Optimization of PID Controller Settings Using the Ziegler–Nichols Method in Pneumatic Pressure Control Systems

The objective of the conducted research was to apply the classical Ziegler–Nichols (ZN) method for optimizing the PID controller settings in a pneumatic pressure control system. The study included both simulations in the Scilab-Xcos environment and experiments on a real laboratory test bench. A model of the process was developed in the form of a transfer function of the controller, based on which the key dynamic parameters were determined: time delay, time constant, and gain. Subsequently, in accordance with the ZN procedure, the appropriate PID controller settings were calculated. A closed-loop system model was constructed, and a step response simulation was performed. The obtained results confirm good control quality: no steady-state error, an overshoot of approximately 10%, and a settling time of about 2.5 seconds. Additionally, the control quality indices were calculated: IAE = 0.6719 and ISE = 0.1004, which confirm the effectiveness of the ZN method as a tool for the preliminary optimization of PID controllers in pneumatic applications.