> On 17 May 2017, at 19:12, michelvanderbregge...@gmail.com wrote: > > acceleration currently is 4000 ( probably insane ).
No, not really > I will try and place the ddt on the PID output, see if that changes something. Also probe the pins of the hpg component > > The reason for the high accelerations is that machinekit slowed the motion so > much that it was visible on the print ( in the form of blobs ). That's because of blending not working with > 3 axes because you have an extruder as 4th axis. > > Thanks for the reply, > Michel > > Op woensdag 17 mei 2017 17:24:32 UTC+2 schreef michelvand...@gmail.com: >> >> Hello All, >> I am trying to measure the velocity and acceleration of the individual axis >> in machinekit. >> >> I have added the ddt components and included them in my hal. >> >> This is a copy of part of my hal file with the DDTs included. >> >> # axis enable chain >> newsig emcmot.00.enable bit >> sets emcmot.00.enable FALSE >> >> net emcmot.00.enable axis.0.amp-enable-out => hpg.stepgen.00.enable >> pid.0.enable >> >> # position command and feedback >> net emcmot.00.pos-cmd axis.0.motor-pos-cmd => pid.0.command ddt.0.in >> net emcmot.00.vel-cmd axis.0.joint-vel-cmd => pid.0.command-deriv >> >> net emcmot.00.pos-fb hpg.stepgen.00.position-fb => axis.0.motor-pos-fb >> pid.0.feedback >> net emcmot.00.command pid.0.output => hpg.stepgen.00.velocity-cmd >> #net emcmot.00.pos-cmd => hpg.stepgen.00.position-cmd ddt.0.in >> >> setp pid.0.error-previous-target true >> setp pid.0.maxerror .001 >> >> # Set the stepgen in velocity mode >> setp hpg.stepgen.00.control-type 1 >> >> # timing parameters >> setp hpg.stepgen.00.dirsetup [AXIS_0]DIRSETUP >> setp hpg.stepgen.00.dirhold [AXIS_0]DIRHOLD >> >> setp hpg.stepgen.00.steplen [AXIS_0]STEPLEN >> setp hpg.stepgen.00.stepspace [AXIS_0]STEPSPACE >> >> setp hpg.stepgen.00.position-scale [AXIS_0]SCALE >> >> setp hpg.stepgen.00.maxvel [AXIS_0]STEPGEN_MAX_VEL >> setp hpg.stepgen.00.maxaccel [AXIS_0]STEPGEN_MAX_ACC >> >> # P8.9 X_Step >> setp hpg.stepgen.00.steppin 0x65 >> # P8.10 X_Dir >> setp hpg.stepgen.00.dirpin 0x64 >> >> # PID settings to prevent PRU pin hunting >> setp pid.0.Pgain [AXIS_0]P >> setp pid.0.Igain [AXIS_0]I >> setp pid.0.Dgain [AXIS_0]D >> setp pid.0.bias [AXIS_0]BIAS >> setp pid.0.FF0 [AXIS_0]FF0 >> setp pid.0.FF1 [AXIS_0]FF1 >> setp pid.0.FF2 [AXIS_0]FF2 >> setp pid.0.deadband [AXIS_0]DEADBAND >> setp pid.0.maxoutput [AXIS_0]MAX_OUTPUT >> >> # set the signals for the velocity and acceleration >> net Xvel ddt.0.out => ddt.1.in >> net Xacc <= ddt.1.out >> >> This is, if I am correct, the same way Bas de Bruin showed in his setup. The >> derivative of the position is the speed ( with the problem that I don't know >> what unit is being used, since the time constant will be the servo-thread >> period ). And the derivative of the speed is the acceleration. >> >> I opened halscope and plotted the Xvel net. But instead of a "logical" speed >> graph I got the following: >> >> >> >> >> Does anybody know why this doesn't look like what I would expect ( something >> more of a straight line with nice slopes )?? >> >> With regards, >> Michel van der Breggen > > -- > website: http://www.machinekit.io blog: http://blog.machinekit.io github: > https://github.com/machinekit > --- > You received this message because you are subscribed to the Google Groups > "Machinekit" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to machinekit+unsubscr...@googlegroups.com. > Visit this group at https://groups.google.com/group/machinekit. > For more options, visit https://groups.google.com/d/optout. -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to machinekit+unsubscr...@googlegroups.com. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
