# Design and Application of Logical Range Framework Based on Digital Twin
## 4 Application Examples and Analysis  
Based on the above research, we implemented a system based on the proposed framework, where the system includes the functions of planning scheme construction and management, Logical Range construction and management, data integration manage  
Figure 7: Virtual–real synchronization mapping process. ment, unified equipment management, and so on. The system was developed through a combination of Browser/Server (B/S) and Client/Server (C/S) architectures. According to the situation of Logical Range flight testing, the proposed system uses a combination of short-range transmission protocols and long-distance network transmission protocols to complete data transmission. Short-distance transmission protocols include Bluetooth, ZigBee, Wi-Fi, and RS-485 serial ports, among others, while long-distance transmission protocols include TCP/IP, UDP, and so on. In terms of data storage, the combination of a relational database PostgreSQL and a non-relational database MongoDB was used to realize the storage, processing, and analysis of massive structured, semi-structured, and unstructured data. In terms of data management, we used Vue.js and SpringBoot to develop a web management platform, and employed container technology to deploy the developed system on the cloud platform. The web management platform realizes data and equipment management for the entire system, including data visualization, data fusion, log management, user management, unified equipment configuration, equipment matching, and so on. The user management and system history information interface in the web management platform is shown in Figure 8.  
In terms of virtual scene construction, 3 DMax was used to build virtual models in various equipment and scenes, and we imported the models into Unity3D. We built the virtual twin scene in Unity3D, and used the C# script language to drive the operation of various models and components in the virtual twin scene. A C/S architecture was adopted to complete the twin system construction. The client can be installed on a user's PC, and can realize the real-time display of equipment data, planning scheme construction, and other functions. Furthermore, the platform was deployed in a cloud server using container technology to realize the functions of data interaction, analysis, and processing. The test plan management interface of the digital twin logic range platform we have built is shown in Figure 9. The overall data flow of the system is depicted in Figure 10.  
Figure 8: Web management platform interface. (**a**) User interface view (**b**) Historical information interface view. Before the test begins, it is necessary to specify the test plan on the digital twin logical range platform, determine how many cross-regional ranges are involved in the test, and determine how many types of equipment are involved in each range. After starting the test, the digital twin logical range platform can monitor the status of each equipment in real-time and save these data for subsequent analysis work. Taking a flight test as an example, this test involves three ranges distributed in different regions, including two radar simulation equipment, one TSPI simulation equipment, four cameras, and two IMU inertial navigation systems. Figure 10(a) shows some of the simulation equipment involved in this test, Figure 10(b) shows the information display interface of the test plan in the digital twin logical range platform, Figure 10(c),d show the real-time data reception and display interface of the equipment in the digital twin logical range platform, and the displayed data are synchronized with the equipment in real time. Figure 12 shows the analysis of user behavior data during the test process in the web management platform. Figure 13 shows the interface for viewing the test plan in the web management platform. For this test, our proposed Logical Range system based on digital twin technology enabled data collection, processing, and analysis across the considered regional ranges.