Method for operating an internal combustion engine

摘要

Disclosed is a method for operating an internal combustion engine 110. The internal combustion engine 110 comprises an engine block 120 defining cylinders 125-128, each of which accommodates a reciprocating piston 140 to rotate a crankshaft 145. The method provides for every engine cy­linder 125-128 the steps of performing a fuel injection in the engine cylinder, determin­ing a value of a combustion parameter indicative of a crankshaft angular position at which a predetermined quantity of the injected fuel has burnt in a current engine cycle, such as the point at which 50% of the mass of fuel has been burnt. An error is calculated between a target value of the combustion parameter for a next engine cycle and the determined value. A correction term is calculated and the method adjusts a value of a parameter of the fuel injection for the next engine cycle on the basis of the error. The combustion parameter value for one or more of the engine cylinders is measured by an in cylinder pressure sensor 360. located in each of them. The combustion parameter value for at least one of the remaining engine cylinders, which does not have a pressure sensor, is estimated as a function of a target value of the combustion parameter for the current engine cycle, and of the last errors calculated for the engine cylinders provided with the in cylinder pressure sensor 360.