Design And Implementation Of Quadrotor Platform For Tunnel Inspection

In recent years,with the progress of quadrotor technology,its application situation is increasing gradually,and its role in the indoor environment is also increasing.At present,in the indoor environment,the research directions of quadrotor mainly include warehouse inspection,unknown environment detection and multi machine cooperation.In addition,the quadrotor has begun to emerge in the complex environment of tunnels.Therefore,based on the application background of the tunnel inspection,the whole quadrotor platform is designed and implemented around the flight control system and the active guided inspection control system of quadrotor.Flight control system is the core of stable flight for quadrotor,mainly including attitude control system and position control system.The attitude control system is composed of attitude estimation and attitude controller,in this paper,the attitude estimation uses the series-wound EKF(extended kalman filter)algorithm to fuse the IMU(inertial measurement unit)data and magnetometer data to get the attitudes information of quadrotor which is used in the feedback link of the attitude control system;and the attitude controller is a dual loop controller,the outer loop uses the PID control algorithm,the inner loop uses the auto disturbance rejection control(ADRC)algorithm,and the output control is allocated to four motors of quadrotor,then,the attitude of the quadrotor is controlled.The position control system mainly includes two parts which are position estimation and position controller,in which the position estimation uses EKF to fuse the acceleration data and position data,and fused data are used in the feedback link of the position control system;the position controller is a dual loop PID control,and the directional saturation is used in the output of each link.In the process of inspection,the aircraft is required to fly autonomously,therefore,this paper designs an active guidance inspection scheme,which is mainly composed of relative position and attitude calculation and two parts of inspection controller.The picture of the LED lamp is obtained through the inspection equipment,and then the image is processed to get the position of the LED,after that,the relative position of the quadrotor and LED lamp plane is calculated by solving the PNP(perspective n point positioning)problem.At the same time,the corresponding controller is designed for the inspection scheme designed in this paper,and the calculated relative position and pose data are sent to the controller to get the control output.After that,the speed of the LED lamp is compensated to the final control,thus achieving the whole inspection control system.Finally,according to the needs of the project,we debug the flight control system and the inspection control system of quadrotor to achieve the best control effect.Aiming at each part of quadrotor,a number of tests are designed to verify the feasibility of the algorithm.