A powertrain system is described, and includes an internal combustion engine and an electric machine configured to generate propulsion torque responsive to a driver torque request. A method for operating the powertrain system includes determining, in response to a request to execute an engine autostart operation, whether a driveline torque sag may occur. The method further includes forgoing executing the engine autostart operation when it is determined that a driveline torque sag will occur during the execution of the engine autostart operation.

An electrically heated catalyst device has a catalyst that purifies exhaust gas from an engine, and is configured to heat the catalyst with electric power that is supplied from an electric storage device. A current sensor detects a current that is supplied to the electrically heated catalyst device. A current sensor detects an input/output current of the electric storage device. A controller executes failure determination control to determine whether the current sensor has a failure. In the failure determination control, the controller estimates a current that is supplied to the electrically heated catalyst device using a detection value of the current sensor and compares the estimated current with a detection value of the current sensor to determine whether the current sensor has a failure.

A system and method for controlling a hybrid vehicle having an engine, first and second electric machines coupled to a traction battery and configured to operate primarily as a motor and a generator, respectively, and a controller in communication with the engine and the first and second electric machines include increasing target engine speed from a sea level speed to deliver a demanded engine power at altitude up to an NVH engine speed limit. The system and method may reduce the demanded engine power based on an attainable engine power associated with the NVH engine speed limit. A demanded wheel power may be reduced in response to the reduced engine power.

A hybrid vehicle includes an internal combustion engine, a rotating electric machine, an electric storage device, a power supply device, and a controller. The controller executes switching control to switch from a first electric power supply to a second electric power supply by starting the internal combustion engine. The first electric power supply is the supply of electric power from the electric storage device to the electric device. The second electric power supply is the supply of electric power from the rotating electric machine to the electric device. The controller controls the power supply device and the internal combustion engine such that the internal combustion engine is started with the first electric power supply being continued during the switching control.

At every ignition cycle, when a duration change amount ΔT30[i] is equal to or less than a reference value ΔT30ref2, a misfire counter Cmf is kept unchanged. When the duration change amount ΔT30[i] is greater than the reference value ΔT30ref2, on the other hand, the misfire counter Cmf is incremented by value 1. A misfire ratio Rmf is set to provide a smaller value when an amount increasing determination flag F[i] is equal to value 1 than a value when the amount increasing determination flag F[i] is equal to value 0. In the case where an ignition counter Ci reaches or exceeds a reference value Ciref, it is determined whether a conversion catalyst is overheated by comparison between the misfire counter Cmf and an accumulated misfire ratio Rmfsum that is an accumulated value of the misfire ratio Rmf.

A propulsion system for an aircraft is provided having a propulsion engine configured to be mounted to the aircraft. The propulsion engine includes an electric machine defining an electric machine tip speed during operation. The propulsion system additionally includes a fan rotatable about a central axis of the electric propulsion engine with the electric machine. The fan defines a fan pressure ratio, R.sub.FP, and includes a plurality of fan blades, each fan blade defining a fan blade tip speed. The electric propulsion engine defines a ratio of the fan blade tip speed to electric machine tip speed that is within twenty percent of the equation, 1.68×R.sub.FP−0.518, such that the propulsion engine may operate at a desired efficiency.

A control method of a power train for a hybrid vehicle is provided. The method includes determining whether an engine corresponds to an optimal operating point when intervention for upshifting is demanded during an HEV driving mode and determining whether an amount of demanded intervention is equal to or less than a value adding maximum intervention torques of a drive motor and an HSG. Each intervention torque of the drive motor and the HSG is determined to adjust a whole energy-collect rate by the drive motor and the HSG to a maximum value of the amount of demanded intervention, and simultaneously, the value adding the intervention torques of the drive motor and the HSG satisfies the amount of demanded intervention.

A propulsion system for an aircraft is provided having a propulsion engine configured to be mounted to the aircraft. The propulsion engine includes an electric machine defining an electric machine tip speed during operation. The propulsion system additionally includes a fan rotatable about a central axis of the electric propulsion engine with the electric machine. The fan defines a fan pressure ratio, R.sub.FP, and includes a plurality of fan blades, each fan blade defining a fan blade tip speed. The electric propulsion engine defines a ratio of the fan blade tip speed to electric machine tip speed that is within twenty percent of the equation, 1.01×R.sub.FP−0.311, such that the propulsion engine may operate at a desired efficiency.

When a catalyst temperature is lower than a predetermined temperature on a second or subsequent start of an engine since system activation of a vehicle, a catalyst warm-up request is output for the purpose of warming up a catalyst in a catalytic converter. An output limit Wout of a battery is not increased in response to a second or subsequent output of the catalyst warm-up request, while being increased in response to a first output of the catalyst warm-up request. Accordingly, the catalyst warm-up in response to the second or subsequent output of the catalyst warm-up request since the system activation suppresses excessive output of electric power from the battery and thereby suppresses deterioration of the battery. Catalyst warm-up is performed in response to the second or subsequent output of the catalyst warm-up request. This suppresses deterioration of emission. As a result, this configuration satisfies both (balances) suppression of deterioration of the battery and suppression of deterioration of emission.

An electronic control device automatically stops an engine operation when a remaining electric power amount index value is equal to or larger than an engine stop permission threshold. The device automatically restarts the engine operation when the remaining electric power amount index value is smaller than an engine restart threshold after the engine operation is automatically stopped. The device changes the engine stop permission threshold from a first threshold, which has been set until a start of an activation of an electric actuator, to a second threshold, which is larger than the first threshold, when the automatic engine stop is not carried out and the activation of the actuator is detected.