Abstract: he trajectory planning of posture adjustment is presented for a weld mobile robot during auto-searching weld line. It is a critical step to adjust the posture of the body of mobile robot and torch to desired status preparing for welding after the weld groove has been recognized according to the model of groove recognition characteristics and the angle between robot and weld line is solved according to some algorithm. Firstly, the configuration of welding mobile robot with the function of auto-searching weld line is introduced, then the trajectory of posture adjustment is planning during auto-searching weld line on the basis of kinematics of mobile robot, at last the trajectory of posture adjustment is modified according to the structure of mobile robot itself. The experiment result is shown that error precision of posture adjustment could be controlled to approximate ±1.5 mm when the above algorithm is applied to the posture adjustment during auto-searching weld line and could be suited for real welding project.

Key words: Auto-searching weld line, Posture adjustment, Trajectory planning, Welding mobile robot