The invention discloses an online demonstration method for a 'J'-shaped groove
welding robot, which relates to the field of
robot welding, and includes the steps: judging whether circumferential deviation is within a first preset range or not by a
microprocessor, acquiring axial deviation if the circumferential deviation is within the first preset range, and if the circumferential deviation is not within the first preset range, rectifying the circumferential deviation by the
microprocessor, and acquiring a first practical weld shape track; and judging whether the axial deviation is within a second preset range or not by a
microprocessor, if the axial deviation is not within the second preset range, rectifying the axial deviation by the microprocessor, and acquiring a second practical weld shape track or a third practical weld shape track, and if the axial deviation is within the second preset range, leading the J-shaped groove
welding robot to return to a start point again, turning off a
laser range finder and starting to weld so as to complete the process. The online demonstration method for the 'J'-shaped groove welding robot has the advantages that the quantity of weld characteristic data points are obviously decreased by means of B-spline interpolation, the problem of quick positioning of a robot-based coordinate
system and a workpiece coordinate
system is fundamentally solved by means of judgment and deviation rectifying of the microprocessor, human factor influence on demonstration is reduced, and weld quality consistency is guaranteed.