A method for operating a hybrid drive assembly for a motor vehicle, which has an internal combustion engine and an electric engine. A separating clutch arranged in drive terms between the internal combustion engine and the electric engine is set to a target clutch torque by at least partially engaging during an attempt to start the internal combustion engine. An actual clutch torque actually transmitted via the separating clutch and a speed of the internal combustion engine are determined during the attempt to start, and if a characteristic value dependent on the actual clutch torque exceeds a threshold value and if an integral of the speed over time continuously falls below a limit value during the attempt to start, the attempt to start is aborted.

In a hybrid vehicle control system, when a first traveling mode using torque of an electric motor is switched to a second traveling mode using torque of an engine, a controller performs an engine start control by applying an engagement pressure to a first clutch and by cranking the engine by the electric motor, so as to start the engine. Specifically, the controller obtains a predicted start time and an actual start time by the engine start control, and corrects the engagement pressure so as to decrease the engagement pressure applied to the first clutch at a subsequent time of starting the engine, when the actual start time is shorter than the predicted start time.

A hybrid vehicle controller is configured to: upon receiving a predetermined mode switching request, bring a clutch into a half-clutch state to start an engine using rotation of a transmission shaft; and upon determining that the engine has started, shift the clutch from the half-clutch state to a stand-by state and subsequently shift the clutch to an engaged state, the stand-by state being a state which is intermediate between the half-clutch state and a disengaged state and in which drive power of the engine is not transmitted to the transmission shaft.

In an electric device control method and an electric device of the present invention, during a period in which a rotational speed of an internal combustion engine shifting from a non-combustion mode to a combustion mode is decreased to a rotational speed within a predetermined rotational-speed range by a first electric motor connected to the internal combustion engine, a torque generated by the internal combustion engine is set lower than a required torque within the predetermined rotational-speed range for the internal combustion engine in the combustion mode.

A method for operating a hybrid drive assembly for a motor vehicle, which has an internal combustion engine and an electric engine. A separating clutch arranged in drive terms between the internal combustion engine and the electric engine is set to a target clutch torque by at least partially engaging during an attempt to start the internal combustion engine. An actual clutch torque actually transmitted via the separating clutch and a speed of the internal combustion engine are determined during the attempt to start, and if a characteristic value dependent on the actual clutch torque exceeds a threshold value and if an integral of the speed over time continuously falls below a limit value during the attempt to start, the attempt to start is aborted.

A hybrid vehicle controller is configured to: upon receiving a predetermined mode switching request, bring a clutch into a half-clutch state to start an engine using rotation of a transmission shaft; and upon determining that the engine has started, shift the clutch from the half-clutch state to a stand-by state and subsequently shift the clutch to an engaged state, the stand-by state being a state which is intermediate between the half-clutch state and a disengaged state and in which drive power of the engine is not transmitted to the transmission shaft.

In an electric device control method and an electric device of the present invention, during a period in which a rotational speed of an internal combustion engine shifting from a non-combustion mode to a combustion mode is decreased to a rotational speed within a predetermined rotational-speed range by a first electric motor connected to the internal combustion engine, a torque generated by the internal combustion engine is set lower than a required torque within the predetermined rotational-speed range for the internal combustion engine in the combustion mode.

In a hybrid vehicle control system, when a first traveling mode using torque of an electric motor is switched to a second traveling mode using torque of an engine, a controller performs an engine start control by applying an engagement pressure to a first clutch and by cranking the engine by the electric motor, so as to start the engine. Specifically, the controller obtains a predicted start time and an actual start time by the engine start control, and corrects the engagement pressure so as to decrease the engagement pressure applied to the first clutch at a subsequent time of starting the engine, when the actual start time is shorter than the predicted start time.

An engine starting system for hybrid vehicle is provided. The engine starting system is applied to a hybrid vehicle in which a friction clutch is disposed between an engine and a power distribution device. In order to reduce gear noise and vibrations, a second motor establishes a cancel torque to cancel a reaction torque acting on an axle when starting the engine. The engine starting system is configured to increase the torque of the second motor in a direction of a drive torque rotating the axle, when starting the engine while bringing the friction clutch into engagement in a slipping manner.

The application relates to a method for stall-starting a hybrid vehicle comprising a combustion engine (12), an electric machine (14), a transmission (16) and two clutches (20, 22). In a first stall phase torque output of the combustion engine (12) is increased and compensated by the electric machine (14) operating as a generator. In the second start phase the method comprises configuring the electric machine (14) not to operate as a generator, in particular to operate as a motor. A further independent claim is directed to a stall-start apparatus. This avoids overheating the clutches (20, 22) and battery depletion, while at the same time providing high acceleration.