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.

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.

A method for extracting characterizing features from an ion current trace retrieved from spark plugs of cylinders of an internal combustion engine, comprises the steps of: i. dividing the ion current signal into crank angle subintervals; 5 ii. calculating a measure of ion current in each crank angle subinterval; and iii. Performing a calculation on the measure of ion currents from different subintervals such that the result of the calculation is dimension free. Further it relates to a method of monitoring combustion processes where a plurality of ion current signals from a number of spark plugs (4A, 4B) are 10 retrieved and used in combination.

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.

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.

An ignition timing control device includes bandpass filters each configured to pass and output only a specific frequency band for the output value of a knocking sensor, a storage device storing first learned neural networks configured to receive the output values of the bandpass filters in respective frequency band, and a processor. Each of the first learned neural networks is pre-learned to output an estimated value for a value representing knocking intensity when receiving the filtered output value of the bandpass filter. The processor calculates an optimal estimated value using a part of acquired estimated values for the value excluding a unique estimated value, and executes retarding control of an ignition timing based on the calculated optimal estimated value.

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 knock 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.

An ignition timing control device includes bandpass filters each configured to pass and output only a specific frequency band for the output value of a knocking sensor, a storage device storing first learned neural networks configured to receive the output values of the bandpass filters in respective frequency band, and a processor. Each of the first learned neural networks is pre-learned to output an estimated value for a value representing knocking intensity when receiving the filtered output value of the bandpass filter. The processor calculates an optimal estimated value using a part of acquired estimated values for the value excluding a unique estimated value, and executes retarding control of an ignition timing based on the calculated optimal estimated value.

A method and a device for knock control of an internal combustion engine, a knock signal of a cylinder of the internal combustion engine being measured by a knock sensor and, on the basis thereof, a knock intensity is generated. The knock intensity is compared to a reference level in order to classify a combustion as a knocking or non-knocking combustion. Moreover, an arrangement is provided, which takes the level of the knock intensity into account for the determination of the reference level.

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.