An engine system is provided, which includes an engine, a swirl control valve, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve provided incliningly with respect to an axial direction of the piston and configured to directly inject fuel into the cylinder. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder at least when the valve closes. When an engine load is below a given threshold, the controller controls the swirl control valve to close, and controls the fuel injection valve to inject fuel during an intake stroke. While the engine load is below the threshold, at a fixed engine speed, the controller controls to advance a fuel injection timing when the engine load is at a first load, compared with at a second load higher than the first load.

An engine system is provided, which includes an engine, a swirl control valve, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve provided incliningly with respect to an axial direction of the piston and configured to directly inject fuel into the cylinder. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder at least when the valve closes. When an engine load is below a given threshold, the controller controls the swirl control valve to close, and controls the fuel injection valve to inject fuel during an intake stroke. While the engine load is below the threshold, at a fixed engine speed, the controller controls to advance a fuel injection timing when the engine load is at a first load, compared with at a second load higher than the first load.

Methods are provided for identifying degradation in components of a compressor recirculation valve (CRV). One method may include inferring degradation of the CRV based on adaptation of a compressor surge line outside an expected range.

Methods and systems for operating an engine during conditions where ambient humidity changes over time are presented. In one non-limiting example, an engine air flow limit is adjusted to increase engine air flow during high humidity conditions such that an engine may provide equivalent torque output during the high humidity conditions as compared to when the engine is operated during low humidity conditions.

Methods and systems for operating an engine during conditions where ambient humidity changes over time are presented. In one non-limiting example, an engine air flow limit is adjusted to increase engine air flow during high humidity conditions such that an engine may provide equivalent torque output during the high humidity conditions as compared to when the engine is operated during low humidity conditions.

An apparatus for controlling an EGR valve, includes: a measurement unit to measure at least one operation condition of an engine system; a fresh air amount setting unit to set a target amount of fresh air based on the operation condition; a fresh air amount sensor to measure a current amount of fresh air introduced through an intake line; a control calculation unit to set a signal for controlling an opening degree of the EGR valve so that the current amount of fresh air follows the target amount of fresh air; and an identifier to simulate an input and an output of the engine system, and output engine system input-output sensitivity which is a ratio of a change rate of the current amount of fresh air to a change rate of the opening degree of the EGR valve.

An apparatus for controlling an EGR valve, includes: a measurement unit to measure at least one operation condition of an engine system; a fresh air amount setting unit to set a target amount of fresh air based on the operation condition; a fresh air amount sensor to measure a current amount of fresh air introduced through an intake line; a control calculation unit to set a signal for controlling an opening degree of the EGR valve so that the current amount of fresh air follows the target amount of fresh air; and an identifier to simulate an input and an output of the engine system, and output engine system input-output sensitivity which is a ratio of a change rate of the current amount of fresh air to a change rate of the opening degree of the EGR valve.

Methods and systems are provided for controlling hybrid vehicle engine operation, where the vehicle engine comprises one or more cylinders dedicated to recirculating exhaust to an intake manifold. In one example, during an engine cold-start event or other event where temperature of one or more exhaust catalysts are below a temperature needed for catalytic activity, fuel injection to the dedicated exhaust gas recirculation cylinder(s) is maintained shut off, while its intake and exhaust valves are maintained activated, thus enabling the dedicated exhaust gas recirculation cylinder(s) to route air to the intake manifold of the engine, resulting in exhaust gas lean of stoichiometry that may serve to heat the catalyst. In this way, during cold start events and other events where temperature of one or more exhaust catalysts are below a temperature for catalytic activity, combustion stability issues may be avoided, and exhaust catalyst(s) rapidly heated, thereby reducing undesired tailpipe emissions.

Methods and systems are provided for controlling hybrid vehicle engine operation, where the vehicle engine comprises one or more cylinders dedicated to recirculating exhaust to an intake manifold. In one example, during an engine cold-start event or other event where temperature of one or more exhaust catalysts are below a temperature needed for catalytic activity, fuel injection to the dedicated exhaust gas recirculation cylinder(s) is maintained shut off, while its intake and exhaust valves are maintained activated, thus enabling the dedicated exhaust gas recirculation cylinder(s) to route air to the intake manifold of the engine, resulting in exhaust gas lean of stoichiometry that may serve to heat the catalyst. In this way, during cold start events and other events where temperature of one or more exhaust catalysts are below a temperature for catalytic activity, combustion stability issues may be avoided, and exhaust catalyst(s) rapidly heated, thereby reducing undesired tailpipe emissions.

An engine system includes an engine, an intake line, an exhaust line, a turbocharger, a water-cooled intercooler, a high-pressure Exhaust Gas Recirculation (EGR) system which includes a high-pressure EGR line, a high-pressure EGR cooler, and a high-pressure EGR valve, a low-pressure EGR system which includes a low-pressure EGR line, and a low-pressure EGR cooler, a radiator which cools the coolant, a low-pressure EGR cooling line, an intercooler cooling line, a low-pressure EGR cooling valve, an intercooler cooling valve, an electric water pump, a driving information detector which detects driving information of a vehicle including an outside air temperature, a temperature of the intake gas supplied to the engine and a coolant temperature, and a controller which controls the low-pressure EGR cooling valve, the intercooler cooling valve, the high-pressure EGR valve and the electric water pump based on the driving information detected by the driving information detector.