A first recirculation system includes a first adjuster to adjust the exhaust-gas flow rate in a first path connecting an upstream position of a turbine of a VG turbocharger to a downstream position of a compressor. A second recirculation system includes a second adjuster to adjust the exhaust-gas flow rate in a second path connecting a downstream position of the turbine to an upstream position of the compressor. A recirculation controller switches between a single use activating the first or second recirculation system and a combination use activating both systems by controlling the adjusters. A pressure controller executes feedback control of an intake-system pressure through adjusting the opening of vanes, and executes feedforward control without the feedback control during a predetermined period from the switching from the single use to the combination use.

Provided is an engine which is provided with an EGR device, wherein: an actual intake/exhaust gas pressure ratio π1 of an intake-gas pressure P1 to an exhaust-gas pressure P2 is calculated from the detected exhaust-gas pressure P2 and the detected intake-gas pressure P1; an estimated intake/exhaust gas pressure ratio π2 of the intake-gas pressure P1 to the exhaust-gas pressure P2 is calculated from an engine rotational frequency N, and a fuel injection amount F; and, in cases when the actual intake/exhaust gas pressure ratio π1 is less than a prescribed value π0, an EGR gas weight Megr is calculated based on the actual intake/exhaust gas pressure ratio π1, and in cases when the actual intake/exhaust gas pressure ratio π1 is equal to or more than the prescribed value π0, the EGR gas weight Megr is calculated based on the estimated intake/exhaust gas pressure ratio π2.

Provided is an internal combustion engine control device capable of appropriately correcting a flow rate of EGR gas. Therefore, an internal combustion engine control device 20 includes moisture amount calculation units 301 and 302, a dew condensation calculation unit 303, and an EGR correction unit 304. The moisture amount calculation unit 301 calculates a total moisture amount contained in the mixed gas. The dew condensation calculation unit 303 calculates a dew condensation generation amount WQcon in an intercooler based on the total moisture amount. The EGR correction unit 304 corrects a flow rate of the EGR gas based on the dew condensation generation amount WQcon.

In a control device for an internal combustion engine in which internal EGR and external EGR are conducted, an ideal in-cylinder gas amount and an ideal in-cylinder gas temperature in an ideal state in which neither of EGR gas recirculates into a cylinder are calculated (steps 1 and 2). A mixed gas amount of intake air and the external EGR gas present on a downstream side of a throttle valve is calculated, based on a rotation speed of the internal combustion engine and intake air pressure (step 21) to detect a mixed gas temperature. An actual in-cylinder gas temperature and amount and an EGR ratio are calculated, based on the ideal in-cylinder gas amount, the ideal in-cylinder gas temperature, the mixed gas amount, and the mixed gas temperature (steps 24, 4, and 5), and an internal combustion engine is controlled based on the EGR ratio.

An apparatus for controlling a low-pressure exhaust gas recirculation (LP-EGR) system for freezing prevention includes an intake air temperature sensor configured to measure a temperature of intake air introduced from outside, at least one engine driving sensor used to diagnose and learn a driving state of an engine, the LP-EGR system configured such that at least a portion of exhaust gas flows into the LP-EGR system as intake air, and a controller configured to perform diagnosis and learning of the driving state of the engine using the at least one engine driving sensor or to operate the LP-EGR system depending on the temperature of the intake air measured by the intake air temperature sensor when coasting conditions of a vehicle are satisfied.

A system and an approach for determining various flows in an internal combustion engine, such as an amount of recirculation exhaust gas flow through a controlled valve and a fresh air mass flow to an intake of an engine. Also, among the sensors accommodated in the system, is an inexpensive but slow-responding lambda sensor in the exhaust stream.

A method for controlling and regulating an internal combustion engine with exhaust gas recirculation, in which an EGR rate is determined by a Kaiman filter from calculated and measured variables of the gas path and from calculated and measured variables of combustion. A method for the model-based control and regulation of an internal combustion engine includes calculating injection system set values for controlling the injection system actuators as a function of a set torque by a combustion model. Gas path set values for controlling the gas path actuators are calculated as a function of an EGR rate by a gas path model. A measure of quality is calculated by an optimizer as a function of the injection system and gas path set values. The measure of quality is minimized by the optimizer by changing the injection system and gas path set values within a prediction horizon. The injection system and gas path set values are set by the optimizer as definitive for adjusting the operating point of the engine by using the minimized measure of quality.

A hybrid vehicle includes an engine, an exhaust gas recirculation device, a traveling motor, and a control device. The exhaust gas recirculation device includes a communication pipe that allows an exhaust pipe and an intake pipe of the engine to communicate with each other and a valve that is provided in the communication pipe. The control device is configured to perform foreign matter removal control for opening and closing the valve when foreign matter caught in the valve is detected and the hybrid vehicle stops.

Methods and systems are provided for a high-pressure exhaust gas recirculation system. In one example, the high-pressure exhaust gas recirculation system comprises pressure seconds arranged on different sides of a valve. The pressure sensors are used to regulate exhaust-gas recirculate flow without a fixed orifice delta pressure sensor.

A controller is configured to control an internal combustion engine that includes an exhaust gas temperature sensor. The exhaust gas temperature sensor detects, as an exhaust gas temperature, a temperature of exhaust gas flowing through an exhaust passage. The controller is configured to execute an estimation process that estimates a generation amount per unit time of condensed water generated in the exhaust passage. In the estimation process, the controller estimates a lower value of the generation amount for a higher value of the exhaust gas temperature that is detected by the exhaust gas temperature sensor.