On Sunday 03 April 2016 16:52:12 Nicklas Karlsson wrote: > > On Sun, Apr 3, 2016, at 12:14 PM, Nicklas Karlsson wrote: > > > Then reading the configuration file I find there max acceleration > > > and velocity is defined twice. They are defined in both [TRAJ] and > > > [AXIS_?] sections. > > > > I am reasonably certain that the TRAJ limits apply to the combined > > motion of the controlled point, while the AXIS limits apply to the > > individual axes. > > > > Consider a 45 degree move. If X is moving at its limit of 10 > > units/sec and Y is also moving at its limit of 10 units/sec, the > > controlled point is moving at 14.14 units/sec. If the TRAJ limit was > > also 10, X and Y would be slowed down to 7.07 units/sec so that the > > controlled point is moving at 10. > > > > > Does the trajectory planner follow the limit in it's own section? > > > In such case what happen if [AXIS_?] limit is lower? > > > > I'm pretty sure lowest limit wins. > > > > Assume X limit is 6, Y limit is 8, and TRAJ limit is 9. > > A move from (0,0) to (10,0) is parallel to X and would be limited to > > 6. A move from (0,0) to (0,10) is parallel to Y and would be limited > > to 8. A move from (0,0) to (12,16) would result in X moving at 5.4 > > units/sec and Y moving at 7.2 units/sec, so that the motion of the > > controlled point is at 9 units/sec even though neither axis is at > > its limit. > > Never thought about it before but interestingly enough it is possible > to get sqrt(2) larger acceleration in the diagonal provided maximum > acceleration is equal for both axis. For three axis it is sqrt(3) > which is a quite large difference.
And that multiplier then is 1.73205080756887729. Intriguing. Do we set the [TRAJ] settings then to be that times the fastest axis, or the slowest one? Seems to me we should use the fastest axis since a slower one will automatically restrain the speeds of the others so it can maintain a straight line path. Interesting thread, do carry on. :) Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785471&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
