Soot burn-off control strategy for a catalyzed diesel particulate filter

摘要

A control system (FIG. 4 ) for controlling regeneration of a DPF comprises a favorable-condition-based control section ( 52 ), a regular control section ( 54 ), and a regeneration termination control section ( 56 ). Section ( 54 ) initiates regeneration when the actual soot loading of the DPF becomes sufficiently large to mandate initiation of regeneration. Section ( 52 ) initiates regeneration when the actual soot loading reaches an amount less than the amount at which section ( 54 ) mandates regeneration, provided that selected engine operating conditions disclose conditions favorable for regeneration. Section ( 56 ) terminates regeneration when soot loading is reduced to some minimum amount or when conditions for continuing regeneration become unfavorable. By burning trapped soot during favorable conditions, the mandatory regeneration is postponed. This can lower the average amount of trapped soot in the CDPF, thereby lowering the average back-pressure on the engine.