# An Initial Dot Encoding Scheme with Significantly Improved Robustness and Numbers
## 4 Experiment and Result Analysis  
### Verification Experiment about Mark Points on Flexible Solar Panel  
The coded mark points designed in this paper have a great increase in the number of coded and the angle of measurement compared to the Schneider coded scheme. In view of the three-dimensional measurement of flexible solar panels, because the size of flexible solar panels is too large, we can use the coded mark points designed in this paper. Here, this paper designs a measurement scheme based on binocular stereo vision. As shown in Figure 7. This system includes a flexible solar panel, 572 coded mark points, two CMOS cameras (IO industries 2M360-CL) with f = 12 mm lenses, a light and a computer.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**The Recognition Rate under the Shooting Angle (\%)** & **0\({}^{\circ}\)** & **30\({}^{\circ}\)** & **45\({}^{\circ}\)** & **60\({}^{\circ}\)** & **75\({}^{\circ}\)** \\ \hline Pixel ratio 0.21\% of Schneider & 100 & 100 & 35 & 17 & 8 \\ Pixel ratio 0.34\% of Schneider & 100 & 100 & 58 & 17 & 17 \\ Pixel ratio 0.55\% of Schneider & 100 & 100 & 92 & 25 & 17 \\ Pixel ratio 0.21\% of Initial Dot & 0 & 0 & 0 & 0 & 0 \\ Pixel ratio 0.34\% of Initial Dot & 100 & 100 & 100 & 25 & 17 \\ Pixel ratio 0.55\% of Initial Dot & 100 & 100 & 100 & 100 & 100 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Comparison coded points’ angle.  
Figure 6: The contrast experiment of the size of the marked point. (**a**) The size of the occupied pixel ratio is 0.21%; (**b**) The size of the occupied pixel ratio is 0.34%; (**c**) The size of the occupied pixel ratio is 0.55%.  
The data in the figure above are calculated separately from the six measurements, and each part has the ability to facilitate the stitching of 3D data because of repeated coded marks. As can be seen from the diagram, the surface of each part of the middle part is relatively neat and can identify completely, while the part of the edge is not recognized. The illumination and camera shooting angle have great influence on the experiment. As can be seen from the diagram, the points received by the six surfaces are approximately similar to one plane, and there is a partial error on the splicing of the flexible plate. There are 572 points on the flexible board, 562 points are identified, and the recognition rate is 98.3%.  
After that, the flexible solar panels are scanned using a scanner in order to verify the reliability of the scheme. Then, we fit the two sets of data to the same coordinate system. Since there is no corresponding matching point here, the software is used to match the corresponding approximation. As shown in Table 4, the R-Square values obtained by fitting the two faces to each other are above 0.995, and the average error of fitting is 3.217 mm. R-Square indicates the correlation between two face types. The closer the value is to 1, the higher the correlation. Because the R-S value measured in this paper is 0.998, it is shown that the results of the two methods are basically similar, thus proving that the reconstructed results are reliable. In this experiment, due to the process of coordinate splicing, the measurement error is accumulated and finally reflected above the average error. However, this experiment can basically prove that this program can help the surface measurement of large flexible solar panels. In general, this experiment can prove that the scheme has good robustness in decoding, and can perform coordinate splicing according to these points, which has great significance for local position tracking.