| In the past decade,the rapid development of uav in the field of civil and military shows the potential of its future development,unmanned aerial vehicle(uav)relative to the manned aircraft,particularly in terms of safety and cost has many outstanding advantages,such as surveillance,the enemy battlefield detective or military action on some dangerous area,unmanned aerial vehicle instead of the risk to the human pilots,the other small unmanned aerial vehicle is more useful because of production,easy maintenance and operation is convenient,reduce its cost,the successful application of unmanned aerial vehicle including surveillance,reconnaissance,battlefield assessment,target tracking and monitoring,search and rescue,traffic monitoring and pipeline inspection,Quadrotor aircraft in flight usually rely on their own in the process of realtime GPS sensors to estimate the position and velocity information,and when the unmanned aerial vehicle need to be on a mission in the indoor or relatively closed environment,GPS signal may be weak or disappear,this will make the unmanned aerial vehicle perception of environment and its variation,affecting the stable flight.Based on this,this paper built a set of quadrotor with visual sensor hardware system,and designed a set of stability control algorithm,implements the four rotor aircraft flying autonomic steadily,finally we design visual picture to input Quadrotor aircraft flying speed,and the ultrasonic sensor information fusion to achieve the Quadrotor aircraft flying high autonomous orbit followed.In this paper,based on the Quadrotor aircraft as the platform,and mainly aiming at the weak GPS signal,this paper studies the stable flight of the Quadrotor aircraft based on visual information.The main research contents are as follows:1)To establish the mathematical model and kinematics model of Quadrotor aircraft,the camera is fixed in the fuselage directly,Quadrotor motion equation is the equation of motion of the camera,in the process of normal flight target is always at the center of the camera,but Quadrotor off-center spacecraft attitude change will lead to the target,resulting in a misjudgment,this paper established a virtual camera plane,which can solve the problem of mistakes;2)In view of the Quadrotor aircraft flying fast stability problem in the process,design based on the second-order sliding mode surface sliding mode PID control algorithm,the simulation analysis found that compared with conventional second-order sliding mode control algorithm,the proposed algorithm in this paper the response time is shorter,adjust the speed faster,stronger stability.3)To choose the appropriate sensor,set up Quadrotor aircraft physical platform,for the design of the algorithm is transplanted into the Quadrotor aircraft hardware platform,through the virtual oscilloscope for actual flight data acquisition,the experimental results show that whether the target movement,Quadrotor aircraft can fly stably and hovering above it. |
