Research on GMAW seam tracking system based on arc sensor

The welding process of gas metal arc welding(GMAW) has nonlinear characteristics such as large inertia, large time delay and uncertain interference factors. In order to improve welding quality, a real-time welding seam tracking technology based on extended kalman filter(EKF) algorithm is proposed in this paper. Hall current sensor is used to capture real-time welding current. In order to realize that the swinging center of the welding torch is always aligned with the weld center, this paper filters the collected current through finite impulse response(FIR), establishes a mathematical model for extracting the height and horizontal deviation of the welding torch, and uses EKF to control the welding torch. Through the experimental verification on the weld with vertical and horizontal deviations, the tracking accuracy can reach ±0.25 mm, so the method can meet the requirements of real-time robot tracking.