A method for ignition control in a combustion chamber of an internal combustion engine by means of acquiring an electric signal relating to ionizing currents emitted in said combustion chamber, comprising a step of detecting a substantially stepped trend of said electric signal and a consequent step of inhibiting a corrective action of an ignition advance and/or of a fuel injection limitation curve in the combustion chamber.

An internal combustion engine has at least one cylinder wall forming a cylinder, and at least one knock sensor held on a housing element. The knock sensor is fixed to a fastening point of the housing element. An intermediate chamber is provided in the radial direction of the cylinder between at least one section of the cylinder wall and the fastening point of the housing element arranged on a side of the cylinder wall facing away from the cylinder, a distance extending at least in the radial direction of the cylinder being provided as a result. At least one sound transmission bridge extends in the intermediate chamber, bridging the distance from the cylinder wall continuously to the fastening point, via which vibrations, on the basis of which knocking combustion can be detected by the knock sensor, are transferrable from the cylinder wall to the fastening point.

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 of monitoring an operating event of a combustion engine includes receiving a noise signal sensed by a knock sensor disposed in or proximate to the combustion engine, correlating the noise signal with a musical instrument digital interface (MIDI) fingerprint having at least an ADSR envelope indicative of the operating event, and detecting if the operating event has occurred based on the correlating of the noise signal with the fingerprint.

Systems and methods for estimating an engine event location are disclosed herein. In one embodiment, a control system is configured to receive feedback from at least one vibration sensor coupled to a reciprocating engine, estimate an engine parameter based at least on the feedback and an Empirical Transform Function (ETF), estimate a location of an engine event based on the engine parameter, and adjust operation of the reciprocating engine based at least on the location of the engine event.

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.

A method of controlling an air-fuel ratio in a pre-ignition (PI) situation, may include: monitoring, by a PI detector, whether PI occurs in a cylinder of a plurality of cylinders of an engine; and when the PI occurs in the cylinder of the plurality cylinders, controlling, by a controller, an air-fuel ratio of the cylinder in which the PI occurs to be smaller than a theoretical air-fuel ratio, and controlling an air-fuel ratio of a remaining cylinder of the plurality of cylinders in which PI does not occur to be larger than the theoretical air-fuel ratio.

A method and control device for automatically identifying knocking in an internal combustion engine, wherein, in a predefined measurement time frame, a signal of the knocking sensor is received and evaluated with respect to a criterion for detecting knocking. A basic threshold value predefined for the identification of knocking is modified by a predefined variable interference factor, which depends on a relative point in time at which an inlet valve of at least one of the cylinders closes in relation to a predefined reference point. A signal based on the sensor signal is only identified as knocking if it reaches at least the modified basic threshold value.

The objective of the present invention is to remove drift of a piezoelectric element and thereby obtain a highly precise pressure detection signal by means of a simple configuration. A pressure detection signal processing device 200 includes: a charge amplifier 210 that accumulates electric charge produced by a piezoelectric element 35 in response to a received pressure and outputs a corresponding voltage signal; drift component extraction units 230 and 240 that extract a drift component of the piezoelectric element 35 by performing differential processing on the voltage signal; and a drift correction unit 250 that generates, based on the extracted drift component, a correction signal for removing the drift component and feeds the correction signal back to an input side of the charge amplifier.

The objective of the present invention is to remove drift of a piezoelectric element and thereby obtain a highly precise pressure detection signal by means of a simple configuration. A pressure detection signal processing device 200 includes: a charge amplifier 210 that accumulates electric charge produced by a piezoelectric element 35 in response to a received pressure and outputs a corresponding voltage signal; drift component extraction units 230 and 240 that extract a drift component of the piezoelectric element 35 by performing differential processing on the voltage signal; and a drift correction unit 250 that generates, based on the extracted drift component, a correction signal for removing the drift component and feeds the correction signal back to an input side of the charge amplifier.