A hybrid vehicle powertrain assembly includes a combustion engine, an electric machine, an input shaft, a ratchet mechanism, and a controller. The input shaft selectively couples the engine and electric machine. The ratchet mechanism includes a base integrated with a transmission housing, a camwheel fixedly coupled to the input shaft, a pawl, and an actuator to move the pawl. The controller is programmed to, in response to receipt of an engine brake command, output an engagement command to the actuator to move the pawl toward the camwheel for engagement to prevent the input shaft from spinning. A method for controlling a hybrid vehicle powertrain is also provided herein. The method includes, responsive to receipt of an engine brake command, outputting via a controller a command for a ratchet mechanism to engage an input shaft coupled to an engine to prevent the input shaft from spinning.

In an all-wheel drive (AWD) vehicle (10,42), torque carrying connections are provided between the powertrain and all four wheels (12,14, 22,24). A multimode mechanical clutch (48) or clutches are provided to selectively disconnect two of the wheels (12,14,22,24) from the powertrain during operating conditions where disconnection improves the performance and efficiency of the AWD vehicle (10, 42). The multimode mechanical clutches (48) may be installed at various locations of the AWD vehicle (10,42), such as within a front or rear differential (20,30), between a half axle (16,18,26,28) and a differential (20, 30) or between a half axle (16,18,26,28) and a corresponding wheel (12,14,22,24), or within a transfer case (36) or power transfer unit (44).

The vehicle based electromechanical process and apparatus providing for the generation of electrical energy from many vehicles, and for its intermediate storage into a cluster of storage batteries that are onboard each vehicle and finally for multiple events for each vehicle of the transfer of the stored energy to the nation's electrical grid. It is the integrated utilization of three components: generation, storage and grid collection. The rationale is that in the U.S., billions of transportation miles are routinely logged each day by more than a quarter billion vehicles and trains, presenting the potential to produce large amounts of electricity, and with the production of electricity, many major related benefits, and some of them ecological. Simply stated, the energy that will be used anyway in the operation of vehicles, will also be used indirectly to create large quantities of electrical energy directed into the nation's electrical grid.

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 modes in response to a request to a negative torque capacity of an electric machine being insufficient to provide a desired driveline braking torque. One cylinder mode operates cylinders with cylinder valves held closed and without fuel being injected to the cylinders while the other cylinder mode operates cylinders with valves that open and close without fuel being injected to the cylinders.

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.