A system and methods are described for a turbocharged engine, comprising powering the engine using a first operating cylinder, supplementing the power using a second switchable cylinder, deactivating the second switchable cylinder responsive to a load below a first threshold, and closing a first shut-off valve downstream of a compressor during the partial deactivation to prevent a first turbocharger from imparting a delivery action into a second compressor during the partial deactivation. Embodiments are further described wherein a bypass line in a second exhaust line further serves as a short-circuit line to prevent the second compressor from imparting a delivery action against the closed first shut-off valve. A variable valve timing is then included to further optimize the combustion process during the partial deactivation.

Methods and systems are provided for a boosted engine having a split exhaust system. In one example, a method comprises directing exhaust from a first cylinder group to one or more of a pre-compressor location, a post-compressor location, and an exhaust turbine, and directing exhaust from a second cylinder group to one or more of the pre-compressor location, and the exhaust turbine. Engine efficiency and knock control may be enhanced by directing exhaust gases to different locations based on engine operating conditions.

The method for controlling valve timing of an engine includes: classifying control regions; applying a maximum duration to an intake valve and a long duration to an exhaust valve in a first control region; advancing Intake Valve Closing timing, applying the long duration to the exhaust valve, and maintaining a maximum valve overlap in a second control region; applying the long duration to the exhaust valve and advancing the IVC timing and Exhaust Valve Closing timing in a third control region; applying a short duration to the exhaust valve and controlling the EVC timing in a fourth control region; controlling a throttle valve, applying the short duration to the exhaust valve, and retarding Exhaust Valve Opening timing in a fifth control region; and controlling the throttle valve and the EVC timing, applying the long duration to the exhaust valve, advancing the EVO timing in a sixth control region.

An intake variable valve timing mechanism (VVT) that collectively changes an intake valve close timing as a close timing of a plurality of intake valves and a control device that controls an engine including a plurality of injectors and the intake VVT are provided. When a specified engine stop condition is satisfied, a fuel cut is performed to stop a fuel supply into a plurality of cylinders by the injector. After the fuel cut, the intake VVT is controlled such that a retarded amount of the intake valve close timing immediately before a stop of a stop-time compression stroke cylinder as a cylinder stopped in a compression stroke from intake bottom dead center is larger than a retarded amount of the intake valve close timing immediately before a stop of a stop-time expansion stroke cylinder as a cylinder stopped in an expansion stroke from the intake bottom dead center.

A method and systems are disclosed for controlling the exhaust emissions an internal combustion engine of a vehicle. The driving state of the vehicle is determined and corresponding driving state signals are generated with the aid of driving state detectors. The emission values of the exhaust gases emitted by the internal combustion engine are determined based on the driving state signals by a computer model stored in a control unit. The determined emission values are compared with predefined emission limits by the control unit. If the determined emission values exceed the predefined emission limits, the internal combustion engine and/or the exhaust aftertreatment device are controlled by the control unit such that the determined emission values are reduced until they lie below the predefined emission limits.

The present invention relates to a method for controlling an internal combustion engine arrangement, which method comprises the steps of controlling an outlet valve to be arranged in an at least partial open position during a portion of an intake stroke; and providing a reducing agent to at least a portion of the flow of combustion gas exhausted from the combustion cylinder during an exhaust stroke.

A control method for an internal combustion engine, the internal combustion engine including a valve timing control mechanism on at least an intake side and configured to control an operation of the valve timing control mechanism on the intake side during acceleration, the method including, calculating a relational expression between an intake valve timing, the intake valve timing being an operation timing of an intake valve, and a cylinder air charge amount in a range in which the intake valve timing can be advanced or retarded within a predetermined calculation cycle from a current value, calculating a target air charge amount, the target air charge amount being a target value of the cylinder air charge amount during the acceleration, based on an operating state of the internal combustion engine, calculating a target value of the intake valve timing corresponding to the target air charge amount from the relational expression for each calculation cycle, and setting a command signal for the valve timing control mechanism on the intake side based on a calculated target value of the intake valve timing.

A method for controlling valve timing of a continuous variable valve duration engine may include: classifying a plurality of control regions depending on an engine speed and an engine load; applying a maximum duration to an intake valve and controlling a valve overlap between an exhaust valve and an intake valve by using an exhaust valve closing (EVC) timing in a first control region; advancing an intake valve closing (IVC) timing and applying a maximum duration to the exhaust valve in a second control region; advancing the IVC timing and the EVC timing in a third control region; controlling the EVC timing in a fourth control region; controlling a throttle valve to be fully opened and controlling the IVC timing in a fifth control region; and controlling the throttle valve to be fully opened and advancing the IVC timing in a sixth control region.

The present disclosure provides a system and a method for controlling valve timing of a continuous variable valve duration engine. The method may include: classifying a plurality of control regions depending on an engine speed and an engine load; applying a maximum duration to an intake valve in a first control region; maintaining the maximum duration of the intake valve and controlling a valve overlap by using exhaust valve closing (EVC) timing in a second control region; advancing intake valve closing (IVC) timing in a third control region; controlling the IVC timing to be close to bottom dead center (BDC) in a fourth control region; controlling a throttle valve to be fully opened and generating a scavenging phenomenon in a fifth control region; and controlling the throttle valve to be fully opened and controlling the IVC timing to prevent knocking in a sixth control region.

Methods and systems are provided for a hydrogen combustion engine. In one example, a method may include operating the hydrogen combustion engine at one of two combustion air ratios, wherein a combustion air ratio between the two is avoided via adjusting one or more operating parameters.