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Problem while using the motion terminal

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Forum 1
(@gregoriorcm)
Posts: 6
Active Member
Topic starter
 

Dear Solo team,We have a problem when using the Motion terminal. Indeed, when we setthe values of speed controllers Kp, Ki and the speed reference (RPM),the real motor speed displayed in the monitor does not correspond to theone defined in the parameters. Furthermore, shortly after this incident,our no-load motor did not respond to any commands, it oscillated weakly.Namely, we had used an unbalanced part fixed to the motor axis, do youthink the problem could come from the use of this part or from thecontrol terminal?Thanks a lot for your helpController: Solo UnoMotor: https://hobbyking.com/en_us/turnigy-trackstar-sct-5t-sensored-brushless-motor-4150kv-550-size.html?___store=en_us Tutorial followed: https://www.solomotorcontrollers.com/blog/setup-tune-motors-using-solo-motion-terminal/

 
Posted : 10/05/2022 1:59 pm
SOLO Team
(@milad)
Posts: 445
Illustrious Member Admin
 

Hi @gregoriorcm,

- For the motor, you are using what value you are putting for the Number of Poles? ( I believe this motor has only 2 poles)

- If you are using the Motor in Sensorless mode, for this specific motor pls put the PWM frequency ( switching frequency ) at 70kHz

- Make sure for this specific motor you are using the "Ultra-fast brushless" type

BTW, can I have a screenshot from your motion terminal?

Regards
Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

 
Posted : 10/05/2022 3:10 pm
Forum 1
(@gregoriorcm)
Posts: 6
Active Member
Topic starter
 

Hello !

Thank you for your answer ! I'm giving you the screenshots of our motion terminal with our settings ! Just so you know, the value of Speed Controller Ki isn't defined when we press the "motor identification" button. We have to put it ourselves. However it worked before by pressing the button. 

Thanks for your upcoming help !

screenshot terminal 1
screenshot terminal 2

 

 
Posted : 12/05/2022 8:22 am
SOLO Team
(@milad)
Posts: 445
Illustrious Member Admin
 

Hi @gregoriorcm,

It seems that your Speed controller Gains are very small, can you try the same thing with the following gains:

Speed controller kp = 0.03

Speed controller Ki = 0.005;

Another point is once you are in sensorless, make sure you don't connect any sensors to the Encoder/Hall sensor input port, the pulse generated by the encoder or Hall sensor once in sensorless mode, especially for high-speed motors can disrupt the DSP and consume it's processing power for not a useful task.

I will remain available.

Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

 
Posted : 16/05/2022 7:47 am
Forum 1
(@gregoriorcm)
Posts: 6
Active Member
Topic starter
 

Thank you once again !

We're going to work again with higher value of Kp and Ki as you suggested ! And we think that we don't have any sensors connected to the Encoder/Hall sensor input port. The only things connected is the power supply and the cables between the motor and the controller !

Also, we wanted to know something about the speed controller Kp and Ki, what do they do exactly ?

Thank you for your upcoming help !

 
Posted : 16/05/2022 8:45 am
SOLO Team
(@milad)
Posts: 445
Illustrious Member Admin
 

@gregoriorcm

Posted by: @gregoriorcm

Also, we wanted to know something about the speed controller Kp and Ki, what do they do exactly ?

 

To learn more about these gains I recommend you to read the following article:

https://www.solomotorcontrollers.com/blog/setup-tune-motors-using-solo-motion-terminal/

after that, if you had other questions, I'll be more than happy to answer them.

Regards
Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

 
Posted : 16/05/2022 8:51 am
Forum 1
(@gregoriorcm)
Posts: 6
Active Member
Topic starter
 

@milad 

 

I've read the article you sent me, I understood that Speed Controller Kp and Ki are gains. I also tried your values of Kp and Ki, and by changing them I found that Kp = 0.03 and Ki = 0.016 work well for some values of RPM (in my case 12000, 18000, 24000 and 30000). But what I don't understand is sometimes when I start the motor with these values of Kp and Ki, it doesn't rotate when it did before. I had to change the values and sometimes it worked sometimes it didn't. 

What could be the best way to find what are the best values of Kp and Ki to put for a specific RPM ?

Thanks for your upcoming help !

 
Posted : 17/05/2022 2:53 pm
SOLO Team
(@milad)
Posts: 445
Illustrious Member Admin
 

@gregoriorcm

Posted by: @gregoriorcm

I've read the article you sent me, I understood that Speed Controller Kp and Ki are gains. I also tried your values of Kp and Ki, and by changing them I found that Kp = 0.03 and Ki = 0.016 work well for some values of RPM (in my case 12000, 18000, 24000 and 30000). But what I don't understand is sometimes when I start the motor with these values of Kp and Ki, it doesn't rotate when it did before. I had to change the values and sometimes it worked sometimes it didn't. 

 

did you try to increase the Speed controller Kp value to higher numbers up to 0.1?

- I believe your motor has Hall sensors too, if you want the best performance and highest accuracy and robustness, I recommend you to test also your motor with Hall sensors and see how the behavior changes? below you can see how to set up and calibrate your motor and Hall sensors with SOLO:

https://www.solomotorcontrollers.com/blog/hall-sensors-to-solo-for-controlling-speed-torque-brushless-motor/

I will remain available.

Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

 
Posted : 19/05/2022 7:17 am
Forum 1
(@gregoriorcm)
Posts: 6
Active Member
Topic starter
 

@milad 

We are trying with the new value of Kp, we're going to see if it's better for our goal ! 

Also we found what's probably the Hall sensor input for our motor, but the cable we got isn't suitable to link the solo controller and the motor ! The tip fits well the solo controller but not the motor.

If we need more help, we'll let know ! Thank you for your help !

 
Posted : 19/05/2022 8:37 am
SOLO Team reacted
Forum 1
(@gregoriorcm)
Posts: 6
Active Member
Topic starter
 

Hello !

We found that our motor has no restrictions on low speed and we'd like to have a small RPM like 1000. We have tried your previous recommendations and also many combinations of Kp and Ki but none of them work for low frequencies. Do you know if we should increase or decrease the Kp and Ki when we lower the speed ?

Thank you for your upcoming help !

 
Posted : 24/05/2022 3:25 pm
SOLO Team
(@milad)
Posts: 445
Illustrious Member Admin
 

Hi @gregoriorcm,

If you are using the sensorless control of SOLO, depending on the motor there will be some minimum speed that you can reach, this is inherited from the sensorless speed estimator, however, if you start using the Sensor-based solutions ( HALL or Encoders) you'd be able to reach to far lower speeds than 1000RPM.

Let me know if you have other questions or issues.

Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

 
Posted : 29/05/2022 2:24 pm
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