Systems and methods for operating a driveline of a hybrid vehicle are disclosed. In one example, an engine may enter or stay in one of two cylinder deactivation modes or enter or stay in a combustion mode in response to a request to downshift a transmission while a vehicle in which the engine resides is coasting.

In a hybrid vehicle control apparatus, driving of the vehicle is switched between driving modes including engine driving mode in which driving is to be powered by an internal combustion engine and electrical machine driving mode in which driving is to be powered by a rotating electrical machine, and required driving force in each of the driving modes in accordance with predetermined characteristics based on accelerator position and vehicle speed to control driving force of the vehicle to the calculated required driving force, when the driving mode is switched, driving force of the vehicle is controlled based on the required driving force of the driving mode before switched unless at least one of the accelerator position and the vehicle speed changes.

A hybrid energy system is provided in a vehicle including an autonomous power supply and being connectable to an external power supply infrastructure along the route of the vehicle, and which vehicle is arranged to operate in an autonomous power supply mode and/or in an external power supply mode. The system includes a first high voltage circuit including a first traction motor connected to an energy storage system by a first power converter for propelling the vehicle; a second high voltage circuit including a second traction motor connectable to an external power supply by a second power converter for propelling the vehicle; and where the first high voltage circuit and the second high voltage circuit are connectable by a third power converter between the first and the second power converters. A method for operating the hybrid energy system is also provided.

A vehicle includes an engine, a first MG (motor generator), a second MG, a planetary gear mechanism provided among the engine, the first MG and the second MG, a battery, and an ECU. The ECU executes batteryless travel control when the battery is abnormal. The batteryless travel control includes engine F/B control for controlling a rotation speed of the engine to become a target rotation speed, and power balance control for controlling a requested driving force to be output and allowing a power generated by the first MG to become equal to a power discharged by the second MG. When the rotation speed of the engine is higher than a threshold speed higher by a prescribed value than the target rotation speed while the batteryless travel control is in execution, the ECU decreases the requested driving force.

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.

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 entering into a parked state in a hybrid electric vehicle that includes a dual clutch transmission. In one example, a driveline operating method comprises in response to a first condition, engaging a first gear and engaging a second gear of a dual clutch transmission in response to a request to enter a vehicle park state where an output of a transmission is held from rotating, and in response to a second condition, engaging a third gear and engaging a fourth gear of a dual clutch transmission in response to a request to enter a vehicle park state. In this way, a park state may be entered into without the use of a park pawl, which may reduce costs associated with the vehicle and which may prevent issues associated with degradation of the park pawl.

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 comprises 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.