SCR Catalyst Ammonia Coverage Ratio Estimation

1 Observer 1 Design Based on Coverage Ratio Dynamics 

The first observer design is based on the NH3 coverage ratio dynamics as shown in the SCR model of Eq. (14.29)  

From the SCR model, it can be seen that all the states and parameters but the ammonia coverage ratio 0nh3 are available. Besides, since the NO2 concentration after the SCR catalyst (CNO2) is always low, it can be assumed that CnO = 0-Under this assumption, an observer can be designed in a straightforward manner. 

With the above assumptions, the following observer can ensure the convergence of the estimation error. 

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