## 4 Results and Discussion
### Optimization of Modeling Results
#### 4.1.2 Characteristics of Variables Based on Optimization Modeling Results
The response reaches a peak at an intermediate distance, which suggests that both overly short and excessively long distances lead to suboptimal outcomes. (c) Spray Pressure-Number of Sprays Interaction  
Figure 6c demonstrates that both spray pressure (A) and number of sprays (D) have a strong positive influence on the LiDAR point cloud value. Notably, a synergistic effect \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Variable** & **Coefficient** & **SE** & **t-Statistic** & _p-Value_ & **VIF** \\ \hline \multicolumn{2}{c}{Intercept} & 1594.8 & 51.6 & 30.91 & 0.000 *** & - \\ \hline \multirow{4}{*}{Main Effect} & A—Spray pressure & 572.4 & 39.1 & 14.62 & 0.000 *** & 1 \\  & B—Spray speed & 61.2 & 39.1 & 1.56 & 0.134 & 1 \\  & C—Spray distance & \(-\)85 & 39.1 & \(-\)2.17 & 0.043 ** & 1 \\  & D—Number of sprays & 610.6 & 39.1 & 15.6 & 0.000 *** & 1 \\ \hline \multirow{4}{*}{Second-Order Effect} & A\({}^{2}\) & \(-\)235 & 103 & \(-\)2.28 & 0.034 ** & 2.78 \\  & B\({}^{2}\) & 181 & 103 & 1.75 & 0.096 * & 2.78 \\  & C\({}^{2}\) & \(-\)357 & 103 & \(-\)3.46 & 0.003 *** & 2.78 \\  & D\({}^{2}\) & \(-\)227 & 103 & \(-\)2.2 & 0.041 ** & 2.78 \\ \hline \multirow{2}{*}{Interaction Effect} & AD & 352.9 & 41.5 & 8.5 & 0.000 *** & 1 \\  & CD & \(-\)115.8 & 41.5 & \(-\)2.79 & 0.012 ** & 1 \\ \hline \hline \end{tabular}  
* * \(p\) < 0.1, ** \(p\) < 0.05, *** \(p\) < 0.01.  
\end{table} 
Table 5: ANOVA results for dust dispersion factors. is observed when both parameters are simultaneously increased, thereby resulting in a significantly enhanced cleaning response. (d) Spray Speed-Distance Interaction  
Figure 6d illustrates the interaction between spray speed (B) and spray distance (C). The influence of spray speed appears ambiguous, whereas spray distance again displays an optimal range. Point cloud performance deteriorates when the distance is either excessively short or long. Moreover, extremely high values for both variables may negatively impact effectiveness. (e) Spray Speed-Number of Sprays Interaction  
Figure 6e depicts the interaction between spray speed (B) and the number of sprays (D). An increased number of sprays is consistently associated with higher LiDAR point cloud values, which indicate improved cleaning performance. In contrast, the influence of spray speed remains inconclusive, although extremely high speeds may reduce effectiveness. These findings suggest that optimizing the number of sprays, while maintaining a moderate spray speed, enhances overall system performance. (f) Spray Distance-Number of Sprays Interaction  
Figure 6f illustrates the combined effect of spray distance (C) and number of sprays (D). An increased number of sprays consistently enhances the LiDAR point cloud value, thereby indicating enhanced cleaning performance. However, the point cloud performance declines when the spray distance deviates from its optimal range. Moreover, simultaneous increases in both variables may lead to reduced effectiveness, thereby highlighting the importance of maintaining spray distance within a moderate and controlled range. Figure 6: Three-dimensional surface plots of the primary experiment. (a) Spray pressure–speed, (b) spray pressure–distance, (c) spray pressure–number of sprays, (d) spray speed–distance, (e) spray speed–number of sprays, (f) spray distance–number of sprays.