# A Police and Insurance Joint Management System Based on High Precision BDS/GPS Positioning
## 4 Key Technologies
### Vehicle Intelligent Terminal
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Tests**} & **The Number of** & **The Proportion** & **The Number of** & **The Proportion** & **The Number of** & **The Proportion** \\  & **Epochs of the** & **of the Location** & **Epochs of the** & **of the Location** & **Epochs of the** & **of the Location** \\  & **Location Error** & **Error Less than** & **Location Error** & **Error Less than** & **Location Error** & **Error Less than** \\  & **Less than 0.5 m** & **0.5 m** & **Less than 1 m** & **1 m** & **Less than 1 m** & **1.5 m** \\ \hline The 1 st lap & 1220 & 45.74428\% & 2435 & 91.30109\% & 1811 & 97.41282\% \\ The 2 nd lap & 1602 & 60.79696\% & 2289 & 86.86907\% & 2069 & 95.59772\% \\ The 3 rd lap & 2108 & 69.59393\% & 2850 & 94.09046\% & 2996 & 98.91053\% \\ The 4 th lap & 1186 & 51.6110\% & 1773 & 77.15405\% & 2519 & 90.03481\% \\ The 5 th lap & 1202 & 57.62224\% & 1655 & 79.33845\% & 2598 & 86.81687\% \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Statistics of location error in the lateral direction of the lane. Figure 5: The location error (fixed solution) in the lateral direction of the lane in five tests. Comparison with a typical mass-market GNSS receiver  
Two groups of qualitative analysis are carried out on the positioning data acquired from test experiments. The reference data obtained from POS 620 is shown as the blue trajectory in Figure 6. Our equipment is installed on the vehicle and can obtain the positioning trajectory data of track points when the vehicle is traveling. The positioning trajectory data used in the first group is provided by our equipment with high precision positioning, and indicated by the green trajectory shown in Figure 6. The data used in the second group, indicated by the red trajectory in Figure 6, is provided by a Ublox UBX-M8030-KT device, a model commonly used in the automotive application field, which applies SPP positioning chip. The contrast performance on the high precision lane level e-map is shown in Figure 6. It is obvious that the red trajectory is off the track and cannot provide lane level positioning while the green one can show which lane the vehicle drives on and whether it has any lane change behavior. The accuracy assessment of the two groups is shown in Table 4. It is clear that the positioning accuracy of the typical mass-market equipment is about 6 m. The track point drifts from side to side. We can judged which road the vehicle is driving on, but it is impossible to judge which lane it is driving in. The terminal is mainly used on the urban expressway and arterial roads. Certainly, there are some sections with noise barriers and tunnels which cannot obtain satellite signals. The length of the section is less than 3 km on average in the urban traffic environment, as shown on the left of the figure. The inertial module is embedded in a high precision module and its performance has been verified as shown on the right of Figure 7. This is a 2.2-km-long section of the 2 nd Ring Rd. with noise barriers. The trajectory with red dots is obtained only by satellite positioning while the trajectory with green dots is obtained by inertial navigation. The red trajectory cannot provide accurate location data while the green one can provide accurate location data when the vehicle enters the tunnel. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Total Number of** & \begin{tabular}{c} **Lateral** \\ **Depoish: 4064** \\ **RMS (m)** \\ \end{tabular} & \begin{tabular}{c} **Lateral** \\ **Deviation** \\ **MEAN (m)** \\ \end{tabular} & \begin{tabular}{c} **Max** \\ **Lateral** \\ **Deviation** \\ **RMS (m)** \\ \end{tabular} & \
\begin{tabular}{c} **Longitudinal** \\ **Deviation** \\ **MEAN (m)** \\ \end{tabular} &
\begin{tabular}{c} **Max** \\ **Longitudinal** \\ **Deviation** \\ **Deviation** \\ \end{tabular} \\ \hline Ublox-M8030-KT & 5.022 & 1.288 & 67.658 & 18.053 & 3.794 & 170.931 \\ terminal & 0.380 & 0.294 & 1.307 & 0.438 & 0.353 & 1.305 \\ \hline \hline \end{tabular}
\end{table}