Methods and systems are provided for reducing torque pulsations during hybrid engine shutdown and restarts. A valve actuating mechanism may be actuated to operate an engine with a selected valve lift profile during engine restart and shutdown events that is distinct from the valve lift profile applied during cylinder combustion. The selected valve lift profile reduces cylinder pressure during engine shutdown and restarts.

A hybrid driveline assembly for a vehicle includes an engine, an electric motor, and a transmission having an input and an output. The transmission input is selectively coupled to the engine and electric motor. The transmission is shiftable between a plurality of drive modes. The driveline assembly further includes a final drive assembly operably coupled to the transmission output. The final drive assembly has a front final drive operably coupled to a rear final drive.

A system for reducing vibration from an engine shock event caused by turning on an engine of a vehicle. The system includes an engine vibration sensor connected to the engine and configured to detect vibration data. The system includes an engine shock dampening unit configured to analyze the vibration data received from the engine vibration sensor to detect the engine shock event. The engine shock dampening unit is further configured to determine a vibration cancellation instruction for partially or completely cancelling the vibration from the engine shock event when the engine shock event is detected. The system includes a vibration unit configured to vibrate in an opposing direction of the vibration from the engine shock event based on the vibration cancellation instruction such that the vibration from the engine shock event is reduced.

A hybrid vehicle may be a series hybrid or a parallel hybrid vehicle. One embodiment of a parallel hybrid vehicle includes an engine, a transmission coupled to the engine, a front drive coupled to the transmission through a prop shaft, a rear drive coupled to the transmission, a traction motor drivingly coupled to the prop shaft, and a battery to operate the traction motor.

Methods and systems are provided for improving surge control. When surge conditions are anticipated, motor torque usage is increased to discharge a battery to a lower state of charge. When surge conditions actually occur, engine torque output is limited to a higher level than the engine output required to meet the reduced torque demand, while the excess wheel torque is offset by charging the battery to a higher state of charge.

In one aspect the present subject matter is directed to a gas-electric propulsion system for an aircraft. The system may include a turbofan jet engine, an electric powered boundary layer ingestion fan that is coupled to a fuselage portion of the aircraft aft of the turbofan jet engine, and an electric generator that is electronically coupled to the turbofan jet engine and to the boundary layer ingestion fan. The electric generator converts rotational energy from the turbofan jet engine to electrical energy and provides at least a portion of the electrical energy to the boundary layer ingestion fan. In another aspect of the present subject matter, a method for propelling an aircraft via the gas-electric propulsion system is disclosed.

A catalyst control system includes a stop and start module that, during a period that the vehicle is ON between (i) a first time when the vehicle is turned ON and (i) a second time when the vehicle is next turned OFF, selectively shuts down and starts a spark ignition engine of the vehicle. A catalyst light off (CLO) control module initiates a first CLO event for a first engine startup during the period and, when a temperature of a catalyst that receives exhaust output by the engine is less than a predetermined temperature, selectively initiates a second CLO event for a second engine startup during the period. A fuel control module richens fueling of the engine during the first and second CLO events of the period. A spark control module retards spark timing of the engine during the first and second CLO events of the period.

Systems and methods for positioning an engine during engine stopping and during vehicle activation are described. In one example, a belt integrated starter/generator rotates an engine before the engine is started to reduce engine starting time and determine engine position before the engine is started. The engine may be rotated to a first or second position based on a destination of the vehicle.

A method for operating a motor vehicle is disclosed. The motor vehicle is provided with a hybrid drive device having an electric machine, an internal combustion engine and a particle filter associated with the internal combustion engine, wherein the internal combustion engine is operated temporarily for regenerating the particle filter. In a first operating mode, the regeneration is only started when it is determined by a navigation device that an electric driving region to be driven through lies ahead, in which region an operation of the internal combustion engine and/or the regeneration of the particle filter is not desired.

A gas turbine engine includes a core having a compressor section with a first compressor and a second compressor, a turbine section with a first turbine and a second turbine, and a primary flowpath fluidly connecting the compressor section and the turbine section. The first compressor is connected to the first turbine via a first shaft, the second compressor is connected to the second turbine via a second shaft, and a motor is connected to the first shaft such that rotational energy generated by the motor is translated to the first shaft. The gas turbine engine includes a takeoff mode of operation, a top of climb mode of operation, and at least one additional mode of operation. The gas turbine engine is undersized relative to a thrust requirement in at least one of the takeoff mode of operation and the top of climb mode of operation, and a controller is configured to control the mode of operation of the gas turbine engine.