Maxon DC motor position instability

[johndoe773]

Hello,

I am using a DC motor from Maxon to make DUT test setup. However I am facing some difficulty attaining stability.

These are the specs of my setup:

Motor: Maxon DC 118751

Encoder: HEDM-5500 B02

Driver: EPOS 24/5 367676

When the motor is in Profile position mode and I set it to a specific angle it will oscillate around that desired angle with a period of 2 seconds.

 - Parameteric file for the motor parameter setup is included for download.

 - A dataplot is included to show the oscillation on a time-base scale.

 - A animated GIF is included to show the oscillation in the Master encoder screen of EPOS studio.

 - I will upload a video of the behavior as well later on.

What could cause this and how do I make it more stable?

[johndoe773]

INF - Uploading a video of the behavior

(will be deleted within one week)

https://we.tl/uKw1Rp2W0D

[lagelian]

Hi johndoe773, thanks for uploading the video and data plot. Are you using any National Instruments products and how do they fit into this application?

Angela L. 

National Instruments

[johndoe773]

The motor setup is controlled by Labview 2015.

I use 2 motors to position a DUT in place in XYZ. After that I use this Maxon motor to move in a rotational movement in the XY plane. These are steered with RS232 Visa ports in labview.

To test I am again connected to Labview with current and voltage measurement through Visa.

I get your concern though, my issue is not NI product related. That is also the reason I did not post under the Labview portion of the forum.

[lagelian]

No worries, I was trying to identify if we could help you with your issue. Can you attach your code that controls the Maxon motor? You mentioned that you would like it to be more stable - what exactly is the desired behavior?

Angela L. 

National Instruments

[johndoe773]

I have added some snip of my main code as well as a picture of the most important part.

Step 4 explained in the picture is where it goes wrong. The motor oscillates with a 2 second interval with a 1 degree shift.

I have contacted Maxon as well as I feel it could be a setting issue or a hardware issue. They will have a try with my motor setting on the 3rd of July.