Method and device for robot-aided remote laser welding with simplified control of focusing direction of laser beam

A device for laser welding for use with a structure consisting of metal sheet elements, comprising:

• a multi-axis handling robot including a plurality of electric motors controlling the movement of elements of the robot around said axes, and a programmable electronic control unit for controlling said electric motors in order to shift a terminal element of the robot in any position along a path of travel;
• an accessory device connected to the terminal element for focusing a laser beam along a rectilinear trajectory to create at least a first weld bead and a second weld bead linearly spaced from the first weld bead, said accessory device operable to selectively orient the focused laser beam by rotating it around one oscillation axis through an electronic controller and at least one motor;
• wherein the robot electronic control unit defines a first rectilinear trajectory speed along the path of travel for the terminal element and the accessory device electronic controller defines a second rectilinear trajectory speed for movement of the laser beam in creating the first and the second weld beads, and a third rectilinear trajectory speed for movement of the laser beam between an end of the first weld bead and a beginning end of the second weld bead, the first speed is greater than the second and the third speed is greater than the first.