Method for the acquisition and processing of an intake pressure signal in an internal combustion engine without an intake manifold

摘要

Method of acquisition and processing of an intake pressure signal in an internal combustion engine (1) without an intake manifold,; the internal combustion engine (1) having at least one cylinder (2) that receives fresh air through an intake duct (3), which is controlled by a butterfly valve (7) and is provided with a pressure sensor (9) connected to an electronic control unit (8). To determine the atmospheric pressure when the internal combustion engine (1) is running and the butterfly valve (7) is not completely open the following steps are performed: determining a start angle and an end angle of a measurement window (W) dependent on the engine speed; measuring, via the pressure sensor (9), the instantaneous induction pressure at a plurality of different crank angles distributed in the measurement window (W); determining a compensation factor dependent on the engine speed and the position of the butterfly valve (7); and determining the atmospheric pressure by applying the compensation factor to the mean of the instantaneous induction pressures measured in the measurement window (W).