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: 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.

Abstract: A control system for a modular hybrid electric vehicle operates an internal combustion engine at a torque level above the driver demanded torque improving the engine's efficiency. A traction motor driveably connected to the engine is operated at a torque level such that the combined torque satisfies the driver demand. The traction motor torque is limited to avoid inefficient combinations of speed and torque at which the motor is inefficient. During idle operation, the traction motor is operated at a torque determined from a battery state of charge and the engine is operated to maintain a predetermined speed. If the engine speed drops below a threshold, motor torque is adjusted to reduce the load on the engine to avoid stalling.

Abstract: A hybrid electric vehicle includes an engine and a traction motor coupled to the engine by a coupling device or a clutch for providing torque to wheels of the vehicle. An inverter is electrically connected to the traction motor. A second coupling device or at least one clutch at least indirectly selectively couples the motor to the drive wheels. A controller controls the second coupling device based upon a temperature of at least one of the fraction motor and the inverter.

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: A vehicle includes an engine and is at least partially propelled by a fraction battery and a traction motor. A clutch is configured to be coupled to the traction motor. An electrical and/or mechanical pump provides pressure to control the clutch. At least one controller determines if the clutch is slipping. In response to the clutch slipping, the at least one controller commands an increase in speed of an input of the clutch such that the available line pressure to control the slipping of the clutch is increased. The line pressure is then applied to the clutch in order to control the slipping of the clutch.

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: A controller and control strategies minimize shift shock in a hybrid electric vehicle during a downshift during regenerative braking by maintaining the transmission input speed substantially linear when the transmission input speed is slowing. The controller and the control strategies control the regenerative braking torque during a downshift occurring during regenerative braking in such a way that the transmission input speed is maintained substantially linear when the transmission input speed is slowing during a torque phase of the downshift.

Abstract: A system and method for controlling a vehicle powertrain is provided. The system and method sets a required transmission input torque during a transient event. A required traction motor torque and a required engine torque, in combination, are set to fulfill the required transmission input torque. The system and method includes estimates an actual engine torque during a delay in providing the required engine torque during the transient event. A transient traction motor torque is commanded based on a difference between the actual engine torque and the required transmission input torque. The commanded transient motor torque compensates for the delay in providing the required engine torque in order to prevent torque disturbances during the transient event.

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: 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 hybrid electric vehicle having a motor and an engine that are selectively connected on a driveline and controlled by a controller. The controller is configured to schedule additional motor torque to compensate for engine inertia drag based upon a clutch pressure value and a clutch slip speed value during a period of clutch engagement. The controller is also configured to maintain vehicle acceleration using a proportional integral controller to adjust the motor torque during a period of clutch engagement.

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.

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.

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: A system and method for controlling energy distribution within a HEV powertrain are provided. A feedforward battery power value is generated in response to input indicative of a driver torque request. A feedback battery power modification value is generated in response to input indicative of actual battery power and the driver torque request. A battery power request is calculated based a sum of the feedforward battery power value and the feedback battery power modification value.

Abstract: A vehicle control system including a combustion engine and an electric motor selectively provided torque to a transmission separately or in combination to meet driver torque demand. The engine has a maximum torque output value and a torque increase delay response function spanning a predetermined time period. A motor torque boost signal requests an increase in torque provided from an electric motor if the engine torque request signal exceeds the maximum torque output of the engine or the torque increase delay response function of the engine. The motor torque boost signal is time limited and a second level of motor torque boost may be provided for a second limited time period.

Abstract: A controller and a control strategy minimizes shift shock in a hybrid electric vehicle during a downshift conducted while the vehicle is in a regenerative braking mode by maintaining total powertrain torque at a desired target during the downshift. The controller has three preferable modes including modulating just engine torque, modulating just electric motor torque or simultaneously modulating both motor and engine torque.

Abstract: In a hybrid electric vehicle, a motor may be downstream of an engine and transmission. This configuration can be exploited by using the motor to buffer and control torque changes between the engine and the wheels, thereby reducing driveline backlash and clunk.