Re: [Emc-developers] Sigma5ABS Implementation - Commutation
Ok good. Both an angle pin and passing the hall signals through should be sufficient to commutate on pico and mesa drives. On Mon, May 11, 2020 at 3:17 PM Jon Elson wrote: > On 05/10/2020 10:20 PM, Curtis Dutton wrote: > > These do have hall > > signals to allow initial commutation. > Ah, that solves the commutation issue. > > If you had to drive fanuc encoder/servos from a bldc component how would > > you (roughly speaking) configure them? > > > Well, I don't. I make brushless servo amps that take the > "Hall" signals to control commutation. > So, they are simple six-step drives, not sinusoidal. But, > that seems to work pretty well. > There IS a slight discontinuity at the commutation changes, > but it is really pretty small. > > So, for the Fanuc encoders, I make converters that provide > simulated Hall signals from the > information available. > > Jon > > > ___ > 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
Re: [Emc-developers] Sigma5ABS Implementation - Commutation
On 05/10/2020 10:20 PM, Curtis Dutton wrote: These do have hall signals to allow initial commutation. Ah, that solves the commutation issue. If you had to drive fanuc encoder/servos from a bldc component how would you (roughly speaking) configure them? Well, I don't. I make brushless servo amps that take the "Hall" signals to control commutation. So, they are simple six-step drives, not sinusoidal. But, that seems to work pretty well. There IS a slight discontinuity at the commutation changes, but it is really pretty small. So, for the Fanuc encoders, I make converters that provide simulated Hall signals from the information available. Jon ___ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
Re: [Emc-developers] Sigma5ABS Implementation - Commutation
I was worried about a phase-angle needing to be added in. I did read somewhere that the 8i20 adds this automatically but I wasn't sure. Sounds like that it does. I will try direct commutation to the 8i20 and report back. On Mon, May 11, 2020 at 4:43 AM andy pugh wrote: > On Mon, 11 May 2020 at 01:18, Curtis Dutton wrote: > > > Would be possible to use the encoder to output a rotor-angle directly to > be > > used with an 8i20 or other type drive thus removing the need for the bldc > > component when using the yaskawa motor. > > That can work, and one of the motors on my lathe is commutated exactly > that way. > > I am using Resolvers. > > If the resolver pole count matches the motor pole count and the > resolver is aligned to the motor, then this works: > > net z-angle hm2_5i24.0.resolver.01.angle hm2_8i20.0003.angle > > (You will note that I am using the option to address smart-serial > devices by their serial number, and that I have one of the very first > 8i20s) > > For the X axis, where nether condition is true, I use bldc to adjust > for pole count differences and offset. > > net x-counts hm2_5i24.0.resolver.00.rawcounts => bldc.0.rawcounts > setp bldc.0.scale -16777216 > setp bldc.0.poles 8 > setp bldc.0.encoder-offset 170 > net x-angle bldc.0.rotor-angle hm2_8i20.008d.angle > > > > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1912 > > > ___ > 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
Re: [Emc-developers] Sigma5ABS Implementation - Commutation
On Mon, 11 May 2020 at 01:18, Curtis Dutton wrote: > Would be possible to use the encoder to output a rotor-angle directly to be > used with an 8i20 or other type drive thus removing the need for the bldc > component when using the yaskawa motor. That can work, and one of the motors on my lathe is commutated exactly that way. I am using Resolvers. If the resolver pole count matches the motor pole count and the resolver is aligned to the motor, then this works: net z-angle hm2_5i24.0.resolver.01.angle hm2_8i20.0003.angle (You will note that I am using the option to address smart-serial devices by their serial number, and that I have one of the very first 8i20s) For the X axis, where nether condition is true, I use bldc to adjust for pole count differences and offset. net x-counts hm2_5i24.0.resolver.00.rawcounts => bldc.0.rawcounts setp bldc.0.scale -16777216 setp bldc.0.poles 8 setp bldc.0.encoder-offset 170 net x-angle bldc.0.rotor-angle hm2_8i20.008d.angle -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." — George Fitch, Atlanta Constitution Newspaper, 1912 ___ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
Re: [Emc-developers] Sigma5ABS Implementation - Commutation
It does sound similar. Yaskawa does have a type of absolute encoder with a battery backup. Based on the datasheet their absolute encoders have connector pins for a battery but these ones do not. These do have hall signals to allow initial commutation. I assume that the yaskawa drives commutate on the hall signals until the reference point is crossed and then adjust for normal operation. If you had to drive fanuc encoder/servos from a bldc component how would you (roughly speaking) configure them? -Curt On Sun, May 10, 2020, 10:50 PM Jon Elson wrote: > On 05/10/2020 07:20 PM, Curtis Dutton wrote: > > I have been able to get the yaskawa sigma5 motors turning with the bldc > > component in qh mode. > > > > The encoders are a sort of hybrid incremental/absolute encoder. Once they > > pass the index point a flag and an offset are returned in the encoder > data > > that allows the exact rotor angle position to be computed. > > > > I'm trying to find the best path forward for facilitating commutation. > Any > > guidance would be appreciated. > > > Fanuc has two types of serial encoders. ABS and INC, for > absolute and incremental. > The incremental type only provide correct shaft angle when > battery backup is provided. > If the battery is disconnected or drained, then you have to > manually crank the motor over > one full turn so the encoder can see the index position. > Then, the controller can determine > commutation from the encoder data. > > The absolute type have an additional low-res track that > provides a 1024 count per quadrant > data that is aligned to the motor poles, so a drive could > immediately get commutation data > when encoder power is on. Although Fanuc provides a backup > battery for these encoders, > it seems it is not totally necessary. > > Perhaps the Yaskawa also have provision for battery backup? > The flag changing when index is sensed > sounds just like what the Fanuc encoders do. > > Jon > > > ___ > 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
Re: [Emc-developers] Sigma5ABS Implementation - Commutation
On 05/10/2020 07:20 PM, Curtis Dutton wrote: I have been able to get the yaskawa sigma5 motors turning with the bldc component in qh mode. The encoders are a sort of hybrid incremental/absolute encoder. Once they pass the index point a flag and an offset are returned in the encoder data that allows the exact rotor angle position to be computed. I'm trying to find the best path forward for facilitating commutation. Any guidance would be appreciated. Fanuc has two types of serial encoders. ABS and INC, for absolute and incremental. The incremental type only provide correct shaft angle when battery backup is provided. If the battery is disconnected or drained, then you have to manually crank the motor over one full turn so the encoder can see the index position. Then, the controller can determine commutation from the encoder data. The absolute type have an additional low-res track that provides a 1024 count per quadrant data that is aligned to the motor poles, so a drive could immediately get commutation data when encoder power is on. Although Fanuc provides a backup battery for these encoders, it seems it is not totally necessary. Perhaps the Yaskawa also have provision for battery backup? The flag changing when index is sensed sounds just like what the Fanuc encoders do. Jon ___ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
[Emc-developers] Sigma5ABS Implementation - Commutation
I have been able to get the yaskawa sigma5 motors turning with the bldc component in qh mode. The encoders are a sort of hybrid incremental/absolute encoder. Once they pass the index point a flag and an offset are returned in the encoder data that allows the exact rotor angle position to be computed. I'm trying to find the best path forward for facilitating commutation. Any guidance would be appreciated. Scenario A BLDC needs a way to set the exact rotor angle in the bldc component once the reference point is crossed. I think this may be a slightly different scenario than bldc currently handles. (Not sure) I imagine hal wiring like so would be appropriate. Perhaps an "r" mode that allows self referencing encoders. bldc config would be "qhr" net sigma5abs.00.referenced bldc.0.referenced net sigma5abs.00.ref-offset bldc.0.ref-offset The motor would be commutated via halls and once the reference point is crossed the referenced pin goes True and the bldc uses the ref-offset value to adjust its internal rotor angle value to match. Scenario B Have the sigma5 encoder module output a "commutation" count which would behave like rawcounts, but would "jump" ahead or behind by the reference offset when the encoder becomes referenced. I don't think that it would be so large of a jump that would be even noticeable as the bldc component would have already determined a fairly close alignment via that hall sensors and the encoder rawcounts. Scenario C Would be possible to use the encoder to output a rotor-angle directly to be used with an 8i20 or other type drive thus removing the need for the bldc component when using the yaskawa motor. That would simplify configuration for users. Would that be possible or recommended? Any other ideas welcome. Thanks, Curt ___ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
