Research On Welding Seam Trajectory Planning System For Automatic Welding Of The Header-nozzle Joints

There are a large number of saddle-type weld seams for header-andnozzle joints welding during the power boiler manufacturing process.Because of the special structure,it is mostly welded by manual welding,which is difficult to meet the quality and efficiency requirements of the company.As a result,to develop the welding automation system for manufacturing corporations,makes a great significance for improving production efficiency and quality,and reducing energy consumption.This paper designs a robot automatic welding system for header-andnozzle joints,and focuses on the saddle-type weld seam trajectory planning algorithm for header-and-nozzle joints.Based on the analysis of the welding needs and process characteristics of the headers of the headers,the functional design of the production line was carried out,an intelligent welding system for header-and-nozzle joints with a welding robot as the core and various sensors and information management systems on site was constructed.Systematically studied mathematical model of 6-axis industrial robot,forward and inverse kinematics algorithm and trajectory interpolation algorithm,a robot path simulation platform is constructed based on these.The calculation results are compared with real robots.The maximum deviation meets the accuracy requirements of enterprises.Integrate into the welding process characteristics of the header-and-nozzle joints and the groove structure,this paper studies the multi-layer and multi-path welding path of the robot and the algorithm of process planning.Through the 3D path planning of the groove,the function of weld seam trajectory planning for multi-layer and multi-pass welding is realized,and by this,it is applied to a software system for automatic welding of multi-layer and multi-pass welding.This system can automatically calculate the welding parameters,welding torch path and other information according to the groove parameters and welding process requirements,and generate a program that can be executed by the robot to improve programming efficiency.Finally,a welding robot test station was set up,and multiple sets of header-and-nozzle joints welding were performed.The test results show that this set of planning system can well complete the automatic welding task of saddle-shaped welds of headers and headers.The welding quality is good and the welding efficiency is improved,which has application value.