# Comparative Real-Time Study of Three Enhanced Control Strategies Applied to Dynamic Process Systems
## 5 Experimental Results
### Results of Tank 1
It was concluded that the increase in error value is related to the system's response time. In order to prove that the FO-APIDSMC control method can perform better than the FF-PI and CNPIR controller, a liquid level position control experiment was conducted and compared. It was observed that the FO-APIDSMC controller could follow the reference better without overshooting and had better steady-state error performance compared to the FF-PI and CNPIR controllers. The signals for the FF-PI, CNPIR, and FO-APIDSMC controllers were obtained, as shown in Figure 11. \begin{table}
\begin{tabular}{c c c c} \hline  & **FF-PI** & **CNPIR** & **FO-APIDSMC** \\ \hline ISE & 684.2 & 587.7 & 452.4 \\ \hline \end{tabular}
\end{table} 
Table 3: ISE values without disturbance according to controllers for Tank 1. Figure 10: Tracking error for Tank 1 configuration. In order to evaluate the performance of the FF-PI, CNPIR, and FO-APIDSMC controllers against instantaneous disturbances, instantaneous disturbances of different durations and intervals were applied in the experimental setup. To apply these disturbances, the external outlet valve located at the bottom of Tank 1, as shown in Figure 12, was used. In order to obtain the response of the proposed controller technique to undesirable situations, the system's drainage tap was opened every 10 s by external intervention into the system, as seen in Figure 12. This valve was fully opened for 10 s in each interval shown in Figure 13, causing the liquid level in Tank 1 to suddenly decrease. Since the amplitude \begin{table}
\begin{tabular}{c c c} \hline
**Controller** & **h Value** & **ISE** \\ \hline CNPIR & 2 ms & 587.7 \\ CNPIR & 10 ms & 595.2 \\ CNPIR & 90 ms & 607.8 \\ CNPIR & 100 ms & 622.2 \\ CNPIR & 200 ms & 635.4 \\ CNPIR & 300 ms & 665.7 \\ CNPIR & 1 s & 698.7 \\ \hline \end{tabular}
\end{table} 
Table 4: ISE values according to CNPIR h parameter change. Figure 11: Tank 1 level control signs. Figure 12: Tank 1 liquid level control giving instant disturbance effect. and magnitude of the suddenly changing disturbance could not be directly measured, this situation became an unmeasurable disturbance for the system. As shown in Figure 13, the response of the Tank 1 control system to the applied disturbance, based on the ISE error values obtained from the control controllers, is provided in Table 5.  
It is evident that the FO-APIDSMC controller performs better than the FF-PI and CNPIR controllers against disturbances applied at different durations and intervals. Against disturbances, the FO-APIDSMC controller exhibited less oscillation and responded faster to the system. Furthermore, its ability to follow the reference signal without overshooting proves its superior performance compared to the FF-PI and CNPIR controllers. As seen in Figure 13, during disturbances lasting 10 s in each interval, the FO-APIDSMC controller generated control signals to quickly bring the liquid level close to the reference value by minimizing the error and forcing the system to stay at the reference value. When the duration and interval of the disturbance, as shown in Figure 13, are increased, it is concluded that the FO-APIDSMC control controller responds better to disturbances compared to the FF-PI and CNPIR controllers. Examining the obtained graphs and the ISE error values, it was concluded that the proposed FO-APIDSMC control technique can control the liquid level in Tank 1 better than the FF-PI and CNPIR controllers.