System and method for controlling regeneration of an exhaust after-treatment device

Abstract

A method for controlling regeneration of an exhaust after-treatment device for an internal combustion engine in a vehicle includes establishing a baseline value for a mass of soot collected in the exhaust after-treatment device. The baseline value is a threshold mass of soot to be reached for regenerating the filter, and is determined as a function of a speed of the engine and a quantity of fuel entering the engine. The method also includes modifying the baseline value in response to an engine operating parameter that alters a fuel-air ratio of a combustible mixture entering the engine to generate a modified baseline value. The method additionally includes regenerating the exhaust after-treatment device using the modified baseline value. A system for controlling regeneration of an exhaust after-treatment device for an internal combustion engine is also provided.

1 . A method for controlling regeneration of an exhaust after-treatment device for an internal combustion engine in a vehicle, comprising:
 establishing a baseline value for a mass of soot collected in the exhaust after-treatment device, wherein the baseline value is a threshold mass of soot to be reached before regenerating the after-treatment device, and is determined as function of a speed of the engine and a quantity of fuel entering the engine;   modifying the baseline value in response to an engine operating parameter to generate a modified baseline value, the engine operating parameter altering a fuel-air ratio of a combustible mixture entering the engine; and   regenerating the exhaust after-treatment device using the modified baseline value.   
     
     
         2 . The method according to  claim 1 , wherein said modifying the baseline value is executed in response to an engine operating parameter that alters the fuel-air ratio by varying a mass of air entering the engine. 
     
     
         3 . The method according to  claim 2 , wherein said modifying the baseline value is executed in response to an engine operating parameter that alters the fuel-air ratio by varying a mass of fuel entering the engine. 
     
     
         4 . The method according to  claim 3 , wherein the mass of fuel entering the engine is varied in one manner when the engine is operating in a steady state and in another manner when the engine is operating in a transient state. 
     
     
         5 . The method according to  claim 3 , wherein the mass of fuel entering the engine is varied by an exhaust gas recirculation in the engine being turned on. 
     
     
         6 . The method according to  claim 1 , wherein said modifying the baseline value is executed via a controller. 
     
     
         7 . The method according to  claim 6 , wherein the controller is programmed with a look-up table that includes a range for the engine operating parameter. 
     
     
         8 . A system for controlling regeneration of an exhaust after-treatment device, comprising:
 an internal combustion engine that generates an exhaust gas as a byproduct of combustion and transfers the exhaust gas to the after-treatment device; and   a controller which is:
 programmed with an established baseline value for a threshold mass of soot collected in the exhaust after-treatment device before regenerating the after-treatment device, wherein the baseline value is determined as a function of a speed of the engine and a quantity of fuel entering the engine; and 
 programmed to modify the baseline value in response to an engine operating parameter that alters a fuel-air ratio of a combustible mixture entering the engine; 
   wherein the controller regenerates the exhaust after-treatment device using the modified baseline value.   
     
     
         9 . The system according to  claim 8 , wherein the baseline value is modified in response to an engine operating parameter that alters the fuel-air ratio by varying a mass of air entering the engine. 
     
     
         10 . The system according to  claim 9 , wherein the baseline value is modified in response to an engine operating parameter that alters the fuel-air ratio by varying a mass of fuel entering the engine. 
     
     
         11 . The system according to  claim 10 , wherein the mass of fuel entering the engine is varied in one manner when the engine is operating in a steady state and in another manner when the engine is operating in a transient state. 
     
     
         12 . The system according to  claim 10 , wherein the mass of fuel entering the engine is varied by an exhaust gas recirculation in the engine being turned on. 
     
     
         13 . The system according to  claim 8 , wherein the controller is additionally programmed with a look-up table that includes a range for the engine operating parameter. 
     
     
         14 . A vehicle comprising:
 an internal combustion engine that generates an exhaust gas as a byproduct of combustion;   an exhaust after-treatment device configured to receive the exhaust gas and adapted to be regenerated; and   a controller which is:
 programmed with an established baseline value for a threshold mass of soot collected in the exhaust after-treatment device before regenerating the after-treatment device, wherein the baseline value is determined as a function of a speed of the engine and a quantity of fuel entering the engine; and 
 programmed to modify the baseline value in response to an engine operating parameter that alters a fuel-air ratio of a combustible mixture entering the engine; 
   wherein the controller regenerates the exhaust after-treatment device using the modified baseline value.   
     
     
         15 . The vehicle according to  claim 14 , wherein the baseline value is modified in response to an engine operating parameter that alters the fuel-air ratio by varying a mass of air entering the engine. 
     
     
         16 . The vehicle according to  claim 15 , wherein the baseline value is modified in response to an engine operating parameter that alters the fuel-air ratio by varying a mass of fuel entering the engine. 
     
     
         17 . The vehicle according to  claim 16 , wherein the mass of fuel entering the engine is varied in one manner when the engine is operating in a steady state and in another manner when the engine is operating in a transient state. 
     
     
         18 . The vehicle according to  claim 16 , wherein the mass of fuel entering the engine is varied by an exhaust gas recirculation in the engine being turned on. 
     
     
         19 . The vehicle according to  claim 14 , wherein the controller is additionally programmed with a look-up table that includes a range for the engine operating parameter.