On 27 July 2015 at 05:31, Brian <turbo94must...@gmail.com> wrote: > I have had an idea lingering in my head for quite some time now. How about > moving the screw/backlash comp out of motion and implement it with a HAL > module.
I think that motion knows things about the required path that are unavailable to HAL. For one, it knows the direction of travel whereas HAL would need to compare subsequent position commands, introducing lag at best and possibly worse problems at very low speed. > The purpose would be for two goals. One it would make it more logical to > implement more sophisticated joint compensation, such as thermal expansion, > deflection, and belt stretch. I think there might be an argument for having backlash compensation in motion, and addign secondary corrections such as these with the "offset" component. > Second, it would set the stage to be more friendly for dual scale/motor > feedback, because it would give control over where the compensation is added > in the feedback loop. This sounds good in principle, but I would need to think about it rather longer to work out whether it is important in practice. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
