[Paparazzi-devel] Re: Strong Wind

[Christophe De Wagter]

Hi Martin,

I added the STRONG_WIND-code to the SVN. The code is in fw_h_ctrl.c. Just call it with the extra -DWIND_INFO and -DSTRONG_WIND flags. If you don't thrust the automatic wind, use the wind.xml setting file (very useful for auto-takeoff) and remove the periodically send wind flag in the GCS.

In the sim, gradually increase the wind once the aircraft has a rough wind estimate and the aircraft will fly backward like in the included picture. By playing with the airspeed you can make the plane hover when the wind speed is within the flight envelope. Unfortunately the paparazzi GCS aircraft symbol does not show the heading of the aircraft but the direction of motion. (Should be easy to change but the GCS is still a big mystery to me as we use our own GCS.)

So I hope your aggressive climb can be as aggressive as the funjet can handle again and maybe even climb almost vertically on windy days. (make sure to program the DASH button in case the altitude wind is higher than cruise speed). 

Regards,

Christophe

PS: The code helps for the landings as the ground speed is often (much) lower but for landings at EMAV08 we also used an airspeed sensor in the vertical control loop. I will see if I can add the airspeed stuff too if anyone is interested

On Thu, Apr 9, 2009 at 1:14 PM, <address@hidden> wrote:

Hi Christophe,

thanks! It was a great time being there and flying in that environment.
Happy to see you in chat watching the flights.

There are issues with slow flying in regard to the ground. You can see
that in the youtube video when we go from the 150m circle to aggressive
climb. The nav/roll loop starts oscillating. What we did was manually
reducing the (aggressive climb) pitch angle. That of course limited the
possible climb rate.

We would like to test the code. Think you were talking about the code
change at EMAV2008 - your landings were much better than from anyone
else using Paparazzi. As we are flying circles in the meteo flights the
wind is usually well predicted - we did some comparsions with tethered
balloons flying right next to the aircraft.

Looking forward to EMAV2009 in Delft.

Best regards,
Martin

highwind.jpg
Description: JPEG image