Research On Trajectory Control And System Development Of Truss Robot For Sub-Trachea Welding

Recently,with the rapid development of science and technology,and the rising cost of labor,industrial robots have been widely used in more and more fields.Welding as a very important part of modern industry,replace the artificial gradually.Pipeline welding is a common processing technology in welding production.For the complex intersecting line trajectory,most of the existing welding robots use the teaching mode to track the track,which is inefficient.In this paper,a new algorithm is proposed to realize the automatic programming and error control of the intersecting line welding trajectory,which greatly improves the effciency of batch welding.In this paper,the welding robot adopts the truss structure,through the lateral displacement selection of different sub-tracheal welding positioning,spindle rotation and lifting to achieve the position of the torch adjustment,thus completing the intersecting line trajectory control.Not only flexible but also do not take up a lot.Based on the analysis of the structure and algorithm of intersecting line welding robot at home and abroad,this paper analyzes the structural characteristics of the truss robot and the characteristic analysis of intersecting line shape,and completes the functional scheme design of the control system.The control system uses Soft Servo Systems' Servo Works S-140 as the development platform,according to the specific function requirements of the system and the actual welding process requirements for secondary development,to achieve the sub-traction welding of the truss robot automatic programming and control.Intersecting line trajectory fitting method of "equidistant helix approximation" is proposed for the control of intersecting line trajectory.Through the rotation axis and the vertical axis of the linkage,constructed a number of equidistant helix,thus approximate the corresponding intersecting line trajectory.The theoretical analysis and test results show that the proposed scheme simplifies the process of intersecting line trajectory under the premise of ensuring the accuracy of trajectory control,and can meet the welding requirements of different size products by changing the fitting parameters.Aiming at the fitting method of "equidistant helix approximation",two different interpolation schemes(angular aliquot interpolation and distance aliquot interpolation)are discussed.The fitting trajectory of the two schemes is analyzed.Mathematical methods are used to model the intersecting line trajectories,and then the interpolation is performed to complete the trajectory fitting.Then,the simulation and error analysis of the two schemes are carried out respectively.The influence of the fitting parameters on the trajectory error is discussed,and the influence of the size of the pipe diameter,the diameter of the pipe,the number of interpolation points on the trajectory error is discussed.Provides a reference for how to choose the track fit program in different situation.The results of actual welding processing show that the CNC system can realize the automatic control of truss welding robot and can be used for rapid automatic programming and batch welding of different sizes of sub-trays,which greatly improves the convenience and efficiency of system operation.