System amd method for controlling an after-treatment component of a compression-ignition engine

Abstract

A method for controlling regeneration within an after-treatment component of an engine includes receiving a signal that is responsive to a change in pressure across an after-treatment component and calculating an estimate of accumulated particulate matter in the after-treatment component using a soot accumulation model calibrated to simulate operation of the engine at a reference condition. A soot model correction factor is based at least in part on an environmental temperature correction and is applied to the estimate of accumulated particulate matter in the after-treatment component to produce a temperature-compensated estimate of accumulated particulate matter in the after-treatment component. The temperature-compensated estimate of accumulated particulate matter in the after-treatment component is compared to a predetermined threshold associated with the after-treatment component, and a remedial action is initiated when the temperature-compensated estimate of accumulated particulate matter in the after-treatment component exceeds the predetermined threshold.

What is claimed is: 
     
         1 . A method for controlling regeneration within an after-treatment component of an engine, comprising:
 receiving a signal that is responsive to a change in pressure across an after-treatment component;   calculating an estimate of accumulated particulate matter in the after-treatment component using a soot accumulation model calibrated to simulate operation of the engine at a reference condition;   determining a soot model correction factor based at least in part on an environmental temperature correction;   applying the soot model correction factor to the estimate of accumulated particulate matter in the after-treatment component to produce a temperature-compensated estimate of accumulated particulate matter in the after-treatment component;   comparing the temperature-compensated estimate of accumulated particulate matter in the after-treatment component to a predetermined threshold associated with the after-treatment component; and   initiating a remedial action when the temperature-compensated estimate of accumulated particulate matter in the after-treatment component exceeds the predetermined threshold.   
     
     
         2 . The method of  claim 1 , wherein the environmental temperature correction is based on an intake air temperature signal. 
     
     
         3 . The method of  claim 1 , wherein the environmental temperature correction is based on a charge air temperature signal. 
     
     
         4 . The method of  claim 1 , wherein the environmental temperature correction is based on an ambient temperature signal. 
     
     
         5 . The method of  claim 1 , wherein the soot model correction factor is determined by interpolating between soot model correction factors associated with various elevations, thereby determining the appropriate soot model correction at the particular environmental temperature correction and operating elevation. 
     
     
         6 . The method of  claim 1 , wherein the soot accumulation model is based on a pressure drop index indicative of a decrease in pressure of an exhaust stream as it passes through the after-treatment component. 
     
     
         7 . The method of  claim 6 , wherein the pressure drop index represents a pressure ratio across the after-treatment component. 
     
     
         8 . The method of  claim 1 , wherein the soot accumulation model is based on a flow rate index indicative of a rate of flow of the exhaust stream. 
     
     
         9 . The method of  claim 8 , wherein the flow rate index is based on a speed of the engine. 
     
     
         10 . The method of  claim 1 , wherein the soot accumulation model is based on a relationship between a pressure drop index indicative of a decrease in pressure of an exhaust stream as it passes through the after-treatment component and a flow rate index indicative of a rate of flow of the exhaust stream. 
     
     
         11 . The method of  claim 1 , wherein initiating a remedial action comprises adjusting one or more engine control parameters so as to modify operation of the engine to promote passive regeneration in the after-treatment component. 
     
     
         12 . The method of  claim 11 , wherein said adjusting is configured to provide a minimum temperature at the after-treatment component to promote regeneration in the after-treatment component. 
     
     
         13 . The method of  claim 11 , wherein said adjusting comprises modifying fueling and timing of the engine. 
     
     
         14 . The method of  claim 11 , wherein said adjusting comprises activating an auxiliary heating element to increase a temperature of the exhaust stream. 
     
     
         15 . The method of  claim 11 , wherein the remedial action comprises activating a warning light instructing an operator to initiate regeneration in the after-treatment component. 
     
     
         16 . A system for controlling regeneration within an after-treatment component of an engine comprising:
 a regeneration controller having a processor coupled to a memory storage device, the regeneration controller being configured to:
 receive a signal that is responsive to a change in pressure across an after-treatment component; 
 calculate an estimate of accumulated particulate matter in the after-treatment component using a soot accumulation model calibrated to simulate operation of the engine at a reference condition; 
 determine a soot model correction factor based at least in part on an environmental temperature correction; 
 apply the soot model correction factor to the estimate of accumulated particulate matter in the after-treatment component to produce a temperature-compensated estimate of accumulated particulate matter in the after-treatment component; 
 compare the temperature-compensated estimate of accumulated particulate matter in the after-treatment component to a predetermined threshold associated with the after-treatment component; and 
 initiate a remedial action when the temperature-compensated estimate of accumulated particulate matter in the after-treatment component exceeds the predetermined threshold. 
   
     
     
         17 . The method of  claim 16 , wherein the environmental temperature correction is based on an intake air temperature signal. 
     
     
         18 . The method of  claim 16 , wherein the environmental temperature correction is based on a charge air temperature signal. 
     
     
         19 . The method of  claim 16 , wherein the environmental temperature correction is based on an ambient temperature signal. 
     
     
         20 . The method of  claim 16 , wherein the soot model correction factor is determined by interpolating between soot model correction factors associated with various elevations, thereby determining the appropriate soot model correction at the particular environmental temperature correction and operating elevation.