Hi everybody,
I have a 6m span glider (ASG29) equipped with a Pixhawk 3 and Arduplane 3.8
I use the Pixhawk manly for safety reasons: when the glider is to far or to high and I have troubles to see it, the RTL mode brings it back.
Every things works perfectly, except that the loiter radius is far too large, about 150m. I have changed many parameters without success. The maximum bank angle is set to 60 degrees, the loiter radius to 10 m and so on… The real bank angle is around 10 degrees.
One thing that might raise turn radius is when the airspeed sensor is not working well , for example if you forget to remove the cap from the Pitot tube the AP will see a speed below ARSPD_FBW_MIN and will prevent sharp turns to avoid stall .
Your ARSPD_FBW_MIN is quite high 18 m/s if the plane speed is under that value it could lead to large turn radius.
BTW your Wp_Loiter_Rad is too small , just 5 meters.
Thank you lucamax for your quick answer.
18 m/s is the normal cruising speed of the glider. Remember it is a 6m span airframe. It stalls at 12 m/s.
I will try with ARSPD_FBW_MIN= 12 and Wp_Loiter_Rad=20
I will give you news as soon as the weather allows to fly.
@Inae you are limiting the vehicle to a 33 m radius bank at sea level (due to the NAVL1_BANK_LIMIT), as you get higher the radius will be expanded past that (although it shouldn’t be possibly expanding you to a 150 meter radius). An actual flight log (dataflash please) would help a lot more for reviewing.
In general ARSPD_FBW_MIN should not be the same as TRIM_ARSPD_CM as this limits TECS strongly.
If the stall speed is 12 m/s I would go for ARSPD_FBW_MIN= 14 and start with Wp_Loiter_Rad=50 then reduce the radius to find what the plane can achieve.
Thank you WickedShell for your fast answer.
The problem seem’s to be solved. During the last flight, I reached a Loiter radius of around 20 m !
I send you an Excel file with the evolution of some parameters during the different flights.
The version of Ardulane is 3.8.5 beta because I use the SPD33 air speed sensor.
The only remain problem is that under loiter, the glider describes a trajectory in eight.
Next flight i will check the 1.12 version of my parmeters to see if it can circle under loiter mode.Evolution paramètres.zip (6.8 KB)
Thank you Lucamax for your answer.
The problem seem’s to be solved. During the last flight, I reached a Loiter radius of around 20 m !
I send you an Excel file with the evolution of some parameters during the different flights.
The version of Ardulane is 3.8.5 beta because I use the SPD33 air speed sensor.
The only remain problem is that under loiter, the glider describes a trajectory in eight.
Next flight i will check the 1.12 version of my parmeters to see if it can circle under loiter mode. Evolution paramètres.zip (6.8 KB)