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 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.