Internal Model Controller Characterization for an Integrating Water Level Process Control

This paper presents an IMC-PD controller tuning for water level process. Water level process is an integrating process whose response increases gradually with time. The process is open-loop unstable but can be stabilized using a feedback control. Many researches had proposed a PD controller to improve its stability but somehow the response can be upset by the presence of disturbance in the process. This research presents an internal model control (IMC) tuning approach for a PD controller to reduce the impact of disturbance to the closed-loop water level control. IMC tuning used model-based tuning approach and hence it may give smooth disturbance response and allows good set point tracking. The closed-loop time constant, λ is the sole tuning parameter required for improving the steady-state behavior and the transient of the process. This paper presented simulation results obtained using MATLAB in characterizing the effect of λ on the water level control loop. Higher value of λ resulted in slower response but less overshoot.