Designation And Implementation Of Ad Hoc Network Protocol For Indoor Micro-UAV Swarm Based On Ultra-wideband Technology

With the development of microelectronics industry technology and the demand for indoor applications,UAVs are gradually developing towards miniaturization and clustering.MicroUAVs have the characteristics of flexible deployment,suitable for complex indoor environments,and can enhance their functions through clustering.Multi-UAV systems have many advantages,but designing an efficient communication architecture for multi-UAV systems is a challenging task.A crude way is to bypass this problem by considering star networks with static routing,but star architectures restrict the operative area of groups of UAVs.In order to avoid this problem,this article uses the flying ad hoc network to design the communication architecture between UAVs,but it still faces the following challenges: on the one hand,frequent changes in the internal topology of the flying ad hoc network cause communication difficulties.on the other hand,The development time of micro-UAVs is relatively short,and its corresponding network communication infrastructure is lacking.Therefore,it is necessary to design a reasonable self-organizing network protocol for indoor micro-UAV systems and realize the corresponding network infrastructure,which has important theoretical significance and application value for the development of indoor micro-UAVs.In recent years,Utrl-Wideband(UWB)technology has been widely used in new i Phones and other smart devices to enhance indoor sensing.The low energy consumption of UWB meets the requirements of the airborne energy limit of micro-UAVs,the anti-multipath interference feature meets the requirements of complex and changeable indoor scenarios,the high-speed and high-bandwidth characteristics are suitable for multi-UAV systems networking and low price greatly reduce the cost of cluster deployment,and the accurate ranging can provide accurate topology perception for indoor micro-UAV systems.To this end,this thesis first designs the U-OLSR protocol based on UWB swarm ranging,and implements and deploys the U-OLSR protocol based on specific software and hardware facilities.Specific research results include:(1)This master’s thesis designs the U-OLSR protocol based on UWB swarm ranging,and we proposed a new message format and processing flow to made the ranging protocol compatible with the OLSR protocol.we consider the characteristics of the rapid degradation of the link quality at the transmission distance boundary with distance and packet loss rate model in the real environment,a link quality estimation method that integrates the current and future distances is designed and implemented for this purpose.The corresponding routing algorithm has been designed.(2)According to the U-OLSR protocol theory proposed in this paper,a complete U-OLSR ad hoc network module is implemented and open sourced based on Free RTOS.In order to enable the module to be migrated to any device with the same software architecture,this article adopts a loose coupling and high cohesion design pattern in the implementation process to isolate storage and algorithms from each other,and finally publish it on the open source community Git Hub.(3)Based on the above results,we use the micro-UAV named Crazyflie2.1 and the corresponding UWB expansion board hardware to designed and deployed an indoor drone selforganizing network prototype system on the STM32F405 architecture.The system is designed with 2.4GHz external communication mechanism and heterogeneous interconnection method,so that the ad hoc network status can be monitored by external equipment.In conclusion,this paper designs a routing protocol based on UWB swarm ranging for indoor micro-UAVs.The results of a series of simulation experiments and real machine tests show that the relevant mechanism designed in this paper can become an effective solution for indoor drone ad hoc network.In addition,the U-OLSR module developed and open sourced in this article can provide other researchers and users with relevant directions with an effective network infrastructure software,and promote the swarm research of unmanned systems,which is provide a positive reference value for the national drone strategy.