Research On Structural Optimization And Trajectory Planning Of Spraying Robot For Large Rocket Components

In the process of aerospace launch vehicle crossing the atmosphere,the surface of the rocket will be exposed to huge heat,so the coverage of its surface protective coating is crucial.As a high-efficiency and high-quality spraying equipment,the spraying robot has been widely used in industrial production.However,currently the spraying robots on the market are mainly used for the spraying of small and medium-sized devices such as automobiles and electronic products,so the aerospace manufacturing industry urgently needs spraying robots specially used for large parts such as rockets.In order to improve the surface spraying quality and working efficiency of the fairing of carrier rocket,this paper studies the structure optimization and trajectory planning of a self-designed and manufactured stretchable spraying robot.The main research contents of the full text are as follows:According to the three-dimensional model of the self-designed painting robot,its kinematics model is obtained by analyzing its structure and working principle,and it is simplified into a 5R series robot.By studying the homogeneous transformation matrix of the robot,the forward and inverse kinematics solutions of the robot are obtained.Based on the construction principle of the robot Jacobian matrix,a method is proposed to determine the singularity of a series robot with with a degree of freedom less than 6.By extending the singular value decomposition algorithm of two-dimensional matrix,an iterative algorithm of singular value decomposition of three-dimensional matrix is obtained,which can decompose the three-dimensional matrix into a series of singular values and three two-dimensional matrices,and it is more accurate than the general algorithm of splitting three-dimensional matrix.By analyzing Jacobian matrix and Hessian matrix condition number of the robot,the global motion performance index of the robot is obtained.According to the index,the structure of the robot is optimized and simulated.The simulation results show the correctness of the optimization index.According to the working principle and spraying characteristics of air gun,the ellipse dual-spraying model is selected as the mathematical model of coating deposition,and the key parameters of the mathematical model are obtained through a series of experiments and calculations.By analyzing the thickness of the paint with a singletrajectory and multiple trajectories of the spray gun,the optimal velocity and trajectory interval of the spray gun at the end of the robot are obtained.On this basis,the motion trajectory of the robot spray gun is generated,and the motion trajectory is optimized by cubic spline curve.At last,the virtual prototype was used to simulate the spraying of the robot,and the maximum rotation Angle,maximum rotation speed and maximum torque of each joint during the robot movement were obtained,so as to facilitate the hardware selection of the robot and the construction of the control system.