STMBL - Finding AC brushless servo parameters RLJ?

Hi

In the STMBL documentation there is a dead link to a tutorial on measuring RLJ parameters for ac servo drives. Please could someone explain how to find these parameters? I have only been able to find instructions for dc brushed or wye connected dc brushless. There are megaohms resistance across the windings, does this exclude the possibility of them being wye or delta?

They are Baldor S1P037W012's and Maxon BSM1R-04-DAX-701's. Datasheets are not available from the usual sources.

Cheers

While I can't answer your question, I too am trying to get STMBL working with baldor ac servos. Docs are lacking a bit - have you figured out how to synchronize the encoder to the motor for commutation?

By the way your maxon motor uses a designation that sounds like baldor's - maybe that could help you find info.

Chris M

Hi Chris, hm not sure. The joints I am driving have resolvers on them, and so far the STMBL's seem to quite happily move them. I have only tested it with servoterm so far though.

And yeah I caught that BSM too and wondered the same thing. Can't find any obvious link to baldor / ABB, am guessing it just means "brushless servo motor"

Cheers

Yes mine are resolvers too (I assumed you were using encoders).
I can get it to turn open loop with seroterm but not closed.
Rene said he would add docs so I'm waiting a bit to see what he can add.

Chris

What specs do you know on your maxon - it sure seems like a baldor part number.
i can find that exact part number under baldor and reliance. - no specs
maybe we could educatedly guess the specs based on modern BSM motors.

Chris M

Hi Chris

I have emailed ABB and Maxon to see if they will mail the datasheets, as well as contacted an ebay seller who has a maxon in stock, will see if any of them come back! I dont have any specs on the maxons.

The baldors have some data such as peak current and stall current, I can dig those off the plate if you think it would be useful.

Wireline wrote: In the STMBL documentation there is a dead link to a tutorial on measuring RLJ parameters for ac servo drives. Please could someone explain how to find these parameters?

The link was probably meant to lead to here:

github.com/rene-dev/stmbl/wiki/motor-parameters

cmorley wrote: Yes mine are resolvers too (I assumed you were using encoders).
I can get it to turn open loop with seroterm but not closed.

If you plot the commanded position and the resolver feedback in Servoterm, do they align perfectly? I think that you basically need to tweak the resolver parameters until they do.

andypugh wrote:

cmorley wrote: Yes mine are resolvers too (I assumed you were using encoders).
I can get it to turn open loop with seroterm but not closed.

If you plot the commanded position and the resolver feedback in Servoterm, do they align perfectly? I think that you basically need to tweak the resolver parameters until they do.

The drive faults before I can see much about commanded vrs feedback.
I assume feed back offset is what I want to change..

probably feedback is not set up right but i don't understand some of the pins...
resolver polecount - 2 I think
resoler mode - is there a certain mode - is there a list of modes - probably default is fine
resolver frequency - how do you decide the frequency it should be?
resolver phase (I got this to work but don't understand what it is)

I asked Rene about more docs - he said he would - but like all of us I'm sure he hates docs
When I get something working I will document it somewhere...

Chris M

cmorley wrote: The drive faults before I can see much about commanded vrs feedback.

It shouldn't fault in open-loop (stepper) mode. You said that you can run the motor in that mode. Then you should be able to plot the resolver position and make them match.