Fanuc Corporation

Akiko Takano

Tetsuya Kosaka

Takayuki Ito

A cylindrical workpiece as a welding object is rotated by an external drive shaft. A welding torch and a laser sensor are attached to a distal end portion of a robot. A deflective scanning laser beam from a laser sensor is projected on a region just ahead of a weld point, whereby a light spot trace is formed extending in a direction perpendicular to a welding center line. A CCD camera of the laser sensor picks up the trace, thereby detecting a change of the thickness of a weld layer. In executing a weaving operation, the robot performs an alternating motion including components in the direction perpendicular to the welding center line. When the workpiece rotates so that the range of projection of the laser beam, starting from a region without any weld layer thereon, reaches a region for the formation of a first weld layer, a layer transition is detected by an increase of the thickness of the weld layer. Based on this point of time, control is effected to execute correction of the robot position, modification of welding conditions, etc.

Robot control system for executing multi-layer welding

A three-dimensional laser beam machining apparatus using a YAG cutting tool. A robot controller functioning as a YAG cutting tool controller is connected to a laser beam supply through a optical fiber and to a robot having an arm end on which the YAG cutting tool is mounted. When a diagrammatic machining command for the YAG cutting tool is given, an first internal program for the diagrammatic machining command and a second internal program for compensating a robot position in a z-axis direction are created. These internal programs are executed in parallel by a multi-task function. The YAG cutting tool is two-dimensionally controlled so as to depict a diagram, such as a rectangle and a circle. When the YAG cutting tool moves across the axis of a cylindrical workpiece, the robot position in the z axis direction is compensated so that the gap between the laser head and an cylindrical surface of the workpiece is kept constant.

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Oshino-mura, Japan

Akiko Takano