METHOD FOR ESTIMATING AND CONTROLLING THE INTAKE EFFICIENCY OF AN INTERNAL COMBUSTION ENGINE

A method is described for determining the mass m of air trapped in each cylinder 2 of an internal combustion engine 1 comprising a given number of cylinders 2, each of which is connected to an intake manifold 4 from which it receives fresh air through an intake valve 5, and to an exhaust manifold 6 into which it introduces the exhaust gases generated by the combustion through an exhaust valve 7. The at least one intake valve 5 is driven to vary the lift H of the intake valve 5 in a controlled manner.The method provides determining, on the basis of a filling model using measured and/or estimated physical quantities, a value for each quantity of a first group of reference quantities comprising at least intake pressure P measured inside the intake manifold 4, engine rotation speed n, mass of gases produced by the combustion in the previous operating cycle (OFF) and present in the cylinder 2, estimated as a function of the lift H and of the closing delay angle IVC of the intake valve depending on the aforesaid lift H.The method then provides determining, based on the aforesaid filling model, the actual inner volume V of each cylinder 2 as a function of said engine rotation speed n, of the lift H of the intake valve and of the closing delay angle IVC of the intake valve.The method finally provides determining the mass m of air trapped in each cylinder 2 as a function of the first group of reference quantities and of the actual volume V inside each cylinder 2, on the basis of the aforesaid quantities P, V, OFF.