Abstract: A vehicle includes a clutch to couple a motor and transmission, and a controller that, in response to a regenerative braking request and a temperature being within a first range, partially capacitizes the clutch for regenerative torque transfer therethrough with slip, and in response to another regenerative braking request and the temperature being within a second range less than the first, fully capacitizes the clutch prior to regenerative torque transfer therethough to preclude slip.

Abstract: A vehicle includes and an engine, a motor, a transmission, and a controller. The transmission is configured is to receive power from the engine and the motor. The transmission is also configured to shift between gears based on a shift schedule. The controller is programmed to, in response to only the motor providing power to the transmission, adjust the shift schedule to narrow an operating speed range of the motor such that the motor speed maintains a peak range of an available motor power output.

Abstract: A vehicle includes a generator, a battery, a transmission, and a controller. The generator is configured to recharge the battery at a maximum power output when a generator speed is above a threshold speed. The transmission is configured to downshift during regenerative braking such that the generator speed is maintained above the threshold speed. The controller is programmed to, in response to a decrease in battery temperature corresponding to a decrease in generator speed required to maintain the maximum power output, decrease the threshold speed.

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.

Abstract: A vehicle includes a powertrain having an electric machine configured to selectively apply regenerative braking torque to decelerate the vehicle. The vehicle also includes a controller programmed to control a rate of change of a regenerative braking torque limit during a transmission downshift that occurs during a regenerative braking event based on a change in speed of an output shaft of the powertrain caused by the transmission downshift.

Abstract: A vehicle and a method of controlling a powertrain are provided. The vehicle may include a controller programmed to operate a powertrain in a hybrid mode. The controller may be further programmed to, responsive to a request to operate the powertrain in electric mode, transition powertrain operation from the hybrid mode to the electric mode without shifting gears until a change in accelerator pedal position exceeds a threshold following the transition.

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 hybrid vehicle includes an engine coupled to a planetary gearset and an electric motor configured to provide motor torque directly to a torque transfer set. An overdrive clutch is configured to, when engaged, bypass at least a portion of engine torque to an overdrive shaft directly connected to the torque transfer set. This allows the engine to also provide torque directly to the torque transfer set along with the motor in an overdrive mode of operation. At least one controller is programmed to control the motor and/or the engine based on an estimated amount of torque transferred through the overdrive clutch.

Abstract: A hybrid electric vehicle having a discrete ratio transmission shifts according to distinct shift schedules in various operating modes. For example, different shift schedules may be used for operating with the engine off, operating with the engine running, and regenerative braking. When the vehicle transitions from one mode to another, the new shift schedule may schedule a shift that the driver would not expect. To avoid annoying the driver, a control strategy inhibits the shift until either the old strategy would also schedule a shift or a customer event occurs.

Abstract: A vehicle and a method of controlling a powertrain are provided. The vehicle may include a controller programmed to operate a powertrain in a hybrid mode. The controller may be further programmed to, responsive to a request to operate the powertrain in electric mode, transition powertrain operation from the hybrid mode to the electric mode without shifting gears until a change in accelerator pedal position exceeds a threshold following the transition.

Abstract: A system and method for controlling a step-ratio transmission gearshift during a regenerative braking event for a hybrid vehicle having an engine selectively coupled to an electric machine and an automatic transmission control transmission input torque based on a measured shift profile and a target shift profile. A torque trim term may be added to the transmission input torque or electric machine output torque in response to a difference between the measured and target shift profiles. The torque trim term may be used to modify the transmission input torque to speed the shift up or shorten the shift time if the measured shift is progressing too slowly. Likewise, the torque trim term may be used to reduce the transmission input torque or electric machine output torque if the shift is progressing too quickly relative to the target shift profile.

Abstract: A system and method for controlling a vehicle having an electric traction motor coupled to a transmission by a clutch include modifying traction motor torque in response to the difference between rotational speed of a driveline component and the filtered rotational speed of the driveline component to reduce driveline oscillation when the clutch is locked. The traction motor torque may be modified in response to a vehicle event that may otherwise induce driveline oscillations, such as a transmission ratio change or regenerative braking, for example.

Abstract: A vehicle includes a motive power source, a transmission, and a clutch system. The vehicle further includes a controller that causes the clutch system to generate a generally constant clutch pressure to mechanically couple the motive power source and transmission as a line pressure associated with the transmission varies.

Abstract: A control strategy is provided for a hybrid vehicle that will increase drivability during low or decreasing driver demands. Coordination between shifting the transmission and stopping or (non-demand) starting of the engine can increase drivability. The vehicle includes a motor/generator with one side selectively coupled to the engine and another side selectively coupled to the transmission. The control strategy acts when an engine start or stop is requested while driver demand is decreasing and a shift of the transmission is demanded. To inhibit these events from proceeding simultaneously, the control strategy delays the engine from starting or stopping until the transmission has finished shifting, or vice versa.

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 vehicle includes an engine and electric machine connected to a planetary gear, a one-way clutch, and a controller. The one-way clutch transfers torque from the planetary gear to an overdrive gear. The controller, in response to a condition requiring disengagement of the one-way clutch, increases a torque of the electric machine based on a torque command for the electric machine and the torque transferred from the planetary gear to the overdrive gear.

Abstract: In response to a transmission upshift command and a transmission element speed being greater than a threshold, a controller may reduce a rate of engine air intake prior to initial engagement of an oncoming shift element, at least until a target speed ratio is achieved. This reduction may reduce a transmission input torque such that upshift driveline disturbances are reduced.

Abstract: A hybrid vehicle includes an engine coupled to a planetary gearset and an electric motor configured to provide motor torque directly to a torque transfer set. An overdrive clutch is configured to, when engaged, bypass at least a portion of engine torque to an overdrive shaft directly connected to the torque transfer set. This allows the engine to also provide torque directly to the torque transfer set along with the motor in an overdrive mode of operation. At least one controller is programmed to control the motor and/or the engine based on an estimated amount of torque transferred through the overdrive clutch.

Abstract: A vehicle includes a powertrain having an electric machine, and friction brakes configured to resist rotation of a vehicle wheel. The further includes at least one controller programmed to (i) issue a command for the electric machine to apply a regenerative torque to decelerate the vehicle in response to driver braking demand, and (ii) cause both a decay in the regenerative torque and a countervailing increase in the resistance of the friction brakes when vehicle speed is reduced to less than a first threshold such that braking demand is substantially satisfied by only the friction brakes when the vehicle speed is less than a second threshold.

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.