Trouble with Cia402 drive configuration

More
11 months 2 weeks ago #338161 by peterpan
I see people use the word tune a lot, but I guess I don't exactly know what it means. Generally, I would think it just means working a certain value towards the best value. How would I tune the servo in this case? I know in the ClearPath Manual it says to auto-tune the servo using their software.

As for FERROR and MIN_FERROR, do those only apply when using PID calcs? Cause I think I have them set to 0 or maybe not included yet.

Lastly, what is ddt?

I might have to ship you a cake after all you've helped me with xD

Please Log in to join the conversation.

More
11 months 2 weeks ago #338167 by Hakan
Tune means to set the parameters in the servo drive so it follows the commanded position as closely as possible.
Usually involves PID parameters P, I and D in the drive, often some inertia setting.
I think there is a general guide in here to tune a servo. It is basically the same for all servos.
But your drive seems to have auto-tune. Check the manual and possibly download software.
And execute the auto-tune.
If your drive provides a following-error PDO use that to see how well it follows the commanded position.

The FERRORs are set as joint.?.f-error-lim from the ini file values outside of your hal file.
Set FERRORs to 1 inch and after you tuned the servos you can reduce them.

ddt takes the derivative of a pin value. ddt of the position feedback at constant velocity should be a constant value.
Very easy to spot if the feedback position isn't smooth. But you don't need to do that. Don't go there.

Summary: auto-tune.

 

Please Log in to join the conversation.

More
11 months 2 weeks ago #338191 by peterpan
Sweet, so setting the following error higher allows it to run at higher speeds. What is the trade-off? Is it less accurate with a higher following error?

How do I know when to edit something in the .ini file vs the .hal file? it sounds like ferror is linked to a hal pin, but is configured in the .ini file..?

Then, regarding a completely different topic, I was wondering about the pros and cons of using the servo's built-in Homing mode. And if it makes sense to, how would I use HM to home, then switch to CSP for operation?

On the same topic of homing, how would I set that up? Is there a hal pin for homing that I would need to link to a homing sensor?

Please Log in to join the conversation.

More
11 months 2 weeks ago #338193 by peterpan
I figured out how to setup homing mode in the ClearView software, and setup a home sensor, but I have no clue how to make it start homing when home is pressed in linuxcnc. I assume I need to do something with the joint.0.index-enable pin?

Please Log in to join the conversation.

More
11 months 2 weeks ago #338203 by Hakan
The following error can be large due to physical reasons, such as the axle sticking, tool breakage, etc.
With a good FERROR setting, the machine stops with a warning instead of destroying all sorts of things.
That's what you want. When the servos are working well, you should tighten the FERROR values ​​to get that protection.

Normally, values ​​are specified in the INI file.
With Ethercat it isn't so stream-lined yet, some values are set directly in the hal file like the pos-scale.
You can do it yourself, but it often introduces one more level of complexity when one just wants the machine to work.
In the ini file create a [ETHERCAT] section like below
Code:
[ETHERCAT] CIA402_POS_SCALE_X = 200.0 and more
and use it in the hal file
Code:
setp cia402.0.pos-scale [ETHERCAT]CIA402_POS_SCALE_X

Optional.

I am not the right person to elaborate on ethercat homing.
I use linuxcnc's homing variant with switches in the traditional way.
Many people have used ethercat homing, search the forum, or maybe someone chimes in.

There are 3-4 lines mentioning homing in the cia402 documentation github.com/dbraun1981/hal-cia402

Please Log in to join the conversation.

More
11 months 2 weeks ago #338214 by peterpan
I can't find much on Ethercat homing. Maybe I'll be able to figure it out down the road. How would I set it up with Inputs on the EL1008 instead, in the meantime?

Please Log in to join the conversation.

More
11 months 2 weeks ago #338261 by Hakan
It's standard linuxcnc homing from here on
linuxcnc.org/docs/html/config/ini-homing.html

Please Log in to join the conversation.

Time to create page: 0.071 seconds
Powered by Kunena Forum