Apparatus and method for monitoring regeneration frequency of a vehicle particulate filter

Abstract

A vehicle includes an engine, a regenerable exhaust stream particulate filter, and a host machine. The host machine has a pair of soot models providing respective actual and modeled soot mass values for the soot contained in the particulate filter, calculates a ratio of a change in the actual and modeled soot masses, and executes a control action when the ratio exceeds a calibrated threshold. A diagnostic code and/or activation of an indicator device may be part of the control action. A system includes the particulate filter and host machine noted above. A method for use aboard the vehicle includes determining the actual and modeled soot mass values using first and second soot models, respectively, calculating a ratio of a change in the actual and modeled soot mass, comparing the ratio to a calibrated threshold, and executing a control action when the ratio exceeds the threshold.

1 . A vehicle comprising:
 an engine;   a particulate filter which collects particulate matter from an exhaust stream of the engine, and which is selectively regenerable using heat; and   a host machine having a first soot model and a second soot model, with the first and the second soot models respectfully providing an actual soot mass and a modeled soot mass contained in the particulate filter;   wherein the host machine is operable for calculating a ratio of a change in the actual soot mass to a change in the modeled soot mass since an immediately prior regeneration event of the particulate filter, and for executing a control action when the ratio exceeds a calibrated threshold.   
     
     
         2 . The vehicle of  claim 1 , wherein the first soot model indexes a differential pressure across the particulate filter to the actual soot mass, and wherein the second soot model determines the modeled soot mass with respect to a set of current vehicle operating conditions not including the differential pressure across the particulate filter. 
     
     
         3 . The vehicle of  claim 1 , wherein the host machine generates a diagnostic code as at least part of the control action. 
     
     
         4 . The vehicle of  claim 3 , wherein the host machine activates an indicator device as an additional part of the control action. 
     
     
         5 . The vehicle of  claim 1 , wherein the engine is a diesel engine and the particulate filter is a diesel particulate filter. 
     
     
         6 . A system for use aboard a vehicle having an internal combustion engine, the system comprising:
 a particulate filter which collects particulate matter from an exhaust stream of the engine, and which is selectively regenerable using heat; and   a host machine having a first soot model and a second soot model, with the first and the second soot models respectfully providing an actual soot mass and a modeled soot mass contained in the particulate filter;   wherein the host machine is operable for calculating a ratio of a change in the actual soot mass to a change in the modeled soot mass since an immediately prior regeneration event of the particulate filter, and for executing a control action when the ratio exceeds a calibrated threshold.   
     
     
         7 . The system of  claim 6 , wherein the first soot model indexes differential pressure across the particulate filter to the actual soot mass, and wherein the second soot model determines the modeled soot mass with respect to a set of vehicle operating conditions not including the differential pressure across the particulate filter. 
     
     
         8 . The vehicle of  claim 6 , wherein the host machine generates a diagnostic code as at least part of the control action. 
     
     
         9 . The vehicle of  claim 8 , wherein the host machine activates an indicator device as an additional part of the control action. 
     
     
         10 . The vehicle of  claim 6 , wherein the engine is a diesel engine and the particulate filter is a diesel particulate filter. 
     
     
         11 . A method for use aboard a vehicle having an internal combustion engine, a particulate filter which is regenerable using heat, and a host machine, the method comprising:
 determining an actual soot mass value in the particulate filter using a first soot model;   determining a modeled soot mass value in the particulate filter using a second soot model, wherein the second soot model provides an estimated soot mass value contained in the particulate filter;   calculating a ratio of a change in the actual soot mass to a change in the modeled soot mass;   comparing the ratio to a calibrated threshold; and   executing a control action when the ratio exceeds a calibrated threshold.   
     
     
         12 . The method of  claim 11 , wherein the first soot model indexes differential pressure across the particulate filter to the actual soot mass value. 
     
     
         13 . The method of  claim 12 , further comprising determining a set of current vehicle operating conditions not including the differential pressure across the particulate filter, wherein the second soot model determines the modeled soot mass with respect to the set of current vehicle operating conditions. 
     
     
         14 . The method of  claim 11 , further comprising:
 generating a diagnostic code as at least part of the control action.   
     
     
         15 . The method of  claim 14 , further comprising:
 activating an indicator device as an additional part of the control action.