Development of high speed rotating arc sensor and seam tracking controller for welding robots

The paper presents a seam tracking controller of high speed rotating arc sensor developed by a microprocessor based system. The seam tracking algorithm is based on the average current value at each interval region of four phase points on one relating cycle. To remove the noise effect for the measured current, the area during one rotating cycle is separated into four regions of front, rear, left and light. The average values at each region are calculated, using the regional current values and a low pass filter incorporating the moving average and exponential smoothing methods are adopted. The effectiveness is proven through the experimental results for several kinds of welding condition.