Curved weld-seam tracking based on information fusion of welding gun inclinations

In the welding of curved weld-seam,in order to obtain a high quality of weld,it is necessary to keep the welding gun tracking the weld-seam and meanwhile to adjust the inclination of welding-gun. In this paper,a wheeled mobile welding robot was developed,and a rotational arc sensor was used to detect the welding-gun deviations as well as its inclinations based on the Fourier transform of the welding currents. Meanwhile,the inclinded angles between the welding-gun and the weld-seam were calculated based on the state of the moving robot,and then the information of welding-gun inclinations and inclined angles were fused based on the T-S fuzzy logic. A two-input and multiple outputs control system was built,in which the welding-gun deviations and the fused inclinations was set as inputs,and the motion of wheels and welding-gun was set as outputs. Based on the fuzzy control theory,a controller was designed,and the welding-gun inclinations were adjusted during the weld-seam tracking. The validity of the proposed method was proved through actual welding experiments.