The present invention relates to a method of controlling a positive-ignition internal combustion engine, in which the ignition advance is controlled (CON) by means of an estimation (EST) of the distribution of the knock measurements (MEAS). This estimation (EST) makes it possible to determine, for these measurements (MEAS), a confidence interval (q.sub.min, q.sub.max) of a predetermined quantile of the distribution of the knock measurements (MEAS).

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.

A method for processing a signal of a pressure measuring device inside an internal combustion engine, the device including: a pressure measuring sensor supplying an output voltage signal (S.sub.B), and a processing unit connected to the pressure measuring sensor, the method including the following steps: I. calculating a duration (Dt1) between a first time (t0) corresponding to a first combustion pressure peak (P0) and a second time (t1) corresponding to a second combustion pressure peak (P1), consecutive to the first combustion pressure peak (P0), II. calculating a correction start time (t.sub.c1) defined according to the previously calculated duration (Dt1), III. measuring a value of the signal (V.sub.OFF1) at the correction start time (t.sub.c1), IV. correcting the signal, on the basis of the correction start time (t.sub.c1) in relation to a reference value (V.sub.REF) and obtaining a first processed signal (S) such that:
S=S.sub.BV.sub.OFF1+V.sub.REF.

A system for project planning for an engine for determining an operating behavior of the engine to be expected under defined operating conditions of the engine includes: a plurality of sensors configured to measure respective ones of the defined operating conditions of the engine; and a knocking intensity prediction tool configured to determine the knocking intensity of the engine to be expected under the defined operating conditions of the engine.

The invention provides a method for determining ignition quality in a fuel, the method including compressing a stoichiometric fuel mixture from a first pressure and temperature to a second temperature and temperature, and measuring the time between the attainment of the second pressure and temperature to auto ignition of the fuel mixture. Also provided is a device for measuring fuel ignition index, the device including a fuel mixture supply; a combustion chamber adapted to receive a stoichiometric fuel-mixture from the fuel-mixture supply; and a system for compressing the fuel mixture within the combustion chamber.

A method and system for monitoring at least one reciprocating machine having a crankshaft and at least one cylinder, comprising providing at least one sensor for monitoring the at least one cylinder, the sensor being in communication with at least one processor configured to measure at least one signal from the at least one sensor and to thereby determine an angular position of the crankshaft; selecting at least one subset of potential crankshaft angular positions; calculating at least one statistic associated with the at least one subset of possible crankshaft angular positions based at least partially on data from the at least one sensor; and automatically providing a user with at least one warning or automatically shutting down the machine if the at least one statistic exceeds at least one predetermined threshold; wherein, the at least one sensor comprises at least one acoustic emission sensor.

A computer-implemented platform may comprise hardware and software configured to manage an engine using knock intensity data. Knock intensities from a plurality of combustion cycles may be used to estimate a statistical distribution of knock intensities. The distribution of knock intensities may be used to determine a Descriptive Statistic, which may represent a state of tune of the engine. A calculated Descriptive Statistic may be compared to a desired Descriptive Statistic (e.g., that is representative of operation during a desired tune state of the engine). A deviation between the calculated and desired knock intensity distributions (e.g., between the calculated DS and desired DS) may be used to adjust a control parameter of the engine. Adjustment may be engine-wide. Adjustment may be cylinder-by-cylinder.

A method and a device are provided for knock recognition of an internal combustion engine, which device Fourier-transforms, weights in frequency-dependent fashion, and sums a signal of a knock sensor in order to produce a first knock signal. Here, from a multiplicity of first knock signals, a concentration point of the multiplicity of the first knock signals is determined, and a first offset value is subtracted from the first knock signal in order to form a second knock signal, the first offset value being ascertained from the concentration point of the multiplicity of the first knock signals, and a second knock signal that has a value below zero being set to the value zero. The further-processed second knock signal is then evaluated as knocking or non-knocking.

A system includes a controller configured to receive noise signals acquired by at least two knock sensors of a plurality of knock sensors coupled to a reciprocating device. Each noise signal represents a noise signature of the reciprocating device detected at a respective knock sensor. The controller is also configured to determine a location of a coincident noise within the reciprocating device based at least on the received noise signals.

A system for project planning for an engine for determining an operating behavior of the engine to be expected under defined operating conditions of the engine includes: a plurality of sensors configured to measure respective ones of the defined operating conditions of the engine; and a knocking intensity prediction tool configured to determine the knocking intensity of the engine to be expected under the defined operating conditions of the engine.