On Thursday 16 March 2017 13:48:51 sam sokolik wrote: > The stepgens (both in mesa and the software) have their own > acceleration setting. you want this to be 20 to 30% higher than the > motion planners acceleration. (when using the stepgen's in position > mode) > Humm. I believe I have that bass-ackwards in at least one place, maybe both.
I had TRAJ set for MAX_LINEAR_VELOCITY = 1.250 # 30 ipm DEFAULT_LINEAR_VELOCITY = 0.5000 MAX_LINEAR_ACCELERATION = 5.50 then AXIS X MAX_VELOCITY = 0.70 MAX_ACCELERATION = 3.0 [joint 0] MAX_VELOCITY = 0.74 MAX_ACCELERATION = 3.0 # Set Stepgen max_accell higher than the axis STEPGEN_MAX_VEL = 0.70 STEPGEN_MAX_ACC = 4.50 [AXIS Z] MAX_VELOCITY = 1.75 MAX_ACCELERATION = 4.00 [JOINT_1] TYPE = LINEAR MAX_VELOCITY = 0.9750 MAX_ACCELERATION = 4.0 # Set Stepgen max 20% higher than the axis STEPGEN_MAX_VEL = 6.0 STEPGEN_MAX_ACC = 7.50 So obviously those ratios are off. Most were determined by how fast I can actually move that axis w/o stalls - 20% or so. And since the joints conversion, no one has said if the [AXIS] assignments can be dropped. Can they? ISTR having noted that I cannot write to a joint if the axis input by the same name is used, but I CAN read the joint and see what I wrote under the axis version of the name. In the meantime I've made the accels a bit more inline with that recommendation, but I got sidetracked with a 7i90 problem and haven't tried to elicit another error out of it. The 7i90 problem that disables any 02 function is also killing some gpio pins. Or could, halshow can't access the hm2 stuff anymore. halscope and halmeter can yet. And I'm fixing dinner, so I'd better go stir it. Later. > when using high latency systems - then it is best to run the stepgens > in velocity mode with PID. > > sam > > On 3/16/2017 12:33 PM, Nicklas Karlsson wrote: > >>>>>>> There are no pid's used in this configuration Jon. Nor is > >>>>>>> there a base-thread. Till now I haven't missed them. > >>>>>> > >>>>>> How do you get a following error without PID? > >>>>> > >>>>> The difference between actual or measured position and position > >>>>> reference value is large enough. > >>>> > >>>> And this difference, Nicklas, is reduced by lower accel limits, > >>>> and a faster servo-thread I assume? Those I can fix. :) > >>> > >>> Yes if you have some kind of feedback loop. > >> > >> If there is, I'd say its hidden in "motion". I don't recall a > >> coupling internal to the hal code. But I'll double-check as I've > >> been concentrating on the other wheel related stuffs. > > > > If you use stepper without feedback they are supposed to fit > > together although I think there may be a small delay. > > > > -------------------------------------------------------------------- > >---------- Check out the vibrant tech community on one of the world's > > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > 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) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
