It seems that motors do not produce thrust equally on all RPM ranges, so to
counter this, the ESC signal needs to be modified a bit to get linear thrust
from the motors. I have tried this approach with a test that I describe here:
http://diydrones.com/forum/topics/linearizing-motor-thrust
I have been flying this modification for a while now, and it really seems to
make that behavior of the copter more consistent, and PID parameters can be
pushed up a bit more with out oscillations.
This solution could be further enhanced with added voltage scaling to the
value, but I am not sure how it should be done, since theoretically it would
leave some "empty" area to the throttle if it would be done so that 50%
throttle would correspond to 50% thrust at full battery, as the voltage drops,
100% throttle on the transmitter would correspond to a 110% or so ESC signal,
which might not be desirable.
As mentioned on the thread, more measurements would also be important, since 5
data points are really not enough to do this kind of thing. And there is also
no idea how this will change with different motor/prop combinations.
Original issue reported on code.google.com by Joonas.M...@gmail.com on 6 Mar 2012 at 10:23
Original issue reported on code.google.com by
Joonas.M...@gmail.comon 6 Mar 2012 at 10:23