Robust control of water tank systems

Water tank systems are widely-used in industry. Due to the widespread use of liquid tank systems, a number of methods and approaches have been developed in order to control these systems. In this study, the water tank system model is implemented. Liquid tank models are principally non-linear systems, therefore system is modelled in continuous time intervals, within the context of independent systems with parameters varied periodically, by open-loop transfer function. The estimation of the system is achieved by Continuous-time Recursive Least Squares Estimation (CRLS). On the resulting estimated model, a robust proportional, integral and derivative (PID) controller is designed and feedback control for the system is implemented. In implementation stage, a robust PID controller is applied to two-tank and three-tank systems separately. Simulation results are obtained by SIMULINK, assummed that system is working under normal conditions. The voltage applied to the water level and the water level provided for the tanks are considered to be equal. In simulation, by using square waves varying at specific intervals, robust PID control is implemented.