Patent ID: 8170774

Claim:
A method for determining and putting in a quantity of fuel, on the basis of predetermined sinusoidal target signal of Lambda into an internal combustion engine equipped with a plurality of cylinders, injectors, an ionization current generating device for each cylinder and a control unit suitable to determine the Lambda value in each cylinder using the ionization current, wherein said method comprises: measurement of the Lambda values in each cylinder of said engine during an interval of time (T) (Cylinder Lambda) and supply of the signal therefore to the control unit; calculation of the average of the Cylinder Lambda values over all the cylinders of said engine (Average Lambda) and supply of the signal therefore; application of a low-pass filter to the Average Lambda signal (Filtered Average Lambda signal); application of a low-pass filter to the predetermined sinusoidal target signal of Lambda (Filtered Target Lambda signal); calculation of the difference between Filtered Average Lambda signal and Filtered Target Lambda signal (Error Lambda) and supply of the signal therefore; calculation of the known mathematical integral of Error Lambda, multiplied by a value between 0.01 and 1 (Lambda Correction) and supply of the signal therefore; calculation of the sum of the predetermined sinusoidal target signal of Lambda and Lambda Correction signal (Lambda to Inject signal) and supply of the signal therefore; and determination of the quantity of fuel to put into each cylinder of said engine on the basis of Lambda to Inject signal and supply of the signal therefore to the injectors.