Abstract: In order to control an internal combustion engine according to the invention, a polytropic exponent is determined in accordance with at least two measured values of the pressure in the combustion chamber of the cylinder, said measured values being detected after closing the gas discharge valve and before successively opening the gas intake valve. An exhaust gas mass which is located in the cylinder after closing the gas discharge valve and before successively opening the gas intake valve is determined according to the polytropic exponent at an estimated value of the pressure after closing the gas discharge valve and before successively opening the gas intake valve as well as at a certain temperature of the exhaust gas located in the cylinder after closing the gas discharge valve and before successively opening the gas intake valve. An actuation signal for controlling an actuating member of the internal combustion engine is generated in accordance with the determined exhaust gas mass.

Abstract: The invention is directed toward a device for controlling an internal combustion engine. An aspect of the invention is determining a polytropic exponent according to at least two measured values of the pressure in a combustion chamber of a cylinder of an internal combustion engine during the working stroke of the cylinder once an air/fuel mixture of a cylinder has been burned and before the gas discharge valve is opened. A first exhaust gas temperature is determined and a second temperature of the exhaust gas is determined in accordance with the first exhaust gas temperature. The pressure associated in the combustion chamber, the pressure prevailing in the combustion chamber after closing the gas discharge valve, and the polytropic exponent are determined. An actuation signal for controlling an actuating member of the internal combustion engine is generated according to the second temperature of the exhaust gas.

Abstract: In a method of operating an internal combustion engine with a switch-over capability between a compression ignition mode of operation and a spark ignition mode of operation in higher load ranges which includes a cam-operated valve drive with a valve control providing, in the compression ignition mode of operation, for an increased valve overlap of the valve opening times, smooth engine operation and optimal exhaust gas emissions are obtained also during rapid load changes upon changing the engine operating mode as the change-over is accompanied by changes of the injection parameters, the throttling parameter and the valve control, which are coordinated with respect to one another as the valve control is switched over by changing the amplitude and phase position of the valve stroke of at least one of the inlet and outlet valves.

Abstract: In a method for operating an internal combustion engine having a variable compression ratio either in a compression ignition or in a spark ignition operating mode depending on the engine operating point, a higher compression ratio is provided in the compression ignition mode than in the spark ignition mode so as to optimize the operation of the internal combustion engine at low and medium engine loads, and to reduce engine emissions.

Abstract: In a method for operating an internal combustion engine in which the angular locations where the fuel/air mix combustions takes place can be controlled by an adjustment of the inlet and outlet valve timing, the timing of at least one of the intake and exhaust valve opening phases is shifted depending on the engine speed so as to reduce engine emissions.

Abstract: In a method of operating a reciprocating-piston internal combustion engine with a combustion chamber in which a fuel mix with fresh gas is provided via intake ports and combustion exhaust gases are discharged through exhaust ports which can be opened by intake valves and, respectively, exhaust valves which are actuated by a valve operating mechanism, wherein an operating mode with external ignition, in which the fuel mix is ignited by a spark plug, is provided in part of the load range of the internal combustion engine, and an operating mode with compression ignition, in which the control of the gas exchange valves is altered so as to retain combustion exhaust gases in the combustion chamber for participation in the formation of the fresh mix is provided in another load range of the internal combustion engine, during a change in the operating mode the valve lift of at least one of the gas exchange valves is altered.

Abstract: In a method for operating an internal combustion engine in which the fuel is injected into a combustion chamber of a pre-injection and a main injection quantity, the quantity of fuel for the pre-injection, which is selected depending on the combustion location, is injected before the top dead center of the gas exchange, and the fuel for the main injection is injected synchronously with the induction of the air. The method is used in connection with internal combustion engines, in particular for passenger and commercial motor vehicles.

Abstract: In a method of operating a supercharged internal combustion engine in which exhaust gas is retained in the combustion chamber during a charge change, wherein the engine is operated with compression ignition or with spark ignition depending on the operating point and in which a charge pressure can be established for the fresh air supplied to the combustion chamber, and the exhaust gas is compressed during the charge change, and a first fuel quantity is optionally injected into the retained exhaust gas and a second fuel quantity is subsequently supplied to the combustion chamber, such that a homogeneous fuel/air mixture is formed in the combustion chamber, the retained exhaust gas quantity in the combustion chamber is corrected in such a way that the center of the combustion is displaced in the direction toward a set point value when the center of the combustion deviates from the set point value because of a change in the charge pressure of the fresh air or because of a change in the temperature of the fresh ai

Abstract: In a method of operating an internal combustion engine in which exhaust gas is retained in the combustion chamber of the internal combustion engine and compressed during a charge change together with fresh combustion air, a first fuel quantity is injected into the retained exhaust gas by means of direct fuel injection, a second fuel quantity is subsequently supplied to the combustion chamber together with the fresh combustion air so that a homogeneous fuel/gas/air mixture is formed in the combustion chamber, and an auto-ignition time of the fuel/gas/air mixture is established as a function of a quantity ratio of the first fuel quantity and the second fuel quantity.