An automatic groove-tracing welding system is capable of carrying out a
welding operation, particularly, a welding operation involving weaving,
without requiring monitoring even if conditions of a groove is different
from design conditions of the groove. An image processor 3 receives an
image signal representing an image of a weld zone 52 including the tip of
a welding wire from a camera head 2 provided with a CCD camera, processes
the image of the weld zone 52 to determine the position of a groove,
calculates the positional relation of the groove with a welding torch 1,
and sends a position correction for correcting the position of the
welding torch 1 so that the welding path of the tip of the welding torch
1 may coincide with a predetermined middle part in the groove to a robot
controller 43 for controlling a welding robot. When the automatic
groove-tracing welding system performs a welding operation involving
weaving, the image processor 3 receives a weaving phase signal
representing phases of weaving from the robot controller 43, calculates
the positional relation between the groove and the welding torch on the
basis of the phase of weaving, and sends a weaving width correction
signal to the robot controller 43.
