## 3 Analysis of Results
### Discrete Element Simulation Analysis
#### 3.1.4 Single-Factor Analysis
In order to investigate the effect of digging depth on the digging resistance caused by the shovel body, this simulation test analysis added a set of test 14 for comparison on the basis of test 2 and test 10 after fully referring to the agronomic requirements of Fritilariae usuriensis maxim cultivation and harvesting operation process requirements. The operating speed is set to 0.3 m/s, the shovel face inclination is set to 25\({}^{\circ}\), and the digging depth of the shovel is set to 100 mm, 120 mm, and 140 mm. At the end of the simulation run, the horizontal resistance and vertical resistance of the shovel in the smooth operation stage are extracted and the average value is taken, and the analysis table of the influence of digging depth is obtained, as shown in Table 11.  
As seen from Table 11, with the increase in excavation depth \(C\), horizontal resistance \(F_{1}\) tends to increase while vertical resistance \(F_{2}\) tends to decrease. Compared to operating speed \(A\) and shovel face inclination \(B\), the digging depth \(C\) has less influence on the digging resistance of the shovel body. In order to further analyze the effect of different excavation depths on the excavation resistance caused by the shovel body, the expression of the agglomerate particles is set to stream in the EDEM 2020 post-processing interface, and the simulation time is recalled to the point before the shovel enters the agglomerate model. In the model display interface, the time step is set from Iterations to Times, and the model type is changed from Playback Speed to Step Playback. After the setting is completed, click Run to generate the trajectory change graph of agglomerate particles, as shown in Figure 18. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Serial Number**} & **Digging Speed** & \multirow{2}{*}{**Angle of Entry \(B\) (\({}^{\circ}\))**} & **Digging Depth** & \multirow{2}{*}{**Horizontal**} & \multirow{2}{*}{**Vertical Resistance**} \\  & \(A\) **(m/s)** & & **C (mm)** & & **Resistance F\({}_{1}\) (N)** & \(F_{2}\) (N)** \\ \hline
14 & 0.3 & 25 & 100 & 278.54 & 87.37 \\
2 & 0.3 & 25 & 120 & 305.32 & 82.72 \\
10 & 0.3 & 25 & 140 & 329.24 & 69.23 \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Impact analysis table of excavation depth. Figure 18: Changes in aggregate particle trajectories under different excavation depths. As seen from Figure 18, when the operating speed and shovel surface inclination are kept consistent, the trajectory of agglomerate particles in the front and middle of the shovel body surface gradually changes from blue-green to green as the digging depth increases. At 140 mm, the trajectory of agglomerate particles near the shovel blade starts to appear red. However, from the overall changes, the impact of excavation depth on the excavation resistance of the shovel body is not very significant. Hence, prior to adjusting the excavation depth parameters, it is crucial to determine if the surface disturbance on the shovel body will inflict harm upon the Fritilariae ussuriensis maxim bulbs. On the premise of ensuring high net harvest rate and low damage rate, specific parameters should be set based on the variation in excavation resistance on the shovel body with excavation depth.