[Paparazzi-devel] Another day at the flying field...

[Gerard Toonstra]

Hi all,

Took my stuff out for another day at the testing site after fixing some mostly structural issues (thrust angle, torn off elevator, etc). 

In my tests I'm still testing out regular flight characteristics so that I know the airplane flies solid. There's no point trying to
tweak / calibrate the AP without the plane achieving correct flight (CG, thrust angle, etc). 

I did fly in both manual and AUTO1 mode. In AUTO1 mode i was surprised by a throttle kill. My flightplan was in "HOLD" because
none of the autonomous stuff had been tested yet. A radio glitch probably occurred due to some boundary settings in the radio
file (I hope). I'm using an EzUHF and this happened 100m away, so shouldn't be interference or anything else.

1.  The gains for roll and pitch in AUTO1 seemed a bit low to me. Is there a specific method that can be used to 
     get "good" settings for how the control surfaces react to offsets in roll/pitch?  When I rotate the airframe on the 
     ground, I'm now getting maximum deflection at 55 deg roll or so and at 60 pitch.  My airframe is a Bormatec Maja.

2. I intend to use a bungee and read the info about the catapult. Soon as I'm ready to start testing autonomous mode, am I correct
    in thinking that if the following is added to the airframe:


 <section name="CATAPULT" prefix="NAV_CATAPULT_" >
    <define name="MOTOR_DELAY" value="45" />
    <define name="HEADING_DELAY" value="(60*3)" />
    <define name="ACCELERATION_THRESHOLD" value="1.75" />
    <define name="INITIAL_PITCH" value="(15.0/57.0)" />
    <define name="INITIAL_THROTTLE" value="0.8" />
  </section>

and this to the flight plan:

    <block name="Holding point" strip_button="Landing Point" strip_icon="target.png">
      <set value="1" var="kill_throttle"/>
      <attitude roll="0" throttle="0" vmode="throttle"/>
    </block>
    <block name="Arm Catapult" strip_button="Takeoff (wp CLIMB)" strip_icon="bungee_launch.png">
      <exception cond="estimator_z > ground_alt+20" deroute="Takeoff"/>
      <set value="0" var="kill_throttle"/>
      <call fun="nav_catapult_init()" />
      <call fun="nav_catapult(WP_TO, WP_CLIMB)"/>
    </block>
    <block name="Takeoff" strip_button="Takeoff (wp CLIMB)" strip_icon="takeoff.png">
      <exception cond="estimator_z > ground_alt+35" deroute="Standby"/>
      <go wp="CLIMB"/>
    </block>
    <block name="Standby" strip_button="Standby" strip_icon="home.png">
      <set value="0" var="kill_throttle"/>
      <set var="v_ctl_auto_throttle_cruise_throttle" value="0.78"/>
      <circle radius="nav_radius" wp="STDBY"/>
    </block>
 
   That I can "arm" the plane on the catapult, release it and it will then take off, wait 0.75 seconds, engage the motor and 
    take off with a 15 deg pitch + 80% throttle?  ( throttle doesn't engage prior to the "acceleration" event, correct? )

3. The GPS course for the skytraq is still off. I'm again investigating this. The course at 90 deg. east seems to be 0 and when actually moving
    counterclockwise has the course increasing. Unfortunately I can't see what values come out of the ned_of_ecef_vect_i   calculation.
    I may have to debug this on my spare lisa and walk around the block here to see this in more detail.

Rgds,

Gerard