A shift control system that reduces drop in driving force and shocks during execution of clutch-to-clutch upshifting is provided. The control system is configured to reduce a torque transmitting capacity of a first clutch at a predetermined rate while increasing a torque transmitting capacity of a second clutch with a reduction in the torque transmitting capacity of the first clutch during execution of the upshifting, to set a target speed of the engine to a level determined by adding a predetermined speed to a synchronous engine speed corresponding to a low speed stage, during a torque phase in which the torque transmitting capacity of the first clutch is being reduced and the torque transmitting capacity of the second clutch is being increased, and to execute a feedback control of an engine torque in such a manner as to maintain the engine speed to the target speed based on a difference between the target speed and an actual engine speed.

A method for operating a drive apparatus including an internal combustion engine and an electric engine. An output shaft of the drive apparatus can be operatively connected to the internal combustion engine by way of a shifting clutch and can be permanently operatively connected to the electric engine, so that the output shaft is disengaged from the internal combustion engine in a first shifting state of the shifting clutch and is engaged with it in a second shifting state.

Transmission torque of a shift progress side engagement device is set based on engine power, shift progressing power, and battery power such that MG1 torque and MG2 torque are limited due to the limitation of the battery power when shifting a stepped transmission is suppressed. The stepped transmission is shifted with the transmission torque which takes into account the input-output balance of the respective powers.

The present disclosure provides a shift control method for a hybrid electric vehicle including: controlling a speed of a vehicle driving source; simultaneously controlling a release element and a connection element in a transmission based on a rotation acceleration of a transmission output shaft when shifting by a power-on down shift.

A vehicle includes an engine and an electric machine coupled to a gearbox through a torque converter. The vehicle includes a controller programmed to command an engine torque and an electric machine torque to achieve a predetermined positive torque at the input of the torque converter when a driver demand torque at the torque converter input decreases to fall within a range between the predetermined positive torque and a predetermined negative torque.

Disclosed is a gear shift control method of a Dual Clutch Transmission (DCT) vehicle. According to the present invention, the gear shift control method of a Dual Clutch Transmission (DCT) vehicle includes: a gear shift start determination step (step S100) of determining whether a kick down shift, which performs a gear shift to a lower gear as an acceleration pedal is handled according to an acceleration intention of a driver, is started; a biaxial shift determination step (step S200) of determining, when the kick down shift is started, whether the gear shift is a biaxial shift, in which a difference of gear level between a target gear and a current gear is as much as an odd-numbered gear level larger than one level; a clutch torque control step (step S300) of uniformly decreasing torque of a release-side clutch and uniformly increasing torque of a connection-side clutch to synchronize revolutions per minute of a target gear input shaft with increasing revolutions per minute of an engine, if a current gear state of the vehicle determined at the biaxial shift determination step is the biaxial shift; a clutch synchronization determination step (step S400) of determining whether the revolutions per minute of the target gear input shaft is synchronized with the revolutions per minute of the engine by the clutch torque control; and a gear shift performing step (step S500) of performing gear shift control for engaging the target gear, when the revolutions per minute of the target gear input shaft is synchronized with the revolutions per minute of the engine.

Systems and methods for improving operation of a driveline disconnect clutch for a hybrid vehicle shifting are presented. In one example, pressure of a working fluid supplied to the driveline disconnect clutch is adjusted in response to a rate of change in accelerator pedal position. Further, pressure of the working fluid may be decreased responsive to selected operating conditions.

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, the engine is started and coupled to the driveline via closing a clutch of a dual clutch transmission. Speed of the engine and clutch pressure are controlled to reduce driveline torque disturbances and provide a desired wheel torque.

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 operating a driveline of a hybrid vehicle powertrain, where the driveline includes an electric machine downstream of a dual clutch transmission, which is downstream of an engine. In one example, a method comprises communicating from a transmission, a torque to accelerate transmission components from a first speed to a second speed with first and second clutches of a dual transmission open, the communicating performed while an electric machine coupled to the dual clutch transmission at a location downstream of the dual clutch transmission is providing torque to propel a vehicle. In this way, wheel speed may remain substantially constant while the transmission is shifted and the engine is stopped.