Methods and systems are provided for controlling clutch capacity in a hybrid electric vehicle. In one example, a method includes adjusting values of a transfer function of a clutch of a dual clutch transmission in response to an operating condition of an engine and/or operating condition of an integrated starter/generator coupled to the engine while a vehicle is propelled via an electric machine coupled to the dual clutch transmission, and maintaining a driver demand wheel torque at vehicle wheels via adjusting torque of the electric machine in response to the operating condition of the engine and/or operating condition of the integrated starter generator. In this way the method may apply pressure to one of the clutches where engine speed is independently controlled to maintain positive or negative slip, thus enabling adaptation of positive and negative clutch transfer functions, which may improve driveline operation and shift quality.

Methods and systems are provided for adjusting clutch pressures and electric machine torques as a function of a stability metric threshold(s) in order to balance performance and charging of an onboard energy storage device. In one example, a method includes during an upshift of a transmission from a first gear to a second gear, adjusting a clutch pressure of the transmission to adjust slippage of a clutch in response to a vehicle stability control parameter exceeding a threshold. In this way, torque delivered to a transmission output shaft may be reduced, which may increase vehicle stability.

An apparatus includes a torque circuit and a clutch circuit. The torque circuit is structured to monitor a torque demand level of an engine. The clutch circuit is structured to (i) disengage an engine clutch of a transmission to decouple the engine from the transmission in response to the torque demand level of the engine falling below a threshold torque level and (ii) disengage a motor-generator clutch of the transmission to decouple a motor-generator from the engine in response to the torque demand level of the engine falling below the threshold torque level. The motor-generator is directly coupled to the transmission.

Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission are described. In one example, torque output from the engine and the electric machine is adjusted to provide controlled vehicle side slip during cornering by a vehicle.

An electric drive axle assembly of a vehicle includes an electric motor having an output shaft. At least one of a gear and a planetary gear assembly is coupled to the output shaft of the electric motor. The at least one of the gear and the planetary gear assembly is coupled to a differential mechanism configured to transfer torque to two axle shafts of the vehicle. The electric drive axle assembly configured to produce a plurality of speed ratios between the electric motor and the differential mechanism.

A hybrid dual clutch transmission includes a first sub-transmission and a first clutch allocated to the first sub-transmission, a second sub-transmission and a second clutch allocated to the second sub-transmission, a separating clutch provided to decouple the hybrid dual clutch transmission from an internal combustion engine. The first clutch has a first outer disc carrier, the second clutch has a second outer disc carrier, and the separating clutch has a further outer disc carrier. The first clutch, the second clutch, and the separating clutch are stacked radially one above the other and are arranged at least substantially axially overlapping. The transmission also includes an electric motor having a rotor, a stator, and a housing. The transmission further includes a drive element permanently non-rotationally connected to the first outer disc carrier of the first clutch to link the electric motor.

Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission are described. In one example, values of an engine spark to engine torque relationship are adjusted to improve engine torque control. The engine is subsequently operated responsive to adjusted values of the engine spark to engine torque relationship.

Methods and systems are provided for launching a vehicle in an electric-only mode of operation. In one example, a driveline operating method comprises engaging a parking pawl to an output shaft of a dual clutch transmission in response to a request to engine a vehicle into a parked state, and disengaging the parking pawl via rotating an engine via an integrated starter/generator in response to a request to propel the vehicle solely via power of an electric machine positioned downstream of the dual clutch transmission. In this way, the vehicle may be launched in the electric-only mode without activating the engine in a fueled mode of operation and then deactivating the engine, which may increase vehicle operator satisfaction and which may improve fuel economy.

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 method is provided for balancing clutch wear in a dual clutch transmission. The method involves performing the steps of determining which clutch unit of first and second clutch units is subjected to the most accumulated wear and selecting a gear actuated by the other clutch unit during launch of the vehicle.