Ifp Energies Nouvelles

Benoist Thirouard

Alexandre Pagot

Laurent Duval

Jean-Marc Zaccardi

Dominique Auclair

An abnormal combustion detection method for spark-ignition internal-combustion engines, from combustion indicator distribution modelling is disclosed. At least one combustion indicator such as CA10 is determined. The distribution of N values of this indicator, acquired over N cycles preceding the cycle in progress, is modelled by determining coefficients of a theoretical distribution law. Modelling is repeated by removing extreme values from among the N values or for various working points of the engine, to obtain an evolution of the coefficients. At least one parameter characterizing evolution of at least one of these coefficients is determined. The start of an abnormal combustion is detected by comparing the parameter with a predetermined threshold, and the course of the abnormal combustion detected in the combustion chamber is controlled.

Abnormal combustion detection method for internal-combustion engines from combustion indicator distribution modelling

An abnormal combustion detection method is disclosed for spark-ignition internal-combustion engines, from combustion indicators. Combustion indicators, such as CA10 and MIP, are determined which are converted to new indicators having lower dispersions than those of indicators for normal combustions that are not converted. A parameter characterizing a distribution of N values of the new combustion indicators, acquired over N cycles preceding the cycle in progress, is then determined. The start of an abnormal combustion is thereafter detected by comparing this parameter with a threshold, and the course of the abnormal combustion detected in the combustion chamber is controlled.

Abnormal combustion detection method for internal-combustion engines from several combustion indicators

The invention is an abnormal combustion detection method for spark-ignition internal-combustion engines. For each engine cycle, a parameter characterizing a distribution of N combustion indicator values, CA10 for example, acquired over N cycles preceding the cycle in progress, is determined while ignoring extreme values. A threshold is defined from this parameter for the combustion indicator. The start of an abnormal combustion is then detected by comparing the combustion indicator with this threshold and the course of the abnormal combustion detected in the combustion chamber is controlled.

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Rueil Malmaison, France

Benoist Thirouard