On 9 May 2012, at 06:51, gene heskett ghesk...@wdtv.com wrote:
pattern of narrow and wide threads in the final
product. Watching the encoder on my scope, it looks very consistent, but
the encoder.0.velocity output has wibbles of +-50% in its speed
G76 doesn't use the velocity, it just
On Wednesday, May 09, 2012 10:34:14 AM Andy Pugh did opine:
On 9 May 2012, at 06:51, gene heskett ghesk...@wdtv.com wrote:
pattern of narrow and wide threads in the final
product. Watching the encoder on my scope, it looks very consistent,
but the encoder.0.velocity output has wibbles of
On 9 May 2012 15:52, gene heskett ghesk...@wdtv.com wrote:
G76 doesn't use the velocity, it just looks at position. There is no way
that that can be varying enough to cause your issue. Have you linked
encoder.position or encoder.position-interpolated?
I used velocity.
Where? If you have
On Tue, 8 May 2012 21:22:29 +0100
andy pugh bodge...@gmail.com wrote:
On 8 May 2012 21:06, Dave e...@dc9.tzo.com wrote:
You have no Pgain, but Igain and Dgain. That's a problem. An all
I and D loop is almost always unstable.
That depends….
For a spindle P gain is not much help, as
On 9 May 2012 17:51, dave dengv...@charter.net wrote:
I've seen P values as low as 15 and as high as 600 FF1 values from 18
(ugh) down to -0.01.
The parameters are not unitless, so will vary even on identical
hardware between mm and inch machines, and depending on whether the
pwmgen is
snip---
I've seen P values as low as 15 and as high as 600 FF1 values from 18
(ugh) down to -0.01.
I think the main reason for this is non-normalized PID input and output values
I like to suggest that for velocity mode drives, the DAC/PWM device be scaled
directly in
On 9 May 2012 18:21, Peter C. Wallace p...@mesanet.com wrote:
Torque mode needs little FF1 and lots of D as effectively it must create the
velocity part of the loop from D
Or you can stack two PID loops in HAL.
--
atp
The idea that there is no such thing as objective truth is, quite simply,
I currently have the commanded spindle velocity, NDI if it is supposed to
be rpms or what, essentially being fed thru the abs function directly into
the pid.0.command input.
I am sending the encoder.0.velocity thru the abs function also then into
pid.0.feedback. This voltage on the hal meter
On Tue, 8 May 2012, gene heskett wrote:
Date: Tue, 8 May 2012 15:45:11 -0400
From: gene heskett ghesk...@wdtv.com
Reply-To: Enhanced Machine Controller (EMC)
emc-users@lists.sourceforge.net
To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net
Subject: [Emc-users] PID
On 8 May 2012 20:45, gene heskett ghesk...@wdtv.com wrote:
setp pid.0.Pgain 0
setp pid.0.Igain 1
setp pid.0.Dgain 1
setp pid.0.maxoutput 401 # to keep it from running away
I know that I-only is what the
Gene,
You have no Pgain, but Igain and Dgain. That's a problem. An all I and
D loop is almost always unstable.
Chances are you are going to want Pgain and a little Igain and little
Dgain(maybe.. if at all).
Start out by trying some Pgain and no Igain or Dgain and see what happens..
Bump up
On 8 May 2012 21:06, Dave e...@dc9.tzo.com wrote:
You have no Pgain, but Igain and Dgain. That's a problem. An all I and
D loop is almost always unstable.
That depends….
For a spindle P gain is not much help, as you need a non-zero PID
output even when at the set speed (and when the error
Controller (EMC)
emc-users@lists.sourceforge.net Subject: [Emc-users] PID controller
Q's
I currently have the commanded spindle velocity, NDI if it is supposed
to be rpms or what, essentially being fed thru the abs function
directly into the pid.0.command input.
I am sending
On Tuesday, May 08, 2012 04:33:56 PM andy pugh did opine:
On 8 May 2012 20:45, gene heskett ghesk...@wdtv.com wrote:
setppid.0.Pgain 0
setppid.0.Igain 1
setppid.0.Dgain 1
setppid.0.maxoutput 401 #
On Tue, 8 May 2012, gene heskett wrote:
Date: Tue, 8 May 2012 16:33:06 -0400
From: gene heskett ghesk...@wdtv.com
Reply-To: Enhanced Machine Controller (EMC)
emc-users@lists.sourceforge.net
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] PID controller Q's
On Tuesday
On Tuesday, May 08, 2012 04:39:15 PM Dave did opine:
Gene,
You have no Pgain, but Igain and Dgain. That's a problem. An all I and
D loop is almost always unstable.
Chances are you are going to want Pgain and a little Igain and little
Dgain(maybe.. if at all).
Start out by trying
On 8 May 2012 21:38, gene heskett ghesk...@wdtv.com wrote:
I believe that FF0 + I is the way to go. WIth FF0 set to rpm/duty
cycle and a much smaller I than you currently have to take up the
error.
Would that not require a dynamic, dependent on speed, FF0 then? Since rps
can easily go from
On Tuesday, May 08, 2012 04:42:52 PM andy pugh did opine:
On 8 May 2012 21:06, Dave e...@dc9.tzo.com wrote:
You have no Pgain, but Igain and Dgain. That's a problem. An all I
and D loop is almost always unstable.
That depends….
For a spindle P gain is not much help, as you need a
On Tue, 8 May 2012, gene heskett wrote:
Date: Tue, 8 May 2012 16:52:37 -0400
From: gene heskett ghesk...@wdtv.com
Reply-To: Enhanced Machine Controller (EMC)
emc-users@lists.sourceforge.net
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] PID controller Q's
On Tuesday, May 08
@lists.sourceforge.net
Subject: Re: [Emc-users] PID controller Q's
On Tuesday, May 08, 2012 04:26:08 PM Peter C. Wallace did opine:
On Tue, 8 May 2012, gene heskett wrote:
Date: Tue, 8 May 2012 15:45:11 -0400
From: gene heskett ghesk...@wdtv.com
Reply-To: Enhanced Machine Controller (EMC
On 8 May 2012 21:52, gene heskett ghesk...@wdtv.com wrote:
Silly Q probably, but could the pid.0.command value also be sent to
sum2.0.in0, and the pid.0.output sent to sum2.0.in1 to furnish the desired
offset, allowing the pid module to work with a much more balanced (read
closer to zero)
This shows the inner workings of the PID comp
Notice that FF0 does exactly what you want, that is copies a scaled portion of
the PID command input directly to the output
http://linuxcnc.org/docs/html/hal/rtcomps.html#sec:PID
Peter Wallace
Mesa Electronics
On 5/8/2012 4:22 PM, andy pugh wrote:
On 8 May 2012 21:06, Davee...@dc9.tzo.com wrote:
You have no Pgain, but Igain and Dgain. That's a problem. An all I and
D loop is almost always unstable.
That depends….
For a spindle P gain is not much help, as you need a non-zero PID
On Tuesday, May 08, 2012 05:00:12 PM andy pugh did opine:
On 8 May 2012 21:38, gene heskett ghesk...@wdtv.com wrote:
I believe that FF0 + I is the way to go. WIth FF0 set to rpm/duty
cycle and a much smaller I than you currently have to take up the
error.
Would that not require a
@lists.sourceforge.net
Subject: Re: [Emc-users] PID controller Q's
On Tuesday, May 08, 2012 04:42:52 PM andy pugh did opine:
On 8 May 2012 21:06, Dave e...@dc9.tzo.com wrote:
You have no Pgain, but Igain and Dgain. That's a problem. An all I
and D loop is almost always unstable
On 8 May 2012 22:37, gene heskett ghesk...@wdtv.com wrote:
On Tuesday, May 08, 2012 05:34:22 PM Peter C. Wallace did opine:
From the pid man page:
pid.N.FF0 float rw
Zero order feed-forward term. Produces a contribution to the
output that is FF0 multiplied by the commanded
On Wednesday, May 09, 2012 12:56:42 AM Peter C. Wallace did opine:
This shows the inner workings of the PID comp
Notice that FF0 does exactly what you want, that is copies a scaled
portion of the PID command input directly to the output
On Wednesday, May 09, 2012 01:12:21 AM Peter C. Wallace did opine:
This shows the inner workings of the PID comp
Notice that FF0 does exactly what you want, that is copies a scaled
portion of the PID command input directly to the output
On Wednesday, May 09, 2012 01:28:26 AM andy pugh did opine:
On 8 May 2012 22:37, gene heskett ghesk...@wdtv.com wrote:
On Tuesday, May 08, 2012 05:34:22 PM Peter C. Wallace did opine:
From the pid man page:
pid.N.FF0 float rw
Zero order feed-forward term. Produces a
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