Patent ID: 8464521

Claim:
A method for estimating soot loading in a DPF, comprising: measuring a pressure drop across the DPF; providing an estimate of soot mass loading in the DPF to a recursive filter, the estimate of soot mass loading comprising a first component determined as a function of the measured pressure drop across the DPF and assuming uniform soot mass distribution and a second, modeled non-uniform soot mass distribution component determined as a function of soot reaction rate and exhaust gas flow velocity in the DPF; and using the recursive filter, updating the estimate of soot mass loading in view of the measured pressure drop to provide an updated estimate of soot mass loading in the DPF; at least periodically measuring the pressure drop across the DPF, and at least periodically updating the updated estimate of soot mass loading in view of the at least periodic pressure drop measurements to generate a. plurality of updated estimates of soot mass loading and calculating a standard deviation of the plurality of updated estimates of soot mass loading; and triggering regeneration when the updated estimate of soot mass loading plus the standard deviation, or a function of the estimated error, of the plurality of updated estimates of soot mass loading exceeds a predetermined value.