Patent ID: 7357822

Claim:
In a filter control apparatus that estimates an accumulated particulate quantity in a filter for trapping particulates contained in engine exhaust gas and regenerates the filter based on the estimation result, a filter control apparatus that includes detection means for detecting the engine operation status, first estimation means that estimates an accumulated particulate quantity of the filter based on a before and after exhaust-gas differential pressure of the filter, second estimation means that estimates an accumulated particulate quantity of the filter based on the engine operation status, selecting means that selects either of the estimation results of the first and second estimation means in response to the differential calculation means and detection means, and means that, when selecting either of the estimation results of the first and second estimation means, calculates deviation amount between the two estimation results, stores the deviation amount between the two estimation results, stores the deviation amount as a learning value, calculates data for correcting the second estimation means in accordance with the learning value and supplies the data to the second estimation means, and determines regeneration timing of the filter in accordance with the selected estimation result selected by the selecting means.