Method of controlling a diesel particulate filter

Abstract

A method and apparatus for controlling a diesel particulate filter is disclosed. The control is carried out with the aid of a soot loading model selected from a plurality of available soot loading models including at least one soot loading physical model which makes use of signals from an exhaust gas pressure sensor. A reliability score is allocated to each soot loading model such that the soot loading model with the best reliability score is used for the diesel particulate filter control. If a DPF parking effect is identified based on an engine shut-off time a DPF inlet temperature either the reliability score of the soot loading physical model or the reliability scores of all remaining (non-physical) soot loading models are changed, and use of the soot loading physical model is avoided or disabled to help the control of the diesel particulate filter.

1 - 9 . (canceled) 
     
     
         10 . A method for controlling a diesel particulate filter (DPF) comprising:
 defining a plurality of soot loading models including a soot loading physical model and at least one soot loading non-physical model which makes use of signals from an exhaust gas pressure sensor;   allocating a reliability score to each of the plurality of soot loading models;   identifying a DPF parking effect when an engine shut-off time is longer than a first time threshold and an inlet temperature of the diesel particulate filter is less than a first temperature threshold; and   changing the reliability score for either the soot loading physical model or all of the soot loading non-physical models from a previous value for disabling the soot loading physical model in the control of the diesel particulate filter;   wherein the soot loading model with the highest reliability score is enabled for controlling the diesel particulate filter.   
     
     
         11 . The method according to  claim 10 , further comprising restoring the reliability scores for either the soot loading physical model or of all of the soot loading non-physical models to the previous values when the inlet temperature is higher than a second temperature threshold and an elapsed time is longer than a second time threshold. 
     
     
         12 . The method according to  claim 10  wherein changing a reliability score is carried out by lowering the reliability score of the soot loading physical model. 
     
     
         13 . The method according to  claim 10  wherein changing the reliability score is carried out by increasing the reliability score for all of the soot loading non-physical models. 
     
     
         14 . The method according to  claim 10  wherein the at least one soot loading non-physical models comprises a soot loading statistical model. 
     
     
         15 . A control apparatus for an exhaust system of an internal combustion of the type having a diesel particulate filter and an exhaust gas pressure sensor, the control apparatus comprising an electronic control unit having:
 a memory storing an instruction set and a plurality of soot loading models including a soot loading physical model and at least one soot loading non-physical model, wherein the soot loading physical model makes use of signals from the exhaust gas pressure sensor; and   a microcontroller executing the instruction set and configured to:
 allocate a reliability score to each of the plurality of soot loading models; 
 identify a DPF parking effect when an engine shut-off time is longer than a first time threshold and an inlet temperature of the diesel particulate filter is less than a first temperature threshold; and 
 change the reliability score for either the soot loading physical model or all of the soot loading non-physical models from a previous value for disabling the soot loading physical model in the control of the diesel particulate filter; 
 wherein the soot loading model with the highest reliability score is enabled for controlling the diesel particulate filter. 
   
     
     
         16 . The control apparatus according to  claim 15 , wherein the microcontroller is configured to restore the reliability scores for either the soot loading physical model or of all of the soot loading non-physical models to the previous values when the inlet temperature is higher than a second temperature threshold and an elapsed time is longer than a second time threshold. 
     
     
         17 . The control apparatus according to  claim 15 , wherein the microcontroller is configured to change a reliability score by lowering the reliability score of the soot loading physical model. 
     
     
         18 . The control apparatus according to  claim 15 , wherein the microcontroller is configured to change the reliability score by increasing the reliability score for all of the soot loading non-physical models. 
     
     
         19 . The control apparatus according to  claim 15 , wherein the at least one soot loading non-physical models comprises a soot loading statistical model.