Application of Desired Dynamic Equation method in simulation of four-tank system

The control of Multi-tank Liquid-level System is both a typical multivariable control problem and a typical problem that is used to verify conception and method of multivariable control. In this paper, a decoupling controller matrix is designed based on the complete decoupling method of feedforward compensation. For the decoupled objective function, the parameters of PI controller are tuned using Desired Dynamic Equation (DDE) method. The method is applied in simulations of several typical four-tank models. And robustness analysis is carried out using the Monte-Carlo stochastic experiment. The simulation results show that the method can achieve a significant decoupling among the responses of system outputs, an effective control of water level of each loop and an obvious improvement of control performance of multivariable interconnected systems.