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 max
(@max)
New Member

Hi,

Hoping to configure a system involving pc control of adjustable stable torque against (i.e. resisting) applied variable torque.

Picture for example a rowing machine, where a cable on a drum on a motor shaft is unwound sometimes vigorously with the motor providing  a programmable resistance winding the spool back again.

I've tried using a closed loop stepper setup but just get collision errors instead of torque control for anything other than gentle force.

If your controller can provide programmable incremental (1% ? ) regen braking torque, that would be even better.

I had in mind a max of 10NM torque or so, would be nice to be able to set a 0.1 NM increments.

Was looking at the attached motor, but am open to alternatives, $ are few ūüėČ

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Posted : 16/09/2020 2:32 pm
(@milad)
Member Moderator

Hi Max, 

I tried to understand what features you exactly are seeking, and I will give my thoughts on that, let me know if they were helpful or any other clarification is needed:

- regarding the Torque control, SOLO totally offers that feature and you can always define the direction of that torque, to be assistive or resistive, so if you ask SOLO to keep a constant Torque, and the user tries to push the motor for further torque ( pulling the string / winding the spool ) it will resist, you can also change the direction and it will try to pull back with defined torque by you.

- The accuracy of torque control in SOLO is :

Torque control resolution [N.M] = Current measurement resolution [A] * Motor Torque constant [N.M/A]

Current measurement resolution in SOLO = 0.016 A

so you need to know how is the accuracy of your motor torque constant, but I think finally, the result should be below 0.1 N.M considering the current measurement resolution of SOLO.

-  Please keep in mind that the current version of SOLO is capable of driving motors with up to 32A of continuous current and 100A for a brief time, I checked the specs of the motor you've mentioned, and it's performance curve, but it wasn't clear that the current plot is for the current inside of the Motor or the current drained from the power supply ( as in brushless motors they are different ). the available version of SOLO is designed for rated powers around 1kW in continuous Mode, so given that you can choose to use it or not.

- SOLO has a USB connector on it, and you can directly connect that to PC, and it provides you the possibility of having a virtual COM port and subsequently Digitally commanding and getting feedbacks from SOLO as can be seen here. in near future we are introducing an "Insulated Universal Protocol Converter" addon to SOLO, which will enable our users to have, USB, CAN bus, RS485 protocols in a totally insulated manner.

I will remain available for further discussions.

Regards

Milad

 

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

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Posted : 17/09/2020 8:56 am
 max
(@max)
New Member

@milad

Great news, it looks very promising thanks.

I saw the packet information for board communication; do you have any code examples / libraries to help with writing windows / web programs to work with it?

thanks max

ReplyQuote
Posted : 17/09/2020 3:15 pm
(@milad)
Member Moderator

 Dear @max,

we have just published a new user manual, and there you can find lots of examples of how to form the data packets for different porpuses. These packets can be sent through the USB of your PC from any software that supports Serial communication (through COM) and we are also working on an open-source PWA solution as can be found here but the work is still on progress.

you can also use software like "Awesome Terminal" to send the packets for testing porpuses. We are working on making a full Motion Terminal, but it will take some time. I will remain available for any further questions.

Regards
Milad

 

 

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

ReplyQuote
Posted : 17/09/2020 4:40 pm
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