Jon, I just saw hm2 stepgen has velocity-cmd and velocity-fb, that would be more to the point; I'll see wether that produces a better visual explanation.
but by now I'm sure it's just playing catch-up with erratic position updates - TP figures the spindle has stopped if it doesnt see updated position for a/some cycles and scrambles to catch up once the encoder gets around stating that, in fact, the spindle has *not* stopped. Everything else is a consequence of this cause. again, I think the max_acceleration is the wrong knob to twist - that doesnt fix the underlying underrun problem and its consequence, namely the TP's 'spindle has stopped' conclusion, it might paper over it a bit though I'd assume reducing max_accel will just increase the time to catch up and thus lengthen the perceived oscillation 'cycle', or just creep at an increasing following error (note that increasing acceleration had the opposite effect - it could be guessed from the f-error plot). -- my problem originated from switching from parport+encoder to hostmot2 whose encoder doesnt have position-interpolated ; I'll see how that can be added. That, and/or a decent hi-res encoder should fix it. -Michael Am 21.10.2009 um 19:17 schrieb Jon Elson: > Haberler, > > OK, the trajectory planner saeems to be running at 1 KHz, same as the > servo thread. > The sawtooth is in signal axis.2.f-error I don't know what other > signals you can get > out of stepgen to help diagnose it. A commanded velocity signal > (which > it has to have > internally) would be MOST instructive, but I don't know if it puts > that > out. There may be > a diagnostic mode option that causes stepgen to export more HAL > signals. > > Have you tried reducing the MAX_ACCELERATION parameter? > > Jon > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart > your > developing skills, take BlackBerry mobile applications to market and > stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
