| With the rapid development of UAV technology,its mission scenarios and application environment are becoming more and more complex.The single UAV system has been unable to meet the growing demand in terms of function,efficiency,reliability and so on.The UAV system has gradually developed from a single execution task mode toward the direction of clustering.The excellent performance of UAV cluster benefits from its complex control algorithm and communication network.At the same time,it also brings difficulties such as the difficulty of cluster oriented algorithm development and strong dynamic network.Therefore,the accidents such as UAV crash occur from time to time,resulting in the loss of human and material resources.In this case,building a real scene of the unmanned to evaluate the indicators will undoubtedly cause difficulties,such as high cost and time-consuming.And the establishment of an appropriate simulation platform is an effective method.However,for the modeling and simulation of UAV cluster,it is necessary to effectively simulate the characteristics of UAV and its ad hoc network in the cluster.At present,the existing simulation platforms can not capture the interdependence between them.On the one hand,the simulators for UAV modeling(such as gazebo,sitl)can not describe the underlying communication network;on the other hand,the simulators for network(such as NS3,OPNET)can not describe the UAV node and its motion in detail.Therefore,based on the current background technology,the dissertation first studies the characteristics of UAV system and its communication network in UAV cluster.Next the dissertation analyzes the requirements of simulation platform and key issues,and formally proves the feasibility of group network collaborative simulation with the help of CPS system and discrete event specification theory.Then the cluster collaborative simulation framework is implemented based on gazebo,ardupilot sitl and NS3,and the hierarchical design is used to solve the simulation requirements of the actual scene.In the collaborative simulation,the UAV simulation terminal captures the dynamic modeling and flight control design of the UAV.Then the network simulation terminal simulates the flight mobile ad hoc network,and adds the middle layer through ZMQ message middleware to process and forward the data flow.Then,aiming at the time synchronization algorithm of the collaborative simulation platform,based on the traditional master-slave and global event synchronization,the time synchronization algorithm with variable step size is optimized,so that the data of the collaborative simulation can be transmitted under a unified clock.At the same time,the distributed simulation is introduced to improve the scalability of the simulation platform.Finally,the performance of collaborative simulation is tested and analyzed.And the typical cases of UAV cluster are simulated and verified based on the collaborative simulation platform,including UAV formation problem and routing protocol of flight ad hoc network.The experimental results show that the networking simulation platform for UAV cluster can effectively capture the motion characteristics of UAV and the network characteristics of cluster flight ad hoc network.It shows its strong simulation ability for UAV cluster,and provides a strong development ecological environment for the development of UAV cluster technology.At the same time,it also plays a positive role in promoting the development of collaborative simulation technology. |
