A stop control device for an internal combustion engine is structured that stops the engine in a state suitable for starting and that does not cause a crank angle to change after the engine is stopped. A four-cycle internal combustion engine includes an electric valve opening and closing timing control device that sets an opening and closing timing of either or both of an intake valve and an exhaust valve. Stop control of stopping the internal combustion engine is performed when a stop signal for stopping the internal combustion engine is acquired, and post-stop phase control of displacing the opening and closing timing of the valve opening and closing timing control device in either an advancing direction or a retarding direction is performed after the internal combustion engine is stopped by the stop control.

A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.

A control system for controlling operation of an internal combustion engine is configured to: receive a first request signal indicative of first torque demand; determine a schedule defining an opening timing of the intake valve and a closing timing of the intake valve of a cylinder of the internal combustion engine in dependence on the first torque demand; and cause the intake valve to open in accordance with the schedule. The control system is also configured to, during a period in which the intake valve is open: receive a second torque request signal indicative of a second torque demand different to the first torque demand; determine an updated schedule defining an updated closing timing of the intake valve in dependence on the second torque demand; and cause the intake valve to close in accordance with the updated schedule.

The present invention concerns a method in a two-stroke engine comprising at least one cylinder (1) with a reciprocating piston (2), a delimited combustion space (5), at least one outlet port (7) and an inlet port (9) which are both uncovered at the bottom dead center position of the piston, an actuator (8) which activates a valve (17) to open and introduce combustion air via an inlet pipe (6), a control system (15) which controls the actuator to open the valve in order to introduce combustion air via the inlet port. The invention is characterized in that the inlet port is closed by the piston after the outlet port has been closed, thus the opposite compared to the two-stroke engines of today.

A technique for fuel system protection for an internal combustion engine comprises determining direct fuel injector temperature as a function of engine operating parameters; and advancing intake valve timing when the temperature rises above a first predetermined value such that the temperature is maintained below a second predetermined value.

A method for increasing a resolution of a magnetic sensor for an internal combustion engine of a motor vehicle. The sensor delivers an electrical synchronization signal having successive, spaced-apart crenels, one of the rising or falling edges of which corresponds to a respective angle of rotation of the element of the engine. A synchronization voltage range is interposed between an upper voltage modulation range above and a lower voltage modulation range below the upper and lower voltage of the synchronization range, respectively, the electrical signal in each of the lower and upper modulation ranges being modulated so as to include additional crenels, which are supplementary to the crenels of the synchronization signal, corresponding to periodic clock crenels with a period dependent on engine speed, an angle of rotation being identified by one of the rising or falling edges of each additional crenel.

Aspects of the present invention relate to a controller (104) and method (400) for controlling operation of an internal combustion engine (101). The controller (104) is configured to: receive a first request signal indicative of a request to stop fuel being supplied to the engine (101), and cause an intake valve (301) of a cylinder (103) of the internal combustion engine (101) to remain closed during the current revolution of the internal combustion engine (101) and revolutions of the internal combustion engine (101) immediately following the current revolution of the internal combustion engine (101) in dependence on at least one of: the intake valve (301) being closed at the time of receiving the first request signal; or a next opening of the intake valve having not been scheduled. The controller (104) is also configured to cause injection of fuel into the cylinder (103) and subsequently cause the intake valve (301) to remain closed during revolutions of the internal combustion engine (101) immediately following a next closing of the intake valve (301), in dependence on at least one of: the intake valve (301) being open at the time of receiving the first request signal; and a next opening of the intake valve (301) having already been scheduled at the time of receiving the first request signal and said next opening of the intake valve (301) is to be performed.

Methods and systems for unsticking a stuck gaspath actuator are disclosed. In one embodiment, an engine operating method includes adjusting exhaust valve timing of one or more cylinders of an engine in response to an indication that a gaspath actuator is stuck in position. In this way, pressure waves in an exhaust manifold and/or an intake manifold may be generated, which may act to unstick the gaspath actuator.

In various aspects, internal combustion engines, engine controllers and methods of controlling engines are described. The engine includes a camshaft and a two cylinder sets. Cylinders in the first are deactivatable and cylinders in the second set may be fired at high or low output levels. The air charge for each fired working cycle is set based on whether a high or low torque output is selected. In some implementations, the camshaft is axially shiftable between first and second positions. First cam lobes are configured to cause their associated cylinders to intake a large air charge during intake strokes that occur when the camshaft is in the first position. Second cam lobes for cylinders in the second set cause their associated cylinders to intake a smaller air charge when the camshaft is in the second position. Second cam lobes for cylinders in the first set deactivate their associated cylinders.

An engine optimization controller may determine values of a set of input parameters of an engine and process, using an engine model, the values to determine a plurality of sets of potential output parameters. The engine optimization controller may determine, based on the plurality of sets of potential output parameters, an engine optimization scheme, which may indicate a first number of cylinders, of one or more cylinders of the engine, to be active and to receive gas; a second number of cylinders, of the one or more cylinders, to be inactive and to receive gas, and/or a third number of cylinders, of the one or more cylinders, to be inactive and to not receive gas. The engine optimization controller may provide the engine configuration scheme to another controller to allow control of the one or more cylinders and one or more fuel injectors according to the engine configuration scheme.