[Paparazzi-devel] new parameter in airframe config file

[Antoine]

Hi everybody

We've added downthrust on our new Twinstar. This results in the plane 
beeing more neutral, but vz (vertical speed) control using throttle-only 
not working anymore.
So we've added a new parameter in the vz loop that command a pitch 
offset according to the desired vz.

This implies that you should add the PITCH_OF_VZ_PGAIN line in your 
airframe config file so that it still compiles with the new code

 <section name="ALT" prefix="CLIMB_">
    <define name="PGAIN" value="-0.03"/>
    <define name="IGAIN" value="0.1"/>
    <define name="MAX" value="1."/>
    <define name="LEVEL_GAZ" value="0.31"/>
    <define name="PITCH_OF_VZ_PGAIN" value="0.00"/>
    <define name="GAZ_OF_CLIMB" value="0.2" unit="%/(m/s)"/>
  </section>

Leaving the value at 0 preserves the old behaviour. A positive value 
will trigger the new behaviour. We tested between 0.05 and 0.1

Here is a plot of one of the test flights we made to tune the new 
controller : 
http://www.nongnu.org/paparazzi/images/calib_vz_control_no_pitch.jpg

A+

Antoine