Control of a water tank system with a two degree of freedom controller

Liquid tank systems are widely used in industry. There are a number of methods to control them. Some of these methods utilize system model, some are barely based on trial-and-error.In this study, model of the system is obtained and with this model, a two degree of freedom controller is designed and feedback control is achieved. Estimation of the system is carried out using the Continuous Time Recursive Least Squares method. For different sampling periods and filter polynomials, simulation studies and applications are carried out.On selecting the best fit of the filter polynomial and sampling period for the estimated model, feedback control is implemented.In this application, a cascaded three equivalent tank system is used. Upon connecting the units to each other with valves, a two degree or three degree system can be constructed. Input and output signals are transfered to computer and applied to the system with the use of Data Acquisition Card and Labview 8.2 software of the Texas Instruments. System identification and control algorithms are developed using Matlab 7 program and embedded to the Labview program. Using Matlab 7 and Labview 8.2, suitable input and output signals are generated and system control is implemented.