## 6 Results and Discussion
### Impact of SPCR Operation on Landscape PV Module
Without the multi-damper unit, the SPCR caused peak deflections of 11.65 mm (along the center) and 11.88 mm (along the upper side) of the PV panel, whereas, with the presence of the multi-damper unit, these values were reduced  
Figure 20: Raw data of PV panel deflection under SPCR operation on the landscape PV module: (a) SPCR moves in the center of the PV panel; (b) SPCR moves at the edge of the PV panel. to 11.40 mm and 11.23 mm, respectively. These values account for the initial deformation due to the SPCR's mass acting on the PV panel. The installation of the multi-suspension unit resulted in peak deflections caused by the SPCR being reduced by 2.15% and 5.47%, respectively. Similar to the previous scenario, the effect of the multi-suspension unit in decreasing peak deflections during the operation of the SPCR is negligible. Additionally, the largest deformation occurs when the SPCR moves near the long edge of the PV panel, which is consistent with the tests of the SPCR stoppage. Furthermore, the distortions occur non-periodically, or the deflection repetition region is very small, and the peak deflection does not occur instantly. This indicates that the deflection occurs more slowly on PV panels compared to other scenarios, resulting in lower fatigue inside the PV glass layer due to the reduced frequency of cyclic loading. The reason for this difference is the distribution of weight force from the SPCR on the PV panels in this scenario, which differs from the previous ones. The SPCR introduces a wheeled track with a smaller width than the timing belt contact length, resulting in a more concentrated force when the SPCR moves along the short edge of the PV panel. Therefore, the PV panels experience minimal deformation in the case of the portrait PV module. Figure 24 presents a histogram portraying the frequency distribution of \(\Delta z\) values in this experiment. The results reveal a reduction in occurrences of large deflections and a corresponding increase in instances of smaller deflections, highlighting the efficacy of the multi-damper unit, as observed in previous cases. Specifically, as the SPCR moves along the side of the PV panel, \(\Delta z\) has a value of approximately 0.5 mm that decreased from 18 counts to 5 counts. Otherwise, \(\Delta z\) with values around 0 to less than 0.25 mm increased from 61 counts to up to 91 counts. In terms of characteristics, the results demonstrate a  
Figure 21: Variation of deflection deviation under SPCR operation on the landscape PV module: **(a)** SPCR passes over the module along the center of PV panels; **(b)** SPCR passes over the module along the side of PV panels. Figure 22: Variation of deflection deviation under SPCR operation on the portrait PV module: **(a)** the SPCR passes over the portrait PV module along the center of the PV panels; **(b)** the SPCR passes over the portrait PV module along the upper side of the PV panels. general symmetry in both scenarios involving the robot's exposure to vibrations. However, the \(\Delta z\) values remain relatively modest, spanning from 0.5 mm to 2.0 mm for both cases, with and without the multi-suspension unit. This reinforces the conclusion that the changes in PV panel deflection occur at a slower pace in this specific scenario. Similar to the results for the case in Section 6.2, because vibration amplitudes have approximately equal values in the two experimental scenarios, the location of the cut-off line is almost similar.