Modeling, simulation and control of liquid level and flow systems using industrial microcontroller

ABSTRACT Modeling, Simulation and Control of Liquid Level and Flow Systems Using Industrial Microcontroller In this thesis, liquid level and flow control systems equipped with industrial type liquid level and flow sensors, solenoid and proportional valves and microprocessor based process controller are constructed. Firstly, characteristics of the sensors and valves used in the control sets are determined and programming of process controllers are examined. Approximate mathematical models of the systems are derived by utilizing the experimental results obtained from step responses of processes. Mathematical models and step responses of the systems are required for PID controller design and PID tuning methods. PID controllers are designed by using root locus analysis technique utilizing the mathematical models of the systems obtained from experiments and some simulation studies are implemented using the MATLAB/Simulink environment. On the other hand, PID controller parameters are calculated from the experimental results using the PID tuning methods such as Ziegler-Nichols and the others. Simulation and experimental results showing the performance of the control systems are given. Keywords: Process Controllers, Liquid Level Control, Liquid Flow Control, PID Control, On / Off Control.