METHOD OF ESTIMATING THE INSTANTANEOUS ENGINE SPEED PRODUCED BY EACH CYLINDER OF AN INTERNAL-COMBUSTION ENGINE

The invention is a method for real-time estimation of the instantaneous engine speed produced by each cylinder of an internal-combustion engine, from an instantaneous engine speed measurement at the end of the engine transmission system. A physical model, representing in real time the dynamics of the transmission system according to the crankshaft angle and to coefficients of a Fourier series decomposition of the instantaneous speed produced by each cylinder, is constructed. These coefficients are determined in real time from coupling between the model and an adaptive type non-linear estimator. The instantaneous speed produced by each cylinder is then deduced from these coefficients. The mean torque produced by each cylinder can also be deduced therefrom. An application is: engine controls.