Methods and systems are provided for synergizing the benefits of a variable compression ratio engine in a hybrid vehicle system. A vehicle controller may hold the engine in a lower compression ratio during engine pull-ups and pull-downs, in particular when passing through a low speed region where compression bobbles can occur. During engine operation, in response to a change in driver demand, the controller may opt to switch the compression ratio or maintain a current compression ratio while smoothing a torque deficit using motor torque, the selection based on fuel economy.

It is provided a control device for a hybrid vehicle including a controller configured to control an engine, a first motor, and an automatic transmission and a control method of the hybrid vehicle. The controller is configured to determine whether or not an operation state of the engine is changeable, when an upshift of the hybrid vehicle is performed, decrease torque of an input shaft of the automatic transmission by outputting negative torque acting to decrease the torque of the input shaft of the automatic transmission from the first motor when a prohibition condition that the operation state of the engine is not changeable is established, and decrease engine torque output from the engine to decrease the torque of the input shaft of the automatic transmission to be decreased accompanied by the upshift when the prohibition condition is not established and the operation state of the engine is changeable.

A system and method for providing torque-assist to a rotary shaft of an internal combustion engine control an electric machine in response to operation of an exhaust gas recirculation (EGR) valve to assist the rotation of the rotary shaft. The system and method facilitate periodic operation of the EGR valve to purge condensation without objectionable torque reduction when the engine is operating near full load.

Methods and systems are provided for monitoring and adapting sensors and actuators in the induction system and exhaust system of an internal combustion engine during a period of time in which fresh air is flowing through the internal combustion engine without fuel delivery. According to the disclosure, the period of time in which fresh air is flowing through the internal combustion engine when fuel delivery is turned off and the monitoring and adapting is being carried out is extended by transferring torque produced by electric motor to the internal combustion engine.

Methods and systems are provided for using compression heating to heat a cylinder piston before cylinder combustion is resumed. Cylinder heating is achieved using combinations of slow unfueled engine rotation where the engine cylinders are heated via compression stroke heating, and slow compressor rotation where the cylinders are heated via compression heating. One or more intake or exhaust heaters may be concurrently operated to expedite cylinder heating.

A vehicle and method for controlling a vehicle having a variable displacement engine with an auxiliary machine connected directly to the engine crankshaft and to an energy storage device includes switching from a cylinder disablement (VDE) mode to a normal mode when the torque demand and engine speed lie outside an outer range defined by a first threshold (T.sub.out), and switching from the normal mode to the VDE mode when the torque demand and engine speed lie within an inner range, which lies within the outer range and defined by a second threshold (T.sub.in). When operating in a band between the two thresholds, the auxiliary machine draws energy from the energy storage device and supplements the output torque from the engine if operating in the VDE mode, and derives torque from the engine crankshaft to recharge the energy storage device if operating in the normal mode.

In a constant-speed traveling mode or a follow-up traveling mode, reduction of fuel consumption and improvement of drivability are both achieved. An ECU 110 has an ISG connected to an engine and a battery connected to the ISG. The ECU 110 has an ISG control unit 606 that performs control for supplying power to the ISG from the battery to rotationally drive the ISG, or to drive the ISG to generate power for charging the battery. In one cycle of a traveling mode until completion of deceleration traveling after acceleration traveling is started so as to achieve a target vehicle speed, the ISG control unit 606 drives the ISG such that a remaining charge amount of the battery falls within a set range at completion of the deceleration traveling, and a traveling acceleration/deceleration falls within a predetermined requested acceleration/deceleration.

An intake system for use with an internal combustion engine having one or more cylinders. The intake system including a compressor assembly having an inlet and an outlet, and where the outlet is configured to be open to and in fluid communication with at least one of the one or more cylinders. The intake system also includes a passageway extending between and in fluid communication with the inlet and the outlet and configured to direct a first flow of gasses and a controller in operable communication with the compressor assembly. Where the intake system is operable in a first mode in which the majority of gasses of the first flow of gasses flow through the passageway toward the outlet, and a second mode in which the majority of gasses of the first flow of gasses flow through the passageway toward the inlet.

An engine control device for a saddle riding vehicle includes a mechanical centrifugal clutch for connecting and disconnecting driving force from an engine to a driving wheel, a throttle operator to adjust output power of the engine, a motor to rotate a crankshaft of the engine, and a control unit to control the motor and a fuel injection system. The control unit executes injection stopping control for stopping fuel injection during deceleration of the vehicle and executes, when an opening operation of the throttle operator is performed after an engine speed becomes equal to or lower than a centrifugal clutch disconnection speed at which the centrifugal clutch is disconnected, acceleration assist control for rotating the crankshaft with the motor.

A method for controlling an electric device including: a step of comparing the rotation speed of an internal combustion engine at the time when it has been determined that the internal combustion engine is to transition to a rotation stop state with a specified threshold; and a step of performing rotation-speed increasing control, in a case where the rotation speed of the internal combustion engine at the time of the determination is higher than the threshold, in which in a case where the rotation speed of the internal combustion engine at the time of the determination is not higher than the threshold, the rotation speed of the internal combustion engine is not made higher than the rotation speed at the time of the determination but is let to decrease to stop the internal combustion engine.