Trajectory Planning Of Welding Manipulator And Obstacle Avoidance Optimization Of Frame Weldment

As the basis of modern manufacturing industry,welding robot has become an important symbol to measure the level of science and technology of a country and the degree of industrial automation and intelligence.In this paper,aiming at the problems such as poor obstacle avoidance accuracy,speed and acceleration mutation when welding robots face complex welding parts,the trajectory planning of welding robots and optimization methods of frame welding parts obstacle avoidance are studied,so that welding robots can achieve the purpose of high efficiency and energy saving in practical welding work.In this paper,ABB IRB120 welding robot is taken as the research object.Firstly,the body configuration of the robot is introduced,the appropriate D-H method is selected to establish the robot connecting rod coordinate system,and the D-H parameter table is listed.Combined with the knowledge of kinematics theory,the forward and inverse kinematics equations of welding robot are solved.D-h parameters were imported into MATLAB/Robot Toolbox for kinematic simulation analysis,and the simulation results were compared with the actual calculation results to verify the correctness and rationality of the kinematic equation and Robot body structure listed.Secondly,in order to reasonably plan the motion trajectory,the Monte Carlo Method was used to solve the practical working range of the welding Robot during welding.In MATLAB/Robot Toolbox,the rotation Angle range of each joint of the Robot and random work points were set for workspace simulation.The spatial position points that the robot can reach in the set range are obtained,and the spatial point cloud image is output,and the feasibility of its work is analyzed according to the distribution of the point cloud image.Then,different interpolation algorithms are used to carry out trajectory planning in joint space coordinate system and Cartesian space coordinate system.By using MATLAB/Robot Toolbox simulation,the curves of joint Angle,angular velocity,angular acceleration and impact of the welding gun at the end of the welding Robot were obtained under the two spatial coordinate systems with time changes,as well as the trajectory changes of the straight and circular trajectory at different interpolation points.Through comparative analysis and combined with the structure and performance of the robot selected in this paper and the work effect to be achieved by using quintic polynomial interpolation method for obstacle avoidance optimization work.Finally,based on the quintic polynomial interpolation method combined with adaptive genetic algorithm(AGA),the welding robot was optimized to avoid obstacles,so that the welding robot could quickly find the optimal path in the welding process.The simulation results show that,compared with the classical genetic algorithm,the adaptive genetic algorithm(AGA)can better generate new individuals to get rid of the local extremum,search the global optimal solution faster,and obtain the motion trajectory of the robot’s end points with steady and continuous changes by adaptively adjusting the values of crossover probability Pc and mutation probability Pm.The convergence speed and solution accuracy are improved to a certain extent.