Abstract: A method for operating a powertrain system of a vehicle includes determining an initial creep torque command in an operator-selected direction of travel, adjusting the initial creep torque command responsive to an operator braking request and responsive to a change in direction of vehicle speed relative to the operator-selected direction of travel, and operating the hybrid powertrain to generate axle torque in response to the adjusted creep torque command.

Abstract: A method for operating a powertrain system including a torque machine coupled to an internal combustion engine that is coupled to a transmission includes, upon commanding a shift in a transmission operating range, activating an immediate response mode to effect the shift. Activating the immediate response mode includes controlling the engine to achieve a predicted engine torque command, and controlling motor torque of the torque machine in response to a difference between an actual engine torque and an immediate crankshaft torque for shift command. An arbitrated predicted motor torque is determined. A possible crankshaft torque is determined in response to the arbitrated predicted motor torque and the predicted engine torque command. Operation of the transmission at the end of the shift event is commanded in response to the possible crankshaft torque. A predicted response mode is activated to complete the shift in the transmission operating range.

Abstract: A method for controlling output torque of a hybrid powertrain system includes determining a constrained output torque in response to an operator torque request, and determining maximum and minimum output torque limits. A time-rate change in the constrained output torque at each of a plurality of torque breakpoints is determined. A desired output torque is determined. A preferred output torque is determined as the desired output torque adjusted using the time-rate changes in the constrained output torque at the plurality of torque breakpoints and limited within the maximum and minimum output torque limits. Torque outputs of torque generators of the hybrid powertrain system are controlled in response to the preferred output torque.

Abstract: A minimum torque module selectively determines a first minimum propulsion torque based on second and third minimum propulsion torques when a torque converter clutch is in unlocked and locked states, respectively. A zero pedal torque module selectively sets a zero pedal torque equal to the first minimum propulsion torque. A pedal request module determines a pedal torque request based on an accelerator pedal position, a vehicle speed, and the zero pedal torque. A driver request module determines a driver axle torque request based on the pedal torque request. A shaping module selectively shapes the driver axle torque request into a shaped driver axle torque request. A conversion module converts the first minimum propulsion torque into a minimum axle torque. A final driver request module sets a final driver axle torque request equal to a greater of the shaped driver axle torque request and the minimum axle torque.

Abstract: A powertrain system includes an electric machine mechanically coupled to an internal combustion engine mechanically coupled to a transmission. A method for operating the powertrain system includes determining an engine stall threshold rate during engine operation in a low load condition. A time-rate change in an accessory load is controlled by the electric machine operating in an electric power generating mode in response to the engine stall threshold rate during the engine operation in the low load condition.

Abstract: A method of output torque smoothing for a hybrid powertrain having an electric machine and a spark ignition engine with a first cylinder and a second cylinder includes commanding a fuel-cut transition, including consecutively initiating and completing deactivation of the first cylinder and initiating and completing deactivation of the second cylinder. The fuel-cut transition is characterized by an absence of retarding spark to the first cylinder and second cylinder. Fuel is supplied to the first cylinder until the first cylinder completes deactivation and to the second cylinder until the second cylinder completes deactivation. The electric machine captures a first torque from the first cylinder by generating electricity until the first cylinder completes deactivation and captures a second torque from the second cylinder by generating electricity until the second cylinder completes deactivation.

Abstract: A powertrain system includes an electric machine mechanically coupled to an internal combustion engine mechanically coupled to a transmission. A method for operating the powertrain system includes determining an engine stall threshold rate during engine operation in a low load condition. A time-rate change in an accessory load is controlled by the electric machine operating in an electric power generating mode in response to the engine stall threshold rate during the engine operation in the low load condition.

Abstract: A method for operating a powertrain system including a torque machine coupled to an internal combustion engine that coupled to a transmission includes, upon commanding a shift in a transmission operating range, activating an immediate response mode to effect the shift. Activating the immediate response mode includes controlling the engine to achieve a predicted engine torque command, and controlling motor torque of the torque machine in response to a difference between an actual engine torque and an immediate crankshaft torque for shift command. An arbitrated predicted motor torque is determined A possible crankshaft torque is determined in response to the arbitrated predicted motor torque and the predicted engine torque command. Operation of the transmission at the end of the shift event is commanded in response to the possible crankshaft torque. A predicted response mode is activated to complete the shift in the transmission operating range.

Abstract: A method for controlling output torque of a hybrid powertrain system includes determining a constrained output torque in response to an operator torque request, and determining maximum and minimum output torque limits. A time-rate change in the constrained output torque at each of a plurality of torque breakpoints is determined A desired output torque is determined A preferred output torque is determined as the desired output torque adjusted using the time-rate changes in the constrained output torque at the plurality of torque breakpoints and limited within the maximum and minimum output torque limits. Torque outputs of torque generators of the hybrid powertrain system are controlled in response to the preferred output torque.

Abstract: A method of executing a downshift in a fixed-gear powertrain having an input node and an output node related by a starting speed ratio before the downshift and a finishing speed ratio after is provided. The downshift includes a torque phase and an inertia phase. A starting output torque is calculated as a function of a starting driver request. An electric machine applies a starting regenerative input torque which is calculated as substantially equal to the starting output torque divided by the starting speed ratio. A finishing output torque is calculated as a function of a finishing driver request. The electric machine applies a finishing regenerative input torque which is calculated as substantially equal to the finishing output torque divided by the finishing speed ratio.

Abstract: A minimum torque module selectively determines a first minimum propulsion torque based on second and third minimum propulsion torques when a torque converter clutch is in unlocked and locked states, respectively. A zero pedal torque module selectively sets a zero pedal torque equal to the first minimum propulsion torque. A pedal request module determines a pedal torque request based on an accelerator pedal position, a vehicle speed, and the zero pedal torque. A driver request module determines a driver axle torque request based on the pedal torque request. A shaping module selectively shapes the driver axle torque request into a shaped driver axle torque request. A conversion module converts the first minimum propulsion torque into a minimum axle torque. A final driver request module sets a final driver axle torque request equal to a greater of the shaped driver axle torque request and the minimum axle torque.

Abstract: A method of controlling a hybrid powertrain of a vehicle includes lowering a target voltage set point of a low voltage battery to a temporary voltage set point to reduce the overall power required by the accessory power module when a requested voltage from a vehicle accessory draws the voltage of the low voltage battery below the target voltage set point. The temporary voltage set point gradually increases over time until equal to the target voltage set point, allowing sufficient time for a high voltage battery to provide the required power for the accessory power module or for an electric motor/generator to generate the current required by the accessory power module.

Abstract: A method of output torque smoothing for a hybrid powertrain having an electric machine and a spark ignition engine with a first cylinder and a second cylinder includes commanding a fuel-cut transition, including consecutively initiating and completing deactivation of the first cylinder and initiating and completing deactivation of the second cylinder. The fuel-cut transition is characterized by an absence of retarding spark to the first cylinder and second cylinder. Fuel is supplied to the first cylinder until the first cylinder completes deactivation and to the second cylinder until the second cylinder completes deactivation. The electric machine captures a first torque from the first cylinder by generating electricity until the first cylinder completes deactivation and captures a second torque from the second cylinder by generating electricity until the second cylinder completes deactivation.

Abstract: A method controls a motor generator unit (MGU) aboard a vehicle. An event signal is generated using a transmission controller, with the event signal predicting a transient vehicle event, e.g., auto start, transmission shift, fuel cycling, etc. The event signal is received by a motor controller, which determines a predicted level of motor output torque required from the MGU during the transient vehicle. Electromagnetic flux of the MGU is increased to a calibrated threshold level prior to commencement of the transient vehicle event. The MGU may be used for regenerating energy during the transient vehicle event. The MGU is then used to facilitate execution of the transient vehicle event. A vehicle having the MGU uses a controller(s) to automatically increase electromagnetic flux of the MGU prior to the transient vehicle event using the method as noted above.