Abstract: A vehicle includes an engine having a crankshaft, a transmission having an input, and an electric machine mechanically coupled to the transmission input. The vehicle further includes a clutch configured to mechanically couple the electric machine and engine crankshaft, and at least one controller. The at least one controller, in response to an engine start condition and subsequent partial engagement of the clutch, outputs a torque command for the electric machine to increase the speed of the crankshaft to a speed of the electric machine before commanding fuel injection of the engine. The torque command is based on driver demanded torque and a change in speed of the crankshaft caused by changes in pressure to the clutch.

Abstract: A vehicle includes an engine having a crankshaft, a transmission having an input, and a torque converter mechanically coupled to the input. The vehicle further includes an electric machine mechanically coupled to the torque converter, a clutch configured to mechanically couple the electric machine and crankshaft, and one or more controllers. The one or more controllers are programmed to, in response to the transmission being in a drive or reverse gear and a speed of the vehicle being less than a predetermined value in an absence of driver demand, control the electric machine to achieve a target speed to cause the torque converter to output torque such that the speed of the vehicle approaches a generally constant speed less than or equal to the predetermined value when the vehicle is on a generally flat grade.

Abstract: A vehicle includes a starter motor, an engine having an output mechanically coupled to the starter motor, a transmission having an input, and an electric machine mechanically coupled to the transmission input. The vehicle further includes a clutch configured to mechanically couple the electric machine and the output of the engine, and at least one controller. The at least one controller is programmed to initiate an engine start based on driver demand. The controller is further configured to enable pressure to the clutch for the engine start if driver demand is less than a calibratable torque value or enable the starter motor for the engine start if the driver demand is greater than a calibratable torque value. The controller may lock the clutch to the output of the engine in response to the speed of the engine being approximately equal to the speed of the electric machine.

Abstract: A powertrain comprising an engine, a motor, a disconnect clutch connected between the engine and the motor, and a transmission. The transmission is connected to the motor by a torque converter and lock-up clutch and selectively and indirectly connected to the engine by the disconnect clutch. A controller receives an engine torque output signal and reduces the torque output of the engine to the clutch capacity limit value. A system and a method are also provided for controlling a powertrain for a hybrid vehicle.

Abstract: A hybrid electric vehicle has a traction motor, a driveline connected to a vehicle wheel, and a controller. The controller is configured to control motor torque through a region surrounding vehicle wheel torque reversal, control driveline input torque during torque reversal of driveline output torque to limit rate of change of driveline output torque, and control motor torque during a torque reversal of at least one driveline component to limit rate of change of the torque applied to the driveline component. A method for controlling a vehicle having a traction motor includes controlling the traction motor torque through a region surrounding a vehicle wheel torque reversal, controlling driveline input torque during torque reversal of driveline output torque to limit rate of change of output torque, and controlling traction motor torque during a torque reversal of a powertrain component to limit rate of change of the torque applied to the component.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, torque output of a motor is controlled to include a reserve torque for starting an engine that may be selectively coupled to the motor. Additionally, the motor torque compensates for disconnect clutch closing.

Abstract: Systems and methods for learning torque estimate errors and updating torque estimation models are presented. In one example, torque errors are learned during an engine shut-down, after a disconnect clutch coupled between an engine and an electric machine has been released. An updated torque estimation model is then used to control torque during subsequent engine operation to improve drive feel and vehicle performance.

Abstract: A powertrain comprising an engine, a motor, a disconnect clutch connected between the engine and the motor, and a transmission. The transmission is connected to the motor by a launch clutch and selectively and indirectly connected to the engine by the disconnect clutch. A controller receives an engine torque output signal and limits the torque output of the engine to the clutch capacity limit value. A system and a method are also provided for controlling a powertrain for a hybrid vehicle.

Abstract: A method of controlling a hybrid vehicle having a step ratio transmission is disclosed. The method utilizes terrain data to reduce the number of shift events. The method comprises receiving data indicative of a grade profile of an anticipated route, identifying a forecast shift sequence comprising a forecast downshift event and an adjacent forecast upshift event, and adjusting the shift criteria based on the time between the forecast shift events, the road grade between the forecast shift events, and the state of a storage battery.

Abstract: A vehicle includes a power source, such as an engine, an electric machine, or combination thereof. A torque converter is selectively coupled to the power source such that torque is altered before being distributed into a transmission of the vehicle. A torque converter bypass clutch enables torque from the power source to selectively transmit torque directly to the transmission with little or no torque altering provided by the torque converter. At least one controller in the vehicle is in communication with a remote facility in a vehicle-to-cloud (V2C) system. The controller sends road condition data to the remote facility regarding a road segment. During a subsequent drive to or over the road segment, the controller receives the road condition data and enables the torque converter bypass clutch to slip to dampen driveline disturbances when the vehicle passes over the road segment.

Abstract: A hybrid vehicle has an engine, an electric machine connected to the engine by an upstream clutch, a transmission gearbox connected to the electric machine by a downstream clutch, and a controller. The controller is configured to start the engine using one of a plurality of start sequences that control the electric machine, the upstream and downstream clutches. The engine start sequence is selected based on transmission gearbox input speed and a driver demand input. A method of controlling a hybrid vehicle is provided. An engine is selectively coupled to an electric machine by an upstream clutch with the electric machine selectively coupled to a transmission gearbox by a downstream clutch. The engine is started using a control sequence to control the electric machine, upstream clutch, and downstream clutch. The control sequence is determined by a vehicle state based on transmission gearbox input speed and a driver demand input.

Abstract: An active damping system provides a torque adjustment command that is combined with the raw motor torque command of a vehicle to compensate for oscillations and vibrations in the driveline of a hybrid vehicle. Active damping may be provided by a derivative controller or by a lead-lag compensation between initiation of clutch engagement and full clutch engagement. Active damping is terminated upon full clutch engagement.

Abstract: Systems and methods for learning torque estimate errors and updating torque estimation models are presented. In one example, torque errors are learned during an engine shut-down, after a disconnect clutch coupled between an engine and an electric machine has been released. An updated torque estimation model is then used to control torque during subsequent engine operation to improve drive feel and vehicle performance.

Abstract: A hybrid vehicle powertrain that has an engine and an electric machine that may separately or jointly provide torque to a multi-speed transmission. A drivetrain including the engine and the motor is controlled to reduce the requested level of torque provided to the transmission during an upshift. The method is initiated by a request for a reduction of the level of torque and checking the operating state of the engine. If the engine is not on, the torque from the motor is reduced. If the engine is on, the torque from the motor is reduced first and then the torque from the engine is reduced to the requested level of torque.

Abstract: Systems and methods for learning torque estimate errors and updating torque estimation models are presented. In one example, torque errors are learned during an engine shut-down, after a disconnect clutch coupled between an engine and an electric machine has been released. An updated torque estimation model is then used to control torque during subsequent engine operation to improve drive feel and vehicle performance.

Abstract: A hybrid vehicle powertrain that has an engine and an electric machine that may separately or jointly provide torque to a multi-speed transmission. A drivetrain including the engine and the motor is controlled to reduce the requested level of torque provided to the transmission during an upshift. The method is initiated by a request for a reduction of the level of torque and checking the operating state of the engine. If the engine is not on, the torque from the motor is reduced. If the engine is on, the torque from the motor is reduced first and then the torque from the engine is reduced to the requested level of torque.

Abstract: A powertrain comprising an engine, a motor, a disconnect clutch connected between the engine and the motor, and a transmission. The transmission is connected to the motor by a launch clutch and selectively and indirectly connected to the engine by the disconnect clutch. A controller receives an engine torque output signal and reduces the torque output of the engine to the clutch capacity limit value. A system and a method are also provided for controlling a powertrain for a hybrid vehicle.

Abstract: Systems and methods for learning torque estimate errors and updating torque estimation models are presented. In one example, torque errors are learned during an engine shut-down, after a disconnect clutch coupled between an engine and an electric machine has been released. An updated torque estimation model is then used to control torque during subsequent engine operation to improve drive feel and vehicle performance.

Abstract: Systems and methods for learning torque estimate errors and updating torque estimation models are presented. In one example, torque errors are learned during an engine shut-down, after a disconnect clutch coupled between an engine and an electric machine has been released. An updated torque estimation model is then used to control torque during subsequent engine operation to improve drive feel and vehicle performance.

Abstract: A system and method for controlling a hybrid electric vehicle during regenerative braking is provided. The system and method include a brake controller adapted to cause, for a selected transmission gear, a first torque ratio to be applied to a regenerative brake system during regenerative braking and a second torque ratio, different from the first torque ratio, to be applied when the vehicle is not regenerative braking. The first torque ratio results in an increased braking torque generated by the regenerative brake system compared with application of the second torque ratio.