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POST No. 2408103
Mx-106T/R (2) Motor Parameters
2022-01-07 14:39:47 josefneto

Happy new year.


I was asked to model your motor, using MATLAB but however your page does not provide some of the motor parameters. It is for this reason that I would like to request your motor parameters so that I can assure that may model works well.

 

I need the following parameters :

  1. Inertia of motor armature
  2. Motor torque constant
  3. Motor induction
  4. Armature resistance

Using you performance graph available at your page, that’s my result:

  1. Choosing Torque 1.20Nm, Current 0.8A, Efficiency 42% from the performance table
  2. Assuming inductance of the armature are very small nearly zero, so backemf becomes voltage supplied - resistance x current armature, by that Ke=backemfvoltage/speed so ke=0.2681 v/rpm
  3. By using the value chosen I found, the torque coefficient kt= torque/current =1.5Nm/A.
  4. To find the inertia, I had to find the acceleration so, I rotate the motor at 41rpm during 30s so the acceleration is 0.002 rev/s2
  5. Since this is equivalent to 1.20Nm torque so, Inertia J=1.20/0.0022 =54.05Nm/rev/s2
  6. Since B viscous friction is very small assumed it to be 0,08
  7. L (inductance)  assumed to be 0.1
  8. I measured R to be 2.44, devide by 2 ,  we have 1.22 ohms.  

In attach, I have placed my modelling results, where it shows the torque and current, and other file where it shows input voltage and speed. 

I need you to confirm that either my values or assumptions are close to the real data, or if you can provide the motor parameters.


Thank you

Josef Neto

 
2022-01-07 14:39:47
josefneto
2022-01-12 13:57:41 Will Son

Hi Josef,


I wish you a Happy New Year too!

Thank you for writing the details of your calculations.

Unfortunately, requested information is disclosed and cannot be shared due to our policy.

If you don't mind, could you explain more about your project?

It might help us to make an exception.

In case your project has sensitive information, you may contact at support@robotis.com as well.

Thank you.

2022-01-12 13:57:41
willson