Arc welding: weaving plane

MaxGAT

Hello,

My task is to program MIG arc welding of objects with axial symmetry. The robotic cell includes an IRB2400L arm and a positioner with a rotating table; RobotWare 5.15.15. The preferred (working) solution is to hold a stationary welding torch at distance R from the centre of the table and continuously rotate the table (number of full revolutions >> 1), which is implemented using ArcL command with the only variable which changes being ToPoint.extax.eax_c. In addition to simplicity, another benefit of this approach is a constant orientation of the tool tangential to the path. The azimuthal angle of the torch position is prescribed and cannot be freely selected.

 I have been asked to add weaving to the welding. I used weavedata with the following fields:

weave_shape := 1 (horizontal weaving);

weave_type := 3 (since the torch is stationary, it has zero weave length; instead weave frequency has to be defined for Rapid weaving);

weave_length := 1 (frequency of weaving for Rapid weaving);

weave_width := 8 (amplitude of deviations of the torch from the equilibrium position, mm).

The rest of the weavedata fields are zero.

Problem: how to set the direction of weaving for a stationary tool at a specified azimuthal angle? I tried changing the following parameters: weave_dir, weave_tilt, weave_ori, tool orientation, work object orientation, world orientation. None of that had any effect on the direction of weaving. I found a quick fix (vertically displace the torch by +-0.1mm). But I would love to know a rigorous solution. 

Thank you very much in advance.

Max

MaxGAT

I attempted to replace \weave with path correction which oscillates about a stationary point (plus/minus deviation values written to a correction generator via a timer interrupt, & using \Corr option in ArcL commands). The approach works fine for a linear path, albeit for very low frequencies (1 Hz), above which the oscillations turn into a drift. But when the path is shrunk to a point, the result is disastrous, I assume because the tool path coordinate frame is not defined. Would be nice to hear from the ABB software developers about this behaviour and a possible solution.