maybe the constraint should be (neglecting e stop) that the control stops at the next block that could contain a zero velocity, given the machinetool's maximum acceleration. single stepping would then be slower than max possible speed, and pausing continuous block execution would occur at an indeterminate number of blocks after a feedhold signal. the lookahead would still have to be an arbitrary amount of blocks. if the physical path length of each block is calculated, then the lookahead could stop searching through blocks when it found a sequence long enough to ensure keeping within machinetool's acceleration limits.
--- On Fri, 4/20/12, Jon Elson <el...@pico-systems.com> wrote: > From: Jon Elson <el...@pico-systems.com> > Subject: Re: [Emc-users] Trajectory planning and other topics from a > EMC(LinuxCNC) newbie (TheNewbie) > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Date: Friday, April 20, 2012, 8:55 PM > Thomas Powderly wrote: > > > > here's how one group worked with the fast turn around > at edge of work > > the machine tool was like the emc2-bipod and the > software built > > huge arcs into the endmotions to keep velocity up and > dampen the bipod swing > > > Certainly fixing this in the CAM is the best approach, then > the machine > never needs to slow down > at all, keeping good speeds right to the end of contact with > the work. > > The problem, of course, is LinuxCNC won't give you the > fastest speed > possible because it > still demands being able to stop at the end of the next > block. > > Jon > > ------------------------------------------------------------------------------ > For Developers, A Lot Can Happen In A Second. > Boundary is the first to Know...and Tell You. > Monitor Your Applications in Ultra-Fine Resolution. Try it > FREE! > http://p.sf.net/sfu/Boundary-d2dvs2 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
