On 18/08/2019 02:41, Dewey Garrett wrote:
It may be better but in many use-cases the expedient of
a simple hal command:
setp joint.N.max_acceleration some_low_value
is sufficient to soften the thump of high mpg accel
and it is considerably simpler than adding components
and nets.
I
On 08/17/2019 03:11 PM, Andy Pugh wrote:
On 17 Aug 2019, at 16:23, Moses McKnight wrote:
g. It also adds optional integer inputs and outputs (useful for MPGs) and
scaling.
There is already ilowpass for MPGs. Not that that necessarily means that adding
it to lowpass is a bad idea.
Hi Andy,
My main reason for adding FIR filtering was for MPGs, because it does a
better job than IIR. After looking at ilowpass and lowpass it seemed a
bit silly to have two components doing basically the same thing. I
decided it would be better to combine the functionality while I was at
Hi Dewey,
A FIR low pass works better than reducing the acceleration. The problem
with just reducing acceleration is that it affects the MPG response over
the whole speed range. If you try to move fast the machine responds
slowly. A FIR filter effectively sets the minimum time to make a jog
> ... issue where the individual pulses at low speeds and
> make the machine shake. ...
For versions LinuxCNC 2.8 and greater, pins are
provided to limit acceleration for MPG (wheel)
jog inputs:
#
$ man motion
...
axis.L.jog-accel-fraction IN
Hi Moses,
I saw bug #579 had been fixed. The mill is running an older buildbot
build so I'm holding off updating it until the homing issue is sorted in
master.
The router (currently running a very recent buildbot build) also uses
ON_ABORT_COMMAND but the bug doesn't really affect it much.
That sounds like it can go in the 2.8 branch - I'll try and commit it soon.
Thanks Les!
Also, since you reported bug #579
(https://github.com/LinuxCNC/linuxcnc/issues/579), as of yesterday that should
be fixed in the latest 2.7, 2.8, and master branches. So if you would like to,
try using
I have attached a rewrite of the lowpass component. This adds an option
to use either IIR or FIR filtering. It also adds optional integer inputs
and outputs (useful for MPGs) and scaling.
FIR filtering is better than IIR for smoothing noisy inputs and it also
works really well for smoothing
