## 3 Results
### Field Experiment Results  
#### 3.2.1 Results and Analysis during S-Turn Transportation  
The displacement change data in Figure 26b were obtained by converting and processing the original angle change data shown in Figure 26a in each direction. The values were obtained at the same frequency as that in the simulation. From the displacement variation data in Figure 26b, the peak value of the bee frame centroid in the roll direction (corresponding to the X-direction in the simulation) ranges from (\(-\)12-17 mm), which is similar to the peak result obtained in the simulation (18.8 mm). The peak variation (\(-\)17 mm) in the pitch direction (corresponding to the Y-direction in the simulation) of the bee frame centroid is nearly three times higher than the peak result obtained in the simulation (4.6 mm). In the field test, the sandy loam soil could not be guaranteed to remain flat under several tests. It is impossible to achieve the perfect simulation conditions during the actual driving process, with the peak pitch angle being approximately three times greater than the peak angle in the simulation. During the driving process, the shaking of the bee frame centroid was only (\(-\)17-17 mm), and no falling occurred. Thus, the bee frames can be transported safely within the apiary. By solving Figure 26c in each direction, we found that during the transportation process, the variation range of velocity in the roll direction (corresponding to the X-direction in the simulation) did not exceed \(\pm\)0.15 mm/s, while the variation range of velocity in the pitch direction (corresponding to the Y-direction in the simulation) was in the range of \(\pm\)0.05 mm/s. The X-direction range in the field test was consistent with the simulation results (\(-\)0.159-0.180 m/s), and the Y-direction range in the field was slightly wider than that in the simulation (\(-\)0.025-0.020 m/s). The speed variation of the bee frames during transportation in the field test was considerably smaller than that of the honey picker (5.7-21.9 m/s), meaning that damage to the bee frames during transportation was considerably less than the damage caused by the honey picker. The transport vehicle can, therefore, safely transport the bee frames. In the field experiment, angle variations with full bee frames loads and full beehive loads are shown in Figure 27. As shown in Figure 27a, the range of roll value change with a full load of bee frames is (\(-\)2.5-5.0\({}^{\circ}\)), and the range of roll value change in the field test is considerably wider than the range of roll value change with a full load of bee frames in the simulation (\(-\)0.8-0.8\({}^{\circ}\)). Moreover, the range of roll value change is (\(-\)1.362-3.419\({}^{\circ}\)) in the result of angle change with a full load of beehives, as illustrated in Figure 27b. The results obtained with the full load of the beehives are slightly smaller than those obtained  
Figure 25: Box plot of (**a**) variation in roll values under each pavement condition when the vehicle is fully loaded with beehives and (**b**) variation in pitch values under each pavement condition when the vehicle is fully loaded with beehives. with the full load of bee frames and larger than the simulation results (\(-1\)-\(1^{\circ}\)). During transportation, the beehives are fixed above the transport vehicle, while the bee frames are free inside the loading box. Therefore, the vehicle with a full load of beehives will be more stable than the vehicle with a full load of bee frames. However, the results are all greater than the simulation results because of the lack of flat terrain due to multiple experiments in the field test, which led to the generation of large error values in the range of variation. In Figure 27, the change in pitch angle is within \(\pm 5^{\circ}\) with either a full load of bee frames or beehives, which is considerably smaller than the maximum uphill limit inclination angle of \(34^{\circ}\). Thus, the vehicle can transport bee frames and beehives safely and stably.