Abstract: A method for detection of abnormal combustion for internal combustion engines is disclosed. A physical model is chosen that describes, as a function of the angle ? of rotation of the engine crankshaft, the development of pressure in the cylinder during combustion without any pre-ignition phenomenon. The cylinder pressure Pe(?) is estimated using this model and the intake pressure is measured. The beginning of abnormal combustion is detected by comparing a first value of a variable calculated using the measurement of the cylinder pressure, to a second value of the variable calculated using the estimation of the cylinder pressure. The amplitude of the pre-ignition is determined by repeating these steps for a defined number of crankshaft angles. Then the progress of the abnormal combustion detected in the combustion chamber is controlled as a function of the amplitude of the pre-ignition phenomenon.

Abstract: 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.

Abstract: 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.

Abstract: A method for detection of abnormal combustion for internal combustion engines is disclosed. A physical model is chosen that describes, as a function of the angle a of rotation of the engine crankshaft, the development of pressure in the cylinder during combustion without any pre-ignition phenomenon. The cylinder pressure Pe(?) is estimated using this model and the intake pressure is measured. The beginning of abnormal combustion is detected by comparing a first value of a variable calculated using the measurement of the cylinder pressure, to a second value of the variable calculated using the estimation of the cylinder pressure. The amplitude of the pre-ignition is determined by repeating these steps for a defined number of crankshaft angles. Then the progress of the abnormal combustion detected in the combustion chamber is controlled as a function of the amplitude of the pre-ignition phenomenon.

Abstract: A method for determining as a function of time the angle of rotation of a crankshaft by estimating the position of missing teeth on a target wheel is disclosed which has application to engine control. A sensor acquires, as a function of time, a periodic signal comprising a pulsating waveform, each pulse indicating the passage of a tooth past this sensor.

Abstract: A method for determining as a function of time the angle of rotation of a crankshaft by estimating the position of missing teeth on a target wheel is disclosed which has application to engine control. A sensor acquires, as a function of time, a periodic signal comprising a pulsating waveform, each pulse indicating the passage of a tooth past this sensor.