Control apparatus and method having a control closed loop observer configuration for scr/scrf component

A controller for a vehicle internal combustion engine exhaust gas after-treatment system, the exhaust gas treatment system including a selective catalyst reduction on filter (SCRF) exhaust gas after-treatment device in communication with exhaust gases from the internal combustion engine and having a treated exhaust gas output, an oxides of nitrogen (NOx) sensor coupled to the treated exhaust gas output, the NOx sensor having a NOx sensor output signal that is NOx and ammonia (NH3) cross-sensitive, and an electronic control unit (ECU) operatively coupled to the internal combustion engine and the exhaust gas after-treatment system, the controller comprising:

• a closed loop observer (CLO) operatively coupled to receive the NOx sensor output signal and to provide a CLO output signal to the ECU, wherein the CLO output signal at least includes an exhaust gas NOx concentration estimate and the ECU is arranged to be operable upon the NOx concentration estimate to control the exhaust gas after-treatment system and the internal combustion engine to effect an overall reduction in actual NOx concentration with the exhaust gases.

A method of controlling a vehicle internal combustion engine exhaust gas after-treatment system, the exhaust gas treatment system including a selective catalyst reduction on filter (SCRF) exhaust gas after-treatment device in communication with exhaust gases from the internal combustion engine and having a treated exhaust gas output, an oxides of nitrogen (NOx) sensor coupled to the treated exhaust gas output, the NOx sensor having a NOx sensor output signal that is NOx and ammonia (NH3) cross-sensitive, and an electronic control unit (ECU) operatively coupled to the internal combustion engine and the exhaust gas after-treatment system, the method comprising:

• providing via a closed loop observer (CLO) operatively coupled to receive the NOx sensor output signal an exhaust gas NOx concentration estimate to the ECU;
• and
• controlling the exhaust gas after-treatment system and the internal combustion engine to effect an overall reduction in actual NOx concentration with the exhaust gases responsive to the NOx concentration estimate.