Patent ID: 8209962

Claim:
A method for controlling an internal combustion engine to protect the engine from damage caused by excessive diesel particulate filter clogging, the method comprising: sensing differential pressure change solely across said diesel particulate filter; monitoring at least one of filter wall permeability by calculating K w as K ow (1 +C 1 T C 2 ( C 3 +C 4 e C 5 T C 6 ) wherein K ow =f (volumetric exhaust flow rate or space velocity); C 1 , C 2 , C 3 , C 4 , C 3 , C 6 =Constants; and T=Exhaust gas temperature as measured, and variable soot cake permeability is determined by calculating K 0c as C 0 ( K t −K v ) wherein K v is a function of mass flow rate, generally increasing as the volumetric exhaust flow rate (space velocity) increases in a convex manner, and, wherein K t is a function of soot cake temperature, as a function of exhaust mass flow rate and exhaust temperature; determining soot mass as a function of said sensing and said monitoring; determining when said soot mass exceeds a threshold selected to reduce damage or regenerate the diesel particulate filter.