Liquid Level Control of Quadruple Conical Tank System using Linear PI and Fuzzy PI Controllers

Design of multivariable control systems are in great demand in process industries. This paper focuses on maintaining the liquid level in a multivariable process, Quadruple Conical Tank System (QCTS). The mathematical model of the system is developed from the first principles. The mathematical model is linearized at an operating point for designing linear PI and fuzzy PI controllers. The linear PI controller is designed using the Ziegler - Nichols reaction curve tuning method. The parameters of the fuzzy PI controller are obtained using a genetic algorithm. Simulation results are obtained with linear PI and fuzzy PI controllers and they are compared.