Methods and systems are provided for operating a cylinder of an engine including a pre-chamber system. In one example, a method includes flowing gases from a pre-chamber to a cylinder of an engine prior to fueling the cylinder during a combustion cycle, adjusting a composition of the gases by adjusting at least one of an air injection amount to the pre-chamber and a fuel injection amount to the pre-chamber, and igniting an air-fuel mixture in the cylinder via a pre-chamber ignition event, the air-fuel mixture in the cylinder including the gas from the pre-chamber. In this way, combustion qualities in the cylinder may be adjusted in order to increase a performance and/or an efficiency of the cylinder.

A method for predicting the combustion state of an engine sets the operating condition of the engine, calculates the temperature of a highest temperature portion of the cylinder before combustion based on the operating condition, calculates the combustion start timing based on the temperature of the highest temperature portion, calculates the temperature of a lowest temperature portion of the cylinder based on the operating condition and the combustion start timing, and calculates the combustion end timing based on the temperature of the lowest temperature portion. The method calculates the temperature of a wall surface layer portion located adjacent the wall surface in the cylinder based on state changes in a burned portion, an unburned portion, and the wall surface layer portion that constitute a combustion chamber inside of the cylinder, and applies the temperature of the wall surface layer portion as the temperature of the lowest temperature portion.

One embodiment is a system comprising an engine including a dedicated EGR cylinder configured to provide EGR to the engine via an EGR loop, a non-dedicated cylinder, a plurality of injectors structured to inject fuel into the dedicated EGR cylinder and the non-dedicated EGR cylinder, and an electronic control system operatively coupled with the fueling system and the ignition system. The electronic control system is configured to evaluate engine operating parameters including an engine load and an engine speed. The electronic control system is responsive to variation of the engine operating parameters to control operation of the fueling system to vary combustion in the at least one dedicated cylinder between rich of stoichiometric and stoichiometric.

A control unit configured to control an electric turbocharger and an EGR valve. While an internal combustion engine is stopped, an oxygen-free period, which is a period during which oxygen surrounding an exhaust gas purifier used for an oxidation reaction runs out, is estimated based on a temperature of the exhaust gas purifier. Before entering the oxygen-free period, the EGR valve is opened and the electric turbocharger is driven. Air surrounding the exhaust gas purifier is replaced with fresh air. After replacement with the fresh air has been completed, the electric turbocharger is stopped.

A method of operating exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit linked to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target in step S1 wherein when motor speed=predetermined target then; determining if a motor torque is within a predetermined target in step S2 wherein when motor torque=predetermined target then; determining if a motor temperature is within a predetermined target in step S3 wherein when motor temperature=predetermined target then; and maintaining operation of the exhaust gas recirculation pump.

Methods and systems are provided for increasing EGR delivered to an engine. In one example, a method may include determining an EVO timing set point and an external EGR setpoint in parallel, based on an inverse model. The EVO timing may be adjusted based on a combination of the EVO timing setpoint and an EGR cylinder balancing feedback loop, thereby varying internal EGR to the engine to supplement external EGR.

Provided is a valve control apparatus for an engine that opens and closes an exhaust valve and intake value of the engine while rotating in conjunction with a crankshaft of the engine, the valve control apparatus including an exhaust valve opening and closing device opening and closing the exhaust valve during a first exhaust valve opening period and an intake valve opening and closing device opening and closing the intake valve during a first intake valve opening period.

Methods and systems are described for combustion engine mode optimization. The system includes a combustion engine, a fuel delivery system, and a controller communicatively coupled to the combustion engine and the fuel delivery system. The controller selects a low temperature combustion mode based on the combustion engine being warmer than a predetermined temperature and low load conditions on the combustion engine. The low temperature combustion mode includes instructions that reduces an intake valve opening duration and an exhaust valve opening duration. The controller reduces the intake valve opening duration and the exhaust valve opening duration to create a delay between an intake valve opening duration and an exhaust valve opening duration in response to selecting the low temperature combustion mode. The delay increases a residual gas temperature in the combustion chamber and induces auto-ignition of fuel in the combustion chamber.

An internal combustion engine comprises a plurality of cylinders, including at least one de-activatable cylinder having at least one deactivator assembly operatively connected to the at least one valve train for the de-activatable cylinder. In such an internal combustion engine, a method for actuating engine valves comprises operating at least one cylinder of the plurality of cylinders to provide positive power generation according to the main valve actuations and, additionally, placing the at least one deactivator assembly for a de-activatable cylinder of the at least one de-activatable cylinder in a deactivation state. While the at least one deactivator assembly for the de-activatable cylinder is in the deactivation state and while the at least one cylinder is operating to provide positive power generation according to main valve actuations, the method further comprises performing at least one secondary valve event via at least one engine valve for the de-activatable cylinder.

Methods and systems are provided for increasing EGR delivered to an engine. In one example, a method may include determining an EVO timing set point and an external EGR setpoint in parallel, based on an inverse model. The EVO timing may be adjusted based on a combination of the EVO timing setpoint and an EGR cylinder balancing feedback loop, thereby varying internal EGR to the engine to supplement external EGR.