Patent ID: 7698888

Claim:
An internal combustion engine comprising: an exhaust system comprising a diesel particulate filter (DPF) for trapping burnable particulates in engine exhaust passing through the exhaust system; a control system comprising a processor for processing certain data relevant to calculating particulate loading of the DPF and for causing the creation of conditions that result in particulates trapped in the DPF being burned off when the processing of the certain data relevant to calculating particulate loading of the DPF calculates a valid data value for particulate loading that discloses a need for burning off trapped particulates; wherein the processor comprises an algorithm that, when executed to calculate particulate loading of the DPF a) calculates a derivative with respect to time of pressure across the DPF and a derivative with respect to time of rate of flow through the DPF, b) processes both of the calculated derivatives for compliance with a defined relationship between the two establishing validity of calculated particulate loading, and c) conditions validity of calculated particulate loading on disclosure of such compliance by the processing of the calculated derivatives.