# INS/Vision Integrated Navigation System Based on a Navigation Cell Model of the [PERSON]
## 4 Experiment and Verification  
In order to verify the performance of the INS/vision brain-like integrated navigation system based on an STM32 and LattePanda, the on-board test is carried out using a high-precision fiber-optic INS/differential GPS system as a reference, and the experimental trajectory is recorded from the ScienceBuilding to Longshan Restaurant, and Fifth Gate to the Science Building, of the North University of China, Taiyuan, Shanxi Province, China. The setup of the experimental platform is shown in Figure 6. It is noted that the geographical location of the experiment is 38.02\({}^{\circ}\) N latitude (\(L_{0}\)) and 112.44\({}^{\circ}\) E longitude (\(\lambda_{0}\)). The starting point of the first experiment is 38.01776\({}^{\circ}\) N latitude and 112.44491\({}^{\circ}\) E longitude. The vehicle test is terminated at the intersection after heading south and then heading east at the first crossroads, which can be seen vividly in Figure 7a. The starting point of the second experiment is from Fifth Gate at 38.01331\({}^{\circ}\) N latitude and 112.44529\({}^{\circ}\) E longitude to the Science Building, which can be seen vividly in Figure 7b. Figure 6: Vehicle testing platform. (**a**) Test vectors; (**b**) high-precision optical fiber inertial navigation/differential global positioning system (GPS) reference; (**c**) INS and LattePanda; (**d**) cameras; (**e**) STIM202 gyroscope; (**f**) 1521L single-axis accelerometer. Figure 7: Experiment place and trajectory. (**a**) The first experiment; (**b**) The second experiment. In addition, four place cell nodes are set up in the whole path, and all of them are successfully matched. When the place cell node is activated, the accurate place information stored by the place cell node is fed back to the INS, so as to correct the accumulated position error of the INS, which can be seen in Figure 8. In total, the experiment is carried out over 462 m and lasts 4 min. The experimental results are shown in Figure 8 and Table 1.  
To further verify the proposed method, another experiment is conducted. The experimental trajectory is also in the campus of North University of China but with a different trajectory, which is from Fifth Gate to the Science Building. In this experiment, three place cell nodes are set up, and the experiment traveled about 500 m, which is shown in Figure 9. It can be directly seen that this time, the vehicle traveled in a straight trajectory, which is different from the previous trajectory. The place experiment results of latitude and longitude are given in Figure 10.  
Figures 9a and 11 represent the motion trajectory of the vehicle. In order to highlight the efficiency of the proposed brain-like navigation method, several different solutions are also investigated for comparison, which comprise the pure INS mode method and the traditional image matching correction method. From the Figure 9a, we can see that the position error based on the pure INS system is accumulated obviously as time goes on, and the position measurement accuracy is improved obviously compared to the pure INS mode after adding the image matching correction method. In addition, it is noted that the red line in Figure 9b,c represents brain-like corrected trajectory errors, and the position error estimated by the brain-like navigation method is fed back to the INS to correct position accuracy according to the proposed method. It is obvious that the positioning result is improved and closer to the true value of high-accuracy trajectory. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Latitude Position Error (m)**} & \multicolumn{2}{c}{**Longitude Position Error (m)**} \\ \cline{2-6}  & **Mean** & **RMSE** & **SD** & **Mean** & **RMSE** & **SD** \\ \hline Brain-like method & 16.0354 & 0.0594 & 11.6656 & 24.2908 & 0.0923 & 17.6252 \\ Image matching method & 18.9697 & 0.0653 & 10.7083 & 24.6879 & 0.0980 & 22.0117 \\ Pure INS & 49.4234 & 0.1555 & 15.7400 & 25.3895 & 0.1017 & 19.2724 \\ \hline \hline \end{tabular}
\end{table}