A method and a device are provided for controlling an internal combustion engine, a knock sensor being provided for acquiring combustion signals of the internal combustion engine. Devices are also provided that, during running operation of the internal combustion engine, select operating ranges of the internal combustion engine that are suitable for a determination of fuel quality, and carry out a determination of the fuel quality in these ranges on the basis of signals of the knock sensor.

Methods and systems are disclosed for operating an engine that includes a knock control system. The methods and system provide for repurposing the engine knock control system to detect and mitigate piston slap. The methods and systems also seek to increase the signal to noise ratio for detecting piston slap.

Methods and systems are disclosed for operating an engine that includes a knock control system that may determine contributions of individual noise sources to an engine background noise level. The contributions of the individual noise sources may be the basis for establishing the presence or absence of knock in one or more engine cylinders.

A method and a device for controlling knocking in an internal combustion engine. A knock signal of a cylinder of the internal combustion engine is measured by a knock sensor and from that, a knock feature is generated. The knock feature is compared to a reference level in order to classify a combustion as a knocking or non-knocking combustion. The reference level is formed in consideration of a plurality of corrected knock features, the corrected knock features being formed from the knock features by determining map values from a program map as a function of operating parameters of the internal combustion engine and linking them additively, or by carrying out a low-pass filtering, or by determining map values from a program map as a function of operating parameters of the internal combustion engine and linking them additively and carrying out a low-pass filtering.

An internal-combustion-engine control unit and control method are provided that can prevent an excessive ignition-timing retard while occurrences of knocking are suppressed. An internal-combustion-engine control unit that controls an internal-combustion engine, the internal-combustion-engine control unit including: a knock-occurrence-frequency sensing section that senses a knock occurrence-frequency of a cylinder; and a cylinder-wall-temperature computing section that computes a wall temperature of the cylinder on a basis of the knock occurrence-frequency sensed at the knock-occurrence-frequency sensing section.

A method for operating an internal combustion engine. The method includes detecting a structure borne sound signal in a time-dependent manner for the at least one combustion chamber during operation of the internal combustion engine, and determining, in a predetermined measuring window, at least one evaluation parameter from the detected structure borne sound signal. The method also includes obtaining at least one comparative result by comparing the at least one evaluation parameter with at least one predetermined comparison value, and assigning to the structure borne sound signal, on the basis of the at least one comparative result, one of a knocking event in the at least one combustion chamber and an interference signal.

An internal combustion engine according to one or more embodiments of the present disclosure may include an engine cylinder having a cylinder head and cylinder sidewalls and a piston that reciprocates within the engine cylinder. The piston, the cylinder head, and the cylinder sidewalls may at least partially define a combustion chamber. The internal combustion engine may also include a fuel injector that is positioned to inject fuel directly into the combustion chamber. The internal combustion engine may further include an engine control module that is in electronic communication with the fuel injector. The engine control module may determine if the internal combustion engine is operating at conditions corresponding to a super knock condition may occur and commands the fuel injector to operate under a split injection mode in which fuel is injected into the combustion chamber in a plurality of injection pulses.

According to one or more embodiments presently described, a method of operating an internal combustion engine that includes injecting fuel into a combustion chamber to form an air-fuel mixture, where the combustion chamber includes a cylinder head, cylinder sidewalls, and a piston that reciprocates within the cylinder sidewalls. The method may also include detecting pre-ignition of the air-fuel mixture during a detected intake or compression stroke of the piston, determining that a super knock condition could occur, and mitigating formation of a super knock condition by deploying a super knock countermeasure within the detected compression stroke.

In one embodiment, a method is provided. The method includes receiving a signal representative of an engine vibration transmitted via a knock sensor, wherein the knock sensor is disposed in an engine. The method additionally includes deriving a valve wear measurement during operation of the engine based on the signal. The method further includes communicating the valve wear measure.

Methods and systems are disclosed for operating an engine that includes a knock control system that may determine contributions of individual noise sources to an engine background noise level. The contributions of the individual noise sources may be the basis for establishing the presence or absence of knock in one or more engine cylinders.