closed llop speed control on AX3500 for one channel only

13 years 5 months ago #17163737 by palejiya

The roborun alllows either both channel in closed loop speed control or none on AX3500. I want to put only one channel in closed loop speed control (through encoder) and keep another in open loop.

How can I do that?
If Roboteq can't do it, does anybody know another motor controller that can do that?

Please Log in or Create an account to join the conversation.

13 years 5 months ago #17164359 by cosma
There are no settings in the controller for doing this.

However, you could achieve practically the same result by configuring the second channel in position mode, with encoder feedback and no encoder attached.

Then, you will set the P parameter to 1, I and D to 0.

When running, a command will cause the motor to spin at the command speed value.

This is because the controller will think the motor is always at position 0 (no encoder attached) and the power applied is equal to command - position (i.e, command - 0) multiplied by the P gain of 1.


Please Log in or Create an account to join the conversation.

13 years 5 months ago #17165970 by palejiya
Thanks Cosma,

I am just trying to do what you said. But I see only one set of gains in Roborun. That means the gains are same for both channel. If I set integral component (I) to zero, wouldn't it affect the performance of another motor running in speed mode?

Please Log in or Create an account to join the conversation.

13 years 5 months ago #17166134 by cosma
You are actually correct. My answer was not totally thought through, and I is the key component for closed loop speed, so it cannot be 0.

You can experiment but I will need to get back to you with a better answer.

Please Log in or Create an account to join the conversation.

13 years 4 months ago #17645426 by cosma
We have a beta version of the firmware that will let you configure each channel differently with different PID values.

If you are still interested, pls let us know.

Please Log in or Create an account to join the conversation.

13 years 4 months ago #17645919 by palejiya
Cosma,

I am from Oceanscience group and We have already discussed this firmware change with you and Tony and Alex. I think our purchasing guy will soon process the payment.

Please Log in or Create an account to join the conversation.

Moderators: tonysantoni
Time to create page: 0.158 seconds