Research On Unmanned Aerial Vehicle Control Technology For Bridge Detection

As an important transportation hub,bridges bring convenience to pedestrians and vehicles.With the long-term use of bridges,bridge diseases arise.Unmanned aerial vehicle(UAV)as a new type of bridge detection tools,with low maintenance costs and does not affect the traffic,can check at or near the bridge disease and some other advantages.Because of the advantages of high stability and easy control,multi-rotor aircraft are usually used as bridges detection flight platform.The bridge support and the bottom of the bridge are the high incidence areas of the bridge disease.This paper aims at the application requirements of the UAV bridge detection,UAV with fixed high control,convenient to check the bridge bottom;joined around the flight control,convenient inspection of bridge bearings from multiple angles;added obstacle avoidance control,improve the security of the user control.First of all,the bridge detection UAV system is designed.The bridge detection UAV system includes quadrotor flying platform,camera and PTZ,image transmission and display system,flight control system and multi-function control terminal.The flight control system uses a variety of sensors.Main controller is used to get and process data of sensor and control flight of the UAV.The multi-function control terminal receives the status information of the flight control system negatively and displays it through the LCD screen,and shows a warning when a system fault is detected.The operator can control the camera gesture and trigger photo shooting through the multi-function control terminal while recording the system information when the photo was taken.Secondly,it was proposed to use strong tracking extended KALMAN filter fusion gyroscope accelerometer and magnetic compass data to solve the attitude angle of the UAV,and to simulate the attitude solution using MATLAB.The quadrotor dynamics model is established,the cascade PID is used to control the attitude and the attitude control performance is further improved by fuzzy-PID.The quadrotor attitude control simulation model is established,and the performance advantage of fuzzy-PID is verified by simulation analysis.Thirdly,using the median filter to dispose the height data of the ultrasonic module,and using Butterworth filter to process the height data of the barometer.We use fuzzy-PID controller as ultrasonic set-height and barometer set-height controller.The 2D laser intensity direction and ranging(LIDAR)is used to detect the information of the surroundings of the aircraft.The slip angle is calculated for UAV head lock around the target control.The calculated target distance is used for fixed distance flight control.lock control and fixed distance flight control are combined together to complete the UAV surrounding flight control.Using LIDAR to detect information for 360 degree obstacle avoidance of the UAV,the PD controller is used to design the obstacle avoidance controller,and the recoil suppression area is set up to decelerate the UAV who leaves obstacle area quickly.Finally,a bridge test UAV flight platform was set up,and the barometer height setting experiment,ultrasonic height setting experiment,surrounding flight experiment and obstacle avoidance control experiment were carried out respectively.The effectiveness of the proposed control method was verified.