Torque control

Hello Chris,

I read chapter 14. Low speed operation with full load.

However, I am able to generate enough torque using the current control (lab 5a). I would like to generate the same torque on startup, but i would like to control the speed as well.

I understand that lab 5b is setting up the speed control, is there any way to control the speed and the torque at the same time or is there a way i can control the speed in lab 5a ?

Regards,

Rajan

the speed loop sets the torque reference.

if the normal operation of 5b isn't working you could try
a) starting in torque mode and then switching on the speed loop or
b) seeding the initial output of the speed controller so the system has an immediate step input of torque, but the speed controller will still be active and start to regulate

Hey Chris,

If i am not mistaken, commanding the speed, should command the torque in lab 5b ?

Is there a specific way of setting up the speed gains so that there is more torque ? I was going though the motorware documentation but it does not explain how it should be set up for a higher torque application.

I wanted to monitor the current that is being commanded by the speed controller to the torque controller, is there such a variable that i could monitor in the watch window ?

Please let me know if I may have a misunderstanding. I will attempt the suggested solutions.

Thank you,

Rajan

"If i am not mistaken, commanding the speed, should command the torque in lab 5b ?"
Correct

"I wanted to monitor the current that is being commanded by the speed controller to the torque controller, is there such a variable that i could monitor in the watch window ?"
In CTRL you will find the speed controller output. This is the IqRef in per unit sent to the Iq current controller

"explain how it should be set up for a higher torque application. "
certainly you can tune the gains to be more aggressive in how quickly the output of the speed controller ramps, especially during start-up. If that doesn't work as mentioned you can start-up in torque mode and then close the speed loop.

Chris, 

I was wondering if having the wrong phases would restrict the motor from having better torque? 

My motor does not have specifications for which wires are ABC, I was wondering if switching them around would cause for a better control ?

Regards,

Rajan

Hey Chris,

I was able to figure it out actually, I am not sure if this is the problem but I was using v6 for CCS and it didnt seem to have the correct libraries maybe ?

Once I switched of v5 of CCS I was able to use the motor to generate enough torque through the speed control !

Thank you for all the help !

Regards,

Rajan

well, if you were using an older version of v6 with one of the bad compilers that could do it...but it should effect the whole operation, not just the maximum torque.

can you post details of the CCS versions and effective compiler versions (right click project --> settings)

Hey Chris,

So I was looking at using speed to change directions for lab 5b, but it didn't seem to work.

I searched the forums and found that the compiler version needs to be higher than or equals to 6.2.3. I had compiler 6.2.3 but the effective compiler was 6.2.0. Everything seemed to work perfectly at that point.

But I tried to increase my compiler version so that my effective compiler version would increase as well and that just created so many problems. Now I'm back to having no torque..... and I can't see what my effective compiler version is...

Is there a specific compiler version that I should use along with the version of ccs.

Please advise.

Looking forward to your help.

Regards,
Rajan

6.2.0 - 6.2.2 compiler has a major issue. you cannot use
e2e.ti.com/.../295599

any other compiler will work

also make sure you are NOT using CCS v6.1.3
e2e.ti.com/.../519654

any other CCS version should work

Hey Chris, 

I don't think the 6.2.0 compiler was the issue for me. 

I realized that when I uninstalled the motorware because i thought motorware maybe the issue, I forgot to set the max current limit of my motor back to 20A. It was functioning at the 3A limit as given in the training guide of motorware.

But now I am using TI v6.1.5 [TI v6.4.11 as my compiler. 

I have attached the screenshot. 

I was able to compile and run the lab perfectly. 

While trying to troubleshoot this problem, I somehow flashed the controller with a different code. I would like to have the temperature sensor back as the flashed code. Is there a way I can get it back ?

Thank you for all your help !

Regards,

Rajan

thanks for the explanation and glad it is working.

the demo for the Launchpad should be the project here:
C:\ti\controlSUITE\development_kits\LAUNCHXL-F28069M\LaunchPadDemo