A method includes substantially eliminating surge of a compressor and reducing specific fuel consumption and exhaust emissions of an engine by adjusting exhaust flow through an exhaust gas recirculation system, by adjusting airflow through a compressor recirculation valve, by adjusting fuel injection timing, or by adjusting a combination thereof in response to variance in a plurality of parameters. The parameters include quantity of exhaust emissions, a maximum in-cylinder pressure of the engine, an area ratio of an exhaust gas recirculation mixer of the exhaust gas recirculation system, estimated or sensed compressor surge, engine load, altitude of operation, or combinations of the parameters thereof.

A method includes substantially eliminating surge of a compressor and reducing specific fuel consumption and exhaust emissions of an engine by adjusting exhaust flow through an exhaust gas recirculation system, by adjusting airflow through a compressor recirculation valve, by adjusting fuel injection timing, or by adjusting a combination thereof in response to variance in a plurality of parameters. The parameters include quantity of exhaust emissions, a maximum in-cylinder pressure of the engine, an area ratio of an exhaust gas recirculation mixer of the exhaust gas recirculation system, estimated or sensed compressor surge, engine load, altitude of operation, or combinations of the parameters thereof.

A fail-safe control method for a vehicle cooling system, in which an engine and a vehicle can be properly operated even when a water temperature sensor malfunctions. When only one of two water temperature sensors malfunctions, control may be performed so that an engine and a vehicle can properly operate. When both the two water temperature sensors malfunction, the fail-safe function of the flow rate control valve can be enabled to entirely prevent cooling water from being overheated, thereby improving the reliability of the operation of the vehicle.

A fail-safe control method for a vehicle cooling system, in which an engine and a vehicle can be properly operated even when a water temperature sensor malfunctions. When only one of two water temperature sensors malfunctions, control may be performed so that an engine and a vehicle can properly operate. When both the two water temperature sensors malfunction, the fail-safe function of the flow rate control valve can be enabled to entirely prevent cooling water from being overheated, thereby improving the reliability of the operation of the vehicle.

Systems, apparatus, and methods are disclosed that include an internal combustion engine having a plurality of cylinders and controlling a device to reduce the pressure in an exhaust gas recirculation loop in response to a pressure condition exceeding a threshold.

Systems, apparatus, and methods are disclosed that include an internal combustion engine having a plurality of cylinders and controlling a device to reduce the pressure in an exhaust gas recirculation loop in response to a pressure condition exceeding a threshold.

An EGR malfunction detection system includes an EGR valve configured to open and close an exhaust recirculation path for recirculating an exhaust gas from an exhaust channel to an intake channel of an engine, a measurement unit configured to measure an intake pressure inside the intake channel, a valve controller configured to control the EGR valve, and a malfunction detector configured to detect an anomaly in the exhaust recirculation path in accordance with a measurement unit output and a valve controller output. The malfunction detector determines whether the EGR valve is stuck in accordance with the intake pressures measured when the EGR valve is controlled to open and close. If the EGR valve is stuck, the malfunction detector determines whether the EGR valve is stuck in an open state, stuck in a closed state, or stuck in an intermediate state by comparing the measured pressure with predetermined thresholds.

An EGR malfunction detection system includes an EGR valve configured to open and close an exhaust recirculation path for recirculating an exhaust gas from an exhaust channel to an intake channel of an engine, a measurement unit configured to measure an intake pressure inside the intake channel, a valve controller configured to control the EGR valve, and a malfunction detector configured to detect an anomaly in the exhaust recirculation path in accordance with a measurement unit output and a valve controller output. The malfunction detector determines whether the EGR valve is stuck in accordance with the intake pressures measured when the EGR valve is controlled to open and close. If the EGR valve is stuck, the malfunction detector determines whether the EGR valve is stuck in an open state, stuck in a closed state, or stuck in an intermediate state by comparing the measured pressure with predetermined thresholds.

To provide a novel power train system capable of improving fuel efficiency, reducing harmful components of an exhaust gas, and improving an output by adjusting a composition of a gas component of the exhaust gas in accordance with an operation condition. Therefore, provided is a power train system including a gas component separation unit (2) which extracts a plurality of gas components having different specific heat ratios from an exhaust gas of a spark ignition type internal combustion engine (1), a recirculation unit which recirculates the plurality of gas components to a combustion chamber of the internal combustion engine, and a ratio adjustment unit (3) which adjusts a ratio of the plurality of gas components recirculated to the combustion chamber in response to an operation state of the internal combustion engine. A composition of a gas recirculated to the internal combustion engine can be adjusted depending on various operation conditions. Accordingly, it is possible to improve fuel efficiency, reduce harmful components of an exhaust gas, and improve an output in a wide range of operation conditions of the internal combustion engine.

A control system and a control method for an internal combustion engine, which are capable of accurately calculating an in-cylinder gas amount and an EGR ratio by a relatively simple method even in a case where an in-cylinder gas temperature is changed by execution of internal EGR, and properly controlling the engine using the EGR ratio thus calculated. An in-cylinder gas amount Gact actually filled in the cylinder is calculated by correcting an ideal in-cylinder gas amount Gth, which is an amount of gases filled in a cylinder in an ideal state in which it is assumed that no exhaust gases of the engine are recirculated into the cylinder, using an ideal in-cylinder gas temperature Tcylth according to an in-cylinder gas temperature Tcyl, and an EGR ratio REGRT is calculated using the in-cylinder gas amount Gact and an intake air amount Gaircyl.