Lift drag plugin usage

Hi, can you explain to me how aerodynamic parameters of the liftDrag plugin used in the IRIS quad demo in SITL / Gazebo was identified ?
Best regards

Hello,

I got no idea. Did you read the lift drag paper, I think I remember that the parameters are closed to the default one’s or copied from px4 version

Hello, thx for your response. I have designed a 25 kg X8 with 29" x 9,5 propeller and i am searching a way to identify lift and drag plugin input params. I recently try with QBlade based on NACA 0018 foil but without success. Maybe a project with near characterictics exists …do you have already simulate an octa quad with ardupilot sitl gazebo ?
----- Mail d’origine -----

Hi. I have identified main aero param of a my own blade based on naca 0018. UAV mass is 25kg. It does not takeoff. Please how to set the multiplier value and other parameters?
----- Mail d’origine -----

Hi,
Well, the X8 UAV does beautiful takeoff but is unstable as described here by Eric Johnson
https://discuss.ardupilot.org/t/arducopter-3-6-sitl-with-gazebo-unstable-flight/34451:

“” The drone takesoff and starts to oscillate varying its position by over a meter in radius.""

The problem is i already have the parameters in .world file who solved his problem.

The other solution based on the modification of the AHRS EKF mode 3 is unavailable.

v4.0.3 dev

Regards

Hi.
To resolve this problem of instability do you think I can add plugin like barometer plugin and communicate directly with ardupilot via a new tcp link?
Regards
----- Mail d’origine -----

Hello,

We are already simulating the barometer.

You should check the performance of gazebo, normally you should be close to have the realtime update close to 1.

Otherwise try, AHRS_EKT_TYPE 10, it will allow you to check if you model is correct. The type 10 feed the drone with its real position.

Hi,

After many iteration on
ATC_RAT_RLL_P / I
ATC_RAT_PIT_P / I
ATC_RAT_YAW_P / I
takeoff correct without any oscillations :slight_smile: but when it arrives at a waypoint with angle < 90° it seems YAW command is inverted !

Hi, from now UAV flights are good enough ! As the liftdragplugin sets rotor blade characteristics only, please could you explain which parameters in the ArduPilotPLugin correspond to motor limits ? (eg “multiplier” value vs rpm ? or eventually how to add them ?