Teaching multiloop control of nonlinear system: three tanks case study

The paper focuses on teaching advanced MIMO control topics using hydraulic system model. Basic steps of nonlinear MIMO system control design are shown on three tank plant model. After modelling part, comprising nonlinear model based on first principles and its linearization about equilibrium point, two approaches to MIMO system control are demonstrated. The first approach designs a full state feedback PI controller in state space, the second one uses multi-loop approach with individual loop design, overall stability condition is used to detune loop PI controllers for the overall system issues. The results are analysed and compared, important teaching issues are indicated.