Method of estimation by an adaptive nonlinear filter wealth in a cylinder of a combustion engine

- The present invention relates to a method for estimating the richness in each cylinder of an injection internal combustion engine having an exhaust circuit on which a sensor measures the richness of the exhaust gases. An estimator based on an adaptive non-linear filter is coupled with a physical model representing the ejection of gas cylinders and their path in the exhaust circuit to the sensor. The estimator is also coupled with an estimation of the richness measured from at least one variable of said model, such that the total mass of exhaust gas and air mass frais.- Application to engine controls.