On Sunday 02 May 2021 16:34:43 Jon Elson wrote: > On 05/02/2021 01:00 PM, Chris Albertson wrote: > > The below is exactly true. The problem is that PID is widely used > > and PID is only "reactive" it can only deal with what has already > > happened and the time lag is the source of oscillations. In the > > past, PID was the only control option because we had limited > > computing power. > > True for classic PID. The PID calculation in LinuxCNC also > has feedforwards (FF0 - FF2) which > are quite useful, as they give an approximation of the > required drive to the motor without the output, move, sample > delay. > Yes, and that I have found usefull. But using them intelligently isn't at all well explained by the docs we have. Time constants and their effects are are not at all well explained. The bottom line is that if and when you hit the magic settings, you still have no idea why this works and that doesn't. > Jon > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users
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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
