On Thu, Jun 27, 2013 at 3:33 PM, Dave wrote:
> >>Analog PID works at a (near) infinite
> rate.
>
> Yeah... when was the last time anyone worked on one of those.
>
All the time. The VAST majority of switching power supplies out there are
analog loops. Wall warts, all your computer power supplie
On 6/27/2013 11:51 AM, Steve Stallings wrote:
>
>
>> I respectfully disagree. As long as the integral term is
>> normalized to the
>> run rate, there is nearly no effect to running the loop
>> faster than then
>> the time constant. Analog PID works at a (near) infinite
>> rate.
>>
> OK
On Thu, 2013-06-27 at 11:13 -0400, Dave wrote:
> I do a fair amount of industrial PID related software work.
>
> The output of a digital Temp control PID is usually a 0-100% "signal".
> Then that signal is used to vary the heat input to whatever you are
> trying to control.
> For instance, wit
> I respectfully disagree. As long as the integral term is
> normalized to the
> run rate, there is nearly no effect to running the loop
> faster than then
> the time constant. Analog PID works at a (near) infinite
> rate.
OK, point taken. My caution comes from the fact that
many digital i
2-Users-List
> Subject: [Emc-users] PID Best Practices
>
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> I am having some issues tuning the PID loop for temperature control on
> my LinuxCNC controlled 3D printer, so I thought I'd ask about some
> best practice
On Thu, Jun 27, 2013 at 11:13 AM, Dave wrote:
> Your PID loop is likely running a lot faster than what is required.
Agreed.
> The PID loop should run 10x to 50x the time constant of the control
> system. Any faster and you will end up with very small changes in tuning
> values that make a hu
Hi Charles.
If I'm not wrong in HAL you can setup "threads" as you need.
So I believe that perform the PID every 1ms is too fast and not needed for
a "relatively slow"
temperature control.
Also because you have a 20ms reading temperature cycle.
If you look at the HAL User Manual you will find the
I do a fair amount of industrial PID related software work.
The output of a digital Temp control PID is usually a 0-100% "signal".
Then that signal is used to vary the heat input to whatever you are
trying to control.
For instance, with band and cartridge heaters, the duty cycle of a Solid
St
On Thu, Jun 27, 2013 at 09:42:37AM -0500, Charles Steinkuehler wrote:
> I was trying some small I gains, mostly between .001 and .024. I
> _think_ the PID thread rate is being accounted for, but if not that
> could easily explain things (I'll have to dig through the code).
The pid manpage tells
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Great info Stephen!
I was trying some small I gains, mostly between .001 and .024. I
_think_ the PID thread rate is being accounted for, but if not that
could easily explain things (I'll have to dig through the code).
I suspect, however, that given
On Thursday 27 June 2013 10:04:30 Charles Steinkuehler did opine:
> I am having some issues tuning the PID loop for temperature control on
> my LinuxCNC controlled 3D printer, so I thought I'd ask about some
> best practices for PID setup.
>
> QUESTION:
> How are gains typically arranged in a PID
The scaling is in the units of the input and output. You don't need to
scale the output 100x as you could just use 100x smaller PID values.
Integral gain should be in the form of output per second given one unit of
input (though I don't know if LCNC normalizes the summing rate or you have
to divi
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I am having some issues tuning the PID loop for temperature control on
my LinuxCNC controlled 3D printer, so I thought I'd ask about some
best practices for PID setup.
QUESTION:
How are gains typically arranged in a PID control loop? Is the PID
outpu
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