Abstract: A vehicle includes an engine, and a transmission including a torque converter having an impeller. The vehicle further includes an electric machine configured to provide drive torque to the impeller. The impeller is selectively coupled to the engine via a clutch. At least one vehicle controller is configured to, in response to the engine being OFF, the transmission being in DRIVE, a vehicle speed being zero and a brake pedal being released beyond a threshold position, command the electric machine to provide a torque to the impeller. The torque is a predetermined feedforward torque adjusted by a feedback torque that is based on a difference between measured and calculated speeds. The speeds may be the speeds of the electric machine.

Abstract: Systems and methods for operating a hybrid vehicle driveline that includes an engine and a motor are presented. In one example, the systems and methods include one or more control modes where engine and/or motor speed or torque is adjusted responsive to different control parameters during a vehicle launch from zero speed or a creep speed.

Abstract: Systems and methods for operating a transmission of a hybrid powertrain that includes a motor/generator are described. The systems and methods may improve engine starting during engine starts where little or larger driver demand torques are requested. In one example, engine torque may be commanded to a torque based on a filtered driver demand torque, the filtered driver demand torque filtered based on a position of an accelerator pedal.

Abstract: Methods and systems are provided for improving engine restart operations occurring during a transmission shift in a hybrid vehicle. Engine speed is controller during cranking and run-up to approach a transmission input shaft speed that is based on the future gear of the transmission shift. Engine speed is controlled via adjustments to spark, throttle, and/or fuel, to expedite engine speed reaching the synchronous speed.

Abstract: A vehicle includes an engine, an electric machine, an engine disconnect clutch, and a transmission input configured to transmit power from the engine and electric machine to a transmission. The vehicle also includes a controller program to close the disconnect clutch and start the engine before downshifting in response to an anticipated transmission downshift in which a predicted speed of the transmission input after the downshift will be outside a predetermined speed range or a torque capacity of the electric machine will be less than a predicted required torque after the downshift.

Abstract: A method of controlling a hybrid vehicle includes commanding a first electric machine to provide a compensating torque. The compensating torque is based on a calculated cylinder pressure. The calculated cylinder pressure is calculated using a dynamic model. The model has an initializing input of engine crank position and real-time inputs of measured speed of the first electric machine and measured speed of the second electric machine.

Abstract: A vehicle control system includes a controller that is programmed to, in response to an accelerator lift-pedal event, generate a drag torque, with at least one of an engine and electric machine, having a magnitude that is based on a deceleration fuel shut-off torque of the engine and a desired power output of the electric machine, and limit the drag torque to a threshold value that is based on the deceleration fuel shut-off torque.

Abstract: A vehicle control system includes a controller that is programmed to, in response to an accelerator lift-pedal event, generate a drag torque, with at least one of an engine and electric machine, having a magnitude that is based on a deceleration fuel shut-off torque of the engine and a desired power output of the electric machine, and limit the drag torque to a threshold value that is based on the deceleration fuel shut-off torque.

Abstract: A system and method for estimating disconnect clutch torque during engine start with the motor in vehicles having an engine selectively coupled to the motor and transmission may be configured to control motor torque based on a clutch torque estimated from a difference in a measured powertrain state and a predicted powertrain state using motor torque as an input. The powertrain states may include, for example, motor speed, turbine speed, engine speed and clutch torque. An adaptive gain may be used to drive the difference between measured and estimated clutch torque toward zero.

Abstract: A shift strategy is provided for a hybrid electric vehicle to cause a speed of a motor to approach a target motor speed to increase fuel economy for an engine operating in a hybrid drive mode. A controller shifts the transmission according to a magnitude of a driver torque demand, the current rotor or impeller speed, and whether the motor is consuming or producing current. The controller shifts the transmission according to one shift schedule when the motor is motoring, and according to another shift schedule when the motor is generating power.

Abstract: Systems and methods for operating a hybrid powertrain that includes an engine and a motor/generator are described. The systems and methods align in time an estimated motor torque and an actual motor torque to provide an estimated driveline torque. The alignment compensates for communications delays between different controllers over a controller area network.

Abstract: Systems and methods for operating a driveline of a hybrid vehicle are described. The systems and methods may improve hybrid driveline performance so that a driver may experience less turbocharger lag and/or less cam phasing lag. The methods and systems may hold engine torque at an elevated level in the presence of a decrease in driver demand torque.

Abstract: A vehicle is provided with a powertrain including a battery-powered electric motor, an internal combustion engine, a transmission, and a powertrain controller. The controller is programmed to permit an upshift of a transmission gear ratio while a powertrain torque demand is less than a forecasted available powertrain torque sustainable over a predetermined upcoming duration of time. The controller is also programmed to inhibit an upshift while the torque demand exceeds the forecasted available powertrain torque to reduce successive gear shifts. The controller may be further programmed to, in response to battery a state of charge being less than a threshold, reduce the forecasted available powertrain torque by an amount sufficient to provide a recharge to a battery. The controller may be further still programmed to reduce the forecasted available powertrain torque by an amount sufficient to restart the engine while the powertrain is operating in an engine-off traction mode.

Abstract: Methods and systems are provided for improving engine restart operations occurring during a transmission shift in a hybrid vehicle. Engine speed is controller during cranking and run-up to approach a transmission input shaft speed that is based on the future gear of the transmission shift. Engine speed is controlled via adjustments to spark, throttle, and/or fuel, to expedite engine speed reaching the synchronous speed.

Abstract: Systems and methods for operating a transmission of a hybrid powertrain that includes a motor/generator are described. The systems and methods may improve engine starting during engine starts where little or larger driver demand torques are requested. In one example, engine torque may be commanded to a torque based on a filtered driver demand torque, the filtered driver demand torque filtered based on a position of an accelerator pedal.

Abstract: A method of controlling a vehicle, in which the vehicle includes an engine, a traction motor, and a clutch configured to selectively couple the engine to the motor, includes commanding the traction motor to provide an incremental torque. The motor is commanded to provide the incremental torque in response to the clutch being in a slipping condition. The magnitude of the commanded incremental torque is in response to the lesser of first and second torques. The first torque corresponds to an engine torque, and the second torque corresponds to a clutch torque capacity.

Abstract: Systems and methods for improving launching of a stopped hybrid vehicle are presented. The systems and methods adjust speed of a motor to reduce the possibility of noticeable impact between driveline gears during vehicle launch. In one example, motor speed is adjusted to a pump pressurization speed where driveline components may be moved to reduce impact between driveline gears during vehicle launch.

Abstract: Methods and systems are provided for improving engine restart operations responsive to a heavy operator pedal tip-in. Engine torque and disconnect clutch capacity are controlled during cranking and engine speed run-up so as to provide excess torque to accelerate the engine to the motor speed and prepare the engine for elevated torque delivery after the engine connects to the driveline. At a time of connecting the engine to the driveline, the engine torque is transiently reduced to avert NVH issues related to engine speed overshooting or undershooting the target speed.

Abstract: A vehicle includes a traction battery and an electric machine electrically connected to the battery. The vehicle further includes a controller configured to, during an inertia phase of a transmission shift from first gear to second gear at a constant accelerator pedal position while battery temperature is less than zero degrees Fahrenheit, alter a torque output by the electric machine to offset inertia torque transfer to a driveline to maintain constant acceleration of the vehicle.

Abstract: A parallel hybrid electric vehicle discrete step-ratio automatic transmission shift strategy attempts to cause a speed of a motor to approach a target motor speed to increase fuel economy for a coupled engine when in hybrid mode. A controller shifts the transmission according to a magnitude of a driver torque demand, the current rotor or impeller speed, and whether the motor is consuming or producing current.