METHOD OF ESTIMATING MASS EMERGED IN THE COMBUSTION CHAMBER OF A CYLINDER OF A MOTOR VEHICLE INTERNAL COMBUSTION ENGINE

摘要

Method of estimating the mass enclosed in the combustion chamber of a cylinder of a motor vehicle internal combustion engine, equipped with a means of measuring the pressure in the cylinder, with a means of measuring the angle of the crankshaft with respect to a reference position and of measuring the temperature of the combustion chamber cooling liquid. The method comprising steps during which the rotational speed of the engine is determined from the measurement of the crankshaft angle and the engine load is determined. The method also comprises the following steps: when the valves of the cylinder are completely closed and before fuel is first injected, the volume of the cylinder is determined as a function of the angle of the crankshaft, calibration parameters connected with the heat losses at the walls are determined from a map dependent on engine rotational speed, the temperature modelled in the cylinder is determined using a non-linear dimensionless model of the pressure and the temperature in the combustion chamber as a function of the measured pressure in the cylinder, of the specific gas constant for the gases in the cylinder, of the specific heat capacity at constant volume of the gases in the cylinder, of the volume of the combustion chamber, and of calibration parameters connected with the heat losses at the walls, and the mass enclosed in the cylinder is determined.