## 3 Results
### Field Experiment Results
#### 3.2.1 Results and Analysis during S-Turn Transportation
Figure 26: Variation of (**a**) angle, (**b**) displacement, and (**c**) velocity of single bee frame during s-turn transportation. 2.2 Results and Analysis of Transportation of Beehives from Placement to Honey Picker (Actual Transportation)  
By converting and processing the original data in Figure 28a to obtain the displacement variation data in Figure 28b along each direction, the values with the same frequency as those in the simulation were obtained. From the displacement change in each direction in Figure 28b, it can be deduced that during actual transportation, the shaking of the bee frame centroid in the loading box reached its peak at 52 mm, which was considerably higher than the simulation test result of 18.8 mm and the field slewing s-turn test result of 17 mm. In the actual transportation process, the uneven ground and constant real-time adjustment of the direction of travel at the beginning of actual transportation resulted in a shaking value of 50 mm for the bee frames at the beginning of the movement. The shaking of the bee frame centroid was reduced to (\(-\)20-20 mm) during the subsequent continuous driving, and it decreased to less than \(\pm\)10 mm at the end of the test conducted on hard and flat ground. The maximum oscillation rate during the actual transportation was 0.47 m/s, which was considerably smaller than the speed range of the comparative reference honey picker (5.7-21.9 m/s). Thus, damage to the bee frames during transportation was considerably less than the damage caused by the honey picker. Therefore, the transportation vehicle can safely transport the frames. Figure 27: Angle variation of (**a**) the vehicle with a full load of bee frames during s-turn transportation, (**b**) vehicle with a full load of beehives during s-turn transportation, and (**c**) all vehicles during s-turn transportation. Figure 29 shows the range of roll and pitch variation, as well as all results of actual transportation when the vehicle is fully loaded with bee frames and beehives. In actual transportation, the roll angle changes in the range of (\(-4.56\)-\(2.97^{\circ}\)), and the pitch angle changes in the range of (\(-3.76\)-\(1.76^{\circ}\)) when the vehicle is fully loaded with bee frames. In actual transportation, the change in roll angle is mainly caused by uneven ground, and the reason for the larger change in roll angle than that in the simulation analysis is that the vehicle must change direction at any time during the overall transportation process. This induces different internal and external pressures on the two sides of the track, resulting in  
Figure 28: Variation in the (**a**) angle, (**b**) displacement, and (**c**) velocity of a single bee frame during actual transportation. greater fluctuations in the peak roll angle (\(-4.56^{\circ}\)) than that in the simulation (1.337\({}^{\circ}\)). The pitch angle variation peaks at \(-3.76^{\circ}\) at the start, and after stabilization, the angle fluctuates between \(\pm 1^{\circ}\), which is not considerably different from the peak angle (1.38\({}^{\circ}\)) and a stable variation range (0.37-0.84\({}^{\circ}\)) results in the simulation analysis. When the vehicle was fully loaded with beehives and the roll and pitch angle values varied in the ranges of (\(-3.59\)-7.39\({}^{\circ}\)) and (\(-3.01\)-8.89\({}^{\circ}\)), respectively, the peak of the roll value reached 8.89\({}^{\circ}\). From Figure 29c, it can be seen that the roll and pitch values when the vehicle is fully loaded with beehives are larger than the roll (\(-4.56\)-2.97\({}^{\circ}\)) and pitch values (\(-3.76\)-1.76\({}^{\circ}\)) when the vehicle is fully loaded with beehives. This is consistent with the trend that the range of pitch angle variation of the vehicle fully loaded with beehives in the simulation is greater than the range of roll angle variation of the vehicle fully loaded with bee frames.