Method for managing pinking in a controlled-ignition internal combustion engine

A method for managing knock in a cylinder of an internal combustion engine, the method being implemented in a system comprising at least one acoustic sensor and a processor, the method being intended to take into account acoustic pollution resulting from a known repeatable parasitic noise of variable temporal position, the method comprising:

• forming and digitizing signals delivered by the acoustic sensor,
• applying a bandpass filter in order to preserve only a frequency range of interest for knock, in a filtered noise,
• determining an adjustable gain-correction function using a gain-correction curve, intended to decrease the influence of the parasitic noise,
• determining, depending on an angular position of an end of injection, a point on the gain-correction curve to be used to convert the filtered noise into a corrected knock score,
• comparing corrected knock score thus obtained to a knock decision threshold,
• deducing therefrom an ignition timing advance correction value to be applied in the next cycle,
• wherein the gain-correction curve is defined by a calibration value (Gin) and four angular points (A, B, C, D), said four angular points being obtained by calculating, based on the start and end positions (WS1, WS2) of a knock-observation window and at least one known characteristic of the noise, the calibration value (Gin) being a gain value at which the decrease is the greatest representing a bottom plateau of the gain-correction curve between the second and third angular points (B, C), and the gain-correction curve taking the value 1 for points prior to the first angular point (A) and for points subsequent to the fourth angular point (D).