## 4 Experimental Validation
### Real Scene Experimental Test
#### 4.2.2 AGV Particle Kidnapping Experiment  
In previous simulation experiments, it was found that the particles generated by the AMCL algorithm were prone to kidnapping events during the positioning process. The improvement of the algorithm as well as the improvement of resampling can effectively avoid such situations, so it is verified in real experiments that the algorithm can effectively improve the robustness and reliability of AGV positioning. Figure 23: The scanning process: (**a**) synchronised Rviz; (**b**) scanning the QR code. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Average** & **Actual Position** & **Particle Triangulation** & **Industrial Camera** & **Scanning Fusion** & **Maximum Left Offset** \\
**Value** & **Coordinates** & **Matching Position** & **Scanning Position** & **Improved AMCL** & **Maximum Right** \\  & & & **Coordinates** & **Coordinates** & **Offset** \\ \hline Cycle 5 times & (0, 375.00) cm & (1.96, 377.92) cm & (3.24, 373.16) cm & (0.59, 374.25) cm & (0.88, 0.53) cm \\ Cycle 10 times & (0, 375.00) cm & (2.88, 373.40) cm & (2.64, 377.88) cm & (0.36, 375.40) cm & (0.56, 0.62) cm \\ Cycle 20 times & (0, 375.00) cm & (3.72, 377.34) cm & (1.52, 377.50) cm & (0.42, 375.34) cm & (0.78, 0.62) cm \\ Cycle 30 times & (0, 375.00) cm & (2.48, 373.68) cm & (2.44, 373.32) cm & (0.44, 375.32) cm & (0.84, 0.66) cm \\ Cycle 50 times & (0, 375.00) cm & (1.54, 377.12) cm & (3.72, 377.48) cm & (0.72, 374.48) cm & (0.76, 0.64) cm \\ \hline \hline \end{tabular}
\end{table} 
Table 5: AMCL and improved AMCL fusion QR code algorithm comparison. The experiments show that the particles in the AMCL algorithm will not disperse automatically after AGV is kidnapped, so it is impossible to relocate. However, the improved AMCL algorithm will scatter some particles at the kidnapped position, which can be relocated. Figure 24 shows the process of the kidnapping and location recovery of the AGV when the improved AMCL algorithm is started. Figure 24a shows the initial state of the AGV. At this time, the AGV is ready to accept the command to move forward, and the particles are in a dispersed state. Figure 24b shows the state that the AGV moves to QR2 point, at which time the particles are in a convergent state. Figure 24c shows that the AGV is kidnapped, and the particles gather in this area and do not diverge with the movement of AGV. As shown in Figure 24d, to detect the kidnapping event, the improved algorithm is adjusted and the positioning state is restored. To calculate the kidnapping time, calculate the duration of the kidnapping time based on the start time and end time of the kidnapping event. To monitor the positioning error, sensors or other positioning systems are used to monitor the difference between the actual position of the AGV and the position estimated by the AMCL algorithm. When the positioning error exceeds a certain threshold, it can be determined that an kidnapping event has occurred. Record the start time of the abduction event. When the positioning error exceeds the threshold, record the current time as the start time of the kidnapping event. To monitor the positioning recovery, continue to monitor the positioning error, and when the positioning error recovers to within an acceptable range, it can be judged that the kidnapping event is over. Figure 24: Kidnapping and location recovery: (**a**) initial stage; (**b**) travelling to QR2; (**c**) kidnapping situations; (**d**) dissolution of kidnapping.