motion control with profidrive

[adam_lhadi]

HI

using a G120 sinamics i used the Profidrive in order to control the position

in the picture i showed how my system is ,alos how i set the mechanics parameters in the Technologie object,but when Comissioning i don't get a good result for the positioning.

am i wrong !!!

 

[kamenges]

You say you are not getting a good result when positioning. What about the result is not good. What is the actual issue?

Keith

 

[robertmee]

If your drawing is accurate, then your ratios don't match. 117mm would yield 78.4, not 78.5. You're accumulating .1mm of error per revolution.

 

[adam_lhadi]

when i aske for a 100mm displacement i get 23mm even in low speed

 

[adam_lhadi]

You say you are not getting a good result when positioning. What about the result is not good. What is the actual issue?

Keith

when i aske for a 100mm displacement i get 23mm even in low speed

 

[adam_lhadi]

If your drawing is accurate, then your ratios don't match. 117mm would yield 78.4, not 78.5. You're accumulating .1mm of error per revolution.

when i aske for a 100mm displacement i get 23mm even in low speed

 

[robertmee]

Where is the encoder for the servo mounted? Motor or Load? If you're getting 23mm movement for a 100mm command, your gearing configuration is not correct.

 

[adam_lhadi]

If your drawing is accurate, then your ratios don't match. 117mm would yield 78.4, not 78.5. You're accumulating .1mm of error per revolution.

when i aske for a 100mm displacement i get 23mm even in low speed

 

[Steve Bailey]

23 mm movement for a 100 mm command sounds like a combination of quadrature configuration and the arithmetic errors that robertmee pointed out. If you're using an A quad B encoder you're getting 4000 lines per revolution, not 1000.
Neither 37.3 mm nor 25 mm represent an integer number of teeth for appears to be an 8mm pitch. To get the most accurate ratio, instead of measuring the diameter of the pulleys, count the teeth and multiply by the pitch to get the distance traveled per revolution.

 

[robertmee]

23 mm movement for a 100 mm command sounds like a combination of quadrature configuration and the arithmetic errors that robertmee pointed out. If you're using an A quad B encoder you're getting 4000 lines per revolution, not 1000.
Neither 37.3 mm nor 25 mm represent an integer number of teeth for appears to be an 8mm pitch. To get the most accurate ratio, instead of measuring the diameter of the pulleys, count the teeth and multiply by the pitch to get the distance traveled per revolution.

I'm with steve. Correct the gear ratio as I pointed out earlier, and set your encoder counts to 4x

 

[adam_lhadi]

I'm with steve. Correct the gear ratio as I pointed out earlier, and set your encoder counts to 4x

i don't have an explanation to this but under basic parameters /encoder i changed A/B count fourfold to A/B count then t works well
i returned to A/B fourfold also worked well

 

[Rob...]

For a system like this where I presume it's just for testing/learning how to set up the software.

I'd ask to move x mm, measure what it actually moved. Then just calculate backwards.

 

[mk42]

i don't have an explanation to this but under basic parameters /encoder i changed A/B count fourfold to A/B count then t works well
i returned to A/B fourfold also worked well

many of the TO parameters have 3 different places the value is stored: in the offline project, in the start value of the TO DB in the PLC, and the actual value in the PLC. If you don't take this into account as you do testing, you can very easily get situations where you make changes that have no effect now, but maybe do later on.

I could very easily see that explaining what you said above, where it didn't work, and then it did work, but then it kept working once you changed the setting back. Something to keep in mind.