Proportional–integral observer for systems modelled by bond graphs

In the present work a bond graph approach to build full-order proportional–integral (PI) observers is shown. The proposed approach is based on the bond graph method defined for designing classical linear observers (Luenberger observers). The method is extended to build a second type of integral observers more robust to the presence of sensor noise. As application, the method is used over the pseudo bond graph model of a continuous stirred tank reactor (CSTR). Simulation results show the performance of the PI observers with respect to the presence of modelling errors and the robustness of integral observers when sensor noise is present.