Respiration Estimation Using Hierarchical Sliding Mode Observer in Application to WWTP

A problem of respiration estimation using a new non-linear observer for wastewater treatment plants is addressed in this paper. In detail, a hierarchical sliding mode observer has been derived to produce stable and bounded respiration estimates. An appropriate mathematical utility model has been used during the synthesis of the observer. The model observability analysis has been performed using classical tools based on differential geometry. The stability of the proposed observer has been proved using the Lyapunov stability theory. The performance of the devised observer was verified by simulation in the Matlab/Simulink environment.