Feed forward control of back bead and bead height in narrow gap robotic welding

Abstract

For high quality welding, it is necessary to form a stable back bead and to melt metal plates. In narrow gap welding, it is difficult to control the bead height and the back bead simultaneously using conventional welding. In order to solve this problem, a switch back welding method is proposed in which the welding torch is moved back and forth along the welding line. In the forward movement of the torch, the arc heat is given to the root edges to obtain a wide back bead. In the backward movement, suitable bead height is formed. From the fundamental experimental results, a numerical model was prepared for this type of welding. Using this model, the optimum stroke length was found. Its validity was verified by carrying out welding experiments.