CONSTRAINTED OPTIMAL CONTROL OF INTEGRATING PROCESS USING INDUSTRIAL PI CONTROLLER FOR SINUSOIDAL DISTURBANCE

Controlling a constrained system using an industrial three term controller can be remarkably challenging to achieve even for processes with the simple dynamics, such as integrating process. If an oscillating input is introduced (for instance, as a result of the cycling of a control loop of an upstream process unit) then both the controlled variable and the manipulated variable will oscillate with the same frequency. In this paper, the liquid level loop under the sinusoidal disturbance is investigated from the point of view of designing the PI controller to satisfy the constraint set. The result is: insight into the feasible region and tuning rules to get the PI parameters for liquid level process.