Development Of Welding Robot Mechanism For Two Intersecting Cylinders

Pipe parts are widely used in many industries such as industry,construction,agriculture,and chemical industry.Especially in the petrochemical fields and enterprises,various types of gas,liquefied gas pipelines,pressure vessels,and energy storage facilities are widely used,which played an indispensable role in the social development and urban construction.Among them,intersecting line welding is the most common form of pipe welding.The current intersecting line welding is mainly done manually which results in low work efficiency and is difficult to guarantee welding quality.Therefore,it is especially necessary to design a welding robot for intersection line welding.Firstly,this paper analyzes the research status of intersecting line welding robots,and then proposes the design of two intersecting cylindrical welding robots based on the idea of intrinsic geometry combined with the relevant models of intersecting line welding.Combining the intrinsic ideas of Gaussian geometry with the Position and Orientation Characteristics(POC)set theory,the topological structures of the welding robot arm are synthesized based on the parallel mechanism topology theory,through which 15 parallel mechanisms are synthesized that can achieve the translation motion along the intersecting line.At the same time,the optimal structure is selected according to relevant performance indices,and the pipe clamping device is designed as well.And then the specific structure of the two intersecting cylindrical welding robot is obtained,after which the design is verified through structural analysis.Secondly,the kinematics analysis of the selected two intersecting cylindrical welding robot mechanism is accomplished.The forward and inverse solution equations are solved through establishing the kinematics equations.And the errors that may influence the accuracy of the mechanism are classified.Then the effects for the trajectory of the end effector from the error of the length,stiffness and relative position are discussed separately according to the independent error principle.A practical example is analyzed based on the MATLAB,through which the relationship between the theoretical trajectory and the actual trajectory is obtained.Finally,the three dimensional model of the two intersecting cylindrical welding robot mechanism is established by SolidWorks and is imported into ADAMS for joint simulation with MATLAB.Then the characteristics of the end effector’s output trajectory are analyzed,which has verified the feasibility of the scheme.The driving device is selected as well,and the prototype experimental platform of the two intersecting cylindrical welding robot is eventually built with a preliminary experiment.