Cylinder individual torque correction

摘要

It is described a method to cause the torques produced by each cylinder (10) of a multi-cylinder internal combustion engine to be substantially equal, said engine including a rotatable crankshaft (20) being driven by combustions in combustion chambers (12, 14) of said cylinders, wherein a pressure in each of said combustion chambers (12, 14) is measured and an amount of torque produced by each of said cylinders is determined based on the pressure measurements, wherein further the pressure is measured intermittently in sample steps (j), thus generating pressure sample value (p j ) for each sample step (j) determining a value (V' j ) of a change of the cylinder's combustion chamber volume for each sample step and a torque value (T) each cylinder produces during a certain rotation angle (”±) of the crankshaft (20) is calculated by multiplying each pressure sample value with the respective volume change value and by summing up all such obtained products and multiplying the result of the sum by ”±/4À.