Controller tuning method for nonlinear conical tank system using MATLAB/Simulink

In the process industries the control of liquid level is mandatory. But the control of nonlinear process is difficult. Many process industries use conical tanks because their nonlinear shape provides better drainage for solid mixtures, slurries and viscous liquids. Conical tanks are extensively used in the process industries, petrochemical industries, food process industries and wastewater treatment industries. So, control of conical tank level is a challenging task due to its nonlinearity and continually varying cross section. This is due to the relationship between the controlled variable level and manipulated variable flow rate, which have a square root relationship. The system identification of the nonlinear process is made and studied using mathematical modeling with Taylor series expansion, and the real time implementation is done in Simulink using MATLAB.