Abstract: A device having a monitoring circuit for a knock control and a control circuit which initiates substitute measures in the event of a fault in the knock control, depending on the output signal of the monitoring circuit, is described. The control unit is designed, for example, so that the number of fuel injection operations per operating cycle of a cylinder of the engine is increased as the substitute measure.

Abstract: A method for operating an internal combustion engine and a corresponding device are described in which a combustion of a fuel in a fuel-air mixture introduced into a cylinder occurs in at least one cylinder. At least one adjusting device is used to influence at least one physical process, which modifies the distribution of the constituents and/or the overall composition of the fuel-air mixture in the at least one cylinder. If knock occurs, a knock control is used to gradually retard an ignition angle in the at least one cylinder from a fundamental ignition angle by an adjustment angle. When the adjustment of the at least one adjusting device exceeds a specifiable first threshold and/or the change in the at least one physical process exceeds a specifiable second threshold, the adjustment angle is rapidly reduced by increments, the more rapid reduction occurring with a larger increment and/or with a higher frequency of increments.

Abstract: A device having a monitoring circuit for a knock control and a control circuit (10) which initiates substitute measures in the event of a fault in the knock control, depending on the output signal (f) of the monitoring circuit, is described. The control unit is designed, for example, so that the number of fuel injection operations per operating cycle of a cylinder of the engine is increased as the substitute measure.

Abstract: A method for operating an internal combustion engine and a corresponding device are described in which a combustion of a fuel in a fuel-air mixture introduced into a cylinder occurs in at least one cylinder. At least one adjusting device is used to influence at least one physical process, which modifies the distribution of the constituents and/or the overall composition of the fuel-air mixture in the at least one cylinder. If knock occurs, a knock control is used to gradually retard an ignition angle in the at least one cylinder from a fundamental ignition angle by an adjustment angle. When the adjustment of the at least one adjusting device exceeds a specifiable first threshold and/or the change in the at least one physical process exceeds a specifiable second threshold, the adjustment angle is rapidly reduced by increments, the more rapid reduction occurring with a larger increment and/or with a higher frequency of increments.

Abstract: A method for knock control during KC emergency operation with which, given low application expenditure, a torque gain can be attained, while the application reliability increases. The method for knock control of multi-cylinder internal combustion engines having 2n cylinders, a cylinder counter, at least one knock sensor and an evaluation unit for evaluating the knock-sensor signal with the aid of an individual knock-recognition characteristic for each cylinder, is characterized in that during KC emergency operation, cylinder pairs are formed from the cylinders operating offset in each case by 360°, and the minimal value of the two knock-recognition characteristics of the cylinder pair is assumed in each case as the knock-recognition threshold for the cylinders of the cylinder pair affected by the malfunction of the phase recognition.

Abstract: A method for knock control during KC emergency operation with which, given low application expenditure, a torque gain can be attained, while the application reliability increases. The method for knock control of multi-cylinder internal combustion engines having 2n cylinders, a cylinder counter, at least one knock sensor and an evaluation unit for evaluating the knock-sensor signal with the aid of an individual knock-recognition characteristic for each cylinder, is characterized in that during KC emergency operation, cylinder pairs are formed from the cylinders operating offset in each case by 360°, and the minimal value of the two knock-recognition characteristics of the cylinder pair is assumed in each case as the knock-recognition threshold for the cylinders of the cylinder pair affected by the malfunction of the phase recognition.