On 03/03/2020 09:22 PM, Peter C. Wallace wrote:
No, command-deriv is only used for the FF1 feedforward
calculation
But, I DO use FF1 in practically all my configs, and it does
seem to work. So, the problem is linking a signal to the
command-deriv pin, but then NOT feeding it the correct
derivative. I can't see any way to fix this in PID.
The new 2.7.15 PID is not wrong, it just exposes an error in
other code (the configs) that hadn't been right for
some time.
I guess without linking to command-deriv then PID calculates
this internally by difference between this command and
the most recent command. If you link a signal to
command-deriv but do not provide the correct value, PID
would misbehave for sure.
Not clear what to do in this case, but fixing the broken
configs and the autoconfig program that creates these
seems important. Documenting the problem is critical, and
explaining what the user needs to do to
make his system run right.
As for the docs, the generic 2.7 docs do NOT show any
reference to pid.x.command-deriv
Am I looking in the wrong place, or has it been removed?
Jon
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