Airground Cooperative Control Technology For The UAV Based Intelligent Spraying Of Ship Exterior Plate

As one of the three pillars of the shipbuilding process,ship painting has a crucial position with the roles of extending service life,reducing maintenance cycle and reducing navigation risk.The existing mode of ship painting has disadvantages,such as low spraying efficiency,difficult quality control and poor equipment practicality,which seriously hinders the intelligent transformation of ship construction.For this reason,it is an important direction of painting innovation to study the spraying equipment of ship exterior plate based on UAV,of which air-ground cooperative control is one of the key technologies.UAV-UGV collaborative control can complement the advantages of UAVs and improve the operation range,which has a broad application prospect.The key research contents include maintaining desired formation and realizing trajectory tracking.Therefore,this thesis takes air-ground cooperative ship painting operation as the research object,develops an intelligent painting platform and material supply platform,designs the formation keeping and trajectory tracking control algorithm,studies the RTK positioning system,and verifies the feasibility of air-ground cooperative operation through painting tests.The main research contents of this thesis are as follows:1.Created the nonlinear dynamics models of UAV and UGVThis chapter introduces the description of the position relationship of UAVs in formation control,analyzes the motion characteristics of UAV and UGV,introduces the body coordinate system of UAVs and the earth coordinate system,and creates the nonlinear dynamics model of UAV and UGV,which provides the basis for the subsequent controller design.2.Proposed the collaborative method based on the virtual piloting strategy(1)The air-ground cooperative control method based on the virtual pilotage strategy is proposed.A virtual UAV is introduced,and the relative position relationship between UAV and UGV is maintained respectively to complete motion control,and the air-ground cooperative control model is established.(2)A formation-keeping control algorithm is designed,and the error model is derived according to the relative position relationship of the UAVs,after which the controller is designed based on the Lyapunov function,and the effectiveness of the formation-keeping control algorithm is proved by stability theory.(3)A trajectory tracking control algorithm is designed.According to the UAV movement,the control system is divided into four sub-control systems: altitude,longitudinal,transverse and yaw.and the controllers of UAV and UGV are improved based on the idea of sliding mode variable structure,and the virtual control input parameters of the control are derived,and the simulation is carried out by Simulink model to verify the feasibility of the control algorithm.3.Studied the RTK positioning system based on edge computingThe acquisition of coordinates information is the basis of UAV-UGV cooperative control,for which an RTK positioning system based on edge computing is proposed.The working principle of RTK positioning technology is studied.The mobile station is loaded into the UAV and UGV,and the base station is connected to the main control computer for edge calculation to obtain the position information of the UAVs.Experiments on static and dynamic positioning as well as three-dimensional motion trajectory positioning of the UAV were conducted,and the accuracy error of the experimental data were all within 25 cm.Compared with the meter-level accuracy of conventional GPS,RTK can provide more effective spatial position information for the air-ground cooperative system.4.UAV-UGV cooperative system platform construction and function verificationAccording to the requirements of ship outer plate spraying operation,a six-axis UAV with strong load capacity and stability is adopted to carry the spraying mechanism for painting operation,and the UGV carries the equipment bin to follow the UAV in real time and supply the UAV with power and paint continuously.Moreover,spraying test was carried out on the exterior plate of ship segment,and the UAVs attitude change curve was monitored to verify the feasibility of the UAV-UGV cooperative system for spraying operation.