Would it be possible to post some comparative example pictures/videos so I can better understand what you are fixing? Thanks Stuart
On Sat, Nov 23, 2019, 5:43 AM Herzog Raoul <raoul.her...@heig-vd.ch> wrote: > dear Andrew, > > The RS274 interpreter is still the original, important concepts like HAL, > pins etc, are still there. > > Even with high end drives, you cannot simply stream position data, the > reference signals for each drive *must* respect the physical constraints > regarding max jerk, max acceleration and max speed ! > > Important for understanding : there is NOT ANY trajectory planning INSIDE > the drive, only feedback loops and feedforward. > > best regards, > > Raoul > > -----Message d'origine----- > De : Andrew <pkm...@gmail.com> > Envoyé : samedi 23 novembre 2019 12:24 > À : EMC developers <emc-developers@lists.sourceforge.net> > Objet : Re: [Emc-developers] announcement OpenCN, a new fork of LinuxCNC > --> Precalculations > > Just wondering what's left from LinuxCNC there ) With such intelligent > servo drives you just have to stream the position data (you made the new TP > for that!). > Do you use Ethercat I/O too? > > сб, 23 лист. 2019 о 12:17 Herzog Raoul <raoul.her...@heig-vd.ch> пише: > > > dear Nicklas, > > > > there is no feedback control loop in OpenCN. > > Feedback and Feedforward is only inside the drives. > > > > We use TSD80E drives from the manufacturer Triamec ( > > https://www.triamec.com/de/triamec-servo-drives.html). > > The sampling frequency for the PWM, current control loop and position > > control loop is 100 kHz ! > > The setpoint values coming from EtherCat at a rate of 10 kHz are fine > > interpolated in the drive and upsampled to 100 kHz. > > > > One remark regarding our feedrate planning. > > At any time, at least one of the constraints is "active", meaning that > > either the max jerk is delivered, or the max acceleration, or the max > speed. > > Sometimes this is called "Bangbang", maybe a misleading term since > > there are no jumps in acceleration. > > Time optimality automatically leads to this "Bangbang" property. > > > > best regards, > > > > Raoul > > > > -----Message d'origine----- > > De : N <nicklas.karlsso...@gmail.com> > > Envoyé : samedi 23 novembre 2019 10:51 À : EMC developers > > <emc-developers@lists.sourceforge.net> > > Objet : Re: [Emc-developers] announcement OpenCN, a new fork of > > LinuxCNC > > --> Precalculations > > > > > dear Nicklas, > > > > > > of course, feedforwards are utilized (and well parametrized) in the > > *drives*, otherwise excessive tracking errors appear. > > > > > > But this is done in the *drive*, *not* in OpenCN. > > > OpenCN calculates physically realizable setpoint values (according > > > to > > "optimal control theory"). > > > > Sounds really good. Physical realisable will be movement calculated > > with feedforward of maximum and minimum voltage with a perfect model, > > sounds simple but to calculate then it is time to slow down to exactly > > hit a point running at the limits is suprisingly hard to get correct for > all cases. > > > > Then there must be some room for the control law. You have gone > > further and included unperfect model and dynamics from the feedback in > > some way or other? > > > > > > Regards Nicklas Karlsson > > > > > > _______________________________________________ > > Emc-developers mailing list > > Emc-developers@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > > > _______________________________________________ > > Emc-developers mailing list > > Emc-developers@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers > > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers > _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
