Research On Manipulator Trajectory Planning Of Saddle Shaped Intersecting Line Weld

Robots are widely used in welding because of their flexibility and efficiency.Saddle-shaped intersecting line weld is a kind of spatial complex curve,which is widely used in pipeline transportation and pressure vessel.The traditional robot welding can not guarantee the quality of welding seam by teaching and replay method,and the welding accuracy is low.In order to improve the welding automation degree of welding robot and avoid the collision between welding gun and workpiece,it is necessary to comprehensively apply welding seam location,data processing and automation program.Therefore,a saddle shaped welding robot welding method based on motion planning and off-line programming is proposed.On this basis,the running time,joint leap and energy consumption of the robot are comprehensively optimized to achieve green production.In this paper,ABB IRB 1410 robot is used as the research object to carry out trajectory planning,and the validity of the method is verified by ADAMS simulation and actual welding experiments.1.The rigid body pose of the robot is described,the homogeneous transformation matrix is established,and the forward and inverse kinematics solving process of the robot is deduced according to the parameters between the robot’s connecting rods and d-H method.Based on the Monte Carlo method,the robot workspace is further analyzed,and the robot terminal simulation cloud point graph is established in MATLAB,which lays the foundation for the robot trajectory planning.2.A digital model was established for the saddle intersecting line weld,and the weld with four positions(orthogonal,oblique,orthogonal bias and oblique bias)was discretized to obtain the Cartesian space discrete graph of the weld;The welding gun attitude model was established,the ship welding attitude coordinate system was established by analyzing the walking Angle and working Angle of the welding gun,and the simulation model was established by MATLAB to get the welding gun collision free welding track.According to the interpolation characteristics of the inverse kinematics analysis polynomial method and NURBS spline curve method,the velocity,acceleration and jump curves of the spline curve are more continuous,smooth and mutation free,which is more superior to the trajectory planning of complex curves.3.Considering the kinematics and dynamics constraints of welding robot,the trajectory planning of robot multi-objective optimization is carried out.An optimization function was established for the robot’s running time,energy consumption and joint impact,and the multi-objective optimization function was transformed into a single optimization function based on MOP optimization model.Adaptive particle swarm intelligent optimization algorithm is proposed to solve the optimal robot joint trajectory,in order to increase the particle optimization ability and avoid falling into local optimum,iterative structure adaptive factor to control the particle velocity and position,introduced in the late particle optimal particle disturbance,increase the individual diversity and group for optimum optimal location convergence speed.Taking the welding seam of the intersecting line in Cartesian space as an example,the trajectory planning analysis of the robot was carried out by MATLAB.The kinematics curve of the joint was continuous and smooth,and the energy and time consumption were significantly reduced compared with before optimization,and the robot operation met all constraints.The algorithm was optimized and compared with other intelligent algorithms.The adaptive particle swarm optimization algorithm has faster convergence speed and better searching ability.4.Verify the accuracy and practicability of the robot trajectory method.Establish IRB1410 virtual prototype in ADAMS and add dynamic constraints.The planning method is used for actual welding operation.From the actual welding effect of the robot,the weld is smooth and meets the actual welding demand.