# A Police and Insurance Joint Management System Based on High Precision BDS/GPS Positioning
## 4 Key Technologies  
### Vehicle Intelligent Terminal  
In this article, the intelligent terminal is based on high precision BDS/GPS positioning with sub-meter level. On the basis of this, the terminal is integrated with an inertial sensor, vehicle vision and network communication. Thus the terminal can record driving data, provide navigation and location services, realize fast claims, advanced driver assistance and so on. As shown in Figure 2, the shape of the terminal in this article is an intelligent rear view mirror. Its standard configuration are as follows: All Winner T3 Quad-core 1.2 G ARM CortexTM-A7 high performance processing chip, assisted by a T3 Mail450 MP3 GPU graphics accelerated processor, standard 4 GB-16 GB EMMC memory, 5.0 inch HD (800 \(\times\) 480) highlight five point capacitive touch screen blue light anti-dazzle display, and embedded 4 G TDD/TDS/GSM/FDD/WCDMA five network communication modules, supporting vehicle HD front and back dual cameras (front camera 1080 P, 1700 wide angle, back camera VGA 576P). The terminal is an afterload device that now can be installed on mainstream vehicles. The terminal developed in this article is an IoV product for civilian use. Crucially, it uses the single frequency navigation consumer electronic device and applies the PPP-RTK positioning  
Figure 2: Appearance photo of our UBI terminal based on high precision BDS/GPS positioning. method. As PPP positioning is not restricted by the distance to reference stations, it is particularly applicable to the dynamic and precise positioning field within a far and wide area and can receive modified information by radio. Therefore, PPP positioning is mainly used in this article. Moreover, the algorithms of space segment, communication segment and user segment, respectively, have been modified in order to improve the positioning accuracy to sub-meter level. The error-correcting method in space segment includes orbit dynamics model, conservative force such as Earth gravity field, non-conservative force such as solar radiation pressure and Earth radiation pressure as well as real-time forecast model. The error-correcting method in communication segment includes space environment model, spatio-temporal transformation characteristics and real-time ionospheric delay modeling. The error-correcting method in user segment includes error identification and compensation for multiple GNSS system, integration processing for observation magnitude of multiple system and real-time fast localization algorithm. The detailed algorithm implementation process will not be explained any more as it is not the main point of this article. The terminal accesses the BDS ground-based augmentation system signal and uses a high precision positioning module with the original observation output. It realizes calculation of high precision positioning algorithms in the Android kernel layer using a kernel positioning driver. Meanwhile, it transfers the calculation results to users through the high precision positioning interface. The Android operating system kernel driver which supports the GNSS/Inertial Navigation System (INS) integrated navigation is detailed in Section 4.2. The high precision positioning module is shown in Figure 3. The high precision positioning module consists of the following sections: battery, BDS/GPS chip, IMU MEMS sensor, STM32 embedded sensor, antenna and six input and output connecting lines. Among them, the role of BDS/GPS chip is to provide observation and ephemeris data for high precision positioning algorithm; the MEMS sensors are to provide real-time vehicle acceleration and angular velocity data. The terminal's location performance will be introduced by test experiments. A number of test experiments have conducted for a month on the 2 nd Ring Rd in Wuhan. The 2 nd Ring Rd is a 48-km-long expressway in the downtown area of Wuhan. 84% of the whole road is without any roadblocks and sheds and 16% of the road is a blocked section with acoustic sheds and tunnels whose length is about 300 m to 2.5 km.