Method for activation of the regeneration of a particulate filter based on an estimate of the quantity of particulate accumulated in the particulate filter

Method for activation of the regeneration of a particulate filter for a motor vehicle engine, comprising the steps of calculating an estimated value (xM) of a quantity of particulate accumulated in the particulate filter; comparing (8) the estimated value (xM) with a threshold value (mTH) corresponding to a predetermined maximum quantity of particulate; and activating the regeneration (9) if the estimated value (xM) exceeds the threshold value (mTH) . The step of calculating an estimated value (xM) comprises the steps of estimating a first quantity of particulate (xMS) accumulated in the particulate filter by means of a statistical model (3) based on experimental data; estimating a second quantity of particulate (xMF) accumulated in the particulate filter by means of a physical model (2) using physical quantities measured; determining a field of admissibility on the basis of the first quantity of particulate (xMS); comparing the estimated value (xM) with the second quantity of particulate (xMF) if the second quantity of particulate (xMF) is within the field of admissibility; and limiting the estimated value (xM) if the second quantity of particulate (xMF) is outside the field of admissibility.