Design And Implementation Of High Speed Traversal Flight Control System For Quadrotor Aircraft

The quadrotor aircraft has good application and development prospects in military reconnaissance and civil fields due to simple structure,low cost,strong maneuverability,and strong concealment.With the advancement of technology in recent years,quadrotor aircraft has gradually integrated into people's daily life and shown its abilities in the fields of remote control aerial photography and package delivery.It is foreseeable that quadrotor will be used in more and more occasions,the complexity of the scene and the difficulty of the task will gradually increase,and higher requirements will be placed on the control algorithm.Aiming at meeting the future application requirements of the quadrotor and solving the high-speed flight control problem it faces,a miniature quadrotor experimental platform is customized in this article;target recognition and gimbal decoupling algorithms,quadrotor position and attitude control algorithms are designed to achieve autonomous take-off,landing and high-speed flight control.After simulation verification,these designs are realised in practical application.The main aspects are given as following.Firstly,starting from the flying principle of the quadrotor,the hardware system composition and design requirements of the quadrotor platform are analyzed.Then the hardware design of the platform including the onboard computer and the gimbal camera is determined,the selection of each composition and the assembly of the body are completed.On this basis,the software function is divided into three parts and the software system frameworks for flight control,airborne computer and ground station are built respectively.Secondly,based on the built experimental platform,a mathematical model of the quadrotor is established and an attitude control algorithm is designed.After that,an image process algorithm of the grayscale transformation and binary processing of the saturation channel and a target recognition algorithm based on Hough circle detection and polygon fitting square detection are designed to achieve rapid recognition of the targets.Then,a gimbal decoupling control algorithm is designed and the conversion relationship between the image information and the relative position of the space is derived through the formula derivation.Thirdly,the flight mission plan and its feasibility analysis are carried out.On this basis,a position-altitude algorithm and a speed-altitude control algorithm are designed respectively for the process.Then,the high-speed traversal process is analyzed and two high-speed traversal control algorithms based on position servo and proportional guidance law are designed.In order to ensure the safety of flight experiments,a safety protection algorithm is also designed to prevent the control quantity and position from exceeding the limit.Finally,the two high-speed traversal flight control algorithms are verified by simulation.The results show that both of them are capable of achieving the high-speed traversal control,and each has advantages and disadvantages in the control effect.The algorithms designed above are finally implemented on the realistic platform,the experimental results show that the system can accurately identify the target,achieve autonomous take-off,traversal and landing control,which fully verifies the effectiveness of the entire system's hardware,software,and algorithms.