Design And Implementation Of A Multi-quadrotor Formation Control System

Since the beginning of the 21^st century,UAV technology has been rapidly developed.As an emerging technology product,quadrotor has become a key research object of universities,scientific establishments and commercial companies,and is widely been used in civil,industrial as well as military field.In some cases,due to the limitations of its own flight capability and load,a single quadrotor is difficult to meet requirements for application,often requiring multiple collaborations to accomplish the mission.Thus,the research on cluster control and formation flight of quadrotor has arisen.This research greatly enhances the complexity and timeliness of the quadrotor's mission,and has important practical significance in many fields such as search,rescue,environmental detection and large-scale monitoring.This paper focuses on the platform design and implementation of the quadrotor formation control system.Firstly,it introduces the basic composition,principle and control method of the quadrotor.By comparing different formation architectures,it describes several distributed formation control methods in detail.On this basis,this paper bulids the quadrotor physical model and the formation model based on graph theory separately,and designs the location estimation method based on extended kalman filter.In addition,the distributed formation control strategy used in the paper is designed based on leader and follower method.The strategy enables the quadrotor cluster to be led by the leader based on local position information and fly in an arbitrary shape.Secondly,according to the requirements of formation tasks,the GPS module,raspberry PI 3B+onboard computer and related components are selected to complete the construction of quadrotor,and the overall hardware construction of formation system platform is completed by combing the communication system built by PC and router.At the same time,based on FreeRTOS,the design of the quadrotor flight control software is completed by the preparation and priority assignment of related tasks.And the design of the upper-layer formation control software is completed by using the different software nodes and communication protocols written by the ROS framework.It realizes the command delivery from the top to the bottom and the wireless transmission of position information between each adjacent quadrotor.Finally,the paper carries out a number of tests on the designed formation control system.Such as the simulation experiments on the control strategy,the performance experiments of a single quadrotor and the formation flight experiments of the physical platform,which prove that the formation control system can effectively complete the tasks like formation maintenance and transformation,and lays a solid foundation for post-application research base on this platform.