Controlling temperature of reprap extruder hot-end
04 Oct 2011 10:43 #13641
by andypugh
Replied by andypugh on topic Re:Controlling temperature of reprap extruder hot-end
fma wrote:
As a first guess I would assume that they were exactly the same thing. If that doesn't work, try multiplying by the servo thread period.How do I determine Ki and Kd for the hal pid component, from Ti and Td (integration time and derivative time)?
Please Log in or Create an account to join the conversation.
04 Oct 2011 11:15 #13642
by fma
Replied by fma on topic Re:Controlling temperature of reprap extruder hot-end
Ok, I'll try that.
I just noticed that there is a auto-tune pid component! I'll give it a try to.
Thanks,
I just noticed that there is a auto-tune pid component! I'll give it a try to.
Thanks,
Please Log in or Create an account to join the conversation.
05 Oct 2011 18:09 #13686
by fma
Replied by fma on topic Re:Controlling temperature of reprap extruder hot-end
I made some tests with the at_pid component: I don't get good results.
I noticed one thing which may be an issue in my case: the pid output goes from -max to + max. When the feedback is higher than the command, the output goes to négative values.
In my case, negatives values have no effect, as the pid output is connected to a pwm. But the pid thinks it can 'brake', which is not the case, as it could be with a servo motor.
Is there a way to tell the pid that the minimum value it can use is 0?
I noticed one thing which may be an issue in my case: the pid output goes from -max to + max. When the feedback is higher than the command, the output goes to négative values.
In my case, negatives values have no effect, as the pid output is connected to a pwm. But the pid thinks it can 'brake', which is not the case, as it could be with a servo motor.
Is there a way to tell the pid that the minimum value it can use is 0?
Please Log in or Create an account to join the conversation.
12 Oct 2011 06:51 #13853
by fma
Replied by fma on topic Re:Controlling temperature of reprap extruder hot-end
No idea?
Please Log in or Create an account to join the conversation.
12 Oct 2011 08:03 #13854
by cmorley
Replied by cmorley on topic Re:Controlling temperature of reprap extruder hot-end
I can't see how to stop pid at zero.
how about using a limit component or absolute component.
or write your own PID component.
how about using a limit component or absolute component.
or write your own PID component.
Please Log in or Create an account to join the conversation.
12 Oct 2011 08:15 #13856
by fma
Replied by fma on topic Re:Controlling temperature of reprap extruder hot-end
I can't truncate, as the at-pid comp still think it can reach -max value, but I just need to match the at_pid output (from -max to +max) with my pwmgen input, with scale and other comps.
Thanks!
Thanks!
Please Log in or Create an account to join the conversation.
Time to create page: 0.157 seconds