LPWAN Based Measurement And Control Technology For Aircraft

Recently,the clustering of low-cost UAVs has attracted widespread attention in both military and civilian applications.Reliable and efficient information interaction of UAV clusters is the basis for supporting collaborative control,collaborative sensing and collaborative decision-making.It also is one of the important development directions of intelligent UAV Bee Colony technology.Aimed at this new scene and special needs,researches on the new concept of wireless measurement and control systems and technologies are underway at home and abroad.Focusing on the problem of lack of communication resources,the contradiction between communication distance and power consumption and the requirement of integration of communication and measurement,we plan to introduce low-power wide-area narrowband Internet of Things(LPWAN)communication technology into small UAV bee colony for building a telemetry sensing system for UAV bee colony.The following key technical issues are highlighted:1)Architecture of the UAV cluster telemetry sensing system.Starting from the limitation of the throughput of IoT communication technology and the business characteristics of the cluster telemetry system,this paper designs a user-oriented scalable communication architecture by “subscribe/publish” mode.Through the support of highlevel protocol middleware and the coordination and adaptation of "publisher" and "subscriber",reduce the pressure on the communication link effectively and improved the overall performance of the network.2)LoRa Chirp spread spectrum signal reception and information interpretation technology.For security and scalability reasons,this paper uses software radio technology to design a custom gateway.Based on the physical nature of Lo Ra signal,the detection technology,the structure of LoRa data and the decoding mechanism and algorithm of LoRa payload are studied.Finally,the self-receiving processing of LoRa signal is realized based on open source software radio platform for the first time in China.It lays the foundation for further expanding and improving the signal design of LPWAN.3)Research on multi-gateway positioning technology.According to the requirements of the integration of measurement communication in UAV cluster,the function of using multiple gateways combined with TDOA positioning to locate the terminal UAV is designed,and the TDOA positioning system based on MQTT protocol is built.The positioning algorithm of precise tracking to determine the initial phase is studied and designed to improve the positioning accuracy.The factors affecting the uncertainty of TDOA positioning system are analyzed in depth,and an improved scheme is proposed.