## 5 Results
### Simulation Results Analysis  
To verify the feasibility of the algorithm presented in this paper for full-coverage operation in three-dimensional special terrains and its effectiveness in reducing energy consumption during such operations, we compare this algorithm with other full-coverage path planning algorithms. The primary comparison metrics include the total length of the coverage path, the total elevation difference traversed, the number of steering actions, the path repetition rate, and the total energy consumption. The simulation results for five typical terrains are presented in Figures 9-13, where the red line represents the robot's coverage path, and the red and blue dots indicate the start and end points of the coverage, respectively. The specific simulation results are detailed in Table 2.  
Figure 8: Typical terrain models.  
Figure 11: Model III simulation effect diagram.  
Figure 12: Model IV simulation effect diagram.  
Figure 10: Model II simulation effect diagram.  
Figure 9: Model I simulation effect diagram.  
Analyzing the results of the simulation experiments conducted above, the algorithm presented in this paper demonstrates good performance in four typical hilly terrains. Compared with the reciprocal covering method and the improved A* algorithm for three-dimensional terrains, the algorithm in this paper has a clear advantage in terms of path elevation difference. While its path length and repetition rate are not as good as those of the reciprocal covering method, which features a simpler path, it still offers a considerable advantage compared to the improved A* method. Taking map model 1 as an example, compared with the improved A* algorithm, the total path length of the algorithm in this paper is shortened by 6.7%. The total elevation difference in the path is reduced by 32%, and the number of steering actions is decreased by 13. Additionally, when compared with the reciprocal method, the total elevation difference in the path is reduced by 46%. Although in some terrains the number of steering actions in this paper's algorithm is slightly higher than that of the improved A* algorithm, the energy consumption associated with steering is relatively smaller compared to the energy consumption resulting from the path elevation difference. Overall, the total energy consumption of this paper's algorithm in the simulation experiments for the five maps is reduced by 25.8%, 21.7%, 47.5%, 33.9%, and 30.8% compared to the reciprocal overlay method, and by 19.6%, 10.3%, 5.2%, 24.2%, and 21.8% compared to the improved A* algorithm. Therefore, the algorithm in this paper exhibits an outstanding overall performance advantage.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Map** & **Covering** & **Path** & **Total Elevation** & **The Number of** & **Recurrence** & **Total Energy** \\
**Models** & **Method** & **Length** & **Difference** & **Steering Actions** & **Rate** & **Consumption** \\ \hline \multirow{3}{*}{Model I} & reciprocal coverage & 399 & 62.03 & 39 & 0 & 17.63 \\  & improved A* & 457 & 48.69 & 167 & 14 & 16.29 \\  & this paper & 426 & 33.72 & 154 & 7 & 13.09 \\ \hline \multirow{3}{*}{Model II} & reciprocal coverage & 399 & 52.54 & 39 & 0 & 15.77 \\  & improved A* & 443.3 & 43.26 & 138 & 11 & 13.77 \\  & this paper & 438.7 & 33.00 & 170 & 9 & 12.35 \\ \hline \multirow{3}{*}{Model III} & reciprocal coverage & 399 & 102.73 & 39 & 0 & 25.34 \\  & improved A* & 431.3 & 38.30 & 169 & 13 & 14.03 \\  & this paper & 423.7 & 35.73 & 164 & 11 & 13.30 \\ \hline \multirow{3}{*}{Model IV} & reciprocal coverage & 399 & 61.96 & 39 & 0 & 17.62 \\  & improved A* & 456.4 & 42.58 & 144 & 13 & 15.34 \\ \cline{1-1}  & this paper & 433.4 & 25.27 & 156 & 8 & 11.63 \\ \hline \multirow{3}{*}{Model V} & reciprocal coverage & 399 & 68.80 & 39 & 0 & 18.90 \\  & improved A* & 465.8 & 57.46 & 165 & 17 & 16.71 \\ \cline{1-1}  & this paper & 460.9 & 32.05 & 208 & 15 & 13.07 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Comparison of simulation data.  
Figure 13: Model V simulation effect diagram.