Liquid Level Tracking Control of Three-tank Systems

Firstly, the flat property of three-tank systems is verified and a feedforward controller is designed accordingly so as to track the ideal trajectories. Secondly, in order to eliminate the tracking errors introduced by model uncertainties or unknown disturbances, a nonlinear model predictive controller is designed in which a terminal equality constraint is added for ensuring asymptotic convergence. Finally, the control performance is confirmed by both simulation and experiment results.