An EGR valve is provided in an EGR passage circulating a part of an exhaust gas of an exhaust pipe in an intake pipe as an EGR gas, the EGR valve adjusting an EGR gas amount flowing in the EGR passage when an engine is in an EGR region, a differential pressure device is provided in the intake pipe, the differential pressure device adjusting a differential pressure of the EGR valve, a control unit is provided to control the EGR valve and the differential pressure device, and the EGR control method includes switching whether to adjust the EGR gas amount using the EGR valve and the differential pressure device or to adjust the EGR gas amount using the EGR valve only on the basis of an exhaust gas pressure of an inlet portion of the EGR passage.

A control device for a compression ignition engine includes a controller configured to operate an engine body by compression ignition combustion when the engine body operates in a predetermined compression ignition range. When the engine body operates in a predetermined high load range of the compression ignition range, the controller maximizes a filling amount of the cylinder using a gas state adjustment system, and lowers an EGR ratio so that the air-fuel mixture in the cylinder is lean with an excess air ratio λ higher than 1 in a lower speed range, and maximizes the filling amount of the cylinder, and increases the EGR ratio so that the air-fuel mixture in the cylinder has the excess air ratio λ of 1 or lower in a higher speed range than the lower speed range.

A control device for a compression ignition engine includes a controller configured to operate an engine body by compression ignition combustion when the engine body operates in a predetermined compression ignition range. When the engine body operates in a predetermined high load range of the compression ignition range, the controller maximizes a filling amount of the cylinder using a gas state adjustment system, and lowers an EGR ratio so that the air-fuel mixture in the cylinder is lean with an excess air ratio λ higher than 1 in a lower speed range, and maximizes the filling amount of the cylinder, and increases the EGR ratio so that the air-fuel mixture in the cylinder has the excess air ratio λ of 1 or lower in a higher speed range than the lower speed range.

The objective of the present invention is to provide a control device for an internal combustion engine that is able to provide a more stable combustion state by suitably setting the amount of recirculated exhaust gas. The present invention is an internal combustion engine control device equipped with air cylinders and an EGR mechanism that returns exhaust gas emitted from the air cylinders to the intake side of the air cylinders, and is characterized by being equipped with an EGR control unit that controls the EGR flow volume of the EGR mechanism, and a humidity detection means that directly or indirectly detects the humidity of outside air supplied to the air cylinders, with the EGR control unit calculating the moisture amount in the outside air and the moisture amount in the recirculated exhaust gas, and controlling the EGR mechanism on the basis of: a stable combustion limit air cylinder mass, which is set in accordance with the combustion state in the air cylinders; the mass of the air introduced into the air cylinders; the mass of the fuel; and the moisture amounts.

The objective of the present invention is to provide a control device for an internal combustion engine that is able to provide a more stable combustion state by suitably setting the amount of recirculated exhaust gas. The present invention is an internal combustion engine control device equipped with air cylinders and an EGR mechanism that returns exhaust gas emitted from the air cylinders to the intake side of the air cylinders, and is characterized by being equipped with an EGR control unit that controls the EGR flow volume of the EGR mechanism, and a humidity detection means that directly or indirectly detects the humidity of outside air supplied to the air cylinders, with the EGR control unit calculating the moisture amount in the outside air and the moisture amount in the recirculated exhaust gas, and controlling the EGR mechanism on the basis of: a stable combustion limit air cylinder mass, which is set in accordance with the combustion state in the air cylinders; the mass of the air introduced into the air cylinders; the mass of the fuel; and the moisture amounts.

An internal combustion engine having intake and exhaust manifolds, a turbocharger with a compressor, and at least one of: an exhaust gas recirculation (EGR) valve and a variable geometry turbine (VGT). The system further includes a control computer configured to determine at least one of torque demand, pressure across the compressor, and pressure gradient ratio between the exhaust manifold and the intake manifold relative to one of exhaust manifold pressure, intake manifold pressure, and 1. The control computer performs at least one of: closing the EGR valve in response to the determined at least one of torque demand, pressure across the compressor, and pressure gradient ratio, and lessening restriction provided by the variable geometry turbine responsive to the determined at least one of torque demand, pressure across the compressor, and pressure gradient between the exhaust manifold and the intake manifold.

An internal combustion engine having intake and exhaust manifolds, a turbocharger with a compressor, and at least one of: an exhaust gas recirculation (EGR) valve and a variable geometry turbine (VGT). The system further includes a control computer configured to determine at least one of torque demand, pressure across the compressor, and pressure gradient ratio between the exhaust manifold and the intake manifold relative to one of exhaust manifold pressure, intake manifold pressure, and 1. The control computer performs at least one of: closing the EGR valve in response to the determined at least one of torque demand, pressure across the compressor, and pressure gradient ratio, and lessening restriction provided by the variable geometry turbine responsive to the determined at least one of torque demand, pressure across the compressor, and pressure gradient between the exhaust manifold and the intake manifold.

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 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 turbocharger control method and related systems are provided. An operational command to control a level of boost provided by the turbocharger is received. In response to receiving the operational command, an exhaust gas recirculation (EGR) valve is instructed to move from a current position to a desired position. A time taken for the EGR valve to move from the current position to the desired position is determined. A maximum rise rate of exhaust manifold pressure corresponding to a predicted EGR valve position is determined. A permitted exhaust manifold pressure limit for the turbocharger is determined based on a current exhaust manifold pressure, the maximum rise rate of exhaust manifold pressure and the time taken. An operation of the turbocharger is controlled such that the permitted exhaust manifold pressure limit is not exceeded.