A basic opening (A0) of an EGR control valve (22) is set, based on a current engine operation state. A differential pressure (P1) across the EGR control valve (22) is calculated, based on an actual exhaust system temperature (T1) sensed by an exhaust temperature sensor (33). A reference differential pressure (P0) is calculated, which is a differential pressure across the EGR control valve (22) in a steady state corresponding to the current engine operation state. A reference pulsation amplitude (D) is calculated, which is an amplitude of pulsation of the reference differential pressure (P0). The basic opening (A0) is corrected, based on the differential pressure (P1), the reference differential pressure (P0), and the reference pulsation amplitude (D).

A method for controlling a setpoint charging pressure for a turbocharger includes determining a charge-based setpoint charging pressure on the basis of a charge of the internal combustion engine, sampling an actual charging pressure, determining a carried-along actual charging pressure on the basis of the actual charging pressure, determining an offset on the basis of the charge-based setpoint charging pressure, and adjusting, by open-loop control, the setpoint charging pressure to the charge-based setpoint charging pressure by a first-order timing element if the carried-along actual charging pressure exceeds a first value which is lower than the charge-based setpoint charging pressure by the offset.

A method of operating an engine assembly is provided. The engine assembly comprises an engine and a turbocharger assembly, wherein a control parameter of the turbocharger assembly is controllable in order to control a level of boost provided by the turbocharger assembly. The method comprises determining a desirable pressure limit of exhaust gases upstream of a turbine of the turbocharger assembly, predicting a desirable limit value of the control parameter to be applied to the turbocharger assembly in order to achieve the desirable pressure limit, determining an error in the desirable limit value of the control parameter, adjusting the desirable limit value of the control parameter based on the error, and controlling the operation of the turbocharger assembly such that the adjusted limit value is not exceeded.

A method for determining a desired intake manifold pressure of an internal combustion engine by means of an iterative method, wherein a cylinder charge is determined for an intake manifold pressure iterated during the iterative method, and the desired intake manifold pressure is determined as a function of the cylinder air charge that has been determined. In addition, a control device for carrying out the method is provided.

A fuel injection valve is for injecting fuel to cause combustion in an internal combustion engine. An injection rate adjuster is for adjusting an injection rate of the fuel injected by the fuel injection valve. A control device for the internal combustion engine includes a signal generator, and an outputter. The signal generator generates a command signal to cause the injection rate adjuster to adjust the injection rate based on a parameter, which is to estimate an internal EGR amount in which a part of exhaust gas remains in a cylinder. The outputter outputs the command signal to the injection rate adjuster.

A method for controlling a two-stroke engine operatively connected to a turbocharger, the turbocharger being in fluid communication with the engine to provide a boost pressure thereto. The method includes determining an exhaust temperature representative of an actual temperature of exhaust gas being discharged by the engine; determining a temperature difference between the exhaust temperature and a threshold temperature; in response to the exhaust temperature being less than the corresponding threshold value: determining a corrective amount of boost pressure to add to the boost pressure of the turbocharger, the corrective amount of boost pressure being determined based on the temperature difference; and controlling the turbocharger to increase the boost pressure of the turbocharger by the corrective amount.

An internal combustion engine has a cylinder configured to combust an air-fuel mixture and expel an exhaust gas and a turbocharger for generating a pressurized airflow to the cylinder. The turbocharger includes a turbine scroll defining an inlet and an outlet, an exhaust gas driven rotating assembly having a turbine wheel disposed inside the turbine scroll, and a waste-gate defining an opening. A first sensor detects turbine outlet pressure. A second sensor detects turbine inlet temperature. A controller determines an effective area of the waste-gate opening and an exhaust gas mass flow-rate. The controller also determines a turbine inlet pressure in response to the detected turbine outlet pressure and the turbine inlet temperature, and the determined waste-gate opening effective area and the exhaust gas mass flow-rate. The controller additionally regulates a supply of fuel to the cylinder corresponding to the pressurized airflow affected by the determined turbine inlet pressure.

Based on an internal EGR ratio and desired external and internal EGR ratios, an EGR valve opening degree is feedback-controlled based on a desired EGR ratio, calculated in such a way as to perform correction so that a total EGR ratio becomes constant, and an EGR effective opening area obtained through learning of the relationship between an EGR valve opening degree and an effective opening area; thus, a correct characteristic of EGR valve opening degree vs. effective opening area can be maintained and hence it is made possible to absorb variations, changes with time, and even environmental conditions, while making an EGR valve and an intake/exhaust VVT collaborate with each other; therefore, an EGR flow rate can accurately be estimated.

Methods and systems are provided for mitigating excessive exhaust pressures in an engine. In one example, a method may include adjusting an intake throttle responsive to exhaust pressure upstream of an exhaust turbine being higher than a threshold without reducing boost level. In this way, boost pressures may be maintained while reducing exhaust pressures.

An internal combustion engine has a cylinder configured to combust an air-fuel mixture and expel an exhaust gas and a turbocharger for generating a pressurized airflow to the cylinder. The turbocharger includes a turbine scroll defining an inlet and an outlet, an exhaust gas driven rotating assembly having a turbine wheel disposed inside the turbine scroll, and a waste-gate defining an opening. A first sensor detects turbine outlet pressure. A second sensor detects turbine inlet temperature. A controller determines an effective area of the waste-gate opening and an exhaust gas mass flow-rate. The controller also determines a turbine inlet pressure in response to the detected turbine outlet pressure and the turbine inlet temperature, and the determined waste-gate opening effective area and the exhaust gas mass flow-rate. The controller additionally regulates a supply of fuel to the cylinder corresponding to the pressurized airflow affected by the determined turbine inlet pressure.