Research On The Control Method And Design Of Quadrotor UAV Grasping System

Unmanned aerial vehicle(UAV)is widely used in many fields due to its flexibility and ease of operation.At present,most applications are based on long-distance interaction.With the rapid development of intelligent navigation technology and automatic control technology,and the booming development of the logistics industry,the research of UAV with robotic arm has attracted the attention of related scholars.However,there are some problems in the research of UAV’s grasping,such as poor autonomy and low grasping success rate.This paper studies the precise control of autonomous grasping of UAV,as follows:(1)A lightweight robotic arm is mounted on the quad-rotor drone,and the forward kinematics of the robotic arm is developed and combined with the kinematic model of the drone.The overall system was modeled with three-dimensional dynamics.In order to reduce the computational overhead,the model was simplified to a hovering model.(2)The overall system is designed with hardware and software.The end effector of the grasping device adopts the PID control method.The cooperative control can be realized through the serial port communication with the onboard computer of the UAV.(3)Aiming at the problem that the indoor control accuracy of the four-rotor drone is low,which leads to the failure of grasping,this paper develops an attitude control system based on a commercial drone development platform applied to the grasping of UAV.Improved model predictive control(INMPC)completes the attitude control of the UAV.It is proposed to add PI to the NMPC pose setting end to adjust the expected position value in real time and add a variable weighting factor to the cost function,which reduces the tracking error and enhances the real-time performance of the algorithm,and the problem of slow state switching in the grasping process has been further improved.(4)In order to solve the problem of poor stability of near-ground grasping,the influence factor of ground effect was added into the model to improve the stability of near-ground hovering.(5)In order to verify the proposed algorithm,this paper performed physical simulation in Gazebo of the robot operating system(ROS),the urdf model of UAV and manipulator is established,and the correctness and robustness of the improved algorithm are verified.Finally,the gripping experiment was completed under the observation of the dynamic capture system.The experimental results show that the designed control system is stable in flight and has high grasping and hovering accuracy.This paper is the exploration and research of drone grabbing.It realizes the trajectory tracking and near-hover grasping control of UAV in indoor environment,which is of great significance for the application of UAV in the logistics industry.