Drone stabilization

#1

Hi guys,

I am having an issue with my drone. Initially my drone never lifted because it tilted immediately. I found the reason for that. My motors were not connected correctly to the PixHawk. I found out in the documentation of the pixhawk that motors need to be connected in a certain order to the pixhawk. So a few days ago I redid the wiring and the drone finally managed to liftoff. The problem I had however is that the drone seems to drift to a certain side everytime. If I lift the drone very fast then it looks to not have the drift but once I try to stay at a certain height the drone starts to move to the sides.

As I am relatively new with drones I can’t really come up with a reason for why this is happening. Calibration could be a reason but I did all the efforts in the world to do the calibration as good as possible already when I had the tilt problem before. So I don’t think that is the problem. The only other thing I can come up with is that the controller parameters maybe are not correct. I just downloaded the software of PixHawk and installed it. So I guess the controller has standard parameter values. Maybe they need to change. But I don’t know if that is common practice. Is it normal to have to adjust the standard control parameters of the pixhawk ?

If anyone can come up with another thing I could try out to eliminate this drift that would be very welcoming also.

#2

A few questions:

  • What is your Setup? Do you have a GPS? Does it show in. QGC?
  • What FlightMode are you in, when drift happens?
  • Did you calibrate the IMU?
  • Do you have any warnings in QGC when you startup the Controller?
#3

My setup is Octo X. I do have a GPS. I am not sure if GPS is visible in ground controller. I will need to check it tonight.
The flight mode I am using is stabilize. I didn’t test any other modes because last time when I had my motors connected wrongly, I changed it to HOLD ALT (I think) and when I liftoff I suddenly lost control of my drone and it crashed and broke a rotor. So for the moment I am only using stabilize flight mode.
I did calibrate the IMU in the pixhawk. I also checked on the ground station and I do get correct values for my angles.
I will have to check again but I don’t remember getting any warnings when starting up the controller.

#4

Ok, so this is perfectly normal. Please read through the PX4 Documentation, regarding the Flightmodes.

Stabilized Flight Mode will “only” Stabilize your Aircraft horizontally but does not prevent Drift due to imperfect balancing or wind. It is similar to manual but will level out your Aircraft when you center the sticks. Stick Input equals to Angle (For Yaw it is Angular-Speed)., but does not make use of GPS for Positioning. Modes that will hold your Vehicle in Position are PosCTL for Example or Hold.

#5

Ok, thanks a lot. I will try tomorrow with the other modes you suggested. I hope my drone doesn’t crash like last time I used them :slight_smile: