The Research Of Active Disturbance Rejection Control For Aerial Manipulator

With the rapid development of science and technology,unmanned aerial vehicle(UAV)have been successfully applied in many fields.However,the UAV mainly performs "passive" tasks such as aerial photography.It lacks the ability to perform "active" operations such as grabbing and maintaining surrounding objects,which limits its application range and advantages.Active working drone is a new type of drone system with active operating capability,which is composed of UAV and the operating device.The active working drone can be applied to in the fields of grasping and transporting dangerous objects,air logistics and maintaining equipment and so on,which has broad application prospects.The aerial manipulator system is a special active working drone that is that is constructed by attaching a multi-degree-of-freedom manipulator to the UAV.It combines the flexibility of the drone with the active working ability of the robot arm.In this system,there exists a strong coupling between UAV platform and the manipulator.The movement of the manipulator leads to the shifting of gravity center,generating reaction forces and moments on the UAV platform,affecting the stability of the aerial manipulator.Thus,the research of aerial manipulator controller faces many difficulties.This paper studies the stable control of aerial manipulator system.Firstly,this thesis mathematically models the quad-rotor UAV and the three-degree-of-freedom manipulator,and establishes the kinematics and dynamics model of the aerial manipulator system.The model provides theoretical basis for the control of the aerial manipulator.Secondly,the whole system adopts a separated control strategy,which means that the aerial vehicle and robotic arm have their own controller.According to the trajectory of the manipulator,the dynamic center-of-gravity compensator is designed to construct ADRC controller based on the dynamic center of gravity compensation,which weakens the influence of manipulator movement on the control performance of the UAV.The stability and anti-disturbance of the system are improved.Thirdly,the simulation model of aerial manipulator is built in Simulink.The simulation experiment of fixed-point hovering anti-disturbance and trajectory tracking based on dynamic gravity center compensation ADRC controller is performed.The comparison experiment with PID algorithm is carried out to verify the reliability of the algorithm.At last,the software and hardware platform of aerial manipulator system is established.Based on this platform,the attitude-fixing anti-disturbance experiment and indoor autonomous grasping object task are carried out.Through the analysis of the experimental data,it is proved that the ADRC control algorithm based on the dynamic center of gravity compensation which is studied in this paper has good stability and anti-interference to the control of the aerial manipulator system.