Abstract:A seam width adaptive seam tracking algorithm based on swing arc sensor welding system is proposed in this paper. The welding swing controller drives the ball screw mechanism by stepping motor to realize the swing of the welding gun. The main controller of robot is developed based on ARM processor to realize the control of motion trajectory, calculation, teaching and reproduction. By analyzing the signal of the swing arc and the previous cycle swing data of the welding torch, the complex function adaptive algorithm control model is established, the swing parameters after the change of the welding seam are calculated and fed back to the control system, then the weld width adaptive tracking welding is completed. The x,y,z three-axis orthogonal coordinate welding robot is used as the moving platform to verify the rationality of the algorithm. The experimental results with 4 mm/s of the welding speed and 0.5 Hz of the welding frequency show that the algorithm can well adapt to the change of weld width in welding process. The performance is stable and motion trajectory is good.