Abstract: A method for operating an internal combustion engine having a cylinder, an intake valve, an air pipe, and a valve element disposed in the air pipe, includes detecting a signal for causing a fuel supply of the cylinder to switch off. The valve element is moved out of a first position into a second position triggering a lower flow cross-section while the fuel supply is still activated, where a first cam for actuating the intake valve is allocated to the intake valve. While the fuel supply is still activated, switching from the first cam to a second cam and via the second cam the intake valve is actuated such that the intake valve causes a reduced air intake. An exhaust cam shaft for actuating an exhaust valve is set in an advance direction such that a valve intersection of the intake valve and of the exhaust valve ceases.

Abstract: A method for operating an internal combustion engine having a cylinder, an intake valve, an air pipe, and a valve element disposed in the air pipe, includes detecting a signal for causing a fuel supply of the cylinder to switch off. The valve element is moved out of a first position into a second position triggering a lower flow cross-section while the fuel supply is still activated, where a first cam for actuating the intake valve is allocated to the intake valve. While the fuel supply is still activated, switching from the first cam to a second cam and via the second cam the intake valve is actuated such that the intake valve causes a reduced air intake. An exhaust cam shaft for actuating an exhaust valve is set in an advance direction such that a valve intersection of the intake valve and of the exhaust valve ceases.

Abstract: A method for operating an exhaust gas purification system of an internal combustion engine, which can be operated in a lean operating mode and in a rich operating mode, is disclosed. The exhaust gas purification system has, arranged one after the other in the direction of flow of the exhaust gas, an ammonia-forming catalyst, a first exhaust gas sensor, an ammonia-SCR catalyst, a nitrogen oxide storage catalyst and a second exhaust gas sensor. Exhaust gas sensors emit a first signal correlating with the nitrogen oxide content of the exhaust gas and a second signal correlating with the lambda value of the exhaust gas. In diagnostic operation, the ammonia storage capacity of the ammonia-SCR catalyst and the oxygen and optionally the nitrogen oxide storage capacity of the nitrogen oxide storage catalyst can be determined by analyzing the signals of the first and second exhaust gas sensors.

Abstract: In order to determine the conversion efficiency of at least one component of a catalytic converter box comprising at least one SCR catalytic converter and an oxides of nitrogen storage catalytic converter for the aftertreatment of the exhaust gases of an internal combustion engine, wherein the catalytic converter box is associated at the downstream end with a NOx sensor, at least for a limited period of time the internal combustion engine is operated such that a first of the two components does not affect the signal detected by means of the NOx sensor and the conversion efficiency of the second component is determined depending on the signal of the NOx sensor that is not affected by the first component.

Abstract: A method for operating an exhaust gas purification system of an internal combustion engine, which can be operated in a lean operating mode and in a rich operating mode, is disclosed. The exhaust gas purification system has, arranged one after the other in the direction of flow of the exhaust gas, an ammonia-forming catalyst, a first exhaust gas sensor, an ammonia-SCR catalyst, a nitrogen oxide storage catalyst and a second exhaust gas sensor. Exhaust gas sensors emit a first signal correlating with the nitrogen oxide content of the exhaust gas and a second signal correlating with the lambda value of the exhaust gas. In diagnostic operation, the ammonia storage capacity of the ammonia-SCR catalyst and the oxygen and optionally the nitrogen oxide storage capacity of the nitrogen oxide storage catalyst can be determined by analyzing the signals of the first and second exhaust gas sensors.

Abstract: In a method for determining a type of air-fuel mixture error of a cylinder of an internal combustion engine of a motor vehicle, wherein a torque parameter (M1) of the cylinder is ascertained, a lambda parameter (?1) of the cylinder is ascertained, a torque reference parameter and a lambda reference parameter are ascertained, as a function of a comparison of the torque parameter (M1) with the torque reference parameter and as a function of a comparison of the lambda parameter (?1) with the lambda reference parameter, the type of air-fuel mixture error is indicated to be a fuel path error or to be an air path error.

Abstract: In a method for determining the charge of an activated carbon container of a tank venting system of a gasoline engine on the basis of the thermal influence of the tank venting system on the exhaust gas of the engine, an exhaust gas temperature measured downstream of a catalytic converter of the engine with the tank venting system activated is compared with a calculated or measured exhaust gas temperature obtained for the same location with the tank venting system inactivated and divided by the exhaust gas temperature measured with the tank venting system activated so as to obtain a temperature quotient on the basis of which the charge of the carbon container is determined.

Abstract: In a method for determining the charge of an activated carbon container of a tank venting system of a gasoline engine on the basis of the thermal influence of the tank venting system on the exhaust gas of the engine, an exhaust gas temperature measured downstream of a catalytic converter of the engine with the tank venting system activated is compared with a calculated or measured exhaust gas temperature obtained for the same location with the tank venting system inactivated and divided by the exhaust gas temperature measured with the tank venting system activated so as to obtain a temperature quotient on the basis of which the charge of the carbon container is determined.

Abstract: A four-stroke reciprocating-piston internal combustion engine includes a fuel injection device, which is arranged centrally in a combustion space and which introduces the fuel in the form of an injection cone into the combustion space, and includes at least one spark plug for each combustion space, the electrodes of which spark plug are arranged at the edge of the injection cone. At least two spark plugs are provided, of which the second spark plug has a markedly higher spark gap than the first spark plug.

Abstract: In a method for detecting knocking combustion during the operation of an internal combustion engine with a device for measuring the ionic current, the raw ionic current signal or the evaluated value of the knocking intensity are normalized. This enables the value of the knocking intensity to be reliably compared with a threshold value. The normalization avoids the falsifying influence of large intensity fluctuations of the raw ionic current signal from one combustion cycle to the next without any relation to the true knocking intensity.

Abstract: A four-stroke reciprocating-piston internal combustion engine includes a fuel injection device, which is arranged centrally in a combustion space and which introduces the fuel in the form of an injection cone into the combustion space, and includes at least one spark plug for each combustion space, the electrodes of which spark plug are arranged at the edge of the injection cone. At least two spark plugs are provided, of which the second spark plug has a markedly higher spark gap than the first spark plug.

Abstract: A method for determining the air/fuel ratio in an internal combustion engine combustion chamber having at least two ignition plugs spaced apart from one another. Ion-current measurement is carried out during successive operating cycles, wherein a first ignition plug is operated as an ion-current sensor and does not release ignition energy. The time of arrival at the first ignition plug of a flame front formed at the ignition point of a second ignition plug, is detected. The detected time of arrival of the flame front, the ignition point and the ignition-plug spacing are used to determine the speed of the flame and, from this, the air/fuel ratio is determined as a function of the speed and/or load of the internal combustion engine.

Abstract: A process and apparatus for determining the breakdown voltage in the case of an ignition of a vehicle is provided. The breakdown point in time is detected and the breakdown voltage is determined based on the breakdown point in time.

Abstract: A method is provided for determining the ion component following a combustion process in a self-igniting internal combustion engine. At least two electrodes are located inside at least one cylinder, to which electrodes an electrical voltage can be applied, with the voltage being an AC voltage or having an AC voltage component.

Abstract: The present invention relates to a method for detecting knocking combustion during the operation of an internal combustion engine with a device for measuring the ionic current, in which the raw ionic current signal or the evaluated value of the knocking intensity are normalized, which enables the value of the knocking intensity to be reliably compared with a threshold value.

Abstract: A method and an apparatus for detecting knocking combustion in an internal combustion engine, by evaluating the ionic current signal sensed in the combustion chamber, is especially adapted to correct or compensate the ionic current signal for longterm variations arising therein, for example due to variations in the composition of the fuel as a result of contamination with metallic components or the like. Thereby, erroneous knock recognition is prevented. To achieve this, a frequency-filtered time-sampled knocking component integral of the ionic current signal generated in the present combustion cycle is multiplied by a correction value determined from at least one integral value of the ionic current signal generated during at least one prior combustion cycle.

Abstract: The present invention relates to a method for determining the running smoothness of an Otto spark ignition engine by measuring the ionic current (I) in at least one combustion chamber of the Otto spark ignition engine. Once the spark plug has fired, a measuring voltage is applied to the spark plug, inducing the ionic current (I). Following each ionic current measurement, initially an active, average ionic-current value (IM) is defined, and a running-smoothness value (L) is subsequently determined from a reference value and the ionic-current average value (IM).

Abstract: A process for recognizing ignition failures in an internal-combustion engine which has two spark plugs per cylinder, based on a measurement of the ionic current at the spark plugs. In this process, the ionic current signals of the two spark plugs are each integrated using an assigned integrator over an entire combustion cycle and the integrator values are compared with one another. Since, in the case of a defective spark plug, an ionic current signal will occur only some time after the ignition (specifically after the arrival of the flame from the ignited spark plug), its integration value is significantly lower than that of the intact spark plug. From this information, the correct operation of the spark plugs is determined.

Abstract: A method for detecting flow-reducing changes in an exhaust-gas catalyst body is provided. The method includes measuring the ion-current signal from an ion-current probe in an internal combustion engine and monitoring the signal to determine whether its signal strength for a particular operating cycle falls below a minimum strength which can be specified as a function of the engine operating state. The method also include providing warning information to the control system when such an event occurs. The method further includes a variety of embodiments used to determine whether the ion current signal falls below a minimum strength.

Abstract: A method for operation of a direct-injection spark-ignition internal combustion engine operated over large areas of the characteristics map with stratified charge by way of fuel injection during the compression stroke. In order to guarantee reliable mixture ignition and combustion, the method of the present invention provides an ignition system which generates alternating voltage so that high voltage rapidly builds up between the electrodes of a spark plug, and generates ignition sparks with a spark duration that can be defined as a function of operating point.