Abstract: In a powertrain that includes an engine driveably connected to a load and an electric machine driveably connected to the load, a method for controlling a vehicle located on an incline against rollback includes determining a magnitude of wheel torque required to prevent the vehicle from rolling back, determining whether the electric machine has a current torque capacity that is equal to or greater than the required wheel torque, using the electric machine to produce the required wheel torque provided the current torque capacity of the electric machine is able to produce the required wheel torque, and using the engine to produce the required wheel torque provided the torque capacity of the electric machine is unable to produce the required wheel torque.

Abstract: A method for controlling transmission engagement during restart of an engine in a hybrid electric powertrain includes moving a gear lever between a forward position and reverse position, using electric power to drive an auxiliary pump whose output causes a transmission to engage a gear that corresponds to the lever position and to stroke, to zero torque capacity, an oncoming clutch that corresponds to said gear, initiating the restart, and discontinuing use of the auxiliary pump.

Abstract: A method for controlling an engine restart in a hybrid electric powertrain, including the steps of stopping the engine, using an electric power source and an electro-mechanical actuator connected to the source to engage a gear and stroke to zero torque capacity a dry clutch of a dual-clutch transmission, initiating an automatic engine restart, and increasing the torque capacity of the clutch to a desired torque capacity during the engine restart.

Abstract: In a vehicle powertrain that includes an engine and an electric machine, a method for preventing rollback of a wheeled vehicle located on an incline includes determining a magnitude of wheel torque required to prevent the vehicle from rolling back, using the electric machine to produce the required magnitude of wheel torque at the wheels, transmitting engine torque to the wheels, and reducing torque produced by the electric machine while increasing engine torque such that the sum of wheel torque produced by the engine and electric machine is substantially equal to said required magnitude of wheel torque.

Abstract: In a hybrid electric vehicle powered by an internal combustion engine that produces torque and an electric machine that produces torque, a method for operating the electric machine to produce electric assist to the engine includes determining a magnitude of power requested by the vehicle operator, determining a minimum power limit and a maximum power limit of the engine that will produce a response to a torque request within a desired period following the torque request, using the magnitude of power requested, the minimum and maximum power limits of the engine to determine the upper and lower limits of the electric power assist such that the requested torque will be provided within the desired period, and operating the electric machine to provide electric power assist within said upper and lower limits.

Abstract: In a powertrain that includes wheels supporting a vehicle, an engine, a first machine able to operate alternately as an electric motor and electric generator, a second machine electric able to operate as an electric motor, and an electric storage battery having a variable state of charge, a method for holding the vehicle stationary on an incline including determining a magnitude of torque at the wheels required to hold the vehicle on the incline, determining whether the state of charge is low or high relative to a reference state of charge, determining whether a temperature of the first machine is low or high relative to a first reference temperature, and whether a temperature of the second machine is low or high relative to a second reference temperature, using the engine and the machines in various combinations to produce the required torque at the wheels.

Abstract: A method for controlling a vehicle launch using a transmission having an input, a current gear, an input clutch associated with a target gear and an output, an engine and an electric machine for driving the input, includes the steps of using the engine and the first electric machine to drive the transmission input at a desired magnitude of torque, determining a desired magnitude of torque capacity of the input clutch, determining a crankshaft speed error, determining a magnitude of a change in torque capacity of the input clutch that will reduce the crankshaft speed error, and increasing the torque capacity of the input clutch to a desired torque capacity whose magnitude is determined by adding the current magnitude of torque capacity of the input clutch and said change in torque capacity of the input clutch.

Abstract: In a powertrain for a vehicle that includes an engine, a transmission having an input, a current gear, an input clutch, a target gear and an output for driving a load, and an electric machine for driving the load, a method for performing a gearshift from the current gear to the target gear comprising the steps of opening the input clutch, releasing a drive connection between the current gear and the output, producing a drive connection between the target gear and the output, using the electric machine to produce torque at the load, closing the input clutch; and reducing the torque produced by the electric machine.

Abstract: A method for controlling a vehicle powertrain that includes a first power path including a first electric machine driveably connected to a first wheel set and a second power path including a second electric machine driveably connected to a second wheel set, including determining a desired wheel torque required to hold the vehicle stationary on an inclined surface, determining a temperature of the first machine and a first reference temperature, determining a torque capacity of the first power path, and using the first power path to produce the desired wheel torque, if the temperature of the first electric machine is less than the first reference temperature and the torque capacity of the first power path is greater than the desired wheel torque.

Abstract: In a powertrain that includes wheels for driving a vehicle, a crankshaft, a machine driveably connected to the crankshaft and able to operate alternately as an electric motor and electric generator, a transmission including an input clutch driveably connected to the crankshaft and an output driveably connected to the wheels, a method for controlling idle speed including producing a desired magnitude of input clutch torque capacity, producing a desired wheel torque, using an error represented by a difference between a desired crankshaft idle speed and a current crankshaft speed to determine a desired change in torque produced by the machine, using the magnitude of input clutch torque capacity and the desired change in torque produced by the machine to determine a desired magnitude machine torque, and using the machine to produce said desired magnitude of machine torque.

Abstract: A method for controlling the launch of a vehicle having a powertrain that includes a first power path for driving a first wheel set and including an engine, a transmission having an input driveably connected to a crankshaft of the engine, a current gear, an input clutch associated with the current gear and an output connected to first wheel set, and a second power path including an electric machine for driving a second wheel set.

Abstract: In a powertrain for a motor vehicle that includes a power source, a transmission driveably connected to the power source and wheels of the vehicle, an electric machine able to operate as an electric motor for transmitting power to at least some of the vehicle wheels, a method for controlling the powertrain includes operating the power source and the transmission in a desired gear to produce a first wheel torque in response to a demanded wheel torque, increasing the demanded wheel torque while turning the vehicle along a curved path, and using the electric motor to provide a second wheel torque, such that a combined magnitude of the first wheel torque produced in the desired gear and the second wheel torque is equal to or greater than the increased demanded wheel torque.

Abstract: In a powertrain for motor vehicle that includes an engine, an electric machine, a transmission having an input driveably connected to the engine and a transmission output driveably connected to the electric machine, and a powertrain output driveably connected to the electric machine and wheels of the vehicle, a method for controlling torque during a shift includes transmitting engine torque through the transmission to the powertrain output; during a shift, operating the electric machine to modify the torque transmitted to the powertrain output; and storing energy generated by the electric machine during the shift.

Abstract: In a powertrain for motor vehicle that includes an engine, a first electric machine and a second electric machine, each machine being able to function alternately as a motor and a generator, a transmission having an input driveably connected to the engine and the first electric machine and a transmission output driveably connected to the second electric machine and wheels of the vehicle, a method for controlling the powertrain includes using the engine to produce wheel torque, performing a gear shift using the transmission, if a reduction in powertrain output torque is to occur while modulating torque during the gear shift, operating one of the first electric machine and the second machine as an electric generator to reduce the powertrain output torque, and if an increase in powertrain output torque is to occur while modulating torque during the gear shift, operating one of the first electric machine and the second machine as an electric motor to increase the powertrain output torque.

Abstract: A method for controlling a vehicle launch using a transmission having an input, a current gear, an input clutch associated with a target gear and an output, an engine and an electric machine for driving the input, includes the steps of determining a desired magnitude of torque to be produced at the transmission output, producing a predetermined magnitude of torque capacity of the input clutch, operating the engine such that a magnitude of torque at the transmission output is substantially equal to the desired transmission output torque, determining an crankshaft speed error, determining a desired change in torque at the transmission input that will reduce the crankshaft speed error, adjusting a magnitude of torque produced by the first electric machine such that the magnitude of torque at the transmission input is substantially equal to the desired torque at the transmission input, and engaging the input clutch.

Abstract: A method for detecting sustained combustion in the engine of a hybrid electric powertrain that includes a starter/generator driveably connected to the engine, a transmission for driving a load, and an input clutch for opening and closing a drive connection between the electric machine and the transmission, includes the steps of using the starter/generator to produce torque and crank the engine, preparing the engine to produce combustion, producing torque capacity across the input clutch while slipping the clutch, and continuing use of the starter/generator until a sum of the crankshaft torque applied by the starter/generator and the crankshaft torque applied by the transmission is less than some torque threshold for a predetermined period length.

Abstract: In a powertrain for a motor vehicle that includes an engine, a transmission driveably connected to the engine and wheels of the vehicle, an electric machine for transmitting power to at least some of the vehicle wheels, a method for controlling the powertrain includes operating the engine and transmission to produce a wheel torque at a desired vehicle speed with the transmission operating in a desired gear in response to a demanded wheel torque, increasing the demanded wheel torque due to the vehicle ascending a grade, determining a magnitude of wheel torque able to be produced in the desired gear, using the electric motor to provide a second wheel torque in combination with wheel torque whose magnitude is equal to or greater than the wheel torque being produced in the desired gear. and continuing to operate the transmission in the desired gear.

Abstract: In a vehicle that includes an engine driveably connected to the vehicle wheels, an accelerator pedal, and an electric motor for transmitting power to at least some of the vehicle wheels, a method for indicating that the vehicle is operating on a grade having positive slope includes determining that displacement of the accelerator pedal is greater than a reference displacement, determining that a rate of change of the accelerator pedal displacement is greater than a reference rate of change of displacement, determining that vehicle deceleration is greater than a reference vehicle deceleration, and producing a signal representing that the vehicle is operating on a grade having positive slope.

Abstract: In a powertrain for motor vehicle that includes an engine, an electric machine able to function alternately as a motor and a generator, and a transmission whose input is driveably connected to the engine and the electric machine, a method for controlling transmission input torque during an downshift including using the engine to produce torque transmitted to the transmission input, during the ratio change phase of the downshift, operating the electric machine as a motor, and controlling a net torque transmitted to the transmission input by using the engine to drive the transmission and the electric machine concurrently, and during the torque transfer phase of the downshift, operating the electric machine as a generator.

Abstract: In a powertrain for motor vehicle that includes an engine, an electric machine able to function alternately as a motor and a generator, and a transmission whose input is driveably connected to the engine and the electric machine, a method for controlling transmission input torque during an upshift including using the engine to produce torque transmitted to the transmission input, during the ratio change phase of the upshift, operating the electric machine as a generator, and during the ratio change phase of the upshift, controlling a net torque transmitted to the transmission input by using the engine to drive the transmission and the electric machine concurrently.