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

System for activation (1) of the regeneration of a particulate filter for a motor vehicle engine, comprising:

• calculation means (2–7) which can calculate an estimated value (xM) of a quantity of particulate accumulated in the said particulate filter;
• comparator means (8) which can compare the said estimated value (xM) with a threshold value (mTH) corresponding to a predetermined maximum quantity of particulate;
• regeneration activator means (9) which are enabled by the said comparator means (8) if the said threshold value (mTH) is exceeded by the said estimated value (xM);
• characterised in that the said calculation means (2–7) comprise:
• first estimator means (3) which can estimate a first quantity of particulate (xMS) accumulated in the said particulate filter by means of a statistical model based on experimental data;
• second estimator means (2) which can estimate a second quantity of particulate (xMF) accumulated in the said particulate filter by means of a physical model using physical values measured;
• determination means (4, 6) which can determine a field of admissibility on the basis of the said first quantity of particulate (xMS);
• limiter means (5, 7) which can compare the said estimated value (xM) with the said second quantity of particulate (xMF), if the said second quantity of particulate (xMF) is within the said field of admissibility, and can limit the said estimated value when the said second quantity of particulate (xMF) is outside the said field of admissibility.