Modeling, control algorithm, and cloud technology application of an automated SAW platform for large-size and thick-wall workpieces

An automated submerged arc welding (SAW) platform for welding of complex seams of large-size and thick-wall workpieces is introduced in this paper. The orthogonal intersection of a cylinder and a brunch pipe is taken as an example. The mathematical models of the weld trajectory in a dynamic coordinate system and in an absolute coordinate system are built respectively. A collaborative control algorithm and control strategy for the pose of the workpieces and the position of the welding torch is proposed based on coordinate transformation and discrete approximation theory. Closed form expressions of the control laws for the workpieces and the welding torch are worked out under the constraints of SAW process. The control effect of the algorithm is simulated and the approximation error is analyzed in MATLAB. Simulation results show that the approximation error of the proposed discrete control method and the tracing accuracy of the welding torch are satisfactory. The proposed welding platform provides a practical method for automated SAW process in intersection seam welding for large-size and thick-wall workpieces, in which stabilized welding quality, high efficiency, high productivity, and good production environment are promising. In the end, the application of cloud technology in the automated welding platform is also discussed, which can further improve the applicability and flexibility of the platform.