[Paparazzi-devel] fixedwing landing with ultrasonic sensor

[Tobias]

Hi,

work is in progress :-)   
sensor is already installed and tested (made two flights) 
unfortunately i m a little short on time right now but you can start wit 
something like this


    <block name="land">
      <call fun="gls_init(WP_AF,WP_SD, WP_TOD, WP_TD)"/>
      <call fun="nav_compute_baseleg(WP_AF, WP_TD, WP__BASELEG, nav_radius)"/>
      <circle radius="nav_radius" until="NavCircleCount() > 0.5" wp="_BASELEG"/>
      <circle radius="nav_radius" 
until="And(NavQdrCloseTo(DegOfRad(baseleg_out_qdr)-(nav_radius/fabs(nav_radius))*10),
 10 > fabs(GetPosAlt() - WaypointAlt(WP__BASELEG)))" wp="_BASELEG"/>
    </block>
    <block name="final">
      <exception cond="(ground_alt + 10 > GetPosAlt())" deroute="final2"/>
      <call fun="gls(WP_AF,WP_SD, WP_TOD, WP_TD)"/>
    </block>
    <block name="final2">
      <exception cond="(2 > sonar_distance)" deroute="flare"/>
      <call fun="gls(WP_AF,WP_SD, WP_TOD, WP_TD)"/>
    </block>

the flare could be done by just reducing the airspeedsetpoint - at least with 
the energy control this will lead to a really smooth flare

for further implementation I recommend to use a separate function in guidance.c 
since this update rate is much higher. 
but as I said work is in progress ;-)

cheers Tobi